@article{tan_orndorff_shirwaiker_2019, title={The Ion Delivery Manner Influences the Antimicrobial Efficacy of Silver Oligodynamic Iontophoresis}, volume={39}, ISSN={["2199-4757"]}, DOI={10.1007/s40846-018-0447-1}, abstractNote={Electrical activation of silver ions, known as oligodynamic iontophoresis, has shown broad-spectrum antimicrobial activities against bacteria, fungi, and viruses. However, it is not clear how the ion delivery manner, which is controlled by the electrical activation, influences the iontophoresis process. This paper focuses on this knowledge gap, aiming to characterize the interactive effects of electric current intensity and activation duration on the antimicrobial efficacy of a silver-based iontophoresis prototype against Gram-positive (S. aureus) and Gram-negative (E. coli) strains respectively. The modified Kirby–Bauer disc diffusion method was adopted to quantify the antimicrobial efficacy. A linear regression model was established and validated by empirical data. This study revealed that the antimicrobial activities of the device was more sensitive to current duration than current intensity, and the marginal antimicrobial efficacy of the device decreased as the current intensity increased. In addition, a sustained release of Ag + had superior antimicrobial efficacy compared to a fast release. These findings will contribute to the performance optimization of silver oligodynamic iontophoresis devices for antimicrobial applications.}, number={4}, journal={JOURNAL OF MEDICAL AND BIOLOGICAL ENGINEERING}, author={Tan, George Z. and Orndorff, Paul E. and Shirwaiker, Rohan A.}, year={2019}, month={Aug}, pages={622–631} }
 @article{kuenemann_spears_orndorff_fourches_2018, title={In silico predicted glucose-1-phosphate Uridylyltransferase (GalU) inhibitors block a key pathway required for Listeria virulence}, volume={37}, number={6-7}, journal={Molecular Informatics}, author={Kuenemann, M. A. and Spears, P. A. and Orndorff, P. E. and Fourches, D.}, year={2018} }
 @article{tan_havell_orndorff_shirwaiker_2017, title={Antibacterial efficacy and cytotoxicity of low intensity direct current activated silver-titanium implant system prototype}, volume={30}, ISSN={["1572-8773"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85009513848&partnerID=MN8TOARS}, DOI={10.1007/s10534-017-9993-1}, abstractNote={Silver-based devices activated by electric current are of interest in biomedicine because of their broad-spectrum antimicrobial activity. This study investigates the in vitro antibacterial efficacy and cytotoxicity of a low intensity direct current (LIDC)-activated silver-titanium implant system prototype designed for localized generation and delivery of silver ions at the implantation site. First, the antibacterial efficacy of the system was assessed against methicillin-resistant Staphylococcus aureus (MRSA) over 48 h at current levels of 3 and 6 µA in Mueller-Hinton broth. The cytotoxicity of the system was then evaluated over 48 h in two phases using an in vitro model with in which the activated electrodes were suspended in growth medium in a cell-seeded tissue culture plate. In phase-1, the system was tested on human osteosarcoma (MG-63) cell line and compared to titanium controls. In phase-2, the cytotoxicity characteristics were validated with normal human diploid osteoblast cells. The LIDC-activated system demonstrated high antimicrobial efficacy against MRSA, but was also toxic to human cells immediately surrounding the electrodes. The statistical analysis showed that the cytotoxicity was a result of the presence of silver, and the electric activation did not make it worse.}, number={1}, journal={BIOMETALS}, author={Tan, Zhuo and Havell, Edward A. and Orndorff, Paul E. and Shirwaiker, Rohan A.}, year={2017}, month={Feb}, pages={113–125} }
 @article{tan_xu_orndorff_shirwaiker_2016, title={Effects of Electrically Activated Silver-Titanium Implant System Design Parameters on Time-Kill Curves Against Staphylococcus aureus}, volume={36}, ISSN={["2199-4757"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84978971017&partnerID=MN8TOARS}, DOI={10.1007/s40846-016-0136-x}, number={3}, journal={JOURNAL OF MEDICAL AND BIOLOGICAL ENGINEERING}, author={Tan, Zhuo and Xu, Guangning and Orndorff, Paul E. and Shirwaiker, Rohan A.}, year={2016}, month={Jun}, pages={325–333} }
 @article{cavanaugh_tan_norris_hardee_weinhold_dahners_orndorff_shirwaiker_2016, title={Evaluation of silver-titanium implants activated by low intensity direct current for orthopedic infection control: An in vitro and in vivo study}, volume={104}, ISSN={["1552-4981"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84976501648&partnerID=MN8TOARS}, DOI={10.1002/jbm.b.33451}, abstractNote={Abstract}, number={5}, journal={JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS}, author={Cavanaugh, Daniel L. and Tan, Zhuo and Norris, James P. and Hardee, Amelia and Weinhold, Paul S. and Dahners, Laurence E. and Orndorff, Paul E. and Shirwaiker, Rohan A.}, year={2016}, month={Jul}, pages={1023–1031} }
 @article{spears_havell_hamrick_goforth_levine_abraham_heiss_azadi_orndorff_2016, title={Listeria monocytogenes wall teichoic acid decoration in virulence and cell-to-cell spread}, volume={101}, ISSN={["1365-2958"]}, DOI={10.1111/mmi.13353}, abstractNote={Summary}, number={5}, journal={MOLECULAR MICROBIOLOGY}, author={Spears, Patricia A. and Havell, Edward A. and Hamrick, Terri S. and Goforth, John B. and Levine, Alexandra L. and Abraham, S. Thomas and Heiss, Christian and Azadi, Parastoo and Orndorff, Paul E.}, year={2016}, month={Sep}, pages={714–730} }
 @misc{orndorff_2016, title={Use of bacteriophage to target bacterial surface structures required for virulence: a systematic search for antibiotic alternatives}, volume={62}, ISSN={["1432-0983"]}, DOI={10.1007/s00294-016-0603-5}, abstractNote={Bacteriophages (phage) that infect pathogenic bacteria often attach to surface receptors that are coincidentally required for virulence. Receptor loss or modification through mutation renders mutants both attenuated and phage resistant. Such attenuated mutants frequently have no apparent laboratory growth defects, but in the host, they fail to exhibit properties needed to produce disease such as mucosal colonization or survival within professional phagocytic cells. The connection between attenuation and phage resistance has been exploited in experimental demonstrations of phage therapy. In such experiments, phage resistant mutants that arise naturally during therapy are inconsequential because of their attenuated status. A more contemporary approach to exploiting this connection involves identifying small effector molecules, identified in high-throughput screens, that inhibit one or more of the steps needed to produce a functioning phage receptor. Since such biosynthetic steps are unique to bacteria, inhibitors can be utilized therapeutically, in lieu of antibiotics. Also, since the inhibitor is specific to a particular bacterium or group of bacteria, no off-target resistance is generated in the host’s commensal bacterial population. This brief review covers examples of how mutations that confer phage resistance produce attenuation, and how this coincidental relationship can be exploited in the search for the next generation of therapeutic agents for bacterial diseases.}, number={4}, journal={CURRENT GENETICS}, author={Orndorff, Paul E.}, year={2016}, month={Nov}, pages={753–757} }
