Implications of Foraging and Interspecies Interactions of Birds for Carriage of Escherichia coli Strains Resistant to Critically Important Antimicrobials
Shewli Mukerji, Samantha Gunasekera, J. N. Dunlop, Marc Stegger, David Jordan, Tanya Laird, Rebecca Abraham, Mary Barton, Mark O’Dea, Sam Abraham
Abstract
It has been shown that 20% of Australian silver gulls carry drug-resistant Escherichia coli strains of anthropogenic origin associated with severe diseases, such as sepsis and urinary tract infections, in humans. To further characterize the dynamics of drug-resistant E. coli in wildlife populations, we investigated the carriage of critically important antimicrobial (CIA) drug-resistant E. coli in four bird species in a common environment. Our results indicated that gulls, pigeons, and penguins carried drug-resistant E. coli strains, and analysis of mobile genetic elements associated with resistance genes indicated interspecies resistance transfer. Terns, representing a bird species that forages on natural food sources at sea and distant from humans, did not test positive for drug-resistant E. coli . This study demonstrates carriage of CIA-resistant bacteria in multiple bird species living in areas commonly inhabited by humans and provides further evidence for a leapfrog effect of resistance in wildlife, facilitated by feeding habits.