@article{neupane_sevala_balakrishnan_marr_wilson_maggi_birkenheuer_lappin_chomel_breitschwerdt_2020, title={Validation of Bartonella henselae Western Immunoblotting for Serodiagnosis of Bartonelloses in Dogs}, volume={58}, ISSN={["1098-660X"]}, DOI={10.1128/JCM.01335-19}, abstractNote={Bartonella spp. are etiological agents of life-threatening zoonotic diseases in dogs worldwide. Due to the poor sensitivity of immunofluorescent-antibody assays (IFAs), a reliable serodiagnostic test for canine bartonelloses is of clinical importance. The utility of Western blotting (WB) for the serodiagnosis of canine bartonelloses has not been critically investigated. The objective of this study was to characterize WB immunodominant proteins that could be used to confirm a serodiagnosis of bartonelloses. ABSTRACT Bartonella spp. are etiological agents of life-threatening zoonotic diseases in dogs worldwide. Due to the poor sensitivity of immunofluorescent-antibody assays (IFAs), a reliable serodiagnostic test for canine bartonelloses is of clinical importance. The utility of Western blotting (WB) for the serodiagnosis of canine bartonelloses has not been critically investigated. The objective of this study was to characterize WB immunodominant proteins that could be used to confirm a serodiagnosis of bartonelloses. Using agar-grown Bartonella henselae San Antonio type 2 (SA2) whole-cell proteins, sera derived from four dog groups were tested by WB to assess immunodominant protein recognition patterns: group I consisted of 92 serum samples (10 preexposure and 82 postexposure serum samples) from 10 adult beagles experimentally inoculated with Bartonella spp., group II consisted of 36 serum samples from Bartonella PCR-positive naturally infected dogs, group III consisted of 26 serum samples from Bartonella PCR-negative and IFA-negative dogs, and group IV consisted of serum samples from 8 Brucella canis IFA-positive and 10 Rickettsia rickettsii IFA-positive dogs. Following experimental inoculation, 9 (90%) group I dogs were variably seroreactive to one or more of six specific immunodominant proteins (13, 17, 29, 50, 56, and 150 kDa). There was a strong but variable recognition of these proteins among 81% of group II dogs. In contrast, 24/26 group III dogs were not reactive to any immunodominant protein. In this study, the sensitivity and diagnostic accuracy of B. henselae SA2 WB were higher than those of B. henselae SA2 IFA testing. Some B. henselae SA2 immunodominant proteins were recognized by dogs experimentally and naturally infected with Bartonella spp. other than B. henselae. Additional research is necessary to more fully define the utility of WB for the serodiagnosis of canine bartonelloses.}, number={4}, journal={JOURNAL OF CLINICAL MICROBIOLOGY}, author={Neupane, Pradeep and Sevala, Sindhura and Balakrishnan, Nandhakumar and Marr, Henry and Wilson, James and Maggi, Ricardo and Birkenheuer, Adam and Lappin, Michael and Chomel, Bruno and Breitschwerdt, Edward B.}, year={2020}, month={Apr} }
 @article{kern_swartley_neupane_balakrishnan_breitschwerdt_2019, title={Pasteurella canis infective endocarditis in a dog}, volume={229}, ISSN={0378-1135}, url={http://dx.doi.org/10.1016/j.vetmic.2018.12.001}, DOI={10.1016/j.vetmic.2018.12.001}, abstractNote={Infective endocarditis, an infrequent clinical syndrome in dogs, is typically associated with nondescript clinical signs such as fever, malaise and loss of appetite. Although an uncommonly reported infection in dogs, Pasteurella canis is an emerging pathogen with increasing relevance in the human microbiology literature. The goal of this study is to detail the clinical presentation and microbiological findings associated with a novel causative agent of infective endocarditis in the dog. Diagnostic evaluation as well as conventional, automated and molecular microbiological methods are highlighted. The recent literature regarding P. canis and infective endocarditis in companion animals and humans is reviewed. Although an unusual etiologic agent of infective endocarditis, awareness of P. canis as a diagnostic possibility is crucial to accurate microbial surveillance.}, journal={Veterinary Microbiology}, publisher={Elsevier BV}, author={Kern, Zachary T. and Swartley, Olivia M. and Neupane, Pradeep and Balakrishnan, Nandhakumar and Breitschwerdt, Edward B.}, year={2019}, month={Feb}, pages={14–19} }
 @article{shelnutt_balakrishnan_devanna_batey_breitschwerdt_2017, title={Death of Military Working Dogs Due to Bartonella vinsonii Subspecies berkhoffii Genotype III Endocarditis and Myocarditis}, volume={182}, ISSN={["1930-613X"]}, DOI={10.7205/milmed-d-16-00125}, abstractNote={OBJECTIVES
As a result of extensive field-related activities, military working dogs (MWDs) have an increased occupational risk for acquiring vector-borne infectious diseases.


METHODS
Indirect fluorescent antibody, Bartonella alpha-proteobacteria growth medium enrichment culture, and 16-23S Bartonella intergenic transcribed spacer polymerase chain reaction were performed using blood, serum, or tissue specimens.


RESULTS
Endocarditis was diagnosed in three MWDs infected with Bartonella vinsonii subspecies (subsp.) berkhoffii genotype III. One dog was also infected with Bartonella rochalimae.


