CHARACTERIZATION AND EPIDEMIOLOGY OF HELICOBACTER INFECTION IN
ZOO ANIMALS
Carmel L. Witte, MS,1* Mark D. Schrenzel,1 DVM, PhD, Dipl. ACVP,1 Justin Bahl PhD,2
Tammy A. Tucker, 1 Niora Fabian MS, 1 Heidi Greger DVM, 1 Chrissie Hollis DVM, 1 Gary
Hsia DVM, 1 Erin Siltamaki DVM, 1 and Bruce A. Rideout DVM, PhD, Dipl. ACVP.1
1Wildlife
Disease Laboratories, San Diego Zoo's Institute for Conservation Research,
Escondido, CA 92027 USA;2 Department of Microbiology, State Key Laboratory of Emerging
Infectious Diseases, Li Ka Shing Faculty of Medicine, The University of Hong Kong,
Pokfulam, Hong Kong SAR, China
Abstract
Helicobacter species have exceptional genetic and phenotypic adaptability which has rendered
them widely successful and allowed for rapid changes in host-bacterium dynamics.1 It is now
recognized that helicobacters are a significant cause of morbidity and mortality in humans and
numerous animal taxa, producing local lesions (gastrointestinal inflammation, ulceration, and
cancer) and systemic disease in some animals and having either no discernible effects or
beneficial influences in others.3 Yet, little is known about their ecology on a broad scale,
including levels of host switching and factors related to disease expression. In this study, we
conducted a cross-sectional fecal survey of 261 individuals and groups of primates and
carnivores to determine helicobacter status and identify phylogenetic strains. PCR and DNA
sequencing analyses were performed and univariate odds ratios were calculated to correlate
broad health characteristics with helicobacter status, presence of multi-infection, and sharedgenotypes. Eighty-one percent (64/79) of species and 63% (138/220) of all surveyed individuals
(70% of primates; 55% of carnivores) were positive for helicobacter infection with 79 distinct
genotypes identified. Presences of multi-infection or infections with shared genotypes were
corroborative with host-switching and were associated with mild clinical signs and management
characteristics. Epidemiologic analyses provided insight into the dynamics of helicobacter
infections in a zoological setting and were valuable for advancing awareness of anthropogenic
effects on infection in animals.2
ACKNOWLEDGMENTS
The authors would like to thank the Ellen Browning Scripps Foundation and Shirley Sikes for funding this study,
and the staffs of the Wildlife Disease Laboratories, Veterinary Services Department, Nutrition department and
Mammal Departments from the San Diego Zoo for assistance with sample collection and processing.
LITERATURE CITED
1. Haesebrouck F, Pasmans F, Flahou B, Chiers K, Baele M, Meyns T, Decostere A,
Ducatelle R. Gastric helicobacters in domestic animals and nonhuman primates and their
significance for human health. Clin Microbiol Rev 2009;22:202–23.
2. Schrenzel, M.D., C.L. Witte, J. Bahl, T.A. Tucker, N. Fabian, H. Gregor, C. Hollis, G.
Hsia, E. Siltamaki, and B.A. Rideout. 2010. Genetic Characterization and Epidemiology of
Helicobacters in Non-domestic Animals. Helicobacter 15:126-142.
3. Solnick JV, Schauer DB. Emergence of diverse Helicobacter species in the pathogenesis
of gastric and enterohepati diseases. Clin Microbiol Rev 2001;14:59–97.