@article{chambers_evans_campellone_mccrackin_moorhead_alworth_2024, title={An Overview of Management Considerations for Mongolian Gerbils (Meriones unguiculatus), Cats (Felis catus), and Dogs (Canis familiaris) as Hosts for Brugia Infection}, volume={74}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85200938379&partnerID=MN8TOARS}, DOI={10.30802/AALAS-CM-24-034}, abstractNote={Lymphatic filariasis is a mosquito-borne parasitic infection affecting an estimated 51.4 million people.}, number={3}, journal={Comparative Medicine}, author={Chambers, C.A. and Evans, C.C. and Campellone, G.A. and McCrackin, M.A. and Moorhead, A.R. and Alworth, L.C.}, year={2024}, pages={142–147} }
 @article{evans_pilotte_moorhead_2024, title={Current Status of the Diagnosis of Brugia spp. Infections}, volume={13}, url={https://doi.org/10.3390/pathogens13090714}, DOI={10.3390/pathogens13090714}, abstractNote={Filarial nematodes of the genus Brugia include parasites that are significant to both human and veterinary medicine. Accurate diagnosis is essential for managing infections by these parasites and supporting elimination programs. Traditional diagnostic methods, such as microscopy and serology, remain vital, especially in resource-limited settings. However, advancements in molecular diagnostics, including nucleic acid amplification tests, offer enhanced sensitivity and specificity. These techniques are becoming increasingly field-friendly, expanding their applications in diagnostics. By refining existing methods, developing novel biomarkers, and understanding the zoonotic potential of various Brugia species, it is possible to improve control measures and better support elimination efforts.}, number={9}, journal={Pathogens}, author={Evans, Christopher C. and Pilotte, Nils and Moorhead, Andrew R.}, year={2024}, month={Aug} }
 @article{fraser_wallace_moorhead_tarigo_brainard_2024, title={Evaluation of coagulation and platelet activation state and function in heartworm-infected dogs}, volume={53}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85193963221&partnerID=MN8TOARS}, DOI={10.1111/vcp.13358}, abstractNote={Abstract Background Enhanced platelet responses have been demonstrated in heartworm‐infected (HWI) dogs; however, the cause and clinical implications of altered platelet function have not been fully elucidated. Objective This study evaluated platelet function in HWI dogs. Methods Anticoagulated whole blood collected from eight HWI and eight uninfected dogs was evaluated using turbidometric platelet aggregometry, a platelet function analyzer (PFA‐100), a total thrombus analysis system (T‐TAS), tissue factor‐activated and tissue plasminogen activator modified thromboelastography (TF‐ and tPA‐TEG), CBC, von Willebrand Factor activity, and fibrinogen concentrations. Platelet activation state and the presence of reticulated platelets were assessed via flow cytometric expression of P‐selection (CD‐62P) and thiazole orange staining. Results Platelet aggregation responses to adenosine diphosphate (ADP, 10 μM) or collagen (20 μg/mL), PFA‐100 closure times, and T‐TAS occlusion times did not differ between groups. TEG values TF‐R, tPA‐R, TF‐K, and TF‐LY60 were decreased ( P = .025, P = .047, P = .038, P = .025) and TF‐MA, tPA‐MA, TF‐G, tPA‐G and TF‐alpha angle were increased ( P < .04) in HWI dogs. HWI dogs had higher fibrinogen concentrations (465.6 ± 161 mg/dL vs 284.5 ± 38 mg/dL, P = .008) and eosinophil counts (0.686 ± 0.27 × 10 3 /μL vs 0.267 ± 0.20 × 10 3 /μL, P = .003). There was no difference in hematocrit, activation state, or percent of reticulated platelets. Non‐activated reticulated platelets exhibited higher CD62P expression compared with mature platelets. Conclusions Chronic canine heartworm disease was accompanied by hypercoagulability, hyperfibrinogenemia, and decreased fibrinolysis. Enhanced platelet activation was not identified in this group of HWI dogs.}, number={2}, journal={Veterinary Clinical Pathology}, author={Fraser, C. and Wallace, M.L. and Moorhead, A. and Tarigo, J. and Brainard, B.M.}, year={2024}, pages={186–195} }
 @article{murillo_campbell_moorhead_wang_2024, title={Evaluation of diagnostic techniques for early detection of heartworm in experimentally infected dogs: identification of Dirofilaria immitis-derived microRNA in the initial 28 weeks post-inoculation}, volume={17}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85195963874&partnerID=MN8TOARS}, DOI={10.1186/s13071-024-06337-y}, abstractNote={Abstract Background Dirofilaria immitis, commonly known as heartworm (HW), is a parasitic nematode transmitted by various mosquito species, leading to heartworm disease (HWD) in dogs. Diagnosis of HW typically involves antigen or microfilariae detection, or visualization of adult worms through imaging or post mortem examination. Polymerase chain reaction (PCR) and micro RNA (miRNA) detection have been explored for HW diagnosis. Methods Three dogs, previously experimentally infected with HW, underwent blood sampling every 4 weeks for 7 months. Samples were assessed for antigen presence after heat treatment, PCR amplification, and microfilaria examination using Giemsa-stained thick smears. Additionally, whole blood aliquots underwent miRNA deep sequencing and bioinformatic analysis. Results Heartworm antigen was detectable after heat treatment at 20 weeks post-inoculation and via PCR at 24 weeks, with microfilariae observed in peripheral blood smears at 28 weeks. However, deep miRNA sequencing revealed that the miRNA candidate sequences are not consistently expressed before 28 weeks of infection. Conclusions While ancillary molecular methods such as PCR and miRNA sequencing may be less effective than antigen detection for detecting immature larval stages in an early stage of infection, our experimental findings demonstrate that circulating miRNAs can still be detected in 28 weeks post-infection. Graphical Abstract}, number={1}, journal={Parasites and Vectors}, author={Murillo, D.F.B. and Campbell, E.J. and Moorhead, A.R. and Wang, C.}, year={2024} }
 @article{power_abdullah_walden_verocai_sanders_luksovsky_moorhead_dzimianski_foster_michalski_et al._2024, title={Population genomics reveals an ancient origin of heartworms in canids}, url={https://doi.org/10.1101/2024.12.26.630432}, DOI={10.1101/2024.12.26.630432}, abstractNote={Heartworms (Dirofilaria immitis) are parasitic nematodes that cause significant cardiopulmonary-associated morbidity and mortality in canids worldwide. The global dissemination of heartworms is believed to have occurred alongside the dispersal of domesticated dogs. To test this theory, we performed the largest population genetics study of heartworms to date, based on whole-genome sequencing of 127 modern adult individuals collected from mammalian carnivore hosts across four continents. Population structure and demographic analyses of the nuclear genome reveal distinct genetic differences between heartworms from different continents, indicating a deeper ancient origin and dispersal in canid hosts than previously recognised. Using admixture analyses, we find an Asian origin for Australian heartworms consistent with the arrival of dingoes thousands of years ago. Finally, the genetic relatedness between European and Central American heartworms suggests that modern dispersal, likely associated with human colonisation of the Americas by Europeans, occurred with domesticated dogs. Our findings shed light on the global population dynamics and evolutionary history of heartworms, which can aid future surveillance and control efforts for this important veterinary parasite.}, author={Power, Rosemonde I. and Abdullah, Swaid and Walden, Heather S. and Verocai, Guilherme G. and Sanders, Tiana L. and Luksovsky, Joe L. and Moorhead, Andrew R. and Dzimianski, Michael T. and Foster, Jeremy M. and Michalski, Michelle L. and et al.}, year={2024}, month={Dec} }
 @article{marriott_dagley_hegde_steven_fricks_dicosty_mansour_campbell_wilson_gusovsky_et al._2023, title={A dirofilariasis mouse model for heartworm preclinical research}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85160353920&partnerID=MN8TOARS}, DOI={10.1101/2023.04.03.535321}, abstractNote={ABSTRACT Use of experimental cats and dogs in veterinary heartworm preclinical drug research is increasing. As a potential alternative primary in vivo heartworm preventative drug screen, we assessed lymphopenic mice with ablation of the interleukin-2/7 common gamma chain (γc) as susceptible to the larval development phase of D. immitis . Non-obese diabetic (NOD) Severe Combined ImmunoDeficient (SCID)γc -/- (NSG / NXG) mice consistently yielded viable D. immitis larvae at 2-4 weeks post-infection across multiple experiments, different batches of infectious larvae inoculates, different isolates of D. immitis and at independent laboratories. Mice did not display any overt clinical signs associated with infection up to 4 weeks. Developing larvae were found in subcutaneous and muscle fascia tissues, the natural site of this stage of heartworm in dogs. Larvae retrieved from NSG / NXG mice were mid-L4 stage of development. Compared with 14-day in vitro propagated larvae, in vivo derived L4 were significantly larger and contained expanded Wolbachia endobacteria titres, determined by QPCR and Fluorescent in situ Hybridisation (FISH). We established an ex vivo 6-day L4 paralytic screening system against nematodicidal agents (moxidectin, levamisole) which highlighted discrepancies in relative drug sensitivities in comparison with in vitro reared L4 D. immitis. We demonstrated effective depletion of Wolbachia by 70-90% in D. immitis L4 following 2-7 day oral in vivo exposures of NSG / NXG infected mice with doxycycline or the rapid-acting investigational anti- Wolbachia drug, AWZ1066S. We validated the NSG / NXG mouse model as a filaricide drug screen by in vivo treatments with single injections of moxidectin, which mediated 60-88% reduction in L4 larvae at 14-28 days. Future adoption of the mouse model as a first-line efficacy screen will benefit end-user laboratories conducting research and development of novel heartworm preventatives via increased access, rapid turnaround and reduced costs whilst simultaneously decreasing need for experimental cat or dog use.}, journal={bioRxiv}, author={Marriott, A.E. and Dagley, J.L. and Hegde, S. and Steven, A. and Fricks, C. and DiCosty, U. and Mansour, A. and Campbell, E.J. and Wilson, C.M. and Gusovsky, F. and et al.}, year={2023} }
 @article{dirofilariasis mouse models for heartworm preclinical research_2023, volume={14}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85164587325&partnerID=MN8TOARS}, DOI={10.3389/fmicb.2023.1208301}, abstractNote={Dirofilariasis, including heartworm disease, is a major emergent veterinary parasitic infection and a human zoonosis. Currently, experimental infections of cats and dogs are used in veterinary heartworm preclinical drug research.As a refined alternative in vivo heartworm preventative drug screen, we assessed lymphopenic mouse strains with ablation of the interleukin-2/7 common gamma chain (γc) as susceptible to the larval development phase of Dirofilaria immitis.Non-obese diabetic (NOD) severe combined immunodeficiency (SCID)γc-/- (NSG and NXG) and recombination-activating gene (RAG)2-/-γc-/- mouse strains yielded viable D. immitis larvae at 2-4 weeks post-infection, including the use of different batches of D. immitis infectious larvae, different D. immitis isolates, and at different laboratories. Mice did not display any clinical signs associated with infection for up to 4 weeks. Developing larvae were found in subcutaneous and muscle fascia tissues, which is the natural site of this stage of heartworm in dogs. Compared with in vitro-propagated larvae at day 14, in vivo-derived larvae had completed the L4 molt, were significantly larger, and contained expanded Wolbachia endobacteria titres. We established an ex vivo L4 paralytic screening system whereby assays with moxidectin or levamisole highlighted discrepancies in relative drug sensitivities in comparison with in vitro-reared L4 D. immitis. We demonstrated effective depletion of Wolbachia by 70%-90% in D. immitis L4 following 2- to 7-day oral in vivo exposures of NSG- or NXG-infected mice with doxycycline or the rapid-acting investigational drug, AWZ1066S. We validated NSG and NXG D. immitis mouse models as a filaricide screen by in vivo treatments with single injections of moxidectin, which mediated a 60%-88% reduction in L4 larvae at 14-28 days.Future adoption of these mouse models will benefit end-user laboratories conducting research and development of novel heartworm preventatives via increased access, rapid turnaround, and reduced costs and may simultaneously decrease the need for experimental cat or dog use.}, journal={Frontiers in Microbiology}, year={2023} }
