Epidemiology of Salmonella on the Paws and in the Faeces of Free‐Ranging Raccoons (Procyon Lotor) in Southern Ontario, Canada

Abstract

Raccoons are common in urban and rural environments and can carry a wide range of bacteria, including Salmonella, that can negatively affect human and livestock health. Although previous studies have reported that raccoons shed a variety of Salmonella serovars in their faeces, it is unknown whether Salmonella is carried on raccoon paws. Our objective was to compare the prevalence of Salmonella on the paws and in the faeces of raccoons in south-western Ontario. Raccoons were sampled in a repeat cross-sectional study on five swine farms and five conservation areas from May to October 2012. A total of 416 paired faecal and paw samples were collected from 285 individual raccoons. Salmonella was detected in 18% (75/416; 95% CI, 14-22%) and 27% (111/416; 95% CI, 22-31%) of paw and faecal samples, respectively. Salmonella was detected only on paws in 8% (35/416; 95% CI, 5.9-11.5%), only in faeces in 17% (71/416; 95% CI, 13.6-21.0%) and on both paws and in faeces in 10% (40/416; 95% CI, 7.0-12.9%) of raccoon captures. Multilevel logistic regression models were used to examine associations between the presence of Salmonella and age (adult, juvenile), sex (male, female), location type (swine farm, conservation area), sample type (faeces, paw) and season (May-July and August-October). Random intercepts were included to account for clustering by individual animal and location. Significant differences, that varied by sample type and season, were noted in the prevalence of Salmonella carriage between sexes. Raccoons can carry Salmonella serovars known to infect humans and livestock on their paws and/or in their faeces and therefore have the potential to mechanically and biologically disseminate Salmonella among livestock facilities and human recreational areas.

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

“…Raccoons were live-trapped and processed as described previously [33]. Briefly, at each site 20 – 40 Tomahawk live traps (Tomahawk Live Trap Co. Tomahawk, Wisconsin, USA) were set 3–4 nights/trapping week at each site in areas with limited public access, but where raccoons were known to be present, including around dumpsters and buildings.…”

“…Sex, age class (adult or juvenile, on the basis of animal size and teeth wear/staining), and body mass were recorded for each animal. Fecal swabs were collected per rectum using Cary-Blair applicators (BBL CultureSwab, BD; Becton, Dickinson and Company, Annapolis, Maryland, USA) and in 2012, paw samples were also collected using a Swiffer ® (Armstrong, Proctor and Gamble, Cincinnati, Ohio, USA) soaked in 25 ml of sterile saline as previously described [33]. Although individuals were only sampled once per trapping week, multiple samples were collected from the same individual if they were caught in subsequent trapping sessions.…”

“…Many AMR studies have focused on mice and voles with small home ranges [9, 10, 13], but migratory birds [31] or wild mammals with larger home-ranges, such as raccoons, may be more involved in the widespread dissemination of antimicrobial resistant bacteria [32], and be better indicators of resistant bacteria present in the environment at the landscape level. Raccoons may also have the potential to mechanically transmit resistant bacteria on their paws [33]. Similarly, antimicrobial resistant bacteria also have been detected on the foot pads [34] and from external wash samples [35] of wild birds.…”

Salmonellosis detection and evidence of antibiotic resistance in an urban raccoon population in a highly populated area, Costa Rica

“…Although they are still classified below the high priority group, the increase in quinolone resistance within this group is of serious concern. While wild animals can both harbour and spread resistance genes, they can also serve as sentinels for environmental AMR (Bondo et al, a; Duncan et al, ; Jobbins & Alexander, ; Loncaric et al, ).…”

“…The close proximity of humans and raccoons can potentially increase the exchange of pathogens and resistance genes within urban landscapes. This presents a serious public health concern that must be considered and addressed (Bondo et al, a; Bradley & Altizer, ; Conover, ). Even more so in Costa Rica, Salmonella epidemiology is limited to reported clinical cases in hospitals (INCIENSA, ).…”