ARS | Publication request: Genotypic and Phenotypic Characterization of Enteric Bacteria in An Integrated Population of Swine and Humans

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 30, 2005
Publication Date: September 6, 2005
Citation: Harvey, R.B., Scott, H.M., Poole, T.L., Hume, M.E., Highfield, L.D., Alali, W.Q., Anderson, R.C., Nisbet, D.J. 2005. Genotypic and phenotypic characterization of enteric bacteria in an integrated population of swine and humans. Proceedings of SafePork 2005. p. 234-237.

Interpretive Summary: Antibiotic resistance (AR) has become a major problem for human and veterinary medicine. We need to know more about how it occurs and if it is associated with antibiotic usage in animal production. In this study, we showed that although bacteria from swine had greater AR than humans, there was no apparent transfer of AR from swine to swine workers. This is important because it shows that AR can come from multiple sources and not just animal production.

Technical Abstract: In two longitudinal studies, we examined the transmission dynamics of antimicrobial resistance (AMR) in an integrated, semi-closed population of humans and swine. A total of 1594 human and 1508 swine Escherichia coli (EC) and Enterococcus faecalis (EF) isolated from human wastewater and swine fecal samples were tested for antimicrobial susceptibility, for the presence of Class I integrons and gene cassettes that encode for AMR, and for the prevalence of vancomycin-resistant Enterococcus faecium (VRE). We showed that swine EC and EF had a higher prevalence of AMR than human isolates and that both swine and human EC had a low prevalence of Class I integrons. We isolated a total of 50 VRE from human wastewater samples and no VRE from swine samples. We concluded there was no apparent transfer of AMR from swine to human or vice versa, and that VRE may be more prevalent in the environment than previously thought.