 @article{moorhead_evans_sakamoto_dzimianski_mansour_dicosty_fricks_mccall_carson_nelson_et al._2023, title={Effects of doxycycline dose rate and pre-adulticide wait period on heartworm-associated pathology and adult worm mass}, volume={16}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85165644193&partnerID=MN8TOARS}, DOI={10.1186/s13071-023-05858-2}, abstractNote={The American Heartworm Society canine guidelines recommend treatment with doxycycline prior to adulticide administration to reduce levels of Wolbachia and its associated metabolites, which are known to be a leading cause of pulmonary pathology. Studies have determined that doxycycline administered at 10 mg/kg BID for 28 days is an effective dose for eliminating Wolbachia, but what has not been determined is the clinical relevance of this elimination. The current guidelines also recommend a 30-day wait period following administration of doxycycline to allow for clearance of metabolites, such as Wolbachia surface protein, and for further reduction in heartworm biomass before administration of adulticide. Reducing the doxycycline dose and eliminating the wait period may carry practical benefits for the animal, client, and practitioner.To investigate these treatment practices, Dirofilaria immitis adults were surgically transplanted into each of 45 dogs, which were divided into nine study groups of five dogs each. Seventy-five days after transplantation, two groups each were administered 5, 7.5, or 10 mg/kg BID doxycycline orally for 28 days and 6 µg/kg ivermectin monthly, with three untreated groups serving as controls. Study animals were necropsied and examined prior to treatment as well as 30 and 60 days post-treatment.Mean worm weight was unaffected by dosage but exhibited a significant increase at 30 days and significant decrease at 60 days post-treatment, including in control groups. Histopathology lesion scores did not significantly differ among groups, with the exception of the lung composite score for one untreated group. Liver enzymes, the levels of which are a concern in doxycycline treatment, were also examined, with no abnormalities in alanine aminotransferase or alkaline phosphatase observed.No consistent worsening of tissue lesions was observed with or without the AHS-recommended 30-day wait period, nor did reduced dosages of doxycycline lead to worsening of pathology or any change in efficacy in depleting worm weight. Mean worm weight did significantly increase prior to, and decrease following, the wait period. Future work that also includes adulticide treatment (i.e. melarsomine) will study treatment recommendations that may improve both animal health and owner compliance.}, number={1}, journal={Parasites and Vectors}, author={Moorhead, A.R. and Evans, C.C. and Sakamoto, K. and Dzimianski, M.T. and Mansour, A. and DiCosty, U. and Fricks, C. and McCall, S. and Carson, B. and Nelson, C.T. and et al.}, year={2023}, pages={251} }
 @article{vetter_meindl_louren?o_coyne_drake_murphy_roth_moorhead_2023, title={Evaluation of renal values during treatment for heartworm disease in 27 client-owned dogs}, volume={16}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85161469547&partnerID=MN8TOARS}, DOI={10.1186/s13071-023-05779-0}, abstractNote={Canine heartworm disease (CHD) caused by Dirofilaria immitis remains a common preventable disease with increasing incidence in some parts of the USA. The treatment guidelines of the American Heartworm Society (AHS) currently recommend monthly macrocyclic lactone administration, 28 days of doxycycline given orally every 12 h and three injections of melarsomine dihydrochloride (1 injection on day 2 of treatment followed 30 days later by 2 injections 24 h apart). Minocycline has also been utilized when doxycycline is unavailable. The systemic effects of CHD, which particularly impact cardiac and renal function, have been described, with infected dogs often experiencing renal damage characterized by an increase in serum concentrations of renal biomarkers. Although the AHS treatment protocol for CHD has been shown to be safe and effective in most cases, the potential for complications remains. No study as of yet has evaluated changes in symmetric dimethylarginine (SDMA), a sensitive marker of renal function, during treatment for CHD. The purpose of the present study was to evaluate renal function in dogs by measuring serum creatinine and SDMA concentrations during the adulticide treatment period.Serum creatinine and SDMA concentrations were measured in 27 client-owned dogs affected by CHD at the following time points: prior to starting doxycycline or minocycline therapy (baseline), during doxycycline or minocycline therapy (interim), at the time of the first dose of melarsomine (first dose), at the time of the second dose of melarsomine (second dose) and at the dog's follow-up visit after treatment, occurring between 1 and 6 months after completion of therapy (post-treatment). Concentrations of creatinine and SDMA were compared between time points using a mixed effects linear model.Mean SDMA concentrations following the second dose of melarsomine were significantly lower (-1.80 ug/dL, t-test, df = 99.067, t = -2.694, P-Value = 0.00829) than baseline concentrations. There were no other statistically significant differences in the concentration of either biomarker between the baseline and the other time points in CHD dogs undergoing treatment.The results suggest that the current AHS protocol may not have a substantial impact on renal function.}, number={1}, journal={Parasites and Vectors}, author={Vetter, C.A.M. and Meindl, A.G. and Louren?o, B.N. and Coyne, M. and Drake, C. and Murphy, R. and Roth, I.G. and Moorhead, A.R.}, year={2023} }
 @article{evans_normile_gamble_guerino_dzimianski_moorhead_2023, title={Treatment of dogs with Bravecto<sup>®</sup> (fluralaner) reduces mosquito survival and fecundity}, volume={16}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85156274672&partnerID=MN8TOARS}, DOI={10.1186/s13071-023-05682-8}, abstractNote={Mosquitoes serve as the vector of canine heartworm (Dirofilaria immitis), which represents a significant and persistent threat to canine health. A reduction in the longevity and/or reproductive success of mosquitoes that take a blood meal from fluralaner-treated dogs may consequently reduce the local transmission of heartworm and prevent new infections. A novel secondary effect of an oral formulation of the ectoparasiticide fluralaner (Bravecto®) against a laboratory strain of the mosquito Aedes aegypti, a potential major vector of canine heartworm, was investigated in this study.Six dogs were administered a single dose of fluralaner orally in the form of Bravecto® Chews (at the labeled fluralaner dose of 25 mg/kg body weight), while six control dogs received no treatment. Mosquitoes were fed on blood that was collected from each dog prior to treatment and weekly for 15 weeks post-treatment to assess the continued effects of fluralaner as its serum level decreased. Mosquito fitness was assessed by three parameters: rate of successful blood-feeding, survival, and egg laying.Successful blood-feeding rate was similar between control and treatment groups. In the fluralaner treatment, mosquito survival was significantly reduced within the first 24 h after blood-feeding, for the first 12 weeks post-treatment of the dogs (efficacy range = 33.2-73.3%). Survival of mosquitoes up until a potentially heartworm-infective timepoint (14 days post-blood-feeding) was significantly reduced in the fluralaner-treated group at several timepoints (1, 2, 5, 11, 12, 13, 14, and 15 weeks post-treatment; efficacy range = 49.4-91.4%), but was less consistently reduced at the other timepoints. Egg laying by mosquitoes was almost completely suppressed for the first 13 weeks following treatment of the dogs with fluralaner (treatment efficacy ≥ 99.8%).Mosquitoes fed blood from fluralaner-treated dogs experienced a significant reduction in survival and fecundity. These findings support the potential for a reduction in heartworm transmission directly by lethal effects on the vector and indirectly through a reduction of the local vector population when mosquitoes are exposed to animals treated with fluralaner.}, number={1}, journal={Parasites and Vectors}, author={Evans, C.C. and Normile, D. and Gamble, S. and Guerino, F. and Dzimianski, M.T. and Moorhead, A.R.}, year={2023} }
 @article{evans_greenway_campbell_dzimianski_mansour_mccall_moorhead_2022, title={The Domestic Dog as a Laboratory Host for <i>Brugia malayi</i>}, volume={11}, url={https://www.mdpi.com/2076-0817/11/10/1073}, DOI={10.3390/pathogens11101073}, abstractNote={Of the three nematodes responsible for lymphatic filariasis in humans, only Brugia malayi is actively maintained in research settings owing to its viability in small animal hosts, principal among which is the domestic cat. While the microfilaremic feline host is necessary for propagation of parasites on any significant scale, this system is plagued by a number of challenges not as pronounced in canine filarial models. For this reason, we investigated the capacity in which dogs may serve as competent laboratory hosts for B. malayi. We infected a total of 20 dogs by subcutaneous injection of 500 B. malayi third-stage larvae (L3) in either a single (n = 10) or repeated infection events (125 L3 per week for four weeks; n = 10). Within each group, half of the individuals were injected in the inguinal region and half in the dorsum of the hind paw. To track the course of microfilaremia in this host, blood samples were examined by microscopy biweekly for two years following infection. Additionally, to identify cellular responses with potential value as predictors of patency, we measured peripheral blood leukocyte counts for the first year of infection. A total of 10 of 20 dogs developed detectable microfilaremia. Peak microfilaria density varied but attained levels useful for parasite propagation (median = 1933 mL-1; range: 33-9950 mL-1). Nine of these dogs remained patent at 104 weeks. A two-way ANOVA revealed no significant differences between infection groups in lifetime microfilaria production (p = 0.42), nor did regression analysis reveal any likely predictive relationships to leukocyte values. The results of this study demonstrate the competence of the dog as a host for B. malayi and its potential to serve in the laboratory role currently provided by the cat, while also clarifying the potential for zoonosis in filariasis-endemic regions.}, number={10}, journal={Pathogens}, author={Evans, Christopher and Greenway, Katelin E. and Campbell, Elyssa J. and Dzimianski, Michael T. and Mansour, Abdelmoneim and McCall, John W. and Moorhead, Andrew}, year={2022}, month={Sep} }
