About

Dr. Edward B. Breitschwerdt is a professor of medicine and infectious diseases at North Carolina State University College of Veterinary Medicine. He is also an adjunct professor of medicine at Duke University Medical Center and a Diplomate of the American College of Veterinary Internal Medicine (ACVIM). Dr. Breitschwerdt directs the Intracellular Pathogens Research Laboratory in the Institute for Comparative Medicine at NC State University, co-directs the Vector Borne Diseases Diagnostic Laboratory, and is the director of the NCSU-CVM Biosafety Level 3 Laboratory. His clinical interests include infectious diseases, immunology, and nephrology. With over 30 years of research emphasis on vector-transmitted, intracellular pathogens, his work has contributed significantly to understanding animal and human bartonellosis, a group of zoonotic bacterial pathogens. His research group has published more than 350 manuscripts in peer-reviewed scientific journals, and he has received notable awards such as the North Carolina State University Alumni Association Outstanding Research Award and the Holladay Medal, the highest faculty honor at NC State University. Dr. Breitschwerdt's research focuses on developing targeted treatments for bartonelloses, evaluating anti-bacterial drugs in vitro and in vivo, and understanding the pathogenesis of these emerging pathogens.

Research topics

• Virology
• Medicine
• Immunology
• Veterinary medicine
• Internal medicine
• Biology
• Microbiology
• Intensive care medicine
• Pathology
• Genetics

Selected publications

• Perinatal transmission of Borrelia burgdorferi: advancing scientific and clinical understanding of Lyme disease in pregnancy

  Frontiers in Medicine · 2026-04-09

  articleOpen access

  sensu lato (Bb), the spirochetal agent of Lyme disease, is an issue of public health importance and research significance. This alternate mode of transmission and the potential risk of adverse pregnancy outcomes were communicated within public health spheres following the first suspected case in 1985. Subsequent studies in reservoir and non-reservoir animal hosts, in addition to case reports of perinatal morbidity and mortality in humans brought further attention to the field. Decades later, however, the incidence and epidemiologic impact of perinatal transmission of Bb, as well as the clinical spectrum and potential long-term health sequelae of gestationally exposed children, remain understudied and poorly defined. In June 2022, a Banbury Conference on Perinatal Transmission of Lyme disease was convened at Cold Spring Harbor Laboratory in New York. This manuscript conveys conference findings and research recommendations to advance scientific and clinical understanding of this important issue.

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• Development of a multiplex serological assay to detect immunoreactivity against a novel <i>Bartonella species</i> in military working dogs

  Microbiology Spectrum · 2025-09-05 · 1 citations

  articleOpen access

  ABSTRACT Bartonella pose a significant health risk to military working dogs (MWDs), and these zoonotic organisms may also cause disease in humans. According to the U.S. Army zoonotic disease surveillance program, there was a 47.4% seroprevalence for Bartonella spp. among feral dogs in Iraq. This surveillance program identified infection with a novel species Candidatus Bartonella merieuxii ( C Bm) in 37% of the dogs by whole blood Bartonella DNA amplification and sequencing for the gltA and rpoB genes and intergenic spacer region. This bacterium has not been successfully cultured to date. The objectives of the present study were to (i) develop an assay to serologically detect infection with C Bm in dogs, and (ii) to define the prevalence and Bartonella species acquired by MWD during deployment to Iraq. To establish a multiplex serological surveillance panel capable of assessing infection with Bartonella spp., with special emphasis on C Bm, we identified in silico 20 peptides representing potential linear B cell epitopes. The newly developed serosurveillance panel was used to test paired samples (pre- and post-Iraq deployment) from 52 MWD. Conventional Bartonella diagnostic testing (PCR and indirect immunofluorescence assays [IFA]) was also performed. Twenty-seven percent (14/52) of the paired samples had statistically significant antibody differences between pre- and post-Iraq deployment, suggesting seroconversion during deployment. In conclusion, the newly developed multiplex serologic assay, with its advantages of high throughput testing, requirement of low sample volumes, and ability to adapt new Bartonella species to the panel, has the potential to serve as a new diagnostic tool and will be useful for serosurveillance. IMPORTANCE Bartonella pose a significant health risk to military working dogs (MWDs), and these organisms also cause disease in humans. Bartonella has not been assessed in MWD deployed to Iraq, despite a report that a novel Bartonella , Candidatus B. merieuxii ( C Bm), was detected in almost half of the stray dogs in Baghdad. Infection in dogs is similar to that in humans, and to date, at least three MWDs have died of Bartonella infection. The goal of the proposed study is to develop an assay to serologically detect infection with C Bm in dogs and to define the prevalence and Bartonella species acquired by MWD during deployment to Iraq. Dogs are potential reservoirs and sentinels for vector-borne infections and are implicated in the transmission of these infections to humans. Detecting the presence of Bartonella in Iraq-deployed MWDs is essential to identify and prevent the introduction of a new Bartonella species to North America.

