Antimicrobial resistance in generic Escherichia coli isolates from wild small mammals living in swine farm, residential, landfill, and natural environments in southern Ontario, Canada.
To assess the impacts of different types of human activity on the development of resistant bacteria in the feces of wild small mammals, we compared the prevalences and patterns of antimicrobial resistance and resistance genes in generic Escherichia coli and Salmonella enterica isolates from fecal samples collected from wild small mammals living in four environments: swine farms, residential areas, landfills, and natural habitats. Resistance to antimicrobials was observed in E. coli isolates from animals in all environments: 25/52 (48%) animals trapped at swine farms, 6/69 (9%) animals trapped in residential areas, 3/20 (15%) animals trapped at landfills, and 1/22 (5%) animals trapped in natural habitats. Animals trapped on farms were significantly more likely to carry E. coli isolates with resistance to tetracycline, ampicillin, sulfisoxazole, and streptomycin than animals trapped in residential areas. The resistance genes sul2, aadA, and tet(A) were significantly more likely to be detected in E. coli isolates from animals trapped on farms than from those trapped in residential areas. Three S. enterica serotypes (Give, Typhimurium, and Newport) were recovered from the feces of 4/302 (1%) wild small mammals. All Salmonella isolates were pansusceptible. Our results show that swine farm origin is significantly associated with the presence of resistant bacteria and resistance genes in wild small mammals in southern Ontario, Canada. However, resistant fecal bacteria were found in small mammals living in all environments studied, indicating that environmental exposure to antimicrobials, antimicrobial residues, resistant bacteria, or resistance genes is widespread.
Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada. cjardi01@uoguelph.ca.
Samantha E
SE
Allen
Patrick
P
Boerlin
Nicol
N
Janecko
John S
JS
Lumsden
Ian K
IK
Barker
David L
DL
Pearl
Richard J
RJ
Reid-Smith
Claire
C
Jardine
D000822:Animal Husbandry; D000818:Animals; D000835:Animals, Wild / Q000382:microbiology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003247:Conservation of Natural Resources; D024881:Drug Resistance, Bacterial; D017753:Ecosystem; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D051379:Mice; D008826:Microbial Sensitivity Tests; D009115:Muridae / Q000382:microbiology*; D009864:Ontario / Q000453:epidemiology; D015995:Prevalence; D012376:Rodent Diseases / Q000453:epidemiology / Q000382:microbiology; D012788:Shrews / Q000382:microbiology*; D013552:Swine; D014197:Trees
D000900:Anti-Bacterial Agents