 @article{evans_normile_gamble_guerino_dzimianski_moorhead_2022, title={Treatment of dogs with Bravecto® (fluralaner) reduces mosquito survival and fecundity}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85167496440&partnerID=MN8TOARS}, DOI={10.21203/rs.3.rs-2321993/v1}, abstractNote={Abstract Background: Mosquitoes serve as the vector of canine heartworm ( Dirofilaria immitis ), which represents a significant and persistent threat to canine health. A reduction in the longevity and/or reproductive success of mosquitoes that take a bloodmeal from fluralaner-treated dogs may consequently reduce the local transmission of heartworm and prevent new infections. This study investigated a novel secondary effect of an oral formulation of the ectoparasiticide fluralaner (Bravecto ® ) against a laboratory strain of mosquito ( Aedes aegypti ). Methods: Six dogs were administered a single dose of fluralaner orally in the form of Bravecto ® Chews (at the labeled fluralaner dose of 25 mg/kg body weight) while six control dogs received no treatment. Mosquitoes were fed on blood collected from each dog; this was performed prior to treatment and weekly for 15 weeks posttreatment to assess the continued duration of effects as serum fluralaner levels decrease. Mosquito fitness was assessed by three parameters: rate of successful blood feeding, survival, and egg laying. Results: Blood feeding was equally successful between control and treatment groups. Fluralaner treatment significantly reduced mosquito survival within the first day of blood feeding for 12 weeks posttreatment (efficacy range = 33.2% – 73.3%). Survival of mosquitoes to a potentially heartworm-infective timepoint (14 days postfeeding) was significantly reduced in the fluralaner-treated group at several timepoints, but less consistently (weeks 1, 2, 5, 11, 12, 13, 14, and 15; efficacy range = 49.4% – 91.4%). Egg laying by mosquitoes was almost completely suppressed for the first 13 weeks following treatment (treatment efficacy = 100%). Conclusions: Mosquitoes fed blood from fluralaner-treated dogs experienced a significant reduction in survival and fecundity. These findings support the potential for reduction in heartworm transmission directly by lethal effects on the vector and indirectly by reduction of the local vector population when mosquitoes are exposed to treated animals.}, journal={Research Square}, author={Evans, C.C. and Normile, D. and Gamble, S. and Guerino, F. and Dzimianski, M.T. and Moorhead, A.R.}, year={2022} }
 @inbook{evans_pilotte_williams_moorhead_2022, title={Veterinary Diagnosis of Filarial Infection}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85149896584&partnerID=MN8TOARS}, DOI={10.1002/9783527823413.ch6}, abstractNote={Filarial worms are a unique group of parasites with importance in both human and veterinary medicine. These parasites are typically long-lived and difficult to detect, often causing chronic disease states over a period of years and, for these reasons, effective diagnostic testing is crucial for their control. Adult filarial worms tend to occupy inaccessible anatomical sites within the host, but microfilariae disperse widely in the blood or skin to allow uptake and transmission by the hematophagous insects necessary to complete the life cycle, and the detection of this microscopic stage represents a fundamental form of diagnostic testing. Immunodiagnostic and DNA-based tests have since been developed for several filarial species, as well as methods for visualizing adult parasites in situ . All these techniques carry their own distinct strengths and weaknesses, so reliable diagnosis often requires a strategic combination of tests. Accurate diagnosis is important for potentially fatal infections like canine heartworm and is also essential for identifying emergent zoonoses, like Onchocerca lupi , and potential animal reservoirs, as with Brugia malayi . Accurate parasite detection and identification is useful not only in clinical settings but also greatly assists research efforts. This chapter will review the diagnostic methods available for some of the most common species of filarial nematodes in small animal veterinary medicine.}, booktitle={Human and Animal Filariases: Landscape, Challenges, and Control}, author={Evans, C. and Pilotte, N. and Williams, S. and Moorhead, A.}, year={2022}, pages={125–159} }
 @article{evans_day_chu_garner_sakamoto_moorhead_2021, title={A rapid, parasite-dependent cellular response to Dirofilaria immitis in the Mongolian jird (Meriones unguiculatus)}, volume={14}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85098843267&partnerID=MN8TOARS}, DOI={10.1186/s13071-020-04455-x}, abstractNote={Abstract Background The Mongolian jird ( Meriones unguiculatus ) has long been recognized as a permissive host for the filarial parasite Brugia malayi ; however, it is nonpermissive to another filarial parasite, canine heartworm ( Dirofilaria immitis ). By elucidating differences in the early response to infection, we sought to identify mechanisms involved in the species-specific clearance of these parasites. We hypothesized that the early clearance of D. immitis in intraperitoneal infection of the jird is immune mediated and parasite species dependent. Methods Jird peritoneal exudate cells (PECs) were isolated and their attachment to parasite larvae assessed in vitro under various conditions: D. immitis and B. malayi cultured separately, co-culture of both parasites, incubation before addition of cells, culture of heat-killed parasites, and culture with PECs isolated from jirds with mature B. malayi infection. The cells attaching to larvae were identified by immunohistochemistry. Results In vitro cell attachment to live D. immitis was high (mean = 99.6%) while much lower for B. malayi (mean = 5.56%). This species-specific attachment was also observed when both filarial species were co-cultured, with no significant change from controls ( U (9, 14) = 58.5, p = 0.999). When we replicated these experiments with PECs derived from jirds subcutaneously infected with B. malayi , the results were similar (99.4% and 4.72% of D. immitis and B. malayi , respectively, exhibited cell attachment). Heat-killing the parasites significantly reduced cell attachment to D. immitis (mean = 71.9%; U (11, 14) = 7.5, p < 0.001) while increasing attachment to B. malayi (mean = 16.7%; U (9, 15) = 20, p = 0.002). Cell attachment to both species was reduced when larvae were allowed a 24-h pre-incubation period prior to the addition of cells. The attaching cells were identified as macrophages by immunohistochemistry. Conclusions These results suggest a strongly species-dependent response from which B. malayi could not confer protection by proxy in co-culture. The changes in cell attachment following heat-killing and pre-incubation suggest a role for excretory/secretory products in host immune evasion and/or antigenicity. The nature of this attachment is the subject of ongoing study and may provide insight into filarial host specificity. Graphical Abstract}, number={1}, journal={Parasites and Vectors}, publisher={BMC}, author={Evans, C.C. and Day, K.M. and Chu, Y. and Garner, B. and Sakamoto, K. and Moorhead, A.R.}, year={2021} }
 @article{evans_burkman_dzimianski_garner_moorhead_2021, title={The Course of Brugia malayi Microfilaremia in Experimentally Infected Cats}, volume={21}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85112430477&partnerID=MN8TOARS}, DOI={10.1089/vbz.2020.2761}, abstractNote={As one of the causative agents of lymphatic filariasis in humans, Brugia malayi has been established as the laboratory model of choice for studying this infection owing to its viability in small animal hosts, with the domestic cat being significant among these. The usefulness of individual feline infections is highly dependent on the levels of circulating microfilariae in the blood; thus, characterizing the course of microfilaremia benefits our understanding of this model. In B. malayi-endemic regions, cats are also known reservoirs of infection, and describing microfilaremia in a controlled setting may improve transmission modeling. We followed the course of B. malayi infection in 10 experimentally infected cats from inoculation to ultimate resolution. Seven cats developed patency, with a peak microfilaria concentration of 6525/mL. In addition, to identify cellular responses with potential value as predictors of patency, we measured the peripheral blood leukocyte counts during the first 8 months of infection and tested for correlations with lifelong microfilaria production. No strong relationships were observed, though cell values did appear to shift with the maturation phases of the parasite. The data we present reflect the course of microfilaremia in an important laboratory model under controlled conditions.}, number={8}, journal={Vector-Borne and Zoonotic Diseases}, author={Evans, C.C. and Burkman, E.J. and Dzimianski, M.T. and Garner, B. and Moorhead, A.R.}, year={2021}, pages={586–592} }
 @article{mattick_libro_bromley_chaicumpa_chung_cook_khan_kumar_lau_misra-bhattacharya_et al._2021, title={X-treme loss of sequence diversity linked to neo-x chromosomes in filarial nematodes}, volume={15}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85118947984&partnerID=MN8TOARS}, DOI={10.1371/journal.pntd.0009838}, abstractNote={The sequence diversity of natural and laboratory populations of Brugia pahangi and Brugia malayi was assessed with Illumina resequencing followed by mapping in order to identify single nucleotide variants and insertions/deletions. In natural and laboratory Brugia populations, there is a lack of sequence diversity on chromosome X relative to the autosomes (πX/πA = 0.2), which is lower than the expected (πX/πA = 0.75). A reduction in diversity is also observed in other filarial nematodes with neo-X chromosome fusions in the genera Onchocerca and Wuchereria, but not those without neo-X chromosome fusions in the genera Loa and Dirofilaria. In the species with neo-X chromosome fusions, chromosome X is abnormally large, containing a third of the genetic material such that a sizable portion of the genome is lacking sequence diversity. Such profound differences in genetic diversity can be consequential, having been associated with drug resistance and adaptability, with the potential to affect filarial eradication.}, number={10}, journal={PLoS Neglected Tropical Diseases}, author={Mattick, J. and Libro, S. and Bromley, R. and Chaicumpa, W. and Chung, M. and Cook, D. and Khan, M.B. and Kumar, N. and Lau, Y. and Misra-Bhattacharya, S. and et al.}, year={2021} }
 @article{savadelis_coleman_rapoport_sharma_sakamoto_keys_ohmes_hostetler_dzimianski_moorhead_2020, title={Clinical assessment of heartworm-infected Beagles treated with a combination of imidacloprid/moxidectin and doxycycline, or untreated}, volume={34}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85088262819&partnerID=MN8TOARS}, DOI={10.1111/jvim.15853}, abstractNote={Abstract Background Administration of moxidectin topically and doxycycline PO has been utilized experimentally as an alternative treatment for heartworm disease. However, clinical effects of this protocol remain poorly characterized. Objective To evaluate the clinical and postmortem findings associated with administration of doxycycline and monthly 10% imidacloprid + 2.5% moxidectin (IMD + MOX, Advantage Multi/Advocate) to Dirofilaria immitis ‐experimentally infected as compared to nontreated control dogs. Animals Sixteen purpose‐bred, female, Beagle dogs. Methods Prospective, blinded, experimental study. Animals with surgically transplanted adult heartworms were randomized into 2 study groups of equal size: a nontreated control group (n = 8) and an IMD + MOX and doxycycline‐treated group (n = 8). Randomization was performed using a complete block design according to circulating microfilarial concentrations, measured before treatment. Serum biochemical profiles, CBCs, thoracic radiographs and echocardiograms were performed prior to and 3 weeks after transplantation, and monthly for 10 months. Postmortem gross and histopathologic evaluations were performed. Results Compared to control animals, mean ± SD serum alanine aminotransferase (181 ± 203 U/L vs 33 ± 7 U/L; P < .0001) and alkaline phosphatase (246 ± 258 U/L vs 58 ± 19 U/L; P < .0001) activities were significantly higher in the treated group on day 28. Radiographic and echocardiographic evidence of heartworm disease was observed in both groups; however, no significant differences in these variables were noted between groups. Mean ± SD pulmonary arterial thrombus score was significantly higher in the treated vs nontreated group (3.9 ± 0.4 and 1.5 ± 2.1, respectively; P = .01). Conclusions and Clinical Importance The treatment protocol was well‐tolerated with no clinically relevant adverse effects for any variable evaluated during the observational period.}, number={5}, journal={Journal of Veterinary Internal Medicine}, publisher={WILEY}, author={Savadelis, M.D. and Coleman, A.E. and Rapoport, G.S. and Sharma, A. and Sakamoto, K. and Keys, D.A. and Ohmes, C.M. and Hostetler, J.A. and Dzimianski, M.T. and Moorhead, A.R.}, year={2020}, pages={1734–1745} }