 @article{fusco_choudhary_routh_ventevogel_smith_koch_almond_orndorff_sempowski_leduc_2014, title={The Haemophilus ducreyi trimeric autotransporter adhesin DsrA protects against an experimental infection in the swine model of chancroid}, volume={32}, ISSN={["1873-2518"]}, DOI={10.1016/j.vaccine.2014.05.031}, abstractNote={Adherence of pathogens to cellular targets is required to initiate most infections. Defining strategies that interfere with adhesion is therefore important for the development of preventative measures against infectious diseases. As an adhesin to host extracellular matrix proteins and human keratinocytes, the trimeric autotransporter adhesin DsrA, a proven virulence factor of the Gram-negative bacterium Haemophilus ducreyi, is a potential target for vaccine development. A recombinant form of the N-terminal passenger domain of DsrA from H. ducreyi class I strain 35000HP, termed rNT-DsrAI, was tested as a vaccine immunogen in the experimental swine model of H. ducreyi infection. Viable homologous H. ducreyi was not recovered from any animal receiving four doses of rNT-DsrAI administered with Freund's adjuvant at two-week intervals. Control pigs receiving adjuvant only were all infected. All animals receiving the rNT-DsrAI vaccine developed antibody endpoint titers between 3.5 and 5 logs. All rNT-DsrAI antisera bound the surface of the two H. ducreyi strains used to challenge immunized pigs. Purified anti-rNT-DsrAI IgG partially blocked binding of fibrinogen at the surface of viable H. ducreyi. Overall, immunization with the passenger domain of the trimeric autotransporter adhesin DsrA accelerated clearance of H. ducreyi in experimental lesions, possibly by interfering with fibrinogen binding.}, number={30}, journal={VACCINE}, author={Fusco, William G. and Choudhary, Neelima R. and Routh, Patty A. and Ventevogel, Melissa S. and Smith, Valerie A. and Koch, Gary G. and Almond, Glen W. and Orndorff, Paul E. and Sempowski, Gregory D. and Leduc, Isabelle}, year={2014}, month={Jun}, pages={3752–3758} }
 @article{samberg_tan_monteiro-riviere_orndorff_shirwaiker_2013, title={Biocompatibility analysis of an electrically-activated silver-based antibacterial surface system for medical device applications}, volume={24}, ISSN={["1573-4838"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84876410058&partnerID=MN8TOARS}, DOI={10.1007/s10856-012-4838-5}, abstractNote={The costs associated with the treatment of medical device and surgical site infections are a major cause of concern in the global healthcare system. To prevent transmission of such infections, a prophylactic surface system that provides protracted release of antibacterial silver ions using low intensity direct electric current (LIDC; 28 μA system current at 6 V) activation has been recently developed. To ensure the safety for future in vivo studies and potential clinical applications, this study assessed the biocompatibility of the LIDC-activated interdigitated silver electrodes-based surface system; in vitro toxicity to human epidermal keratinocytes, human dermal fibroblasts, and normal human osteoblasts, and antibacterial efficacy against Staphylococcus aureus and Escherichia coli was evaluated. The study concluded that the technological applications of the surface system for medical devices and surgical tools, which contact human tissues for less than 1.5 h, are expected to be self-sterilizing without causing toxicity in vivo.}, number={3}, journal={JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE}, author={Samberg, Meghan E. and Tan, Zhuo and Monteiro-Riviere, Nancy A. and Orndorff, Paul E. and Shirwaiker, Rohan A.}, year={2013}, month={Mar}, pages={755–760} }
 @inproceedings{tan_shirwaiker_orndoff_2013, title={Determining optimal current intensity and duration for electrically activated silver-based prophylactic hip implant prototype design}, volume={1 B}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84894644307&partnerID=MN8TOARS}, DOI={10.1115/sbc2013-14141}, abstractNote={Infections associated with medical prostheses result in notable morbidity, and traditional osteomyelitis treatments are often accompanied by high risk and cost. The probability of prosthetic joint infections is 1–2.5 % for primary hip or knee replacements and 2.1–5.8 % for revision surgeries, and the cost of treating such an infection is estimated to be over $50,000 per episode. [1] While the potential benefits of silver surfaces stimulated by low intensity direct current (LIDC) have been discussed in literature, we have recently utilized that concept in the actual design of prophylactic indwelling residual hardware prostheses for the very first time. [2–4] A modular titanium hip stem coated with silver at the anode (and titanium as the cathode) and activated by a watch battery encapsulated within the two electrode modules (Figure 1) will result in oligodynamic iontophoresis (OI) in the soft tissue surrounding the implant which is prone to infections. Preliminary in vitro and in vivo results have demonstrated the potency of silver-based OI as an effective local antibacterial therapy in osteomyelitis treatment with advantages over various antibiotics. However, the main challenge here is achieving the antibacterial potency while minimizing any potential toxic effects on local tissues. [4]}, booktitle={ASME 2013 Summer Bioengineering Conference, SBC 2013}, author={Tan, Z. and Shirwaiker, Rohan and Orndoff, P.E.}, year={2013} }
 @article{suyemoto_hamrick_spears_horton_washington_havell_borst_orndorff_2013, title={Extrauterine Listeriosis in the gravid mouse influences embryonic growth and development}, volume={8}, number={8}, journal={PLoS One}, author={Suyemoto, M. M. and Hamrick, T. S. and Spears, P. A. and Horton, J. R. and Washington, I. M. and Havell, E. A. and Borst, L. B. and Orndorff, P. E.}, year={2013} }