CONCLUSIONS
B. vinsonii subsp. berkhoffii genotype III may represent an occupational risk for MWDs that develop endocarditis or myocarditis. Comprehensive periodic screening for canine vector-borne infections, in particular occult infections caused by Bartonella spp, is prudent to avoid serious or life-threating illnesses.}, number={3-4}, journal={MILITARY MEDICINE}, author={Shelnutt, Leslie M. and Balakrishnan, Nandhakumar and DeVanna, Justin and Batey, Kenneth L. and Breitschwerdt, Edward B.}, year={2017}, pages={E1864–E1869} }
 @article{shapiro_brown_norris_bosward_marriot_balakrishnan_breitschwerdt_malik_2017, title={Vector-borne and zoonotic diseases of dogs in North-west New South Wales and the Northern Territory, Australia}, volume={13}, ISSN={1746-6148}, url={http://dx.doi.org/10.1186/s12917-017-1169-2}, DOI={10.1186/s12917-017-1169-2}, abstractNote={Vector-borne diseases of dogs in Australian Aboriginal communities are relatively unexplored. These dogs represent a unique group with variable ecto- and endo-parasitic burdens, nutritional stresses and a general lack of veterinary intervention. We investigated haemoprotozoal and bacterial pathogen prevalences in relation to erythrocyte and platelet numbers in dogs from North-West New South Wales (N-W NSW) and the Northern Territory (NT; Central Australia).Real-time PCR (qPCR) amplification of Anaplasma platys, Babesia vogeli, Mycoplasma haemocanis, Candidatus Mycoplasma haematoparvum and Bartonella spp., serological screening for Coxiella burnetii, and Bartonella spp. and haematological analyses were performed on dogs from the two cohorts (96 dogs in total). Brucella suis serology was determined additionally for the N-W NSW cohort.Anaplasma platys (n = 26 dogs), Babesia vogeli (n = 7), Candidatus Mycoplasma haematoparvum (n = 10 dogs), and Mycoplasma haemocanis (n = 14) were detected in the sample population (n = 96) using qPCR. There were significant associations between (i) A. platys and anaemia (OR 8.7, CI 2.4-31.7; P < 0.001), thrombocytopenia (OR 12.1, CI 3.4-43.2; P < 0.001) and breed (OR 16.1, CI 2.1-121.5; P = 0.007), and (ii) between B. vogeli and anaemia (OR 11.8, CI 2.3-61.6; P = 0.003). Neither protozoal nor bacterial DNA loads, estimated using qPCR, were positively correlated with anaemia or thrombocytopenia. Haemotropic mycoplasmas were not associated with any haematologic abnormality. Four dogs from the NT were seropositive for Coxiella burnetii, while no dogs were seropositive for Brucella suis or to a panel of Bartonella spp. antigens. Despite directed efforts, Bartonella DNA was not detected in blood from any of the cohorts studied. A sample of dogs from the NT recruited specifically for Bartonella α-proteobacteria growth medium enrichment blood culture were also Bartonella PCR negative.Vector-borne pathogens occur in dogs free ranging near Aboriginal communities, with higher detection rates in NT than N-W NSW. The preponderant haematologic abnormalities were anaemia and thrombocytopenia, likely attributable to A. platys and B. vogeli infections, but also probably affected by nutritional, parasitic, lactational and environmental stressors. The absence of Bartonella spp. is of importance to the Australian setting, and work needs to be extended to tropical coastal communities where fleas are present as well as ticks. Dogs living in and around Aboriginal communities may provide valuable sentinel information on disease infection status of human public health significance.}, number={1}, journal={BMC Veterinary Research}, publisher={Springer Nature}, author={Shapiro, Amanda J. and Brown, Graeme and Norris, Jacqueline M. and Bosward, Katrina L. and Marriot, Debbie J. and Balakrishnan, Nandhakumar and Breitschwerdt, Edward B. and Malik, Richard}, year={2017}, month={Aug} }
 @article{ericson_balakrishnan_mozayeni_woods_dencklau_kelly_breitschwerdt_2016, title={Culture, PCR, DNA sequencing, and second harmonic generation (SHG) visualization of Bartonella henselae from a surgically excised human femoral head}, volume={36}, ISSN={0770-3198 1434-9949}, url={http://dx.doi.org/10.1007/s10067-016-3524-2}, DOI={10.1007/s10067-016-3524-2}, number={7}, journal={Clinical Rheumatology}, publisher={Springer Nature}, author={Ericson, M. and Balakrishnan, N. and Mozayeni, B.R. and Woods, C.W. and Dencklau, J. and Kelly, S. and Breitschwerdt, E. B.}, year={2016}, month={Dec}, pages={1669–1675} }