 @article{evans_bradner_savadelis_nelson_moorhead_2019, title={Acetic acid as an alternative reagent in the modified Knott test}, volume={276}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85075290558&partnerID=MN8TOARS}, DOI={10.1016/j.vetpar.2019.108975}, journal={Veterinary Parasitology}, author={Evans, C.C. and Bradner, J.L. and Savadelis, M.D. and Nelson, C.T. and Moorhead, A.R.}, year={2019} }
 @article{savadelis_evans_mabry_lefavi_klink_simson_moorhead_2019, title={Canine gastrointestinal nematode transmission potential in municipal dog parks in the southeast United States}, volume={18}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85070869402&partnerID=MN8TOARS}, DOI={10.1016/j.vprsr.2019.100324}, journal={Veterinary Parasitology: Regional Studies and Reports}, author={Savadelis, M.D. and Evans, C.C. and Mabry, K.H. and LeFavi, L.N. and Klink, B.D. and Simson, C. and Moorhead, A.R.}, year={2019} }
 @article{dixon-jimenez_coleman_rapoport_creevy_roth_correa_moorhead_2018, title={Approaches to Canine Heartworm Disease Treatment Among Alumni of a Single College of Veterinary Medicine}, volume={54}, ISSN={["1547-3317"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85054893462&partnerID=MN8TOARS}, DOI={10.5326/JAAHA-MS-6601}, abstractNote={ABSTRACT This descriptive study was designed to ascertain the current heartworm treatment strategies employed by veterinary graduates of a single college of veterinary medicine, to assess the frequency with which each of these treatment strategies is prescribed, and to report the motivation behind the use of these treatment strategies. A survey containing a combination of multiple-choice and open-ended questions was distributed via e-mail with an online link during 2013 to graduates of the University of Georgia College of Veterinary Medicine. Demographic data and opinions regarding treatment for cases of canine heartworm disease (HWD) were obtained, and motivation for recommending different treatment strategies was assessed. Nearly all 170 respondents (99%) indicated that they recommend melarsomine dihydrochloride for first-line treatment of canine HWD. Exercise restriction (80%) and monthly heartworm preventive (75%) were components of the treatment approach to HWD with no clinical signs. The majority of respondents (74%) indicated that when first-line treatment recommendations were declined, they endorsed long-term administration of ivermectin (i.e., “slow-kill” method) despite current American Heartworm Society guidelines that recommend against the use of long-term macrocyclic lactone administration for the monotherapy treatment of canine HWD. Respondents also indicated that owners’ financial concerns frequently result in modification of HWD treatment. Routine inclusion of exercise restriction is commonly, but not universally, utilized and may represent an opportunity for improvement in the management of this disease. In addition, when first-line recommendations for heartworm disease treatment are declined, a two-dose melarsomine protocol instead of the slow-kill method should be considered.}, number={5}, journal={JOURNAL OF THE AMERICAN ANIMAL HOSPITAL ASSOCIATION}, author={Dixon-Jimenez, Amy C. and Coleman, Amanda E. and Rapoport, Gregg S. and Creevy, Kate E. and Roth, Ira and Correa, Maria and Moorhead, Andrew R.}, year={2018}, pages={246–256} }
 @article{savadelis_day_bradner_wolstenholme_dzimianski_moorhead_2018, title={Efficacy and side effects of doxycycline versus minocycline in the three-dose melarsomine canine adulticidal heartworm treatment protocol}, volume={11}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85059226656&partnerID=MN8TOARS}, DOI={10.1186/s13071-018-3264-z}, abstractNote={The American Heartworm Society currently recommends the use of a monthly macrocyclic lactone, a 28-day course of 10 mg/kg doxycycline BID, and the 3-dose protocol of melarsomine dihydrochloride for the treatment of canine heartworm disease. Doxycycline is necessary for the reduction of the bacterium Wolbachia, found in all heartworm life-stages. Previous price increases and decreasing availability prompted us to evaluate alternative tetracycline antibiotics, i.e. minocycline, for the reduction of Wolbachia during canine heartworm treatment. Thirty-two heartworm-positive dogs were randomized to receive 10 mg/kg or 5 mg/kg of either doxycycline or minocycline for 28 days BID, for a total of 8 dogs per experimental group. All dogs received 6 months of Heartgard Plus® (ivermectin/pyrantel) and the 3-dose protocol of 2.5 mg/kg melarsomine dihydrochloride. Blood samples were collected prior to the initiation of treatment, every 7 days throughout tetracycline treatment, and then monthly thereafter until the dog tested negative for the presence of heartworm antigen. DNA was isolated from circulating microfilarial samples and qPCR was performed on each sample. A greater number of dogs in the 10 mg/kg doxycycline and minocycline treated groups experienced gastrointestinal side effects as compared to the 5 mg/kg doxycycline and minocycline treated groups. All eight dogs in the 10 mg/kg doxycycline-treated group tested negative for the presence of Wolbachia DNA by 28 days post-tetracycline treatment. A total of two dogs in both the 5 mg/kg doxycycline- and 10 mg/kg minocycline-treated groups and three dogs in the 5 mg/kg minocycline-treated group remained positive for the presence of Wolbachia DNA by the end of tetracycline treatment. No lung pathology was assessed in this clinical trial, therefore the clinical effect of the remaining Wolbachia DNA in the 10 mg/kg minocycline-, 5 mg/kg doxycycline- and 5 mg/kg minocycline-treated groups cannot be determined. Owner compliance in the proper administration of these tetracyclines may be impacted by the increased severe gastrointestinal side effects reported for the 10 mg/kg doxycycline- and minocycline-treated groups. We recommend that veterinarians prescribe the recommended 10 mg/kg doxycycline for canine heartworm treatment and reduce the dosage to 5 mg/kg in cases of severe gastrointestinal side effects in order to improve owner compliance in administration of medications.}, number={1}, journal={Parasites and Vectors}, author={Savadelis, M.D. and Day, K.M. and Bradner, J.L. and Wolstenholme, A.J. and Dzimianski, M.T. and Moorhead, A.R.}, year={2018} }
 @article{savadelis_roveto_ohmes_hostetler_settje_dzimianski_moorhead_2018, title={Evaluation of heat-treating heartworm-positive canine serum samples during treatment with Advantage Multi<sup>®</sup> for Dogs and doxycycline}, volume={11}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85042275874&partnerID=MN8TOARS}, DOI={10.1186/s13071-018-2685-z}, abstractNote={The use of heat-treatment in canine and feline serum has been hypothesized to break the formation of antigen-antibody complexes, thereby freeing the heartworm antigen allowing for detection by commercially available heartworm antigen kits. While studies have analyzed the effect of heat-treating serum and plasma samples in the detection of heartworm antigen, these studies have not utilized necropsy verified results for validation. This study evaluated the use of heat-treating serum samples in experimentally infected dogs during adulticidal treatment in comparison with necropsy adult heartworm recovery. As part of a primary study, a total of 16 dogs were experimentally infected with 16 sexually mature adult heartworms using surgical transplantation, allocating 8 dogs in both the control and treated group. Treated dogs received 10 months of topical administration of Advantage Multi® for Dogs (10% Imidacloprid + 2.5% Moxidectin) every 4 weeks and 30 days of 10 mg/kg doxycycline BID. Blood samples were collected from all study animals prior to surgical transplantation of adult heartworms, on study days 0, 1, 3, 7, 14, 21, 28, and every 4 weeks thereafter for the duration of this study. Concentration of heartworm antigen was tested using the DiroCHEK® heartworm antigen test kit using serum samples both pre- and post-heat-treatment. Serum samples were heat-treated at 103 °C in a dry heat block for 10 min and centrifuging at 1818× g for 20 min. There were a total of 4 instances (days 56, 140, 224 and 252) in 3 treated dogs in which a serum sample converted from negative for the detection of heartworm antigen prior to heat-treatment to positive for the detection of heartworm antigen post-heat-treatment. At necropsy, these dogs had no adult heartworms recovered and were all negative on antigen testing prior to and after heat treatment. There was 100% accuracy in the detection of either no infection, or 1–2 adult heartworm infections using the DiroCHEK in serum samples with and without heat-treatment at the time of necropsy. The DiroCHEK accurately diagnosed all dogs with live adults recovered at necropsy as heartworm antigen positive and all those dogs with no live adults recovered at necropsy as heartworm antigen negative without the use of heat-treatment for samples taken on the day of necropsy. Therefore, these results indicate that the use of heat-treating serum samples did not provide data of any additional value in the diagnosis of heartworm-positive dogs receiving treatment in this study. Additionally, these results may indicate that the conversion of serum samples from negative to positive for the presence of heartworm antigen with heat-treatment may not always accurately diagnose live adult heartworm infections since no adult heartworms were recovered at necropsy for those dogs in which a conversion event occurred. These conversion events may be detecting residual antigen leftover after all adult worms have died or may even be detecting off- target antigens, which have been denatured during heat-treatment. While a necropsy was not performed at the time of the conversion events, no live adult worms were recovered from any of the dogs in which a conversion event occurred earlier in treatment.}, number={1}, journal={Parasites and Vectors}, author={Savadelis, M.D. and Roveto, J.L. and Ohmes, C.M. and Hostetler, J.A. and Settje, T.L. and Dzimianski, M.T. and Moorhead, A.R.}, year={2018} }
 @article{moorhead_evans_kaplan_2017, title={A diagnostic algorithm for evaluating cases of potential macrocyclic lactone-resistant heartworm}, volume={10}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85033586916&partnerID=MN8TOARS}, DOI={10.1186/s13071-017-2441-9}, abstractNote={The emergence of macrocyclic lactone resistance in canine heartworm poses a substantial threat to what is currently the only effective, FDA-approved available method of prevention. Further study of the biotypes is necessary to understand the mechanism of resistance and evaluate novel prevention options. Identifying cases of drug-resistant infection remains problematic, however, especially when poor compliance and insufficient testing are concerns. Furthermore, a definitive demonstration of resistance requires experimental infection and treatment, which is prohibitively costly.With the aim of identifying likely cases of macrocyclic lactone-resistant heartworm and preventing their continued spread, we describe an algorithm for determining the likelihood of drug resistance and appropriate treatment strategies for each case.This algorithm relies on the microfilarial suppression test (MFST), which has been used previously as an efficient and discrete measure of suspected resistance. By standardizing this method in a format that is readily available to practitioners, it could become possible to preliminarily survey the emergence and spread of resistance.Heartworm isolates identified through this method can be used in research to better understand macrocyclic lactone resistance so prevention strategies can be adapted.}, journal={Parasites and Vectors}, author={Moorhead, A.R. and Evans, C.C. and Kaplan, R.M.}, year={2017} }
