Risk of Urban Zoonosis from Geese Colonized with Antimicrobial Resistant Bacteria

Abstract

Abstract Introduction/Objective Zoonotic disease occurs through direct fecal contact with increased exposure resulting in higher infection rates. Antimicrobial resistant colonization occurs in wild birds, however the spread of microbial resistance correlates with increased human activity. Anchorage actively develops urban park environments with pastoral lawns and abundant water sources creating an inviting habitat for human and geese populations. By 2018, Alaska Fish and Game reported a 10-fold increase in migrating Canadian Geese resulting in significant environmental damage, including fecal contamination. At the same time, Anchorage experienced an uptake use of their parks and costal trails for both recreation and homeless camps. To determine potential exposure, sixty-eight geese fecal samples were collected in fourteen urban park locations. Methods Fecal samples were incubated in thioglycolate broth at 37oC for 24 hours then cultured to chromogenic screening agar for vancomycin resistant enterococcus (VRE), methicillin resistant Staphylococcus aureus (MRSA), and extended spectrum beta-lactamase (ESBL) enterobacteriaceae. Potential MRSA, VRE or ESBL colonies were further identified using standard biochemical testing with confirmation of antimicrobial resistance by disk diffusion. Results Forty percent of all fecal samples collected were colonized with VRE or ESBL producing Escherichia coli with eighty-six percent of collection sites positive for one or more antimicrobial resistant bacterium. Seven percent of fecal samples were positive for both organisms. MRSA was not identified. The highest concentration of antimicrobial resistant bacteria was discovered on the Campbell Creek Trail (83%), which winds alongside Providence Hospital. Conclusion Transmission of infectious agents can occur due to environmental exposure, which increases in individuals who are either housing insecure or chronically homeless. Urban green spaces are often sites for unregulated camping by individuals who lack consistent residential housing. Discovery of antimicrobial resistant colonization in geese populating nearly ninety percent of Anchorage’s parks and trails creates a significant public health issue, with the homeless population targeted for poor outcome due to their immunocompromised status. Continued evaluation is essential to predict infection risk and impact on healthcare delivery, especially in vulnerable populations.