 @article{palerme_jones_ward_balakrishnan_linder_breitschwerdt_keene_2016, title={Infective endocarditis in 13 cats}, volume={18}, ISSN={1760-2734}, url={http://dx.doi.org/10.1016/j.jvc.2016.04.003}, DOI={10.1016/j.jvc.2016.04.003}, abstractNote={To describe the clinical presentation, clinicopathological abnormalities and outcomes of a series of cats diagnosed with infective endocarditis (IE) at two tertiary care referral institutions.Thirteen client-owned cats presenting to the cardiology or emergency services of tertiary referral institutions with a diagnosis of endocarditis based on the modified Duke criteria.Retrospective case series. Medical records were reviewed to extract relevant data. In addition, cases that had cardiac tissue available were evaluated by polymerase chain reaction for the presence of Bartonella DNA.Prevalence of feline IE was 0.007%. Cats with endocarditis tended to be older (median age: 9 years, range: 2-12 years) and no sex or breed was overrepresented. Commonly encountered clinical signs included respiratory distress (n = 5) and locomotor abnormalities of varying severity (n = 5). Echocardiographic examination detected valvular lesions consistent with endocarditis on the aortic (n = 8) or mitral (n = 5) valves. Nine cats were diagnosed with congestive heart failure at the time of endocarditis diagnosis. Overall, prognosis was grave with a median survival time of 31 days.In contrast to dogs, cats with IE typically present with clinical signs consistent with cardiac decompensation and locomotor abnormalities suggestive of either thromboembolic disease or inflammatory arthritis. Given the advanced state of disease when diagnosis typically occurs, prognosis is grave.}, number={3}, journal={Journal of Veterinary Cardiology}, publisher={Elsevier BV}, author={Palerme, Jean-Sébastien and Jones, Ashley E. and Ward, Jessica L. and Balakrishnan, Nandhakumar and Linder, Keith E. and Breitschwerdt, Edward B. and Keene, Bruce W.}, year={2016}, month={Sep}, pages={213–225} }
 @article{donovan_fox_balakrishnan_ericson_hooker_breitschwerdt_2016, title={Pyogranulomatous Pancarditis with Intramyocardial Bartonella henselae San Antonio 2 (BhSA2) in a Dog}, volume={31}, ISSN={0891-6640}, url={http://dx.doi.org/10.1111/jvim.14609}, DOI={10.1111/jvim.14609}, abstractNote={A 6-year-old, female, spayed American Pitbull terrier was presented for progressive lethargy, weakness, and anorexia of 3-weeks duration. The dog was found as a stray in New York City (NYC) approximately 4 years earlier, assessed to be 2 years of age, and in very poor condition. Pertinent past medical history included a deep hindquarter wound and minor injuries resulting from porcupine encounters. After adoption, the dog lived in NYC, spending summers and weekends in western Massachusetts, running freely on a large property with open fields and woodlands. Before presentation, the dog was healthy and had received routine vaccinations. Ticks were found by her owners on the surface of her fur but were not embedded. Initial physical examination revealed a body weight of 19 kg, pyrexia (103.6°F), and sensitivity over the epaxial muscle region. Clinical pathology abnormalities included mild hypoalbuminemia (2.4 g/dL, range 2.7– 3.9 g/dL), hyperglobulinemia (5.9 g/dL, range 2.4– 4.8 g/dL), and lymphopenia (847/lL, range 1060–4950/ lL). Fecal flotation test results were negative. An injection of meloxicam (dose not provided) was given SC, and metronidazole (20 mg/kg PO q12h) was prescribed for 8 days. During the following week, the dog was reexamined for increasing lethargy, weakness, and pyrexia (103.4°F). Lyme quantitative C6 ELISA (Enzyme linked immunosorbent assay) was negative (<10 U/mL, range <30 U/ mL) . The dog was seroreactive to Anaplasma phagocytophilum (1 : 400) and Ehrlichia canis (1 : 25) antigens by immunofluorescence antibody immunoassay, but was not seroreactive to Rickettsia rickettsii. Doxycycline (10 mg/kg PO q24h) and meloxicam (6 mg/kg PO q24h) were prescribed. When reexamined 4 days later, the patient’s rectal temperature was 100.2°F. Multiple, nonpainful, 1–2 cm diameter, raised cutaneous masses were observed on the left thigh and right ventral abdomen. Punch biopsies were obtained from the 2 ulcerated mass lesions and immediately fixed in formalin, after which the dog was prescribed metoclopramide (0.3 mg/kg PO q12h) and firocoxib (6 mg/kg PO q24h) and referred to the Animal Medical Center (AMC). Upon presentation to the AMC, the dog was hypothermic (95.9°) and eupneic at rest. Respiratory rate and effort increased with ambulation. Thoracic auscultation revealed focal, right-sided, fine, inspiratory crackles, and a sinus arrhythmia. Femoral pulse pressure was synchronous and hypokinetic. Neurological examination revealed lethargic mentation, decreased response to stimuli, and inconsistent conscious proprioceptive deficits. Gentle abdominal palpation elicited cranial and caudal discomfort. Venous blood gas findings were consistent with a metabolic acidosis. The dog was hypoxemic (SpO2, 84%). Oscillometric blood pressure was 109/73 mmHg; however, systolic blood pressure dropped to 70 mmHg during hospitalization. Other laboratory abnormalities included neutrophilia (13.6 K/lL, range, 2.940—12.7 K/lL), thrombocytopenia (51 K/lL, range, 143–448 K/lL), increased alkaline phosphatase (587 U/L, range, 5–160 U/L), aspartate aminotransferase (76 U/L, range, 16–55 U/L) and creatine kinase (320 U/L, range, 10–200 U/L), hypoalbuminemia (1.1 g/dL, range, 2.7–3.9 g/dL), hyperglobulinemia (5.9 g/dL, range, 2.4–4.0 g/dL), hyperbilirubinemia (2.2 mg/dL, range, 0.0–0.3 mg/dL), (unconjugated 1.2 mg/dL, range, 0.0–0.2 mg/dL, conjugated 1.0 mg/dL, range, 0.0–0.1 mg/dL), azotemia (blood urea nitrogen 168 mg/dL, range, 9–31 mg/dL; creatinine 1.9 mg/dL, range, 0.5–1.5 mg/dL), and hyponatremia (124.4 mmol/L, range 135.0–148.0 mmol/L). Thoracic radiographs revealed a diffuse, alveolar pulmonary pattern. From the Department of Pathology, (Donovan); Department of Cardiology, The Animal Medical Center, New York, NY (Fox); Department of Clinical Sciences, Intracellular Pathogens Research Laboratory, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, NC (Balakrishnan, Breitschwerdt); University of Minnesota Imaging Center, Minneapolis, MN (Ericson); and the The Animal Medical Center, New York, NY (Hooker). Corresponding author: T. Donovan, Department of Pathology, The Animal Medical Center, 510 East 62nd St. New York, NY 10065; e-mail: Taryn.Donovan@amcny.org. Submitted January 11, 2016; Revised September 21, 2016; Accepted October 18, 2016. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. DOI: 10.1111/jvim.14609 Abbreviations:}, number={1}, journal={Journal of Veterinary Internal Medicine}, publisher={Wiley}, author={Donovan, T.A. and Fox, P.R. and Balakrishnan, N. and Ericson, M. and Hooker, V. and Breitschwerdt, E.B.}, year={2016}, month={Nov}, pages={142–148} }
 @article{balakrishnan_alexander_keene_kolluru_fauls_rawdon_breitschwerdt_2016, title={Successful treatment of mitral valve endocarditis in a dog associated with 'Actinomyces canis-like' infection}, volume={18}, ISSN={["1875-0834"]}, DOI={10.1016/j.jvc.2016.04.005}, abstractNote={Infective endocarditis, an inflammation of the endocardial surface due to invasion by an infectious agent, is more common in middle sized to large breed dogs. We herein report a case of mitral valve endocarditis in a 9-year-old male-castrated Weimaraner caused by an Actinomyces canis-like bacterium, not previously reported in association with infection in dogs.}, number={3}, journal={JOURNAL OF VETERINARY CARDIOLOGY}, author={Balakrishnan, N. and Alexander, K. and Keene, B. and Kolluru, S. and Fauls, M. L. and Rawdon, I. and Breitschwerdt, E. B.}, year={2016}, month={Sep}, pages={271–277} }
 @article{balakrishnan_ericson_maggi_breitschwerdt_2016, title={Vasculitis, cerebral infarction and persistent Bartonella henselae infection in a child}, volume={9}, ISSN={1756-3305}, url={http://dx.doi.org/10.1186/s13071-016-1547-9}, DOI={10.1186/s13071-016-1547-9}, abstractNote={The genus Bartonella is comprised of a rapidly increasing number of pathogenic species that induce a seemingly diverse spectrum of neurological symptoms. During the 12 year period that followed the initial onset of neurological and gastrointestinal symptoms, an 11 year-old girl experienced a spectrum of neurological complaints including frequent headaches, visual and auditory hallucinations, anxiety, vision loss involving the lower left quadrant of both eyes, episodic bouts of generalized paralysis, facial palsy, chronic insomnia, seizures, dizziness, cognitive dysfunction, and memory loss. PCR assays targeting Bartonella spp. were used to test formalin-fixed, paraffin embedded brain tissue, patient blood specimens and Bartonella alpha Proteobacteria growth medium (BAPGM) enrichment blood cultures. PCR positive amplicons were sequenced directly and compared to GenBank sequences. Bartonella spp. serology was performed by indirect fluorescent antibody testing and confocal laser scanning microscopy was used to visualize B. henselae organisms in resected brain. Bartonella henselae DNA was independently PCR amplified and sequenced from the girl’s right parietal lobe, surgically resected in 2000 and from a blood specimen collected in 2012. Although causation cannot be established by a case report, prior diagnostic testing resulted in findings that were either inconclusive or within normal reference ranges and no etiological diagnosis had been obtained to explain the patient’s initial or progressive neurological symptoms. As intravascular, intra-erythrocytic and endotheliotropic bacteria, it is possible that B. henselae initially induced a vasculitis, resulting in secondary cerebral infarction, tissue necrosis and surgical resection. Bartonella bacteremia, potentially spanning a 12-year time frame, in conjunction with the therapeutic administration of immunosuppressive drugs may have resulted in a progression and potentiation of the neurological disease that was partially reversible following antibiotic administration.}, number={1}, journal={Parasites & Vectors}, publisher={Springer Nature}, author={Balakrishnan, Nandhakumar and Ericson, Marna and Maggi, Ricardo and Breitschwerdt, Edward B.}, year={2016}, month={May} }