 @article{savadelis_ohmes_hostetler_settje_zolynas_dzimianski_moorhead_2017, title={Assessment of parasitological findings in heartworm-infected beagles treated with Advantage Multi® for dogs (10% imidacloprid + 2.5% moxidectin) and doxycycline}, volume={10}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85019857083&partnerID=MN8TOARS}, DOI={10.1186/s13071-017-2190-9}, abstractNote={Anecdotal reports support the position that the adulticidal heartworm treatment utilizing doxycycline and Advantage Multi®/Advocate® for Dogs (10% imidacloprid + 2.5% moxidectin) has successfully converted antigen-positive dogs to antigen-negative. To date, no controlled experimental studies have demonstrated the adulticidal efficacy of this treatment regimen. The aim of this study was to evaluate the parasitological and clinical efficacy of Advantage Multi® for Dogs (IMD + MOX) and doxycycline in heartworm-infected beagles.This study utilized 16 dogs, 8 dogs in each of non-treated control and treated groups. A total of 16 adult Dirofilaria immitis (Missouri strain) were surgically transplanted into the jugular vein of each study dog. The treatment regimen of monthly IMD + MOX topically (per labeled dosage and administration) for 10 months and 10 mg/kg doxycycline BID orally for 30 days was initiated 30 days post-surgical transplant. Echocardiograms, radiographs, complete blood counts, clinical chemistry profiles, heartworm antigenemia and microfilaremia were evaluated every 4 weeks. Serum samples were assayed for heartworm antigen using the DiroCHEK® heartworm antigen test. The DiroCHEK® was performed according to the manufacturer's recommendations and read using a spectrophotometer at 490 nm.All dogs tested positive for the presence of heartworm antigen post-surgical transplant and prior to treatment. Heartworm antigen levels began declining in treated dogs 3 months post-treatment. Non-treated control dogs remained antigen-positive. No microfilariae were detected in treated dogs after 21 days post-treatment. At necropsy, adult heartworms were recovered from all non-treated control dogs with a range of 10-12 adult worms/dog for an average recovery of 10.6 adult heartworms/dog. In the IMD + MOX- and doxycycline-treated dogs, the range of adult heartworms recovered was 0-2 adult worms/dog, with five dogs having no adult heartworms present. The average adult heartworm recovery was 0.6/dog in the treated group. This treatment regimen demonstrated a 95.9% efficacy in eliminating adult heartworms (P < 0.0001).This study demonstrated that this treatment regimen successfully eliminated D. immitis microfilariae by 21 days post-treatment, reduced heartworm antigen concentration over time, and had a 95.9% efficacy in the elimination of mature adult heartworms. Based on this study, we conclude that this treatment regimen is a relatively quick, reliable and safe option to treat canine heartworm infection as compared to other treatment regimens involving macrocyclic lactones, when the approved drug melarsomine dihydrochloride is unavailable, contraindicated or declined by an owner unable to afford the more costly treatment or concerned about the potential side effects.}, number={1}, journal={Parasites and Vectors}, author={Savadelis, M.D. and Ohmes, C.M. and Hostetler, J.A. and Settje, T.L. and Zolynas, R. and Dzimianski, M.T. and Moorhead, A.R.}, year={2017} }
 @article{maclean_savadelis_coates_dzimianski_jones_benbow_storey_kaplan_moorhead_wolstenholme_2017, title={Does evaluation of in vitro microfilarial motility reflect the resistance status of Dirofilaria immitis isolates to macrocyclic lactones?}, volume={10}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85033588542&partnerID=MN8TOARS}, DOI={10.1186/s13071-017-2436-6}, abstractNote={Several reports have confirmed that macrocyclic lactone-resistant isolates of Dirofilaria immitis are circulating in the United States; however, the prevalence and potential impact of drug resistance is unknown. We wished to assess computer-aided measurements of motility as a method for rapidly assessing the resistance status of parasite isolates. Blood containing microfilariae (MF) from two clinical cases with a high suspicion of resistance was fed to mosquitoes and the resultant L3 injected into dogs that were then treated with six doses of Heartgard® Plus (ivermectin + pyrantel; Merial Limited) at 30-day intervals. In both cases patent heartworm infections resulted despite the preventive treatment. Microfilariae isolated from these dogs and other isolates of known resistance status were exposed to varying concentrations of ivermectin in vitro and their motility assessed 24 h later using computer-processed high-definition video imaging. We produced two isolates, Yazoo-2013 and Metairie-2014, which established patent infections despite Heartgard® Plus treatments. Measurements of the motility of MF of these and other isolates (Missouri, MP3 and JYD-27) following exposure to varying concentrations of ivermectin did not distinguish between susceptible and resistant heartworm populations. There was some evidence that the method of MF isolation had an influence on the motility and drug susceptibility of the MF. We confirmed that drug-resistant heartworms are circulating in the southern United States, but that motility measurements in the presence of ivermectin are not a reliable method for their detection. This implies that the drug does not kill the microfilariae via paralysis.}, journal={Parasites and Vectors}, author={Maclean, M.J. and Savadelis, M.D. and Coates, R. and Dzimianski, M.T. and Jones, C. and Benbow, C. and Storey, B.E. and Kaplan, R.M. and Moorhead, A.R. and Wolstenholme, A.J.}, year={2017} }
 @article{evans_moorhead_storey_blagburn_wolstenholme_kaplan_2017, title={Evaluation of the larval migration inhibition assay for detecting macrocyclic lactone resistance in Dirofilaria immitis}, volume={246}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85029350477&partnerID=MN8TOARS}, DOI={10.1016/j.vetpar.2017.09.003}, journal={Veterinary Parasitology}, author={Evans, C.C. and Moorhead, A.R. and Storey, B.E. and Blagburn, B.L. and Wolstenholme, A.J. and Kaplan, R.M.}, year={2017}, pages={76–81} }
 @article{evans_burkman_dzimianski_moorhead_savadelis_angenendt_zymny_kulke_2017, title={Periodicity of Dirofilaria immitis in Longterm Infections}, volume={116}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85024479572&partnerID=MN8TOARS}, DOI={10.1007/s00436-017-5493-z}, abstractNote={The concentration of Dirofilaria immitis microfilariae in peripheral blood samples was measured in four experimentally infected dogs.Samples were collected at hourly intervals from 6.30h to 17.30h from all dogs at 11, 22, and 27 months postinfection, and at 39 months post-infection for two dogs only.Microfilarial periodicity follows the form of a simple harmonic wave over a 24h period, and concentration data was fit to sine wave for each sample date to characterize changes in periodicity over time.We found the periodicity index (i.e.wave amplitude) to decrease with time (p = 0.016, R 2 = 0.97) dropping from 74.57 (95 % CI, 63.79 to 85.34) at 11 months post-infection to 5.55 (95 % CI, 0 to 14.82) at 39 months post-infection.The time of peak microfilaremia was calculated to be 17.36 h (95 % CI, 17.01h to 18.08 h) at 11 months post-infection and did not change significantly with time (p = 0.17, R 2 = 0.70).No significant trend was observed in total microfilarial count for individual dogs (p > 0.10).The data presented here indicate a gradual but significant loss of periodicity over the two-year study period despite maintenance of overall microfilarial levels.}, journal={Parasitology Research}, author={Evans, C.C. and Burkman, E.J. and Dzimianski, M.T. and Moorhead, A.R. and Savadelis, M.D. and Angenendt, C. and Zymny, S. and Kulke, D.}, year={2017}, pages={75–80} }
 @article{o’neill_njouendou_dzimianski_burkman_ndongmo_kengne-ouafo_wanji_moorhead_mackenzie_geary_2018, title={Potential role for flubendazole in limiting filariasis transmission: Observations of microfilarial sensitivity}, volume={98}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85040519330&partnerID=MN8TOARS}, DOI={10.4269/ajtmh.17-0390}, abstractNote={Flubendazole (FLBZ) is a potent and efficacious macrofilaricide after parenteral administration. Studies in animal models and one trial in patients infected with Onchocerca volvulus revealed that FLBZ elicits minimal effects on microfilariae (mf). Severe complications after ivermectin (IVM) treatment of patients with high Loa loa microfilaraemia are of great concern. We examined the potential of FLBZ to rapidly kill L. loa mf, the phenomenon proposed to underlie the complications. Mf of L. loa were exposed to FLBZ, its reduced metabolite, albendazole, or IVM in vitro. Viability of L. loa mf was unaffected by FLBZ (10 μM, 72 hours); similar results were obtained with mf of Brugia malayi. We also measured the effects of FLBZ on transmission of mf. Aedes aegypti were fed FLBZ-exposed B. malayi mf and dissected 24 hours or 14 days postfeeding to count mf that crossed the midgut and developed to infective L3. FLBZ impaired the ability of mf to cross the midgut, regardless of duration of exposure (≥ 2 hours). FLBZ also prevented the development of mf to L3s, irrespective of duration of exposure or concentration. FLBZ is not microfilaricidal under these conditions; however, it blocks transmission. These results support the possibility that FLBZ may be a useful macrofilaricide in loiasis regions and may limit transmission from treated individuals.}, number={1}, journal={American Journal of Tropical Medicine and Hygiene}, author={O’Neill, M. and Njouendou, J.A. and Dzimianski, M. and Burkman, E. and Ndongmo, P.C. and Kengne-Ouafo, J.A. and Wanji, S. and Moorhead, A. and MacKenzie, C.D. and Geary, T.G.}, year={2018}, pages={21–26} }
 @article{mhashilkar_adapa_jiang_williams_zaky_slatko_luck_moorhead_unnasch_2016, title={Phenotypic and molecular analysis of the effect of 20-hydroxyecdysone on the human filarial parasite Brugia malayi}, volume={46}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84963804640&partnerID=MN8TOARS}, DOI={10.1016/j.ijpara.2016.01.005}, number={5-6}, journal={International Journal for Parasitology}, author={Mhashilkar, A.S. and Adapa, S.R. and Jiang, R.H.Y. and Williams, S.A. and Zaky, W. and Slatko, B.E. and Luck, A.N. and Moorhead, A.R. and Unnasch, T.R.}, year={2016}, pages={333–341} }
 @article{o’neill_ballesteros_tritten_burkman_zaky_xia_moorhead_williams_geary_2016, title={Profiling the macrofilaricidal effects of flubendazole on adult female Brugia malayi using RNAseq}, volume={6}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84990841507&partnerID=MN8TOARS}, DOI={10.1016/j.ijpddr.2016.09.005}, abstractNote={The use of microfilaricidal drugs for the control of onchocerciasis and lymphatic filariasis (LF) necessitates prolonged yearly dosing. Prospects for elimination or eradication of these diseases would be enhanced by the availability of a macrofilaricidal drug. Flubendazole (FLBZ), a benzimidazole anthelmintic, is an appealing candidate. FLBZ has demonstrated potent macrofilaricidal effects in a number of experimental rodent models and in one human trial. Unfortunately, FLBZ was deemed unsatisfactory for use in mass drug administration campaigns due to its limited oral bioavailability. A new formulation that enables sufficient bioavailability following oral administration could render FLBZ an effective treatment for onchocerciasis and LF. Identification of drug-derived effects is important in ascertaining a dosage regimen which is predicted to be lethal to the parasite in situ. In previous histological studies, exposure to FLBZ induced damage to tissues required for reproduction and survival at pharmacologically relevant concentrations. However, more precise and quantitative indices of drug effects are needed. This study assessed drug effects using a transcriptomic approach to confirm effects observed histologically and to identify genes which were differentially expressed in treated adult female Brugia malayi. Comparative analysis across different concentrations (1 μM and 5 μM) and durations (48 and 120 h) provided an overview of the processes which are affected by FLBZ exposure. Genes with dysregulated expression were consistent with the reproductive effects observed via histology in our previous studies. This study revealed transcriptional changes in genes involved in embryo development. Additionally, significant downregulation was observed in genes encoding cuticle components, which may reflect changes in developing embryos, the adult worm cuticle or both. These data support the hypothesis that FLBZ acts predominantly on rapidly dividing cells, and provides a basis for selecting molecular markers of drug-induced damage which may be of use in predicting efficacious FLBZ regimens.}, number={3}, journal={International Journal for Parasitology: Drugs and Drug Resistance}, author={O’Neill, M. and Ballesteros, C. and Tritten, L. and Burkman, E. and Zaky, W.I. and Xia, J. and Moorhead, A. and Williams, S.A. and Geary, T.G.}, year={2016}, pages={288–296} }
