#15-070

Progress

Date Full Report Received

10/04/2017

Date Abstract Report Received

10/04/2017

Investigation

Institution:
Primary Investigator:

The goal of our project was to determine if there are important changes in the prevalence of Salmonella serotypes in swine. This is important because if the serotypes remain unchanged on 20 years, then we know that there are no changes required in our currently effective Salmonella control approaches. However, new serotypes are emerging or patterns are shifting, this might signal a change in the ecology of Salmonella and we would need to determine if the controls we are remain effectives. The pork industry does currently do not have evidence that Salmonella control programs need to be serotypes specific, however it is important to be proactive and understand which pathogens are circulating in swine populations and found of pork products.

We used 4 longitudinal datasets which looked at Salmonella from 1996 to 2014. We observed decreasing proportions of S. enterica serovar Typhimurium, serovar Derby, and serovar Heidelberg and increasing proportions of S. enterica serovar 4,[5],12:i:-, serovar Infantis, and serovar Johannesburg in swine. We also observed positive correlations for the yearly changes in S. enterica serovar 4,[5],12:i:-, serovar Anatum, and serovar Johannesburg between swine and human data; in S. enterica Worthington between avian and human data; and in S. enterica serovar 4,[5],12:i:- between bovine and human data were observed
These data suggested that some serovars are emerging while others are decreasing. In particular, serovar 4,[5],12:i:- is found commonly in swine submitted to diagnostic laboratories in the past 5 years. As this organism has been associated with large outbreaks of disease, this is an important finding. These data also suggested that veterinary diagnostic laboratory data are potentially timely for detecting changes in serotypes and that serovar 4,[5],12:i:- is common in swine submitted to VDLs.

Contact information: Annette O’Connor oconnor@iastate.edu