 @article{maggi_balakrishnan_bradley_breitschwerdt_2015, title={Infection with Bartonella henselae in a Danish Family}, volume={53}, ISSN={0095-1137 1098-660X}, url={http://dx.doi.org/10.1128/JCM.02974-14}, DOI={10.1128/jcm.02974-14}, abstractNote={ABSTRACT Bartonella species constitute emerging, vector-borne, intravascular pathogens that produce long-lasting bacteremia in reservoir-adapted (natural host or passive carrier of a microorganism) and opportunistic hosts. With the advent of more sensitive and specific diagnostic tests, there is evolving microbiological evidence supporting concurrent infection with one or more Bartonella spp. in more than one family member; however, the mode(s) of transmission to or among family members remains unclear. In this study, we provide molecular microbiological evidence of Bartonella henselae genotype San Antonio 2 (SA2) infection in four of six Danish family members, including a child who died of unknown causes at 14 months of age.}, number={5}, journal={Journal of Clinical Microbiology}, publisher={American Society for Microbiology}, author={Maggi, Ricardo G. and Balakrishnan, Nandhakumar and Bradley, Julie M. and Breitschwerdt, Edward B.}, editor={Fenwick, B. W.Editor}, year={2015}, month={Mar}, pages={1556–1561} }
 @article{pultorak_linder_maggi_balakrishnan_breitschwerdt_2015, title={Prevalence of Bartonella spp. in Canine Cutaneous Histiocytoma}, volume={153}, ISSN={0021-9975}, url={http://dx.doi.org/10.1016/j.jcpa.2015.04.001}, DOI={10.1016/j.jcpa.2015.04.001}, abstractNote={Canine cutaneous histiocytoma (CCH) is a common, benign neoplastic proliferation of histiocytes of Langerhans cell origin that often ulcerate, become secondarily infected and regress spontaneously. Bartonella is a fastidious genus of facultative intracellular pathogens that can be transmitted through arthropod bites and epidermal animal scratches and has been identified previously in the cytoplasm of histiocytes within granulomatous lesions and in skin biopsy samples of inflammatory pustules and papules. Based on the established inflammatory and oncogenic properties of Bartonella, we hypothesized that Bartonella spp. DNA could be amplified from CCH more often than from non-lesional skin and bacteria could be localized within skin tumours using indirect immunofluorescence (IIF). Paraffin wax-embedded surgical biopsy samples from dogs with CCH and non-neoplastic skin adjacent to osteosarcomas (control group selected due to wide surgical margins) were retrieved from the archive of the pathology service of North Carolina State University College of Veterinary Medicine. DNA was extracted and regions of the 16S–23S rRNA intergenic transcribed spacer (ITS) region and the pap31 and gltA genes were amplified by polymerase chain reaction (PCR) using Bartonella-specific primers. IIF was performed using a primary Bartonella henselae monoclonal antibody to localize B. henselae in tissues of PCR-positive dogs. Bartonella vinsonii subsp. berkhoffii was amplified from 1/17 (5.8%) control tissues and B. henselae was amplified from 4/29 (13.8%) CCH tissues. The prevalence of B. vinsonii subsp. berkhoffii (P = 0.37) or B. henselae (P = 0.28) did not vary statistically between study groups. B. henselae could be visualized in 2/4 (50.0%) CCH tissues using IIF. Based on this study, Bartonella spp. are unlikely to cause CCH.}, number={1}, journal={Journal of Comparative Pathology}, publisher={Elsevier BV}, author={Pultorak, E.L. and Linder, K. and Maggi, R.G. and Balakrishnan, N. and Breitschwerdt, E.B.}, year={2015}, month={Jul}, pages={14–21} }
 @article{friedenberg_balakrishnan_guillaumin_cooper_lewis_russell_breitschwerdt_2015, title={Splenic vasculitis, thrombosis, and infarction in a febrile dog infected with Bartonella henselae}, volume={25}, ISSN={1479-3261}, url={http://dx.doi.org/10.1111/vec.12367}, DOI={10.1111/vec.12367}, abstractNote={OBJECTIVE
To describe the clinical course and successful management of a febrile dog with polyarthritis, splenic vasculitis, thrombosis, and infarction that was infected with Bartonella henselae.


CASE SUMMARY
An 8-year-old female spayed Labrador Retriever was referred to The Ohio State University Veterinary Medical Center Emergency Service for evaluation of limping, fever, vomiting, and malaise of 4 days' duration. Physical examination abnormalities included generalized weakness, diminished conscious proprioception, bilateral temporalis muscle atrophy, and diarrhea. Peripheral lymph nodes were normal, and there were no signs of abdominal organomegaly, joint effusion, or spinal pain. Abdominal ultrasound identified a nonocclusive splenic vein thrombus. Fine-needle aspirates of the spleen revealed pyogranulomatous inflammation, mild reactive lymphoid hyperplasia, and mild extramedullary hematopoiesis. Splenic histopathology found marked, multifocal to coalescing acute coagulation necrosis (splenic infarctions) and fibrinoid necrotizing vasculitis. Bartonella henselae DNA was amplified by polymerase chain reaction and sequenced from the splenic tissue. The dog responded favorably to antimicrobials and was healthy at the time of follow-up evaluation.