 @article{samberg_orndorff_monteiro-riviere_2011, title={Antibacterial efficacy of silver nanoparticles of different sizes, surface conditions and synthesis methods}, volume={5}, ISSN={["1743-5404"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000290936000012&KeyUID=WOS:000290936000012}, DOI={10.3109/17435390.2010.525669}, abstractNote={Abstract Silver nanoparticles (Ag-nps) are used as a natural biocide to prevent undesired bacterial growth in clothing and cosmetics. The objective of this study was to assess the antibacterial efficacy of Ag-nps of different sizes, surface conditions, and synthesis methods against Escherichia coli, Ag-resistant E. coli, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and Salmonella sp. Ag-nps samples were synthesized by: Base reduction with unmodified surfaces and used as synthesized (‘unwashed’; 20, 50 and 80 nm) or after 20 phosphate buffer washes (‘washed’; 20, 50 and 80 nm), or synthesized by laser ablation with carbon-stabilized surfaces (‘carbon-coated’; 25 and 35 nm). Unwashed Ag-nps were toxic to all bacterial strains at concentrations between 3.0–8.0 μg/ml. The washed Ag-nps and carbon-coated Ag-nps were toxic to all bacterial strains except Ag-resistant E. coli at concentrations between 64.0–1024.0 μg/ml. Ag-resistant E. coli died only when treated with unwashed Ag-nps or its supernatant, both of which contained formaldehyde.}, number={2}, journal={NANOTOXICOLOGY}, author={Samberg, Meghan E. and Orndorff, Paul E. and Monteiro-Riviere, Nancy A.}, year={2011}, month={Jun}, pages={244–253} }
 @article{spears_suyemoto_hamrick_wolf_havell_orndorff_2011, title={In Vitro Properties of a Listeria monocytogenes Bacteriophage-Resistant Mutant Predict Its Efficacy as a Live Oral Vaccine Strain}, volume={79}, ISSN={["1098-5522"]}, DOI={10.1128/iai.05700-11}, abstractNote={ABSTRACT}, number={12}, journal={INFECTION AND IMMUNITY}, author={Spears, Patricia A. and Suyemoto, M. Mitsu and Hamrick, Terri S. and Wolf, Rebecca L. and Havell, Edward A. and Orndorff, Paul E.}, year={2011}, month={Dec}, pages={5001–5009} }
 @article{lee_su_wyse_barbas_palestrandt_shieh_everett_devalapalli_orndorff_bollinger_et al._2011, title={Incorporation of secretory immunoglobulin A into biofilms can decrease their resistance to ciprofloxacin}, volume={55}, ISSN={["1348-0421"]}, DOI={10.1111/j.1348-0421.2010.00297.x}, abstractNote={Extracellular matrices utilized by biofilms growing on inert surfaces are generally produced entirely by the bacteria growing within those biofilms, whereas symbiotic (mutualistic) biofilms growing in or on a wide range of plants and animals utilize host‐derived macromolecules, such as mucoid substances, as components of their extracellular matrix. Incorporation of host‐derived molecules may have a profound effect on the resistance to antibiotics of symbiotic biofilms, which may have important implications for medicine and biology. As an initial probe of the potential effects of host‐derived molecules in the extracellular matrix on the sensitivity of biofilms to antibiotics, an in vitro model was used to evaluate the effects of ciprofloxacin on biofilms grown in the presence and absence of SIgA, a host‐derived glycoprotein associated with biofilms in the mammalian gut. In five out of six strains of Escherichia coli tested, the incorporation of SIgA into the biofilms apparently reduced the resistance of the bacteria to ciprofloxacin. On the other hand, SIgA generally increased the resistance of planktonic bacteria to ciprofloxacin, perhaps due in part to the SIgA‐mediated aggregation of the bacteria. These findings suggest that incorporation of host‐derived molecules into the extracellular matrix of symbiotic biofilms might profoundly alter the properties of those biofilms, including the resistance of those biofilms to antibiotics.}, number={3}, journal={MICROBIOLOGY AND IMMUNOLOGY}, author={Lee, Yu-Huei and Su, Kuei-Ying and Wyse, Aaron and Barbas, Andrew and Palestrandt, Daniel and Shieh, Karl and Everett, Mary Lou and Devalapalli, Aditya and Orndorff, Paul E. and Bollinger, R. Randal and et al.}, year={2011}, month={Mar}, pages={174–183} }
 @article{leduc_fusco_choudhary_routh_cholon_hobbs_almond_orndorff_elkins_2011, title={Passive Immunization with a Polyclonal Antiserum to the Hemoglobin Receptor of Haemophilus ducreyi Confers Protection against a Homologous Challenge in the Experimental Swine Model of Chancroid}, volume={79}, ISSN={["1098-5522"]}, DOI={10.1128/iai.00017-11}, abstractNote={ABSTRACT}, number={8}, journal={INFECTION AND IMMUNITY}, author={Leduc, Isabelle and Fusco, William G. and Choudhary, Neelima and Routh, Patty A. and Cholon, Deborah M. and Hobbs, Marcia M. and Almond, Glen W. and Orndorff, Paul E. and Elkins, Christopher}, year={2011}, month={Aug}, pages={3168–3177} }
 @article{lee_wyse_lesher_everett_lou_holzknecht_whitesides_spears_bowles_lin_et al._2010, title={Adaptation in a Mouse Colony Monoassociated with Escherichia coli K-12 for More than 1,000 Days}, volume={76}, ISSN={["0099-2240"]}, DOI={10.1128/aem.00358-10}, abstractNote={ABSTRACT}, number={14}, journal={APPLIED AND ENVIRONMENTAL MICROBIOLOGY}, author={Lee, Sean M. and Wyse, Aaron and Lesher, Aaron and Everett, Mary Lou and Lou, Linda and Holzknecht, Zoie E. and Whitesides, John F. and Spears, Patricia A. and Bowles, Dawn E. and Lin, Shu S. and et al.}, year={2010}, month={Jul}, pages={4655–4663} }
 @article{suyemoto_spears_hamrick_barnes_havell_orndorff_2010, title={Factors Associated with the Acquisition and Severity of Gestational Listeriosis}, volume={5}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0013000}, abstractNote={Gravid mammals are more prone to listeriosis than their nongravid counterparts. However, many features of the disease in gravid animals are not well defined. We determined, in mice, that increased susceptibility to lethal infection following oral inoculation begins surprisingly early in pregnancy and extends through embryonic development. Pregnancy did not demonstrably increase the spread of listeriae from the intestine to the liver and spleen in the initial 96 h period post inoculation. Consequently, it appeared that gravid animals were competent to contain an enteric infection, but in those instances where escape did occur, a lethal outcome was more likely. Interestingly, colonic colonization level and prevalence, measured 96 h post inoculation, was significantly higher in gravid individuals. In terms of human risk factors for listeriosis, our results suggest that the window of listeriosis susceptibility afforded by pregnancy may be open longer than previously appreciated. Our results also suggest that while gravid animals are competent to contain an enteric infection, enteric carriage rate may be more of a factor in defining disease incidence than previously considered.}, number={9}, journal={PLOS ONE}, author={Suyemoto, M. Mitsu and Spears, Patricia A. and Hamrick, Terri S. and Barnes, Jill A. and Havell, Edward A. and Orndorff, Paul E.}, year={2010}, month={Sep} }
