Investigation of the Prevalence and Spatial Distribution of Salmonella enterica Infections in the Pennsylvania Common Raccoon (procyon lotor)

Open Access
Author:
Very, Katherine Joanne
Graduate Program:
Pathobiology
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
None
Committee Members:
  • Bhushan M Jayarao, Thesis Advisor
  • Subhashinie Kariyawasam, Thesis Advisor
Keywords:
  • Raccoon
  • Salmonella
  • Pennsylvania
Abstract:
Salmonella has been shown to have a niche in human, domestic food animal, and pet populations. A less studied niche of the organism is in wildlife populations. This study was conducted to determine the prevalence and spatial distribution of Salmonella enterica infection in the Pennsylvania raccoon (Procyon lotor), a common wildlife mammal known to have overlapping habitats with human and domestic food animal species. In this study, a total of 371 raccoon intestinal samples were obtained by the Pennsylvania Game Commission from trapped and road killed raccoons between May and November 2011 and tested for Salmonella infection. Salmonella was isolated from 57 raccoons (15.4%) in 36 counties (55%) across Pennsylvania. The five most commonly isolated serovars were S. Newport (22.8%), S. Enteritidis (15.8%), S. Bareilly (8.8%), S. Braenderup (8.8%), and S. Typhimurium (8.8%). Pulsed Field Gel Electrophoresis (PFGE) analysis of the Salmonella isolates and subsequent comparison to the Pennsylvania Department of Health human Salmonella PFGE database revealed 34 unique PFGE pulsotypes in raccoons, of which 33 raccoon samples matched 16 previously identified human Salmonella pulsotypes . When investigated further, it was found that seven of these samples had a direct match to 56 human reported cases of salmonellosis by month and region location. The findings of this study show that several PFGE pulsotypes of Salmonella serotypes were observed to be shared between humans and raccoons in Pennsylvania indicating raccoons as a potential reservoir for Salmonella.