Waterfowl and the introduction of foodborne pathogens to agricultural environments in Southern Ontario

Canada geese (Branta canadensis) have quickly become one of the most common waterfowl species in North America. Over the past few decades, Southern Ontario has experienced a population explosion which can primarily be... [ view full abstract ]

Canada geese (Branta canadensis) have quickly become one of the most common waterfowl species in North America. Over the past few decades, Southern Ontario has experienced a population explosion which can primarily be attributed to landscape changes resulting in the establishment of ideal breeding habitat. There are concerns that Canada geese, being highly mobile, may transmit pathogens between agricultural and recreational areas. To determine whether geese pose a potential biosecurity risk to farms in Southern Ontario, a cross-sectional study was performed to measure the carriage of antimicrobial-resistant E. coli, Salmonella, and Campylobacter isolates obtained from goose fecal samples. A total of 418 samples were obtained from three different sources: hunter-caught birds, diagnostic specimens submitted to the Canadian Wildlife Health Cooperative, and fresh fecal samples. E. coli isolates were tested for susceptibility to 15 antimicrobials using the Canadian Integrated Program for Antimicrobial Resistance Surveillance panel. The following risk factors for prevalence of pathogens and associated antimicrobial resistance were examined: season, year, geographic location, source-type, and bird demographics. The overall prevalence of Campylobacter, Salmonella, and E. coli were 11.8%, 0%, and 71.4%, respectively. No significant difference in prevalence of Campylobacter by season or source-type was found based on exact logistic regression (p>0.05). Season and source-type had a significant effect on the odds of recovering E. coli from a sample (p<0.001). Of the 299 E. coli isolates, 8.0% had reduced susceptibility to one or more antimicrobials, and 5.7% were multi-drug resistant. Nineteen unique E. coli resistance patterns were identified with some including resistance to antimicrobials of highest importance in human medicine. Isolating Campylobacter and antimicrobial-resistant E. coli from Canada Geese suggests that these birds may play a role in disseminating these pathogens within the environment, and pose a threat to agricultural biosecurity and public health.