 @article{temple_miyamoto_mehta_capitini_von stetina_barnes_christensen_horton_spears_orndorff_2010, title={Identification and Characterization of Two Bordetella avium Gene Products Required for Hemagglutination}, volume={78}, ISSN={["1098-5522"]}, DOI={10.1128/iai.00140-10}, abstractNote={ABSTRACT}, number={6}, journal={INFECTION AND IMMUNITY}, author={Temple, Louise M. and Miyamoto, David M. and Mehta, Manju and Capitini, Christian M. and Von Stetina, Stephen and Barnes, H. John and Christensen, Vern L. and Horton, John R. and Spears, Patricia A. and Orndorff, Paul E.}, year={2010}, month={Jun}, pages={2370–2376} }
 @article{fusco_afonina_nepluev_cholon_choudhary_routh_almond_orndorff_staats_hobbs_et al._2010, title={Immunization with the Haemophilus ducreyi Hemoglobin Receptor HgbA with Adjuvant Monophosphoryl Lipid A Protects Swine from a Homologous but Not a Heterologous Challenge}, volume={78}, ISSN={["1098-5522"]}, DOI={10.1128/iai.00217-10}, abstractNote={ABSTRACT}, number={9}, journal={INFECTION AND IMMUNITY}, author={Fusco, William G. and Afonina, Galyna and Nepluev, Igor and Cholon, Deborah M. and Choudhary, Neelima and Routh, Patricia A. and Almond, Glenn W. and Orndorff, Paul E. and Staats, Herman and Hobbs, Marcia M. and et al.}, year={2010}, month={Sep}, pages={3763–3772} }
 @article{barbas_lesher_thomas_wyse_devalapalli_lee_tan_orndorff_bollinger_parker_2009, title={Altering and Assessing Persistence of Genetically Modified E. coli MG1655 in the Large Bowel}, volume={234}, ISSN={["1535-3699"]}, DOI={10.3181/0812-RM-358}, abstractNote={ One of the primary factors limiting the efficacy of probiotic therapies is short persistence time. Utilizing a novel method for assessment of persistence in the large bowel independent of survival of the organisms in the upper GI tract, we tested whether overexpression of the type 1 pilus, a colonization factor, or the presence of secretory immunoglobulin A (sIgA) might increase the persistence time of a laboratory strain of E. coli in the gut. For this purpose, cecal ostomies were created in mice and bacteria were placed in the ostomies, with or without sIgA. The persistence of the bacteria was assessed by evaluating the length of time after placement in which the bacteria were found in fecal samples. E. coli MG1655 expressing pili with the mannose-specific adhesin persisted in vivo significantly longer [mean (hours) ± SEM: 91.50 ± 15.98, n = 12] than bacteria expressing pili without adhesin [43.67 ± 8.22, n = 12] ( P = 0.01) and significantly longer than bacteria expressing neither pili nor adhesin [22.00 ± 4.22, n = 12] ( P = 0.0004). Although the persistence time of bacteria was not significantly affected by the presence of sIgA, the sIgA did cause a relative increase in retention of inert particles. These results, combined with an acute increase in stool production and stool water content in those animals not receiving sIgA following introduction of bacteria, suggest that sIgA might have anti-inflammatory properties in the gut when administered with enteric bacteria. Modifying expression of probiotic colonization factors may provide substantial benefit to patients with digestive tract diseases by virtue of increased persistence of the probiotic and, in the case of sIgA, an anti-inflammatory effect. This novel in vivo model may be useful in evaluating persistence time in a variety of current and future probiotic regimens. }, number={10}, journal={EXPERIMENTAL BIOLOGY AND MEDICINE}, author={Barbas, Andrew S. and Lesher, Aaron P. and Thomas, Anitra D. and Wyse, Aaron and Devalapalli, Aditya P. and Lee, Yu-Huei and Tan, Hung-Enn and Orndorff, Paul E. and Bollinger, R. Randal and Parker, William}, year={2009}, month={Oct}, pages={1174–1185} }
 @article{zhu_holtz_wang_wang_orndorff_guo_2009, title={Quantitative Glycomics from Fluidic Glycan Microarrays}, volume={131}, ISSN={["1520-5126"]}, DOI={10.1021/ja902783n}, abstractNote={A hallmark of cell-surface processes involving glycans is their multivalent interaction with glycan binding proteins (GBPs). Such a multivalent interaction depends critically on the mobility and density of signaling molecules on the membrane surface. While glycan microarrays have been used in exploring multivalent interactions, the lack of mobility and the difficulty in controlling surface density both limit their quantitative applications. Here we apply a fluidic glycan microarray, with glycan density varying for orders of magnitude, to profile cell surface interaction using a model system, the adhesion of Escherichia coli to mannose. We show the quantitative determination of monovalent and multivalent adhesion channels; the latter can be inhibited by nanopartices presenting a high density of mannosyl groups. These results reveal a new E. coli adhesion mechanism: the switching in the FimH adhesion protein avidity from monovalent to multivalent as the density of mobile mannosyl groups increases; such avidity switching enhances binding affinity and triggers multiple fimbriae anchoring. Affinity enhancement toward FimH has only been observed before for oligo-mannose due to the turn on of secondary interactions outside the mannose binding pocket. We suggest that the new mechanism revealed by the fluidic microarray is of general significance to cell surface interactions: the dynamic clustering of simple sugar groups (homogeneous or heterogeneous) on the fluidic membrane surface may simulate the functions of complex glycan molecules.}, number={38}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Zhu, X. -Y. and Holtz, Bryan and Wang, Yini and Wang, Lai-Xi and Orndorff, Paul E. and Guo, Athena}, year={2009}, month={Sep}, pages={13646–13650} }
