Epidemiology of Antimicrobial Resistance in Escherichia coli Isolates from Raccoons (Procyon lotor) and the Environment on Swine Farms and Conservation Areas in Southern Ontario

Abstract

Antimicrobial resistance is a global threat to livestock, human and environmental health. Although resistant bacteria have been detected in wildlife, their role in the epidemiology of antimicrobial resistance is not clear. Our objective was to investigate demographic, temporal and climatic factors associated with carriage of antimicrobial resistant Escherichia coli in raccoons and the environment. We collected samples from raccoon paws and feces and from soil, manure pit and dumpsters on five swine farms and five conservation areas in Ontario, Canada once every five weeks from May to November, 2011–2013 and tested them for E. coli and susceptibility to 15 antimicrobials. Of samples testing positive for E. coli, resistance to ≥ 1 antimicrobials was detected in 7.4% (77/1044; 95% CI, 5.9–9.1) of raccoon fecal samples, 6.3% (23/365; 95% CI, 4.0–9.3) of paw samples, 9.6% (121/1260; 8.0–11.4) of soil samples, 57.4% (31/54; 95% CI, 43.2–70.8) of manure pit samples, and 13.8% (4/29; 95% CI, 3.9–31.7) of dumpster samples. Using univariable logistic regression, there was no significant difference in the occurrence of resistant E. coli in raccoon feces on conservation areas versus farms; however, E. coli isolates resistant to ≥ 1 antimicrobials were significantly less likely to be detected from raccoon paw samples on swine farms than conservation areas and significantly more likely to be detected in soil samples from swine farms than conservation areas. Resistant phenotypes and genotypes that were absent from the swine farm environment were detected in raccoons from conservation areas, suggesting that conservation areas and swine farms may have different exposures to resistant bacteria. However, the similar resistance patterns and genes in E. coli from raccoon fecal and environmental samples from the same location types suggest that resistant bacteria may be exchanged between raccoons and their environment.

Salmonella, Campylobacter, Clostridium difficile, and anti‐microbial resistant Escherichia coli in the faeces of sympatric meso‐mammals in southern Ontario, Canada

“…No individual skunks or opossums were caught more than twice within the duration of the study, and no animals were captured on more than one site except for one individual male skunk, which was caught on two different swine farms in two consecutive months. The results pertaining to the prevalence and epidemiology of Salmonella , C. difficile , and anti‐microbial resistant E. coli in raccoon faecal swabs and the environment are reported elsewhere (Bondo et al; Bondo, Weese et al, ).…”

“…The methods used for Salmonella , E. coli , Campylobacter spp., and C. difficile isolation and typing have been described previously (Bondo et al,; Bondo, Weese et al, ; Jardine, Reid‐Smith, Janecko, Allan, & McEwen, ; Jokinen et al, ). For C. difficile , one isolate from each sample was characterized by PCR detection of tcdA , tcdB and cdtA/cdtB and PCR ribotyping.…”

“…The methods used for anti‐microbial susceptibility testing of E. coli and Salmonella isolates have been described previously (Bondo et al). Briefly, the National Anti‐microbial Monitoring System (NARMS) CMV2AGNF Sensititre microbroth dilution panel was used for anti‐microbial resistance testing of E. coli and Salmonella isolates.…”

“…Raccoon data for the statistical analyses were taken from Bondo et al (), Bondo et al () and Bondo, Weese et al (). Univariable exact logistic regression was used to model each bacterial species ( Salmonella , Campylobacter spp., C. difficile , or E. coli with resistance to ≥1 anti‐microbial) separately as a binary outcome (positive or negative) with animal species (skunk, opossum, or raccoon) as an explanatory variable.…”

“…These included striped skunks ( Mephitis mephitis ) and Virginia opossums, which share many of the same habitats and food sources with raccoons (Azevedo et al, ; Kasparian, Hellgren, & Ginger, ). The results pertaining to the prevalence and epidemiology of Salmonella , C. difficile , and anti‐microbial resistant E. coli in raccoon faeces and the environment are described elsewhere (Bondo et al, ; Bondo, Weese, Rouseau, & Jardine, ).…”