  PublisherDOI

• Repeated Detection of Bartonella DNA in Feline Placenta: Potential Implications for Placental and Fetal Development

  Animals · 2025-07-11 · 1 citations

  articleOpen accessSenior authorCorresponding

  The domestic cat is the primary reservoir host of three flea-borne Bartonella species, one of which (Bartonella henselae) causes reduced fertility and reproductive failure in experimentally infected cats. Vertical transmission of Bartonella has been documented only in B-cell deficient mice, but not immunocompetent animals. As many free-roaming cats are chronically infected with Bartonella and may be immunocompromised by environmental stress or coinfection, we attempted to isolate Bartonella from the fetal and placental tissues of pregnant queens spayed during trap–neuter–release. Four samples from each tissue (ovary, uterus, fetus, and placenta) were split for direct DNA extraction, liquid culture, and culture on a blood agar plate. Samples from infected queens were inoculated into liquid media and sampled weekly for three weeks for DNA extraction and plating. Bartonella DNA was sequenced directly from 28% (5/18) of the free-roaming queens. For these five queens, liquid enrichment culture was attempted in duplicate for fetal and placental samples. Bartonella clarridgeiae DNA was amplified using qPCR liquid enrichment cultures from the placentas of two cats. These findings suggest that viable Bartonella organisms are present in feline reproductive tissue. Additional studies are needed to assess the transplacental transmission of Bartonella spp. and Bartonella’s influence on fetal development.

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• <i>Bartonella henselae</i> , <i>Babesia odocoilei</i> and <i>Babesia divergens</i> -like MO-1 infection in the brain of a child with seizures, mycotoxin exposure and suspected Rasmussen's encephalitis

  Journal of Central Nervous System Disease · 2025-03-12 · 4 citations

  articleOpen access1st authorCorresponding

  Background In conjunction with more sensitive culture and molecular diagnostic testing modalities, simultaneous or sequential infection with more than 1 vector borne zoonotic pathogen is being increasingly documented in human patients. On a frequent basis, many people are exposed to apparently healthy, but infected, domestic and wild animals, the arthropod vectors with which these animals have co-evolved, and the bacterial, protozoal and other pathogens for which various animals are reservoirs. Unsuspected zoonotic transmission by scratch, bite, or vector exposures can result in chronic, indolent, or potentially life-threatening infections. Methods In December 2016, at 2 years of age, a male child residing in Ontario, Canada received facial scratches from a feral cat. In August 2018, seizures began 8 days after the child developed a focal, suspected insect bite rash. In June 2019, potential mold toxicity in the child’s bedroom was assessed by fungal culture and urinary mycotoxin assays. Beginning in January 2022, Bartonella spp. serology (indirect fluorescent antibody assays), polymerase chain reaction (PCR) amplification, DNA sequencing, and enrichment blood and brain cultures were used on a research basis to assess Bartonella spp. bloodstream and central nervous system (brain biopsy) infection. In 2024, using recently developed PCR and DNA sequencing targets, Babesia species infection was retrospectively assessed due to the rash observed in 2018. Results Although there was historical cat and suspected tick exposures, serological testing for Bartonella henselae and Borrelia burgdorferi were repeatedly negative. Sequential neurodiagnostic testing partially supported a diagnosis of Rasmussen’s encephalitis. Astrogliosis was the only brain biopsy histopathological abnormality. Bartonella henselae DNA was amplified and sequenced from enrichment cultures of brain tissue. Retrospectively, Babesia odocoilei and Babesia divergens -like MO-1 infections were confirmed by amplification and sequencing of DNA extracted from enrichment blood cultures processed in January 2022, from blood and brain tissue cultures in June 2022, and blood in January and June 2023. Conclusions Infection with B . henselae , B . odocoilei , and B . divergens -like MO-1, complicated by mycotoxin exposure, created a complex clinical scenario for this child, his parents, and his doctors.