 @article{spears_suyemoto_palermo_horton_hamrick_havell_orndorff_2008, title={A Listeria monocytogenes mutant defective in bacteriophage attachment is attenuated in orally inoculated mice and impaired in enterocyte intracellular growth}, volume={76}, ISSN={["0019-9567"]}, DOI={10.1128/IAI.00283-08}, abstractNote={ABSTRACT}, number={9}, journal={INFECTION AND IMMUNITY}, author={Spears, Patricia A. and Suyemoto, M. Mitsu and Palermo, Angela M. and Horton, John R. and Hamrick, Terri S. and Havell, Edward A. and Orndorff, Paul E.}, year={2008}, month={Sep}, pages={4046–4054} }
 @article{sebaihia_orndorff_2006, title={Comparison of the genome sequence of the poultry pathogen Bordetella avium with those of B-bronchiseptica, B-pertussis, and B-parapertussis reveals extensive diversity in surface structures associated with host interaction}, volume={188}, number={16}, journal={Journal of Bacteriology}, author={Sebaihia, M. and Orndorff, P. E.}, year={2006}, pages={6002–6015} }
 @article{fulcher_cole_janowicz_toffer_fortney_katz_orndorff_spinola_kawula_2006, title={Expression of Haemophilus ducreyi collagen binding outer membrane protein NcaA is required for virulence in swine and human challenge models of chancroid}, volume={74}, ISSN={["1098-5522"]}, DOI={10.1128/IAI.74.5.2651-2658.2006}, abstractNote={ABSTRACT}, number={5}, journal={INFECTION AND IMMUNITY}, author={Fulcher, RA and Cole, LE and Janowicz, DM and Toffer, KL and Fortney, KR and Katz, BP and Orndorff, PE and Spinola, SM and Kawula, TH}, year={2006}, month={May}, pages={2651–2658} }
 @misc{orndorff_hamrick_smoak_havell_2006, title={Host and bacterial factors in listeriosis pathogenesis}, volume={114}, ISSN={["1873-2542"]}, DOI={10.1016/j.vetmic.2005.12.003}, abstractNote={Members of the Genus Listeria are ubiquitous environmental saprophytic microorganisms. If ingested they can cause a severe disseminated disease (listeriosis) that has a high mortality rate, the highest of any food-borne pathogen, even with antibiotic therapy. Central to the high mortality rate is the hallmark characteristic of the microorganism to grow intracellularly. The presence of listeriae in food processing plants has resulted in many outbreaks of human disease and large scale recalls of processed foods. Despite the ubiquity of the microorganism, the actual disease rate (those animals showing disease signs over those exposed) is quite low and disease is almost always associated with an underlying predisposition (pregnancy being the most common in otherwise normal individuals). There are many features of the pathogenesis of listeriosis that have remained mysterious despite the extensive use of the microorganism in the study of cell-mediated immunity and intracellular growth. Informational advances such as the sequence of the mouse and listerial genomes, and technical advances such as the discovery of listeria-susceptible mouse strains, may renew interest in the study of the natural pathogenesis of the disease. This may be further facilitated by studies that employ the natural inoculation route and mimic common predisposing conditions witnessed in victims of natural outbreaks.}, number={1-2}, journal={VETERINARY MICROBIOLOGY}, author={Orndorff, PE and Hamrick, TS and Smoak, IW and Havell, EA}, year={2006}, month={Apr}, pages={1–15} }
 @article{afonina_leduc_nepluev_jeter_routh_almond_orndorff_hobbs_elkins_2006, title={Immunization with the Haemophilus ducreyi hemoglobin receptor HgbA protects against infection in the swine model of chancroid}, volume={74}, ISSN={["1098-5522"]}, DOI={10.1128/IAI.74.4.2224-2232.2006}, abstractNote={ABSTRACT}, number={4}, journal={INFECTION AND IMMUNITY}, author={Afonina, G and Leduc, I and Nepluev, I and Jeter, C and Routh, P and Almond, G and Orndorff, PE and Hobbs, M and Elkins, C}, year={2006}, month={Apr}, pages={2224–2232} }
 @article{bollinger_everett_wahl_lee_orndorff_parker_2006, title={Secretory IgA and mucin-mediated biofilm formation by environmental strains of Escherichia coli: role of type 1 pili}, volume={43}, ISSN={["0161-5890"]}, DOI={10.1016/j.molimm.2005.02.013}, abstractNote={Recent studies suggest the importance of secretory IgA (SIgA) and mucin in the mediation of biofilm formation by commensal bacteria within the mammalian gut. Studies using a variety of strains of Escherichia coli have indicated that the interaction between E. coli and SIgA is dependent on the type 1 pilus. In this study, the importance of the pilus in SIgA-mediated biofilm formation by a laboratory strain (MG1655) and environmental (fecal) strains of E. coli was evaluated. Transient expression of the type 1 pilus by the laboratory strain of E. coli failed to facilitate SIgA-mediated biofilm formation, whereas constitutive expression of the type 1 pilus by the laboratory strain was sufficient. In contrast, transient expression of the type 1 pilus was sufficient to facilitate SIgA-mediated biofilm formation by environmental isolates. The "threshold" for mucin-mediated biofilm formation appeared to be lower than that for SIgA-mediated biofilm formation, perhaps reflecting disparate roles of mucin and SIgA in mediating biofilm formation in the gut. These studies also provide the first procedures for the growth of bacterial biofilms on live epithelial cells in vitro, an important development that may facilitate future studies on the effects of bacterial biofilms on epithelial cells.}, number={4}, journal={MOLECULAR IMMUNOLOGY}, author={Bollinger, RR and Everett, ML and Wahl, SD and Lee, YH and Orndorff, PE and Parker, W}, year={2006}, month={Feb}, pages={378–387} }
 @article{orndorff_devapali_palestrant_wyse_everett_bollinger_parker_2004, title={Immunoglobulin-mediated agglutination of and biofilm formation by Escherichia coli K-12 require the type 1 pilus fiber}, volume={72}, ISSN={["1098-5522"]}, DOI={10.1128/IAI.72.4.1929-1938.2004}, abstractNote={ABSTRACT}, number={4}, journal={INFECTION AND IMMUNITY}, author={Orndorff, PE and Devapali, A and Palestrant, S and Wyse, A and Everett, ML and Bollinger, RR and Parker, W}, year={2004}, month={Apr}, pages={1929–1938} }
 @article{cole_toffer_fulcher_san mateo_orndorff_kawula_2003, title={A humoral immune response confers protection against Haemophilus ducreyi infection}, volume={71}, ISSN={["0019-9567"]}, DOI={10.1128/IAI.71.12.6971-6977.2003}, abstractNote={ABSTRACT}, number={12}, journal={INFECTION AND IMMUNITY}, author={Cole, LE and Toffer, KL and Fulcher, RA and San Mateo, LR and Orndorff, PE and Kawula, TH}, year={2003}, month={Dec}, pages={6971–6977} }
 @article{hamrick_diaz_havell_horton_orndorff_2003, title={Influence of extracellular bactericidal agents on bacteria within macrophages}, volume={71}, ISSN={["0019-9567"]}, DOI={10.1128/IAI.71.2.1016-1019.2003}, abstractNote={ABSTRACT}, number={2}, journal={INFECTION AND IMMUNITY}, author={Hamrick, TS and Diaz, AH and Havell, EA and Horton, JR and Orndorff, PE}, year={2003}, month={Feb}, pages={1016–1019} }