NEW AND UNIQUE INFORMATION PROVIDED
Bartonella henselae is an incompletely characterized emerging canine pathogen. This case report establishes a potential role for this bacterium as a cause of vasculitis and thromboembolism, which have not been previously reported in association with B. henselae infection in dogs.}, number={6}, journal={Journal of Veterinary Emergency and Critical Care}, publisher={Wiley}, author={Friedenberg, Steven G. and Balakrishnan, Nandhakumar and Guillaumin, Julien and Cooper, Edward S. and Lewis, Kristin and Russell, Duncan S. and Breitschwerdt, Edward B.}, year={2015}, month={Aug}, pages={789–794} }
 @article{qurollo_balakrishnan_cannon_maggi_breitschwerdt_2014, title={Co-infection with Anaplasma platys, Bartonella henselae, Bartonella koehlerae and ‘Candidatus Mycoplasma haemominutum’ in a cat diagnosed with splenic plasmacytosis and multiple myeloma}, volume={16}, ISSN={1098-612X 1532-2750}, url={http://dx.doi.org/10.1177/1098612X13519632}, DOI={10.1177/1098612x13519632}, abstractNote={Anaplasma platys (Apl), ‘Candidatus Mycoplasma haemominutum’ (CMh), Bartonella henselae (Bh) and Bartonella koehlerae (Bk) were confirmed by polymerase chain reaction (PCR) amplification and DNA sequencing in a cat diagnosed with multiple myeloma. Other inconsistently documented hematologic abnormalities included anemia, thrombocytopenia, eosinophilia and hypoglycemia. Persistent Apl infection was confirmed for the first time in a North American cat by sequencing three bacterial genes (16S rRNA, p44 and GroEL) in peripheral blood samples collected 100 days apart. Following doxycycline treatment for Apl, multiple myeloma was diagnosed based upon a monoclonal gammopathy and splenic plasmacytosis, and the cat was treated with melphalan, chlorambucil and prednisolone. Apl DNA was not amplified from post-treatment blood samples and the hyperglobulinemia resolved temporarily following chemotherapy. Retrospective PCR analysis of stored DNA extracts identified CMh, Bk and Bh infections. Retrospective PCR for antigen receptor rearrangements (PARR) of splenic aspirates did not confirm B- or T-cell clonality. Co-infection with multiple vector-borne pathogens should be a diagnostic consideration in cats with chronic hypergammaglobulinemia, monoclonal gammopathy and splenic plasmacytosis.}, number={8}, journal={Journal of Feline Medicine and Surgery}, publisher={SAGE Publications}, author={Qurollo, Barbara A and Balakrishnan, Nandhakumar and Cannon, Coralie Zegre and Maggi, Ricardo G and Breitschwerdt, Edward B}, year={2014}, month={Jan}, pages={713–720} }
 @article{rossi_balakrishnan_linder_messa_breitschwerdt_2014, title={ConcurrentBartonella henselaeinfection in a dog with panniculitis and owner with ulcerated nodular skin lesions}, volume={26}, ISSN={0959-4493}, url={http://dx.doi.org/10.1111/vde.12174}, DOI={10.1111/vde.12174}, abstractNote={BACKGROUND
Bartonella henselae, a Gram-negative, zoonotic Alphaproteobacteria that infects erythrocytes, endothelial cells and dendritic cells, has previously been implicated as a cause of panniculitis in dogs and a human.


ANIMAL AND OWNER
An 8-year-old, spayed female Labrador retriever and its 78-year-old male owner living in the same household.


METHODS AND RESULTS
When preliminary and advanced testing failed to identify the cause of near-simultaneous-onset dermatological lesions, Bartonella serology, Bartonella Alphaproteobacteria growth medium (BAPGM) enrichment blood culture/PCR and immunohistochemistry were used to test specimens from the dog and owner. Bartonella henselae, genotype San Antonio 2 DNA was amplified and sequenced from the man's BAPGM enrichment blood culture and the dog's panniculitis lesion. The bacterium was visualized by immunohistochemistry in the dog's panniculitis lesion; however, neither the dog nor the owner was B. henselae seroreactive. Antibiotic therapy elicited dermatological improvement in both dog and owner.


CONCLUSIONS AND CLINICAL IMPORTANCE
Bartonella henselae is an emerging zoonotic pathogen that induces granulomatous inflammatory lesions in various tissues of animals, including humans. We conclude that this bacterium had a contributory or causative role in the development of the dermatological lesions in the dog and owner.}, number={1}, journal={Veterinary Dermatology}, publisher={Wiley}, author={Rossi, Michael A. and Balakrishnan, Nandhakumar and Linder, Keith E. and Messa, Jacqueline B. and Breitschwerdt, Edward B.}, year={2014}, month={Oct}, pages={60–e22} }
 @article{yore_digangi_brewer_balakrishnan_breitschwerdt_lappin_2014, title={Flea species infesting dogs in Florida and Bartonella spp. prevalence rates}, volume={199}, ISSN={0304-4017}, url={http://dx.doi.org/10.1016/j.vetpar.2013.10.017}, DOI={10.1016/j.vetpar.2013.10.017}, abstractNote={Several Bartonella spp. associated with fleas can induce a variety of clinical syndromes in both dogs and humans. However, few studies have investigated the prevalence of Bartonella in the blood of dogs and their fleas. The objectives of this study were to determine the genera of fleas infesting shelter dogs in Florida, the prevalence of Bartonella spp. within the fleas, and the prevalence of Bartonella spp. within the blood of healthy dogs from which the fleas were collected. Fleas, serum, and EDTA-anti-coagulated whole blood were collected from 80 healthy dogs, and