  PublisherDOI

• Vector‐Borne Pathogens and Immune‐Mediated Disease

  2025-09-12

  otherOpen accessSenior author
  PublisherOA PDFDOI

• Diversity of Cytauxzoon spp. (Piroplasmida: Theileriidae) in Wild Felids from Brazil and Argentina

  Pathogens · 2025-02-04 · 6 citations

  articleOpen access

  Domestic and wild felids are frequently parasitized by apicomplexan protozoa in the genus Cytauxzoon. Expanding species diversity has recently been described within this genus, with potential implications for epidemiology and pathogenesis. In light of these findings, this study assessed the genetic diversity of Cytauxzoon spp. in wild felids (n = 66) from different eco-regions of Brazil and Argentina. Of the 66 blood samples analyzed, 53 (80.3%) were 18S rRNA gene PCR-positive for Cytauxzoon spp., including 43 jaguars (Panthera onca) and 10 ocelots (Leopardus pardalis). Panthera onca specimens (100%, 43/43) were most frequently infected, followed by Leopardus pardalis (76.9%; 10/13). Cytauxzoon spp. were not detected in Leopardus braccatus (n = 1) or Puma concolor (n = 9). Phylogenetic analyses of fragments of the 18S rRNA, cytB, and cox-1 gene sequences from jaguars were closely related to Cytauxzoon felis. In contrast, sequences from ocelots were more closely associated with Cytauxzoon brasiliensis. Distance and haplotype analysis further confirmed the circulation of at least two distinct genovariants of C. felis among jaguars, as evidenced by their close positioning and low genetic divergence (0–0.14% for 18S rRNA, 0.37–0.56% for cytB, and 0.08–0.74% for cox-1). Additionally, sequence data from ocelots suggested that multiple genovariants of C. brasiliensis are circulating among these cats in different Brazilian eco-regions. Our study provides evidence of two distinct Cytauxzoon organisms parasitizing free-ranging and captive jaguars and ocelots, respectively, in Brazil and Argentina.

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• Peliosis hepatis and hepatic fibrosis in a dog infected with multiple <i>Bartonella</i> species

  Journal of Veterinary Diagnostic Investigation · 2025-01-07 · 2 citations

  articleOpen accessSenior author

  A 13-y-old, spayed female dog had regenerative anemia, lymphopenia, hypoalbuminemia, and elevated hepatic biochemical parameters. Liver biopsy revealed hepatic peliosis (hepatic sinusoidal angiectasis), frequently associated with perisinusoidal fibrosis. The dog was seroreactive to Bartonella antigens by indirect fluorescent antibody assays, and quantitative PCR from blood identified Bartonella vinsonii subsp. berkhoffii genotype II. The dog was euthanized 9 mo later because of acute decompensation. Autopsy revealed icteric adipose tissues, end-stage liver, and abdominal effusion. Microscopically, there was marked mixed-cell chronic hepatitis with hepatocellular loss, nodular hepatocellular regeneration, and capillary proliferation. Retrospective molecular testing documented B. koehlerae and B. rochalimae DNA in the dog’s blood at 2 or more times during liver disease progression. B. koehlerae DNA was also amplified and sequenced from the autopsy sample of liver. Our case emphasizes that Bartonella infection may be associated with hepatic peliosis and end-stage liver in dogs and expands the spectrum of Bartonella species that potentially play a role in canine hepatic diseases.

