Strain Dynamics in a Raccoon () Population in Southern Ontario, Canada: High Prevalence and Rapid Subtype Turnover.

Free-ranging wildlife are increasingly recognized as potential reservoirs of disease-causing species such as and . Raccoons (), which live at the interface of rural, urban, and more natural environments, are ideal subjects for exploring the potential role that wildlife play in the epidemiology of campylobacteriosis. We studied the prevalence and genetic diversity of from live-captured raccoons on five swine farms and five conservation areas in southwest Ontario. From 2011 to 2013, we collected fecal swabs ( = 1,096) from raccoons, and ( = 50) manure pit samples from the swine farm environment. We subtyped the resulting isolates ( = 581) using Comparative Genomic Fingerprinting (CGF) and 114 distinct subtypes were observed, including 96 and 18 subtypes among raccoon and manure pit isolates, respectively. prevalence in raccoons was 46.3%, with 98.7% of isolates recovered identified as . Novel raccoon-specific CGF subtypes ( = 40/96) accounted for 24.6% ( = 143/581) of isolates collected in this study. Our results also show that is readily acquired and lost in this wild raccoon population and that a high prevalence is observed despite transient carriage typically lasting 30 days or fewer. Moreover, although raccoons appeared to be colonized by species-adapted subtypes, they also harbored agriculture-associated genotypes that accounted for the majority of isolates observed (66.4%) and that are strongly associated with human infections. This suggests that raccoons may act as vectors in the transmission of clinically-relevant subtypes at the interface of rural, urban, and more natural environments.