total DNA was extracted for PCR amplification of Bartonella spp. The genera of fleas infesting 43 of the dogs were determined phenotypically. PCR amplicons from blood and flea pools were sequenced to confirm the Bartonella species. Amplicons for which sequencing revealed homology to Bartonella vinsonii subsp. berkhoffii (Bvb) underwent specific genotyping by targeting the 16S–23S intergenic spacer region. A total of 220 fleas were collected from 80 dogs and pooled by genus (43 dogs) and flea species. Bartonella spp. DNA was amplified from 14 of 80 dog blood samples (17.5%) and from 9 of 80 pooled fleas (11.3%). B. vinsonii subsp. berkhoffii DNA was amplified from nine dogs and five of the flea pools. Bartonella rochalimae (Br) DNA was amplified from six dogs and two flea pools. One of 14 dogs was co-infected with Bvb and Br. The dog was infested with Pulex spp. fleas containing Br DNA and a single Ctenocephalides felis flea. Of the Bvb bacteremic dogs, five and four were infected with genotypes II and I, respectively. Of the Bvb PCR positive flea pools, three were Bvb genotype II and two were Bvb genotype I. Amplification of Bvb DNA from Pulex spp. collected from domestic dogs, suggests that Pulex fleas may be a vector for dogs and a source for zoonotic transfer of this pathogen from dogs to people. The findings of this study provide evidence to support the hypothesis that flea-infested dogs may be a reservoir host for Bvb and Br and that ectoparasite control is an important component of shelter intake protocols.}, number={3-4}, journal={Veterinary Parasitology}, publisher={Elsevier BV}, author={Yore, K. and DiGangi, B. and Brewer, M. and Balakrishnan, N. and Breitschwerdt, E.B. and Lappin, M.}, year={2014}, month={Jan}, pages={225–229} }
 @article{balakrishnan_pritchard_ericson_grindem_phillips_jennings_mathews_tran_birkenheuer_breitschwerdt_et al._2014, title={Prostatitis, Steatitis, and Diarrhea in a Dog following Presumptive Flea-Borne Transmission of Bartonella henselae}, volume={52}, ISSN={0095-1137 1098-660X}, url={http://dx.doi.org/10.1128/JCM.00942-14}, DOI={10.1128/jcm.00942-14}, abstractNote={ABSTRACT Bartonella henselae is increasingly associated with a variety of pathological entities, which are often similar in dogs and human patients. Following an acute flea infestation, a dog developed an unusual clinical presentation for canine bartonellosis. Comprehensive medical, microbiological, and surgical interventions were required for diagnosis and to achieve a full recovery.}, number={9}, journal={Journal of Clinical Microbiology}, publisher={American Society for Microbiology}, author={Balakrishnan, N. and Pritchard, J. and Ericson, M. and Grindem, C. and Phillips, K. and Jennings, S. and Mathews, K. and Tran, H. and Birkenheuer, A. J. and Breitschwerdt, Edward and et al.}, editor={Munson, E.Editor}, year={2014}, month={Jun}, pages={3447–3452} }
 @article{kehoe_chomel_stuckey_kasten_balakrishnan_sacks_breitschwerdt_2014, title={Zoonotic Bartonella Species in Cardiac Valves of Healthy Coyotes, California, USA}, volume={20}, ISSN={1080-6040 1080-6059}, url={http://dx.doi.org/10.3201/eid2012.140578}, DOI={10.3201/eid2012.140578}, abstractNote={We investigated whether Bartonella spp. could cause endocarditis in coyotes or localize to cardiac valves before lesions develop. Bartonella DNA was amplified more often from coyote cardiac valves than spleen. Bartonella infection apparently leads to cardiac valve tropism, which could cause endocarditis, an often lethal complication in mammals, including humans.}, number={12}, journal={Emerging Infectious Diseases}, publisher={Centers for Disease Control and Prevention (CDC)}, author={Kehoe, Spencer P. and Chomel, Bruno B. and Stuckey, Matthew J. and Kasten, Rickie W. and Balakrishnan, Nandhakumar and Sacks, Benjamin N. and Breitschwerdt, Edward B.}, year={2014}, month={Dec}, pages={2133–2136} }
 @article{maggi_mascarelli_balakrishnan_rohde_kelly_ramaiah_leach_breitschwerdt_2013, title={"Candidatus Mycoplasma haemomacaque" and Bartonella quintana Bacteremia in Cynomolgus Monkeys}, volume={51}, ISSN={0095-1137}, url={http://dx.doi.org/10.1128/JCM.03019-12}, DOI={10.1128/jcm.03019-12}, abstractNote={ABSTRACT Here, we report latent infections with Bartonella quintana and a hemotropic Mycoplasma sp. in a research colony of cynomolgus monkeys (Macaca fascicularis). Sequence alignments, evolutionary analysis, and signature nucleotide sequence motifs of the hemotropic Mycoplasma 16S rRNA and RNase P genes indicate the presence of a novel organism.}, number={5}, journal={Journal of Clinical Microbiology}, publisher={American Society for Microbiology}, author={Maggi, R. G. and Mascarelli, P. E. and Balakrishnan, N. and Rohde, C. M. and Kelly, C. M. and Ramaiah, L. and Leach, M. W. and Breitschwerdt, E. B.}, year={2013}, month={Feb}, pages={1408–1411} }