 @article{hamrick_horton_spears_havell_smoak_orndorff_2003, title={Influence of pregnancy on the pathogenesis of listeriosis in mice inoculated intragastrically}, volume={71}, ISSN={["1098-5522"]}, DOI={10.1128/IAI.71.9.5202-5209.2003}, abstractNote={ABSTRACT}, number={9}, journal={INFECTION AND IMMUNITY}, author={Hamrick, TS and Horton, JR and Spears, PA and Havell, EA and Smoak, IW and Orndorff, PE}, year={2003}, month={Sep}, pages={5202–5209} }
 @article{valenski_harris_spears_horton_orndorff_2003, title={The product of the fimI gene is necessary for Escherichia coli type 1 pilus biosynthesis}, volume={185}, ISSN={["0021-9193"]}, DOI={10.1128/JB.185.16.5007-5011.2003}, abstractNote={ABSTRACT}, number={16}, journal={JOURNAL OF BACTERIOLOGY}, author={Valenski, ML and Harris, SL and Spears, PA and Horton, JR and Orndorff, PE}, year={2003}, month={Aug}, pages={5007–5011} }
 @article{spears_temple_miyamoto_maskell_orndorff_2003, title={Unexpected similarities between Bordetella avium and other pathogenic bordetellae}, volume={71}, ISSN={["0019-9567"]}, DOI={10.1128/IAI.71.5.2591-2597.2003}, abstractNote={ABSTRACT}, number={5}, journal={INFECTION AND IMMUNITY}, author={Spears, PA and Temple, LM and Miyamoto, DM and Maskell, DJ and Orndorff, PE}, year={2003}, month={May}, pages={2591–2597} }
 @article{murphy_sacco_dickenson_metzger_hu_orndorff_connell_2002, title={BhuR, a virulence-associated outer membrane protein of Bordetella avium, is required for the acquisition of iron from heme and hemoproteins}, volume={70}, ISSN={["0019-9567"]}, DOI={10.1128/IAI.70.10.5390-5403.2002}, abstractNote={ABSTRACT}, number={10}, journal={INFECTION AND IMMUNITY}, author={Murphy, ER and Sacco, RE and Dickenson, A and Metzger, DJ and Hu, Y and Orndorff, PE and Connell, TD}, year={2002}, month={Oct}, pages={5390–5403} }
 @article{shelton_temple_orndorff_2002, title={Use of bacteriophage Ba1 to identify properties associated with Bordetella avium virulence}, volume={70}, DOI={10.1128/IAI.70.3.121901224.2002}, number={3}, journal={Infection and Immunity}, author={Shelton, C. B. and Temple, L. M. and Orndorff, P. E.}, year={2002}, pages={1219–1224} }
 @article{harris_spears_havell_hamrick_horton_orndorff_2001, title={Characterization of Escherichia coli type 1 pilus mutants with altered binding specificities}, volume={183}, ISSN={["0021-9193"]}, DOI={10.1128/JB.183.13.4099-4102.2001}, abstractNote={ABSTRACT}, number={13}, journal={JOURNAL OF BACTERIOLOGY}, author={Harris, SL and Spears, PA and Havell, EA and Hamrick, TS and Horton, JR and Orndorff, PE}, year={2001}, month={Jul}, pages={4099–4102} }
 @article{lu_hill_hood_greeson_horton_orndorff_herndon_tonelli_2001, title={Formation of antibiotic, biodegradable polymers by processing with Irgasan DP300R (Triclosan) and its inclusion compound with beta-cyclodextrin}, volume={82}, DOI={10.1002/app.1852.abs}, abstractNote={The inclusion compound (IC) between the FDA-approved antibacterial Irgasan DP300 (Trichlosan), and β-cyclodextrin (CD) has been formed. When the Irgasan–β-CD–IC is embedded in biodegradeable/bioabsorbable films of poly(ϵ-caprolactone) (PCL) at low levels (a few wt %), they are rendered resistant to the growth of E. coli bacteria. When these same PCL films embedded with Irgasan–β-CD–IC are used as the adhesive for laminating cotton fabrics, we observe the resulting cotton laminates to also be resistant to the growth of E. coli bacteria. These results hold promise for the fabrication of bacteria-resistant polymer films and fibers, as well as antibacterial fabrics, by means of simple melt processing with Irgasan–β-CD–IC. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 300–309, 2001}, number={2}, journal={Journal of Applied Polymer Science}, author={Lu, J. and Hill, M. A. and Hood, M. and Greeson, D. F. and Horton, J. R. and Orndorff, P. E. and Herndon, A. S. and Tonelli, A. E.}, year={2001}, pages={300–309} }
 @article{spears_temple_orndorff_2000, title={A role for lipopolysaccharide in turkey tracheal colonization by Bordetella avium as demonstrated in vivo and in vitro}, volume={36}, ISSN={["0950-382X"]}, DOI={10.1046/j.1365-2958.2000.01963.x}, abstractNote={We isolated two insertion mutants of Bordetella avium that exhibited a peculiar clumped‐growth phenotype and found them to be attenuated in turkey tracheal colonization. The mutants contained transposon insertions in homologues of the wlbA and wlbL genes of Bordetella pertussis. The wlb genetic locus of B. pertussis has been previously described as containing 12 genes involved in lipopolysaccharide (LPS) biosynthesis. Polyacrylamide gel analysis of LPS from B. avium wlbA and wlbL insertion mutants confirmed an alteration in the LPS profile. Subsequent cloning and complementation of the wlbA and wlbL mutants in trans with a recombinant plasmid containing the homologous wlb locus from B. avium eliminated the clumped‐growth phenotype and restored the LPS profile to that of wild‐type B. avium. Also, a parental level of tracheal colonization was restored to both mutants by the recombinant plasmid. Interestingly, complementation of the wlbA and wlbL mutants with a recombinant plasmid containing the heterologous wlb locus from B. pertussis, B. bronchiseptica, or Bordetella parapertussis eliminated the clumped‐growth phenotype and resulted in a change in the LPS profile, although not to that of wild‐type B. avium. The mutants also acquired resistance to a newly identified B. avium‐specific bacteriophage, Ba1. Complementation of both wlbA and wlbL mutants with the homologous wlb locus of B. avium, but not the heterologous B. pertussis locus, restored sensitivity to Ba1. Complementation of the wlbL mutant, but not the wlbA mutant, with the heterologous wlb locus of Bordetella bronchiseptica or B. parapertussis restored partial sensitivity to Ba1. Comparisons of the LPS profile and phage sensitivity of the mutants upon complementation by wlb loci from the heterologous species and by B. avium suggested that phage sensitivity required the presence of O‐antigen. At the mechanistic level, both mutants showed a dramatic decrease in serum resistance and a decrease in binding to turkey tracheal rings in vitro. In the case of serum resistance, complementation of both mutants with the homologous wlb locus of B. avium restored serum resistance to wild‐type levels. However, in the case of epithelial cell binding, only complementation of the wlbA mutant completely restored binding to wild‐type levels (binding was only partially restored in the wlbL mutant). This is the first characterization of LPS mutants of B. avium at the genetic level and the first report of virulence changes by both in vivo and in vitro measurements}, number={6}, journal={MOLECULAR MICROBIOLOGY}, author={Spears, PA and Temple, LM and Orndorff, PE}, year={2000}, month={Jun}, pages={1425–1435} }