 @article{ballesteros_tritten_o?neill_burkman_zaky_xia_moorhead_williams_geary_2016, title={The Effect of In Vitro Cultivation on the Transcriptome of Adult Brugia malayi}, volume={10}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84969429404&partnerID=MN8TOARS}, DOI={10.1371/journal.pntd.0004311}, abstractNote={Filarial nematodes cause serious and debilitating infections in human populations of tropical countries, contributing to an entrenched cycle of poverty. Only one human filarial parasite, Brugia malayi, can be maintained in rodents in the laboratory setting. It has been a widely used model organism in experiments that employ culture systems, the impact of which on the worms is unknown.}, number={1}, journal={PLoS Neglected Tropical Diseases}, author={Ballesteros, C. and Tritten, L. and O?Neill, M. and Burkman, E. and Zaky, W.I. and Xia, J. and Moorhead, A. and Williams, S.A. and Geary, T.G.}, year={2016} }
 @article{ballesteros_tritten_o?neill_burkman_zaky_xia_moorhead_williams_geary_2016, title={The Effects of Ivermectin on Brugia malayi Females In Vitro: A Transcriptomic Approach}, volume={10}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84988693259&partnerID=MN8TOARS}, DOI={10.1371/journal.pntd.0004929}, abstractNote={Background Lymphatic filariasis and onchocerciasis are disabling and disfiguring neglected tropical diseases of major importance in developing countries. Ivermectin is the drug of choice for mass drug administration programs for the control of onchocerciasis and lymphatic filariasis in areas where the diseases are co-endemic. Although ivermectin paralyzes somatic and pharyngeal muscles in many nematodes, these actions are poorly characterized in adult filariae. We hypothesize that paralysis of pharyngeal pumping by ivermectin in filariae could result in deprivation of essential nutrients, especially iron, inducing a wide range of responses evidenced by altered gene expression, changes in metabolic pathways, and altered developmental states in embryos. Previous studies have shown that ivermectin treatment significantly reduces microfilariae release from females within four days of exposure in vivo, while not markedly affecting adult worms. However, the mechanisms responsible for reduced production of microfilariae are poorly understood. Methodology/Principal Findings We analyzed transcriptomic profiles from Brugia malayi adult females, an important model for other filariae, using RNAseq technology after exposure in culture to ivermectin at various concentrations (100 nM, 300 nM and 1 μM) and time points (24, 48, 72 h, and 5 days). Our analysis revealed drug-related changes in expression of genes involved in meiosis, as well as oxidative phosphorylation, which were significantly down-regulated as early as 24 h post-exposure. RNA interference phenotypes of the orthologs of these down-regulated genes in C. elegans include “maternal sterile”, “embryonic lethal”, “larval arrest”, “larval lethal” and “sick”. Conclusion/Significance These changes provide insight into the mechanisms involved in ivermectin-induced reduction in microfilaria output and impaired fertility, embryogenesis, and larval development.}, number={8}, journal={PLoS Neglected Tropical Diseases}, author={Ballesteros, C. and Tritten, L. and O?Neill, M. and Burkman, E. and Zaky, W.I. and Xia, J. and Moorhead, A. and Williams, S.A. and Geary, T.G.}, year={2016} }
 @article{alworth_berghaus_kelly_supakorndej_burkman_savadelis_cooper_salyards_harvey_moorhead_2015, title={Assessment of Blood Collection from the Lateral Saphenous Vein for Microfilaria Counts in Mongolian Gerbils (Meriones unguiculatus) Infected with Brugia pahangi}, volume={65}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85008952003&partnerID=MN8TOARS}, number={6}, journal={Comparative Medicine}, author={Alworth, L.C. and Berghaus, R.D. and Kelly, L.M. and Supakorndej, P. and Burkman, E.J. and Savadelis, M.D. and Cooper, T.L. and Salyards, G.W. and Harvey, S.B. and Moorhead, A.R.}, year={2015}, pages={492–498} }
 @article{dooley_froese_chung_burkman_moorhead_ardelli_2015, title={Host ABC transporter proteins may influence the efficacy of ivermectin and possibly have broader implications for the development of resistance in parasitic nematodes}, volume={157}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84938526231&partnerID=MN8TOARS}, DOI={10.1016/j.exppara.2015.06.006}, journal={Experimental Parasitology}, author={Dooley, L.A. and Froese, E.A. and Chung, Y.T. and Burkman, E.J. and Moorhead, A.R. and Ardelli, B.F.}, year={2015}, pages={35–43} }
 @article{zamanian_fraser_agbedanu_harischandra_moorhead_day_bartholomay_kimber_2015, title={Release of Small RNA-containing Exosome-like Vesicles from the Human Filarial Parasite Brugia malayi}, volume={9}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84943178967&partnerID=MN8TOARS}, DOI={10.1371/journal.pntd.0004069}, abstractNote={Lymphatic filariasis (LF) is a socio-economically devastating mosquito-borne Neglected Tropical Disease caused by parasitic filarial nematodes. The interaction between the parasite and host, both mosquito and human, during infection, development and persistence is dynamic and delicately balanced. Manipulation of this interface to the detriment of the parasite is a promising potential avenue to develop disease therapies but is prevented by our very limited understanding of the host-parasite relationship. Exosomes are bioactive small vesicles (30–120 nm) secreted by a wide range of cell types and involved in a wide range of physiological processes. Here, we report the identification and partial characterization of exosome-like vesicles (ELVs) released from the infective L3 stage of the human filarial parasite Brugia malayi. Exosome-like vesicles were isolated from parasites in culture media and electron microscopy and nanoparticle tracking analysis were used to confirm that vesicles produced by juvenile B. malayi are exosome-like based on size and morphology. We show that loss of parasite viability correlates with a time-dependent decay in vesicle size specificity and rate of release. The protein cargo of these vesicles is shown to include common exosomal protein markers and putative effector proteins. These Brugia-derived vesicles contain small RNA species that include microRNAs with host homology, suggesting a potential role in host manipulation. Confocal microscopy shows J774A.1, a murine macrophage cell line, internalize purified ELVs, and we demonstrate that these ELVs effectively stimulate a classically activated macrophage phenotype in J774A.1. To our knowledge, this is the first report of exosome-like vesicle release by a human parasitic nematode and our data suggest a novel mechanism by which human parasitic nematodes may actively direct the host responses to infection. Further interrogation of the makeup and function of these bioactive vesicles could seed new therapeutic strategies and unearth stage-specific diagnostic biomarkers.}, number={9}, journal={PLoS Neglected Tropical Diseases}, author={Zamanian, M. and Fraser, L.M. and Agbedanu, P.N. and Harischandra, H. and Moorhead, A.R. and Day, T.A. and Bartholomay, L.C. and Kimber, M.J.}, year={2015} }
 @article{wolstenholme_evans_jimenez_moorhead_2015, title={The emergence of macrocyclic lactone resistance in the canine heartworm, Dirofilaria immitis}, volume={142}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84937811684&partnerID=MN8TOARS}, DOI={10.1017/S003118201500061X}, abstractNote={SUMMARY Prevention of heartworm disease caused by Dirofilaria immitis in domestic dogs and cats relies on a single drug class, the macrocyclic lactones (MLs). Recently, it has been demonstrated that ML-resistant D. immitis are circulating in the Mississippi Delta region of the USA, but the prevalence and impact of these resistant parasites remains unknown. We review published studies that demonstrated resistance in D.immitis , along with our current understanding of its mechanisms. Efforts to develop in vitro tests for resistance have not yet yielded a suitable assay, so testing infected animals for microfilariae that persist in the face of ML treatment may be the best current option. Since the vast majority of D. immitis populations continue to be drug-sensitive, protected dogs are likely to be infected with only a few parasites and experience relatively mild disease. In cats, infection with small numbers of worms can cause severe disease and so the clinical consequences of drug resistance may be more severe. Since melarsomine dihydrochloride, the drug used to remove adult worms, is not an ML, the ML-resistance should have no impact on our ability to treat diseased animals. A large refugium of heartworms that are not exposed to drugs exists in unprotected dogs and in wild canids, which may limit the development and spread of resistance alleles.}, number={10}, journal={Parasitology}, author={Wolstenholme, A.J. and Evans, C.C. and Jimenez, P.D. and Moorhead, A.R.}, year={2015}, pages={1249–1259} }
 @article{kassis_skelton_lu_moorhead_dixon_2014, title={An Integrated In Vitro Imaging Platform for Characterizing Filarial Parasite Behavior within a Multicellular Microenvironment}, volume={8}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84920499862&partnerID=MN8TOARS}, DOI={10.1371/journal.pntd.0003305}, abstractNote={Lymphatic Filariasis, a Neglected Tropical Disease, is caused by thread-like parasitic worms, including B. malayi, which migrate to the human lymphatic system following transmission. The parasites reside in collecting lymphatic vessels and lymph nodes for years, often resulting in lymphedema, elephantiasis or hydrocele. The mechanisms driving worm migration and retention within the lymphatics are currently unknown. We have developed an integrated in vitro imaging platform capable of quantifying B. malayi migration and behavior in a multicellular microenvironment relevant to the initial site of worm injection by incorporating the worm in a Polydimethylsiloxane (PDMS) microchannel in the presence of human dermal lymphatic endothelial cells (LECs) and human dermal fibroblasts (HDFs). The platform utilizes a motorized controllable microscope with CO2 and temperature regulation to allow for worm tracking experiments with high resolution over large length and time scales. Using post-acquisition algorithms, we quantified four parameters: 1) speed, 2) thrashing intensity, 3) percentage of time spent in a given cell region and 4) persistence ratio. We demonstrated the utility of our system by quantifying these parameters for L3 B. malayi in the presence of LECs and HDFs. Speed and thrashing increased in the presence of both cell types and were altered within minutes upon exposure to the anthelmintic drug, tetramisole. The worms displayed no targeted migration towards either cell type for the time course of this study (3 hours). When cells were not present in the chamber, worm thrashing correlated directly with worm speed. However, this correlation was lost in the presence of cells. The described platform provides the ability to further study B. malayi migration and behavior.}, number={11}, journal={PLoS Neglected Tropical Diseases}, author={Kassis, T. and Skelton, H.M. and Lu, I.M. and Moorhead, A.R. and Dixon, J.B.}, year={2014} }
