Prevalence of Campylobacter in Wild Bird Populations

Keller, Judith Ina
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University of Delaware
Campylobacter bacteria have had a significant impact on human health, being responsible for the majority of food borne illnesses and gastroenteritis worldwide. Especially within poultry such as chickens and turkeys, Campylobacter infections have played a large role in causing infection within human populations due to the consumption of undercooked meat. Wild birds have been thought to factor into the epidemiology of this bacterium, although few studies have estimated the prevalence of Campylobacter species within wild birds of the United States. This study evaluated the overall occurrence of three Campylobacter species – C. jejuni, C. coli, and C. lari – from 333 out of 914 wild bird fecal samples collected at Tri-State Bird Rescue and Research in Newark, Delaware. Samples were plated on Campylobacter selective agar, confirmed by catalase and oxidase tests and examined under a light microscope, followed by multiplex-PCR and Multi-locus sequencing typing PCR to identify Campylobacter species. Prevalence rates of Campylobacter from nine avian families averaged 7.5% overall with rates ranging widely between different families. Crows (Corvus brachyrhynchos and Corvus ossifragus) had the highest prevalence, followed by laughing gulls (Larus atricilla) and blue jays (Cyanocitta cristata) with considering only groups of species where sample size was at least greater than 7 individuals. All positive samples were Campylobacter jejuni. It remains somewhat unknown as to why certain species are more prone to carrying the bacterium than others, although feeding habits and ecological niches occupied by individual species are sure to play a role. With possible implications of wild birds transmitting the bacterium to other avian species such as chickens and other poultry or even directly to humans, this study provided valuable baseline values of the occurrence of the bacterium within selected wild bird populations.