 @article{ryan_apperson_orndorff_levine_2000, title={Characterization of Lyme disease spirochetes isolated from ticks and vertebrates in North Carolina}, volume={36}, ISSN={["1943-3700"]}, DOI={10.7589/0090-3558-36.1.48}, abstractNote={Borrelia burgdorferi isolates obtained from numerous locations and from different hosts in North Carolina, were compared to previously characterized strains of the Lyme disease spirochete and other Borrelia spp. The spirochete isolates were confirmed to be B. burgdorferi sensu stricto based on immunofluorescence (IFA) using a monoclonal antibody to outer surface protein A (Osp A [H5332]) and polymerase chain reaction (PCR) using a species-specific nested primer for a conserved region of the gene that encodes for flagellin. In addition, the isolates tested positive in Western blots with species-specific monoclonal antibodies for outer surface protein A and OspB (84c), and the genus-specific, monoclonal antibody to flagellin (H9724). Infectivity studies with several of these isolates were conducted using Mus musculus and Oryzomys palustris and the isolates exhibited markedly different levels of infectivity. This study demonstrates that B. burgdorferi sensu stricto is present and naturally transmitted on the Outer Banks and in the Coastal Plain and Piedmont regions of North Carolina.}, number={1}, journal={JOURNAL OF WILDLIFE DISEASES}, author={Ryan, JR and Apperson, CS and Orndorff, PE and Levine, JF}, year={2000}, month={Jan}, pages={48–55} }
 @article{shelton_crosslin_casey_ng_temple_orndorff_2000, title={Discovery, purification, and characterization of a temperate transducing bacteriophage for Bordetella avium}, volume={182}, ISSN={["1098-5530"]}, DOI={10.1128/JB.182.21.6130-6136.2000}, abstractNote={ABSTRACT}, number={21}, journal={JOURNAL OF BACTERIOLOGY}, author={Shelton, CB and Crosslin, DR and Casey, JL and Ng, S and Temple, LM and Orndorff, PE}, year={2000}, month={Nov}, pages={6130–6136} }
 @article{metcalf_almond_routh_horton_dillman_orndorff_2000, title={Experimental Salmonella typhi infection in the domestic pig, Sus scrofa domestica}, volume={29}, ISSN={["0882-4010"]}, DOI={10.1006/mpat.2000.0367}, abstractNote={The domestic pig, Sus scrofa domestica, was examined as a model for typhoid fever, a severe and systemic disease of humans caused by Salmonella typhi. Six pigs were inoculated 1 week post-weaning with approximately 10(10)colony forming units (cfu) of wild type Salmonella typhi strain ISP1820 intranasally and observed for 3 weeks. S. typhi was cultured from the tonsils of 50% of the pigs at necropsy. Cultures from all other organs analysed (ileum, colon, spleen and liver) were negative. No clinical or histopathological signs of disease were observed. Pigs inoculated in parallel with swine-virulent S. choleraesuis all exhibited signs of systemic salmonellosis indicating that the parameters of the experimental infection with S. typhi (e.g. route) were appropriate. Whereas the pig has a gastrointestinal tract that is very similar to humans, our results indicated that the unique features of host and microbe interaction needed to produce typhoid fever were not mimicked in swine. Nevertheless, our observation of tonsillar involvement was consistent with former observations of S. choleraesuis and S. typhimurium infections in swine and supports a role for the tonsil in all porcine salmonella infections.}, number={2}, journal={MICROBIAL PATHOGENESIS}, author={Metcalf, ES and Almond, GW and Routh, PA and Horton, JR and Dillman, RC and Orndorff, PE}, year={2000}, month={Aug}, pages={121–126} }
 @article{hamrick_harris_spears_havell_horton_russell_orndorff_2000, title={Genetic characterization of Escherichia coli type 1 pilus adhesin mutants and identification of a novel binding phenotype}, volume={182}, ISSN={["0021-9193"]}, DOI={10.1128/JB.182.14.4012-4021.2000}, abstractNote={ABSTRACT}, number={14}, journal={JOURNAL OF BACTERIOLOGY}, author={Hamrick, TS and Harris, SL and Spears, PA and Havell, EA and Horton, JR and Russell, PW and Orndorff, PE}, year={2000}, month={Jul}, pages={4012–4021} }
 @article{hamrick_havell_horton_orndorff_2000, title={Host and bacterial factors involved in the innate ability of mouse macrophages to eliminate internalized unopsonized Escherichia coli}, volume={68}, ISSN={["0019-9567"]}, DOI={10.1128/IAI.68.1.125-132.2000}, abstractNote={ABSTRACT}, number={1}, journal={INFECTION AND IMMUNITY}, author={Hamrick, TS and Havell, EA and Horton, JR and Orndorff, PE}, year={2000}, month={Jan}, pages={125–132} }
 @article{huang_taylor_gerber_orndorff_horton_tonelli_1999, title={Formation of antibiotic, biodegradable/bioabsorbable polymers by processing with neomycin sulfate and its inclusion compound with beta-cyclodextrin}, volume={74}, ISSN={["0021-8995"]}, DOI={10.1002/(SICI)1097-4628(19991024)74:4<937::AID-APP20>3.0.CO;2-K}, abstractNote={Samples of pure neomycin sulfate and its inclusion compound (IC) with β-cyclodextrin were implanted into films of poly(L-lactic acid) (PLLA) and poly(e-caprolactone) (PCL). Both polymers have been widely used commercially to make sutures. The antibacterial activity of these films against Escherichia coli was tested. Films made by either solution casting or melt pressing were divided into the following three groups: (1) plain polymer films, (2) those embedded with pure neomycin sulfate, and (3) those embedded with neomycin sulfate-β-cyclodextrin IC. Filter paper treated with 1.5 μL of 10 mg/μL Kanamycin and neomycin were used as controls and resulted in 11- and 8-mm zones of inhibition/or antibacterial activity, respectively. Small discs (ca. 2% of total area) cut from solution-cast films of PLLA and PCL containing 50 wt % neomycin sulfate IC had 17- and 16-mm zones of inhibition, and PLLA and PCL containing 50 wt % pure neomycin sulfate deterred bacterial growth, resulting in 19-mm zones of inhibition. Melt-pressed films containing 10 wt % pure neomycin sulfate or its IC, showed 17- and 11-mm zones of inhibition for PLLA films, respectively, while PCL films showed 13- and 9-mm zones of inhibition, respectively. For melt-pressed films that contain 0.01 wt % pure neomycin sulfate or its IC, PLLA films showed 11- and 9.5-mm zones of inhibition, respectively, while PCL films showed 11- and 10-mm zones of inhibition, respectively. Since an antibiotic, bioabsorbable suture does not require surgical removal, implanting an inclusion compound in the suture might allow the slow release of antibiotic, thereby guarding against postsurgical infection and also protecting the antibiotic from degradation during the melt-spinning process used to make the suture. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 937–947, 1999}, number={4}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Huang, L and Taylor, H and Gerber, M and Orndorff, PE and Horton, JR and Tonelli, A}, year={1999}, month={Oct}, pages={937–947} }