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• Molecular detection of Bartonella spp. DNA in dogs with hemangiosarcoma

  PLoS ONE · 2025-04-22 · 1 citations

  articleOpen accessSenior author

  INTRODUCTION: The potential role of pathogens, particularly vector-transmitted infectious agents, as a cofactor or cause of neoplasia has not been intensively investigated. We previously reported a potential link between Bartonella spp. bacteremia and splenic hemangiosarcoma (HSA) in dogs living in the United States. The purpose of this study was to: 1/ further determine the prevalence of Bartonella spp. DNA in dogs with splenic HSA from throughout the United States; 2/ assess the impact of sample preservation methods on Bartonella spp. DNA amplification using characterized tissue samples from dogs diagnosed with HSA. METHODS: In a blinded manner, we determined the presence of Bartonella spp. DNA in scrolls from biorepository formalin-fixed paraffin-embedded (FFPE) spleens from dogs living in three distant locations geographically transecting the United States. DNA extracted from non-lesional spleens (n = 249), nodular lymphoid hyperplasia spleens (n = 248), and splenic HSA (n = 330) were tested by quantitative polymerase chain reaction (qPCR), and droplet digital PCR (ddPCR). Subsequently, Bartonella PCR results from FFPE tissues and formalin-fixed tissues were compared using previously tested fresh frozen tissues from an additional 48 dogs with HSA. RESULTS: There was no significant difference in the proportion of Bartonella PCR positive FFPE tissues from dogs diagnosed with an alesional spleen, nodular lymphoid hyperplasia, and splenic HSA. Regardless of the histological diagnosis, the most common Bartonella species identified was B. henselae (32/38). Bartonella spp. DNA was detected in a significantly larger proportion of fresh frozen tissues compared to FFPE tissues, when tested by qPCR (22/48 versus 1/48; p <0.0001) or ddPCR (19/48 versus 1/48; p <0.0001). Using ddPCR, Bartonella DNA was more often amplified from formalin-fixed tissues compared to FFPE tissues (15/39 versus 1/39; p <0.0001). The sensitivity of qPCR on FFPE samples and formalin-fixed samples, when comparing to fresh frozen samples as the reference standard, was 4.5% and 11.8%, respectively. CONCLUSION: Due to decreased DNA amplification efficiency, FFPE scrolls should not be used for the detection of Bartonella infection in spleen samples from dogs with HSA. PCR testing of fresh frozen tissues substantially improves the detection of Bartonella spp. infection. If fresh frozen tissues are not available, formalin-fixed tissues should be tested with digital PCR to enhance Bartonella DNA detection.

  PublisherDOI

• Development and validation of enzyme-linked immunosorbent assays for the serodiagnosis of canine bartonelloses

  Journal of Clinical Microbiology · 2025-11-26 · 1 citations

  articleOpen accessSenior author

  ABSTRACT Bartonella species, emerging vector-borne pathogens of dogs, are increasingly associated with severe, chronic sequelae, as well as potentially life-threatening diseases, such as endocarditis and myocarditis. Diagnosis of bartonelloses is mainly based on PCR, culture, and serological assays. Despite molecular and biotechnological advances, serological assays employing immunofluorescence antibody (IFA), Western blotting, and enzyme-linked immunosorbent assay (ELISA) technologies have encountered diagnostic limitations, primarily due to poor sensitivity. Using sera from Bartonella -infected and naïve dogs, we applied an immunoproteomic approach to develop a reliable ELISA assay for the diagnosis of bartonelloses in dogs. Five recombinant Bartonella henselae immunodominant proteins (rATP-β, rGroEL, rLemA, rSucB, and rVirB5) were tested in an ELISA format. Sensitivity and specificity of each protein were calculated based on an imperfect reference IFA assay. Dogs comprised Group I: 36 Bartonella spp. naturally infected dogs (all B. henselae IFA seroreactive) and Group II: 34 Bartonella spp. PCR-negative and IFA-negative dogs. Based upon the ELISA seroreactivity results, rATP-β and rGroEL represented the most sensitive and specific candidate peptide targets for utilization in a canine diagnostic ELISA assay. rGroEL resulted in the sensitivity of 83% and specificity of 94% at an optical density (OD) cutoff value of 0.439 and area under curve (AUC) score of 0.93 (95% CI 0.87–0.99), while the sensitivity and specificity of rATP-β were 69% and 94%, respectively, at a cutoff value of 0.565. The combination of rATP-β with rGroEL resulted in an improved sensitivity of 88% and specificity of 92% at an OD cutoff value of 0.505. A receiver operating characteristic curve analysis for the rATP-β plus rGroEL yielded an AUC score of 0.899 (95% CI 0.809–0.989). Combining rATP-β with rGroEL could potentially further improve both the diagnostic sensitivity and specificity of an ELISA assay for the diagnosis of canine bartonelloses. IMPORTANCE Bartonella species are associated with a wide spectrum of clinical signs and life-threatening diseases in dogs. There is an increased risk of Bartonella transmission from dogs to dogs, and from dogs to other animals and humans via vectors, such as ticks, fleas, or direct contact with infected clinical specimens. Due to the poor sensitivity of currently available molecular and serological assays, the diagnosis, treatment, and prevention of Bartonella infection in dogs remains challenging. Developing a reliable serodiagnostic assay is essential for the clinical management of canine bartonelloses, a group of infections caused by Bartonella species in dogs. Rapid diagnosis and timely treatment of canine bartonelloses could save the lives of thousands of dogs worldwide each year. This study provides key insights into the design of diagnostic tools utilizing Bartonella henselae proteins that show promise as serological markers to improve the diagnosis of canine bartonelloses.

