STAR PROJECT LEADS TO DISCOVERY OF BARTONELLA INFECTION IN COYOTE HEART VALVES
Bartonella are blood-borne bacteria infecting a wide variety of domestic and wild animal
species. One species, Bartonella vinsonii subsp. berkhoffii (B. v. berkhoffii), is known to cause
severe cardiac disease by destroying the cardiac valves (endocarditis) in domestic dogs and
humans. Coyotes are the main reservoir for B. v. berkhoffii, but it was not known if infected
coyotes developed endocarditis like their domestic counterparts. Therefore, Spencer Kehoe
(DVM Class 2015) and his STAR mentor Dr. Bruno Chomel (Department of Population Health
and Reproduction) hypothesized that coyotes serve as a naturally-occurring epidemiological and
physiological sentinel models to study infection kinetics and pathology caused by this bacterium
in reservoir (coyotes) and accidental hosts (humans/ dogs).
The investigation involved dissecting 70 coyote hearts and examining the cardiac valves to look
for endocarditis lesions. In addition, several molecular techniques (DNA extraction, PCR, PCRRFLP, DNA partial sequencing, species subtyping) were used to investigate the presence of
Bartonella in the aortic and mitral heart valves, to prove the bacteria had infected the valvular
tissues. The results of the study revealed that 21% of coyotes tested positive for Bartonella in
their blood and heart tissues, and 17% of coyotes had Bartonella specifically infecting the heart
valves. This is the first study that highlights the overall burden of heart valve infection due to
zoonotic Bartonella species in a natural reservoir host, and extrapolation of these observations to
dogs or humans, suggests a high frequency of cardiac valve colonization in people and animals
infected with Bartonella. Additionally, Bartonella henselae and B. v. berkhoffii genotype III
were identified for the first time in coyotes, adding them to the list of mammals susceptible to
these Bartonella species.
The study was accepted for publication August 18 in the CDC Journal Emerging Infectious
Diseases, a top-ranked journal in Epidemiology.
Authors and Title:
"Molecular identification of zoonotic Bartonella species in aortic and mitral valves of
healthy coyotes"
Kehoe SP1, Chomel BB1*, Stuckey MJ1, Kasten RW1, Balakrishnan N2, Sacks BN1,
Breitschwerdt EB2.
1. Department of Population Health and Reproduction, School of Veterinary Medicine, University
of California, Davis, USA
2.
Intracellular Pathogens Research Laboratory, Center for Comparative Medicine and
Translational Research, College of Veterinary Medicine, North Carolina State University,
Raleigh, NC, USA
Corresponding author: Bruno B. Chomel, DVM, PhD
Department of Population Health and Reproduction,
School of Veterinary Medicine, VM3B, 1089 Veterinary Medicine Drive,
University of California, Davis,
Davis, 95616, USA
E-mail: bbchomel@ucdavis.edu
Tel.: 530-752-8112 Fax.: 530-752-2377