 @article{san mateo_toffer_orndorff_kawula_1999, title={Immune cells are required for cutaneous ulceration in a swine model of chancroid}, volume={67}, number={9}, journal={Infection and Immunity}, author={San Mateo, L. R. and Toffer, K. L. and Orndorff, P. E. and Kawula, T. H.}, year={1999}, pages={4963–4967} }
 @article{san mateo_toffer_orndorff_kawula_1999, title={Neutropenia restores virulence to an attenuated Cu,Zn superoxide dismutase-deficient Haemophilus ducreyi strain in the swine model of chancroid}, volume={67}, number={10}, journal={Infection and Immunity}, author={San Mateo, L. R. and Toffer, K. L. and Orndorff, P. E. and Kawula, T. H.}, year={1999}, pages={5345–5351} }
 @article{ryan_levine_apperson_lubke_wirtz_spears_orndorff_1998, title={An experimental chain of infection reveals that distinct Borrelia burgdorferi populations are selected in arthropod and mammalian hosts}, volume={30}, ISSN={["1365-2958"]}, DOI={10.1046/j.1365-2958.1998.01071.x}, abstractNote={The prokaryotic, spirochaetal microorganism Borrelia burgdorferi is the causative agent of Lyme disease, an arthropod‐borne disease of a variety of vertebrates and the most prevalent arthropod‐borne disease of humans in the United States. In order to understand better the normal life cycle of B. burgdorferi, an experimental chain of infection was devised that involved multiple sequential arthropod and mammalian passages. By examining populations of B. burgdorferi emerging from different points in this infectious chain, we demonstrate that selection of B. burgdorferi populations peculiar to arthropod or vertebrate hosts is a property of at least one of the two ecologically distinct strains we examined. Distinct B. burgdorferi populations were identified using an antigenic profile, defined by a set of monoclonal antibodies to eight B. burgdorferi antigens, and a plasmid profile, defined by the naturally occurring plasmids in the starting clonal populations. These two profiles constituted the phenotypical signature of the population. In the strain exhibiting selection in the different hosts, transition from one host to another produced a striking series of alternating phenotypical signatures down the chain of infection. At the molecular level, the alternating signatures were manifested as a reciprocal relationship between the expression of certain antigenic forms of outer surface protein (Osp) B and OspC. In the case of OspC, the antigenic changes could be correlated to the presence of one of two distinctly different alleles of the ospC gene in a full‐length and presumably transcriptionally active state. In the case of OspB, two alleles were again identified. However, their differences were minor and their relationship to OspB antigenic variation more complicated. In addition to the reciprocating changes in the antigenic profile, a reciprocating change in the size (probably the multimeric state) of a 9.0 kbp supercoiled plasmid was also noted. Selection of distinct populations in the tick may be responsible for the microorganism's ability to infect a wide range of vertebrate hosts efficiently, in that the tick might provide selective pressure for the elimination of the population selected in the previous host.}, number={2}, journal={MOLECULAR MICROBIOLOGY}, author={Ryan, JR and Levine, JF and Apperson, CS and Lubke, L and Wirtz, RA and Spears, PA and Orndorff, PE}, year={1998}, month={Oct}, pages={365–379} }
 @article{temple_weiss_walker_barnes_christensen_miyamoto_shelton_orndorff_1998, title={Bordetella avium virulence measured in vivo and in vitro}, volume={66}, number={11}, journal={Infection and Immunity}, author={Temple, L. M. and Weiss, A. A. and Walker, K. E. and Barnes, H. J. and Christensen, V. L. and Miyamoto, D. M. and Shelton, C. B. and Orndorff, P. E.}, year={1998}, pages={5244–5251} }
 @article{maurelli_routh_dillman_ficken_weinstock_almond_orndorff_1998, title={Shigella infection as observed in the experimentally inoculated domestic pig, Sus scrofa domestica}, volume={25}, ISSN={["0882-4010"]}, DOI={10.1006/mpat.1998.0230}, abstractNote={The domestic pig, Sus scrofa domestica, was investigated as a potential animal model for shigellosis. We examined the effects of pig age, pig breed and antibiotic pretreatment upon Shigella infection. Shigella dysenteriae, and Shigella flexneri (both virulent and avirulent strains) were utilized. Our results indicated that young (4-week-old), conventionally re ared, domestic pigs were routinely, but briefly, colonized (average=3.5+/-2.5 days) following oral or gavage administration ofS. flexneri, as determined by direct rectal cultures. The duration of S. dysenteriae colonization was significantly shorter. Inoculation of younger (2 days) or older (9 weeks) pigs with S. flexneri had no significant effect on infection duration. Similarly, infection of 4-week-old pigs with virulent and avirulent strains of S. flexneri had no effect upon the duration of infection, nor did the use of a swine-passaged S. flexneri isolate. Marked clinical, histopathological (gross and microscopic) and immunoIhistopathological signs of disease were absent in all infections. However, in instances where microscopic histopathological evidence was used to correctly identify infected pigs, tonsillar lesions were the consistently noted criteria. The tonsils are believed to be an important portal of entry for Salmonella choleraesuis, another member of the Enterobacteriaceae and a prevalent pig pathogen. Taken altogether, our results indicate that the domestic pig is unsuitable as a model for shigellosis.}, number={4}, journal={MICROBIAL PATHOGENESIS}, author={Maurelli, AT and Routh, PR and Dillman, RC and Ficken, MD and Weinstock, DM and Almond, GW and Orndorff, PE}, year={1998}, month={Oct}, pages={189–196} }