  PublisherDOI

• Detection of <i>Dirofilaria repens</i> and <i>Mansonella llewellyni</i> in the United States by <i>Wolbachia</i> Surveillance

  Transboundary and Emerging Diseases · 2025-01-01

  articleOpen accessSenior authorCorresponding

  In mammals, detection of Wolbachia bacteria can be used to diagnose filarial infection, while antibiotic treatment to eliminate Wolbachia can assist in eliminating filarial infections. Because Wolbachia are necessary for survival of several filarioids and closely related to Anaplasma and Ehrlichia , we analyzed Wolbachia DNA amplification by Anaplasma/Ehrlichia qPCR, from 39,526 domestic and wildlife animal blood samples submitted to a diagnostic laboratory between 2017 and 2023. Filarial infection was confirmed by 28S gene amplification, followed by phylogenetic analysis utilizing filarial cytochrome oxidase subunit 1 ( cox1 ), myosin heavy chain ( myoHC ), and 70 kilodalton heat shock protein ( hsp70 ) gene sequencing. Wolbachia DNA was detected in 57 domestic dogs ( Canis familiaris ) and three raccoons ( Procyon lotor ) from 23 states and Puerto Rico. A majority of the Wolbachia sequences from dogs were Dirofilaria immitis ‐associated (89%, 51/57), whereas DNA from other Wolbachia were associated with insects (9%, 5/57) or Dirofilaria repens (2%, 1/57). D. immitis infection was confirmed by 28S filarial PCR for all samples with D. immitis ‐associated Wolbachia available for testing ( n = 41). D. repens infection was confirmed by 28S and cox1 PCR in the dog infected with D. repens ‐associated Wolbachia . This dog was originally imported from Slovakia. The Wolbachia DNA amplified from raccoons most closely aligned with Wolbachia from Mansonella ozzardi (98.9%). 28S filarial, cox1 , myoHC , and hsp70 sequencing did not align with currently available GenBank sequences but did align with Mansonella . Morphologically, microfilariae from additional raccoons were consistent with Mansonella llewellyni . Molecular surveillance for Wolbachia in wildlife and domestic animals has the potential to identify novel filarial species in the United States, including zoonotic species.

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Frequent coauthors

• Ricardo G. Maggi

  North Carolina State University

  187 shared

• Barbara C. Hegarty

  North Carolina State University

  115 shared

• Melissa J. Beall

  IDEXX Laboratories (United States)

  72 shared

• Ramaswamy Chandrashekar

  IDEXX Laboratories (United States)

  69 shared

• Michael R. Lappin

  65 shared

• Michael G. Levy

  61 shared

• Matthew D. Eberts

  IDEXX Laboratories (United States)

  45 shared

• Barbara A. Qurollo

  North Carolina State University

  44 shared

Education

• Ph.D., Pathology

  North Carolina State University

  1990

• M.S., Pathology

  North Carolina State University

  1985

• B.S., Animal Science

  University of California, Davis

  1983

Awards & honors

• North Carolina State University Alumni Association Outstandi…
• Holladay Medal, the highest award bestowed on a faculty memb…