 @article{luck_evans_riggs_foster_moorhead_slatko_michalski_2014, title={Concurrent transcriptional profiling of Dirofilaria immitis and its Wolbachia endosymbiont throughout the nematode life cycle reveals coordinated gene expression}, volume={15}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84928713006&partnerID=MN8TOARS}, DOI={10.1186/1471-2164-15-1041}, abstractNote={Dirofilaria immitis, or canine heartworm, is a filarial nematode parasite that infects dogs and other mammals worldwide. Current disease control relies on regular administration of anthelmintic preventives, however, relatively poor compliance and evidence of developing drug resistance could warrant alternative measures against D. immitis and related human filarial infections be taken. As with many other filarial nematodes, D. immitis contains Wolbachia, an obligate bacterial endosymbiont thought to be involved in providing certain critical metabolites to the nematode. Correlations between nematode and Wolbachia transcriptomes during development have not been examined. Therefore, we detailed the developmental transcriptome of both D. immitis and its Wolbachia (wDi) in order to gain a better understanding of parasite-endosymbiont interactions throughout the nematode life cycle. Over 215 million single-end 50 bp reads were generated from total RNA from D. immitis adult males and females, microfilariae (mf) and third and fourth-stage larvae (L3 and L4). We critically evaluated the transcriptomes of the various life cycle stages to reveal sex-biased transcriptional patterns, as well as transcriptional differences between larval stages that may be involved in larval maturation. Hierarchical clustering revealed both D. immitis and wDi transcriptional activity in the L3 stage is clearly distinct from other life cycle stages. Interestingly, a large proportion of both D. immitis and wDi genes display microfilarial-biased transcriptional patterns. Concurrent transcriptome sequencing identified potential molecular interactions between parasite and endosymbiont that are more prominent during certain life cycle stages. In support of metabolite provisioning between filarial nematodes and Wolbachia, the synthesis of the critical metabolite, heme, by wDi appears to be synchronized in a stage-specific manner (mf-specific) with the production of heme-binding proteins in D. immitis. Our integrated transcriptomic study has highlighted interesting correlations between Wolbachia and D. immitis transcription throughout the life cycle and provided a resource that may be used for the development of novel intervention strategies, not only for the treatment and prevention of D. immitis infections, but of other closely related human parasites as well.}, number={1}, journal={BMC Genomics}, author={Luck, A.N. and Evans, C.C. and Riggs, M.D. and Foster, J.M. and Moorhead, A.R. and Slatko, B.E. and Michalski, M.L.}, year={2014} }
 @article{tritten_burkman_moorhead_satti_geary_mackenzie_geary_2014, title={Detection of Circulating Parasite-Derived MicroRNAs in Filarial Infections}, volume={8}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84905484571&partnerID=MN8TOARS}, DOI={10.1371/journal.pntd.0002971}, abstractNote={Filarial nematodes cause chronic and profoundly debilitating diseases in both humans and animals. Applications of novel technology are providing unprecedented opportunities to improve diagnosis and our understanding of the molecular basis for host-parasite interactions. As a first step, we investigated the presence of circulating miRNAs released by filarial nematodes into the host bloodstream. miRNA deep-sequencing combined with bioinformatics revealed over 200 mature miRNA sequences of potential nematode origin in Dirofilaria immitis-infected dog plasma in two independent analyses, and 21 in Onchocerca volvulus-infected human serum. Total RNA obtained from D. immitis-infected dog plasma was subjected to stem-loop RT-qPCR assays targeting two detected miRNA candidates, miR-71 and miR-34. Additionally, Brugia pahangi-infected dog samples were included in the analysis, as these miRNAs were previously detected in extracts prepared from this species. The presence of miR-71 and miR-34 discriminated infected samples (both species) from uninfected samples, in which no specific miRNA amplification occurred. However, absolute miRNA copy numbers were not significantly correlated with microfilaraemia for either parasite. This may be due to the imprecision of mf counts to estimate infection intensity or to miRNA contributions from the unknown number of adult worms present. Nonetheless, parasite-derived circulating miRNAs are found in plasma or serum even for those species that do not live in the bloodstream.}, number={7}, journal={PLoS Neglected Tropical Diseases}, author={Tritten, L. and Burkman, E. and Moorhead, A. and Satti, M. and Geary, J. and Mackenzie, C. and Geary, T.}, year={2014} }
 @article{moorhead_2014, title={Heartworm treatment: Navigating a changing landscape}, volume={27}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84911490897&partnerID=MN8TOARS}, DOI={10.1016/j.asams.2014.11.001}, number={11}, journal={Advances in Small Animal Medicine and Surgery}, author={Moorhead, A.R.}, year={2014}, pages={1–3} }
 @article{sassi_geary_leroux_moorhead_satti_mackenzie_geary_2014, title={Identification of dirofilaria immitis proteins recognized by antibodies from infected dogs}, volume={100}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84902519110&partnerID=MN8TOARS}, DOI={10.1645/13-437.1}, abstractNote={The identification of excreted–secreted (ES) proteins of filarial nematodes as potential diagnostic reagents is an important requirement for the development of methods to determine level of infection in the host, especially for human filariae. Dirofilaria immitis, the canine heartworm, is a widespread and important veterinary pathogen and is a useful model for filarial parasites of humans. An analysis of proteins released from adult D. immitis (the secretome) in culture is available. We sought to identify D. immitis ES proteins found in vivo to validate the in vitro secretome and to investigate them as potential diagnostic reagents. Cultures of D. immitis adults obtained from infected dogs were maintained for 72 hr with daily changes of media. Proteins were concentrated from spent media by standard methods and were passed through Protein-A columns containing purified IgG antibodies from heartworm-infected dogs. Following extensive washing, heartworm proteins recognized by the antibodies were eluted from these columns and submitted for analysis by tandem mass spectrometry (MS/MS). As a comparison, somatic proteins from adult D. immitis female parasites and microfilaria were also processed and analyzed by the same protocol. Six, 9, and 12 proteins were identified by MS/MS in the ES, adult female, and microfilaria samples, respectively. The identification of the most abundant parasite proteins present in the serum of infected hosts offers a rational approach to the development of new diagnostic assays that may be applicable across the Filarioidea.}, number={3}, journal={Journal of Parasitology}, author={Sassi, A.J. and Geary, J.F. and Leroux, L.P. and Moorhead, A.R. and Satti, M. and MacKenzie, C.D. and Geary, T.G.}, year={2014}, pages={364–367} }
 @article{vatta_dzimianski_storey_camus_moorhead_kaplan_wolstenholme_2014, title={Ivermectin-dependent attachment of neutrophils and peripheral blood mononuclear cells to Dirofilaria immitis microfilariae in vitro}, volume={206}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84919650782&partnerID=MN8TOARS}, DOI={10.1016/j.vetpar.2014.02.004}, number={1-2}, journal={Veterinary Parasitology}, author={Vatta, A.F. and Dzimianski, M. and Storey, B.E. and Camus, M.S. and Moorhead, A.R. and Kaplan, R.M. and Wolstenholme, A.J.}, year={2014}, pages={38–42} }
 @inbook{moorhead_2014, title={Zoonotic Helminths of Livestock}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85042818498&partnerID=MN8TOARS}, DOI={10.1016/B978-0-444-52512-3.00191-1}, booktitle={Encyclopedia of Agriculture and Food Systems}, author={Moorhead, A.R.}, year={2014}, pages={466–474} }
 @article{evans_moorhead_storey_wolstenholme_kaplan_2013, title={Development of an in vitro bioassay for measuring susceptibility to macrocyclic lactone anthelmintics in Dirofilaria immitis}, volume={3}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84880385460&partnerID=MN8TOARS}, DOI={10.1016/j.ijpddr.2013.05.001}, abstractNote={For more than 20 years, anthelmintics of the macrocyclic lactone (ML) drug class have been widely and effectively used as preventives against the canine heartworm, Dirofilaria immitis. However, in recent years an increased number of lack of efficacy (LOE) cases are being reported, in which dogs develop mature heartworm infections despite receiving monthly prophylactic doses of ML drugs. While this situation is raising concerns that heartworms may be developing resistance to MLs, compelling evidence for this is still lacking. Resolution of this dilemma requires validated biological or molecular diagnostic assays, but, unfortunately, no such tests currently exist. To address this need, we developed and optimized a larval migration inhibition assay (LMIA) for use with D. immitis third-stage larvae. The LMIA was used to measure the in vitro dose-response of two ML drugs (ivermectin and eprinomectin) on a known ML-susceptible laboratory strain of D. immitis. A nonlinear regression model was fit to the dose-response data, from which IC50 values were calculated; the mean IC50 and 95% confidence interval for IVM was 4.56 μM (1.26-16.4 μM), greater than that for EPR at 2.02 μM (1.68-2.42 μM), and this difference was significant (p = 0.0428). The R (2) value for EPR assays (0.90) was also greater than that for IVM treatment (0.71). The consistency and reproducibility of the dose-response data obtained with this assay suggests that it may be a useful technique for investigating the relative susceptibilities to ML drugs in other D. immitis populations.}, journal={International Journal for Parasitology: Drugs and Drug Resistance}, author={Evans, C.C. and Moorhead, A.R. and Storey, B.E. and Wolstenholme, A.J. and Kaplan, R.M.}, year={2013}, pages={102–108} }
 @article{gebreselassie_moorhead_fabre_gagliardo_lee_lee_appleton_2012, title={Eosinophils preserve parasitic nematode larvae by regulating local immunity}, volume={188}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84855384507&partnerID=MN8TOARS}, DOI={10.4049/jimmunol.1101980}, abstractNote={Abstract Eosinophils play important roles in regulation of cellular responses under conditions of homeostasis or infection. Intestinal infection with the parasitic nematode, Trichinella spiralis, induces a pronounced eosinophilia that coincides with establishment of larval stages in skeletal muscle. We have shown previously that in mouse strains in which the eosinophil lineage is ablated, large numbers of T. spiralis larvae are killed by NO, implicating the eosinophil as an immune regulator. In this report, we show that parasite death in eosinophil-ablated mice correlates with reduced recruitment of IL-4+ T cells and enhanced recruitment of inducible NO synthase (iNOS)-producing neutrophils to infected muscle, as well as increased iNOS in local F4/80+CD11b+Ly6C+ macrophages. Actively growing T. spiralis larvae were susceptible to killing by NO in vitro, whereas mature larvae were highly resistant. Growth of larvae was impaired in eosinophil-ablated mice, potentially extending the period of susceptibility to the effects of NO and enhancing parasite clearance. Transfer of eosinophils into eosinophil-ablated ΔdblGATA mice restored larval growth and survival. Regulation of immunity was not dependent upon eosinophil peroxidase or major basic protein 1 and did not correlate with activity of the IDO pathway. Our results suggest that eosinophils support parasite growth and survival by promoting accumulation of Th2 cells and preventing induction of iNOS in macrophages and neutrophils. These findings begin to define the cellular interactions that occur at an extraintestinal site of nematode infection in which the eosinophil functions as a pivotal regulator of immunity.}, number={1}, journal={Journal of Immunology}, author={Gebreselassie, N.G. and Moorhead, A.R. and Fabre, V. and Gagliardo, L.F. and Lee, N.A. and Lee, J.J. and Appleton, J.A.}, year={2012}, pages={417–425} }