 @article{hegarty_bradley_lappin_balakrishnan_mascarelli_breitschwerdt_2013, title={Analysis of Seroreactivity against Cell Culture-DerivedBartonellaspp. Antigens in Dogs}, volume={28}, ISSN={0891-6640}, url={http://dx.doi.org/10.1111/jvim.12263}, DOI={10.1111/jvim.12263}, abstractNote={Background Little is known about the specificity of Bartonella spp. immunofluorescent antibody (IFA) assays in dogs. Bacteremia in sick dogs most often has been associated with Bartonella henselae (Bh), Bartonella vinsonii subspecies berkhoffii (Bvb), and Bartonella koehlerae (Bk). Clarification of the diagnostic utility of IFA serology when testing against these organisms is needed. Objective To evaluate the specificity of Bartonella IFA assays utilizing 6 cell culture–grown antigen preparations. Animals Archived sera from SPF dogs (n = 29) and from dogs experimentally infected with Bvb (n = 10) and Bh (n = 3). Methods Antibodies (Abs) to Bvb genotypes I, II, and III, Bh serotype I, strains H‐1 and SA2, and to Bk were determined by IFA testing. Results Serum from naïve SPF dogs shown to be negative for Bartonella bacteremia did not react with any of the 6 Bartonella antigens by IFA testing. Dogs experimentally infected with Bvb genotype I developed Abs against homologous antigens, with no cross‐reactivity to heterologous Bvb genotypes, Bh H‐1, SA2 strains, or to Bk. Dogs experimentally infected with Bh serotype I developed Abs against Bh H‐1, but not to Bh SA2 strain with no cross‐reactive Abs to Bvb genotypes I–III or to Bk. Conclusions and Clinical Importance Bartonella spp. Ab responses during acute experimental infections are species and type specific.}, number={1}, journal={Journal of Veterinary Internal Medicine}, publisher={Wiley}, author={Hegarty, B.C. and Bradley, J.M. and Lappin, M.R. and Balakrishnan, N. and Mascarelli, P.E. and Breitschwerdt, E.B.}, year={2013}, month={Dec}, pages={38–41} }
 @article{balakrishnan_cherry_linder_pierce_sontakke_hegarty_bradley_maggi_breitschwerdt_2013, title={Experimental infection of dogs with Bartonella henselae and Bartonella vinsonii subsp. berkhoffii}, volume={156}, ISSN={0165-2427}, url={http://dx.doi.org/10.1016/j.vetimm.2013.09.007}, DOI={10.1016/j.vetimm.2013.09.007}, abstractNote={The lack of a suitable infection model remains an important obstacle for the pathophysiological understanding of Bartonella spp. The following pilot study was designed to determine whether cell culture-grown Bartonella henselae SA2 and Bartonella vinsonii subsp. berkhoffii genotype III would cause persistent bacteremia in dogs. Pre-inoculation screening established that two laboratory-raised Golden retrievers were naturally-infected with Bartonella koehlerae. Despite prior infection, one dog each was inoculated subcutaneously with 5 × 10(4)B. henselae (SA2 strain) or 3 × 10(4)B. vinsonii subsp. berkhoffii genotype III. Dogs were bled weekly for serological testing and culture using Bartonella alpha proteobacteria growth medium (BAPGM) diagnostic platform. Dog 1 seroconverted to B. henselae and Dog 2 seroconverted to B. vinsonii subsp. berkhoffii genotype III. Throughout the study period, Bartonella spp. DNA was neither amplified nor isolated in ante-mortem BAPGM enrichment blood cultures. B. henselae SA2 was isolated from a postmortem bone marrow from Dog 1 and B. koehlerae DNA was amplified from postmortem lung from Dog 2 following BAPGM enrichment culture. Limitations include lack of uninfected controls, a potentially suboptimal B. vinsonii subsp. berkhoffii inoculum and a relatively short duration of study. We conclude that following intradermal infection, sequestration of Bartonella spp. in tissues may limit diagnostic detection of these bacteria in dog blood samples.}, number={1-2}, journal={Veterinary Immunology and Immunopathology}, publisher={Elsevier BV}, author={Balakrishnan, Nandhakumar and Cherry, Natalie A. and Linder, Keith E. and Pierce, Eric and Sontakke, Neal and Hegarty, Barbara C. and Bradley, Julie M. and Maggi, Ricardo G. and Breitschwerdt, Edward B.}, year={2013}, month={Nov}, pages={153–158} }
 @article{balakrishnan_jawanda_miller_breitschwerdt_2012, title={Bartonella henselae infection in a man with hypergammaglobulinaemia, splenomegaly and polyclonal plasmacytosis}, volume={62}, ISSN={0022-2615 1473-5644}, url={http://dx.doi.org/10.1099/jmm.0.052134-0}, DOI={10.1099/jmm.0.052134-0}, abstractNote={Bartonella henselae is an infrequently reported cause of polyclonal plasmacytosis and hypergammaglobulinaemia. We herein document B. henselae infection in a 66-year-old patient who presented with hypergammaglobulinaemia, splenomegaly with polyclonal plasmacytosis, stroke, and suspected prosthetic aortic arch infection. Clinicians should remain cognizant of the heterogeneous clinical presentations associated with bartonellosis.}, number={Pt_2}, journal={Journal of Medical Microbiology}, publisher={Microbiology Society}, author={Balakrishnan, N. and Jawanda, J. S. and Miller, M. B. and Breitschwerdt, E. B.}, year={2012}, month={Nov}, pages={338–341} }
 @article{balakrishnan_tortoli_engel_breitschwerdt_2012, title={Isolation of a Novel Strain of Mycobacterium iranicum from a Woman in the United States}, volume={51}, ISSN={0095-1137}, url={http://dx.doi.org/10.1128/JCM.02560-12}, DOI={10.1128/jcm.02560-12}, abstractNote={ABSTRACT A novel strain of Mycobacterium iranicum, a recently described nontuberculous Mycobacterium species, was isolated from the sputum of a woman. The source of infection was not determined; however, fomite transmission of inhaled aerosolized secretions from her husband's sleep apnea equipment was historically possible.}, number={2}, journal={Journal of Clinical Microbiology}, publisher={American Society for Microbiology}, author={Balakrishnan, N. and Tortoli, E. and Engel, S. L. and Breitschwerdt, E. B.}, year={2012}, month={Dec}, pages={705–707} }