 @article{stone_frontera-acevedo_saba_ambrose_moorhead_brown_2011, title={Lymphosarcoma associated with heterobilharzia americana infection in a dog}, volume={23}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84857129801&partnerID=MN8TOARS}, DOI={10.1177/1040638711416972}, abstractNote={Hepatic T-cell lymphosarcoma with involvement of regional lymph nodes and concurrent schistosomiasis were diagnosed in an 11-year-old male neutered mixed-breed dog with a history of chronic weight loss, inappetence, vomiting, and diarrhea. Trematode ova present in the hepatic parenchyma and mesenteric node were surrounded by sheets of neoplastic lymphocytes while those in the intestinal wall were surrounded by large numbers of non-neoplastic lymphocytes. Immunohistochemistry revealed that both the neoplastic and hyperplastic populations were T lymphocytes. The ova were identified by fecal saline sedimentation as Heterobilharzia spp., and fecal ova shedding resolved after praziquantel anthelmintic treatment. The lymphoma progressed despite chemotherapy, and the dog was euthanized after developing neurologic signs and a necropsy was performed. A monomorphic population of neoplastic T cells expanded and replaced normal architecture in the liver and spleen, surrounded nerve roots within the cauda equina, and infiltrated the meninges of the brain. The presence of schistosome ova embedded within neoplastic T-cell infiltrates suggests that, as previously reported in human schistosomiasis, heterobilharziasis may be associated with neoplasia.}, number={5}, journal={Journal of Veterinary Diagnostic Investigation}, author={Stone, R.H. and Frontera-Acevedo, K. and Saba, C.F. and Ambrose, D. and Moorhead, A.R. and Brown, C.A.}, year={2011}, pages={1065–1070} }
 @article{michalski_griffiths_williams_kaplan_moorhead_2011, title={The NIH-NIAID filariasis research reagent resource center}, volume={5}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-82555173811&partnerID=MN8TOARS}, DOI={10.1371/journal.pntd.0001261}, abstractNote={Filarial worms cause a variety of tropical diseases in humans; however, they are difficult to study because they have complex life cycles that require arthropod intermediate hosts and mammalian definitive hosts. Research efforts in industrialized countries are further complicated by the fact that some filarial nematodes that cause disease in humans are restricted in host specificity to humans alone. This potentially makes the commitment to research difficult, expensive, and restrictive. Over 40 years ago, the United States National Institutes of Health-National Institute of Allergy and Infectious Diseases (NIH-NIAID) established a resource from which investigators could obtain various filarial parasite species and life cycle stages without having to expend the effort and funds necessary to maintain the entire life cycles in their own laboratories. This centralized resource (The Filariasis Research Reagent Resource Center, or FR3) translated into cost savings to both NIH-NIAID and to principal investigators by freeing up personnel costs on grants and allowing investigators to divert more funds to targeted research goals. Many investigators, especially those new to the field of tropical medicine, are unaware of the scope of materials and support provided by the FR3. This review is intended to provide a short history of the contract, brief descriptions of the fiilarial species and molecular resources provided, and an estimate of the impact the resource has had on the research community, and describes some new additions and potential benefits the resource center might have for the ever-changing research interests of investigators.}, number={11}, journal={PLoS Neglected Tropical Diseases}, author={Michalski, M.L. and Griffiths, K.G. and Williams, S.A. and Kaplan, R.M. and Moorhead, A.R.}, year={2011} }
 @article{moorhead_jung_smirnov_kaufer_scidmore_2010, title={Multiple host proteins that function in phosphatidylinositol-4-phosphate metabolism are recruited to the chlamydial inclusion}, volume={78}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77951231154&partnerID=MN8TOARS}, DOI={10.1128/IAI.01340-09}, abstractNote={Chlamydiae replicate within a nonacidified vacuole, termed an inclusion. As obligate intracellular bacteria, chlamydiae actively modify their vacuole to exploit host signaling and trafficking pathways. Recently, we demonstrated that several Rab GTPases are actively targeted to the inclusion. To define the biological roles of inclusion localized Rab GTPases, we have begun to identify inclusion-localized Rab effectors. Here we demonstrate that oculocerebrorenal syndrome of Lowe protein 1 (OCRL1), a Golgi complex-localized phosphatidylinositol (PI)-5-phosphatase that binds to multiple Rab GTPases, localizes to chlamydial inclusions. By examining the intracellular localization of green fluorescent protein (GFP) fusion proteins that bind to unique phosphoinositide species, we also demonstrate that phosphatidylinositol-4-phosphate (PI4P), the product of OCRL1, is present at the inclusion membrane. Furthermore, two additional host proteins, Arf1, which together with PI4P mediates the recruitment of PI4P-binding proteins to the Golgi complex, and PI4KII alpha, a major producer of Golgi complex-localized PI4P, also localize to chlamydial inclusions. Depletion of OCRL1, Arf1, or PI4KII alpha by small interfering RNA (siRNA) decreases inclusion formation and the production of infectious progeny. Infectivity is further decreased in cells simultaneously depleted for all three host proteins, suggesting partially overlapping functions in infected cells. Collectively, these data demonstrate that Chlamydia species create a unique replication-competent vacuolar environment by modulating both the Rab GTPase and the PI composition of the chlamydial inclusion.}, number={5}, journal={Infection and Immunity}, author={Moorhead, A.M. and Jung, J.-Y. and Smirnov, A. and Kaufer, S. and Scidmore, M.A.}, year={2010}, pages={1990–2007} }
 @article{rzomp_moorhead_scidmore_2006, title={The GTPase Rab4 interacts with Chlamydia trachomatis inclusion membrane protein CT229}, volume={74}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33748070817&partnerID=MN8TOARS}, DOI={10.1128/IAI.00539-06}, abstractNote={ABSTRACT Chlamydiae, which are obligate intracellular bacteria, replicate in a nonlysosomal vacuole, termed an inclusion. Although neither the host nor the chlamydial proteins that mediate the intracellular trafficking of the inclusion have been clearly identified, several enhanced green fluorescent protein (GFP)-tagged Rab GTPases, including Rab4A, are recruited to chlamydial inclusions. GFP-Rab4A associates with inclusions in a species-independent fashion by 2 h postinfection by mechanisms that have not yet been elucidated. To test whether chlamydial inclusion membrane proteins (Incs) recruit Rab4 to the inclusion, we screened a collection of chlamydial Incs for their ability to interact with Rab4A by using a yeast two-hybrid assay. From our analysis, we identified a specific interaction between Rab4A and Chlamydia trachomatis Inc CT229, which is expressed during the initial stages of infection. CT229 interacts with only wild-type Rab4A and the constitutively active GTPase-deficient Rab4AQ67L but not with the dominant-negative GDP-restricted Rab4AS22N mutant. To confirm the interaction between CT229 and Rab4A, we demonstrated that DsRed-CT229 colocalized with GFP-Rab4A in HeLa cells and more importantly wild-type and constitutively active GFP-Rab4A colocalized with CT229 at the inclusion membrane in C. trachomatis serovar L2-infected HeLa cells. Taken together, these data suggest that CT229 interacts with and recruits Rab4A to the inclusion membrane and therefore may play a role in regulating the intracellular trafficking or fusogenicity of the chlamydial inclusion.}, number={9}, journal={Infection and Immunity}, author={Rzomp, K.A. and Moorhead, A.R. and Scidmore, M.A.}, year={2006}, pages={5362–5373} }
 @article{moorhead_rzomp_scidmore_2007, title={The Rab6 effector bicaudal D1 associates with Chlamydia trachomatis inclusions in a biovar-specific manner}, volume={75}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33846823056&partnerID=MN8TOARS}, DOI={10.1128/IAI.01447-06}, abstractNote={ABSTRACT Chlamydia species are obligate intracellular bacteria that replicate within a membrane-bound vacuole, the inclusion, which is trafficked to the peri-Golgi region by processes that are dependent on early chlamydial gene expression. Although neither the host nor the chlamydial proteins that regulate the intracellular trafficking have been clearly defined, several enhanced green fluorescent protein (EGFP)-tagged Rab GTPases, including Rab6, are recruited to Chlamydia trachomatis inclusions. To further characterize the association of Rab6 with C. trachomatis inclusions, we examined the intracellular localization of guanine nucleotide-binding mutants of Rab6 and demonstrated that only active GTP-bound and not inactive GDP-bound EGFP-Rab6 mutants were recruited to the inclusion, suggesting that EGFP-Rab6 interacts with the inclusion via a host Rab6 effector or a chlamydial protein that mimics a Rab6 effector. Using EGFP-tagged fusion proteins, we also demonstrated that the Rab6 effector Bicaudal D1 (BICD1) localized to C. trachomatis inclusions in a biovar-specific manner. In addition, we demonstrated that EGFP-Rab6 and its effector EGFP-BICD1 are recruited to the inclusion in a microtubule- and Golgi apparatus-independent but chlamydial gene expression-dependent mechanism. Finally, in contrast to the Rab6-dependent Golgi apparatus localization of endogenous BICD1, EGFP-BICD1 was recruited to the inclusion by a Rab6-independent mechanism. Collectively, these data demonstrate that neither Rab6 nor BICD1 is trafficked to the inclusion via a Golgi apparatus-localized intermediate, suggesting that each protein is trafficked to the C. trachomatis serovar L2 inclusion by a unique, but as-yet-undefined, mechanism.}, number={2}, journal={Infection and Immunity}, author={Moorhead, A.R. and Rzomp, K.A. and Scidmore, M.A.}, year={2007}, pages={781–791} }
 @article{moorhead_grunenwald_dietz_schantz_1999, title={Trichinellosis in the United States, 1991-1996: Declining but not gone}, volume={60}, ISSN={["0002-9637"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0032901042&partnerID=MN8TOARS}, DOI={10.4269/ajtmh.1999.60.66}, abstractNote={Since the U.S. Public Health Service began recording statistics on trichinellosis in 1947, the number of cases reported by state health departments has decreased steadily. In the late 1940s, health departments reported an average of 400 cases and 10-15 deaths each year. From 1991 to 1996, the period covered in this report, three deaths in 230 cases were reported to the Centers for Disease Control and Prevention (an average of 38 cases per year), including 14 multiple case outbreaks from 31 states and Washington, DC. Information on the suspected food item was available for 134 (58%) of the 230 reported cases. Pork was implicated in 80 (60%) cases, bear meat in 31 (23%), walrus meat in 13 (10%), and cougar meat in 10 (7%). Sausage was the most frequently implicated pork product (i.e., 57 of the 64 cases for which the form of the pork product was identified). The proportion of trichinellosis cases attributable to consumption of commercial pork continued to decrease; this decrease was probably due to a combination of factors, including the continued reduction in the prevalence of Trichinella spiralis in domestic swine, the increased use of home freezers, and the practice of thoroughly cooking pork. As a proportion of all cases reported, those associated with wild game meat products has increased; however, the absolute numbers of such cases have remained similar at approximately 9-12 per year. The continued multiple case outbreaks and the identification of nonpork sources of infection indicate the need for further education and control measures.}, number={1}, journal={AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE}, author={Moorhead, A and Grunenwald, PE and Dietz, VJ and Schantz, PM}, year={1999}, month={Jan}, pages={66–69} }