|HENZLER, DAVID - PENNSYLVANIA DEPARTMENT OF AGRICULTURE|
|RAMADAN, HAZEM - MANSOURA UNIVERSITY|
|DAVISON, SHERRILL - PENNSYLVANIA DEPARTMENT OF AGRICULTURE|
|ALLARD, MARC - FOOD AND DRUG ADMINISTRATION(FDA)|
Submitted to: Journal of Food Safety
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/3/2018
Publication Date: 3/30/2018
Citation: Guard, J.Y., Henzler, D.J., Ramadan, H., Jones, D.R., Gast, R.K., Davison, S., Allard, M.W. 2018. Serotyping of Salmonella enterica isolated from mice caught on US poultry farms 1995 through 1998. Journal of Food Safety. 6:44-50.
Interpretive Summary: Understanding how serotype Enteritidis become one out of 2500 Salmonella enterica to increase in incidence to become the world’s leading cause of salmonellosis associated with poultry and eggs is a topic of great importance for increasing the safety of the food supply. In this retrospective study, mice caught live on-farms were used to obtain a normally sterile organ, the spleen, as paired with an anatomical site harboring a multitude of organisms, namely the intestines. Culturing for Salmonella indicated that the 1st and 2nd highest incidence serotypes associated with food borne disease, serotypes Enteritidis and Typhimurium, were efficient at surviving in both spleens and intestines. Serotypes Heidelberg and Schwarzengrund were much easier to recover from either intestines or spleens, respectively. Mice appear to be a primary vector of risk for spreading disease causing Salmonella serotypes on poultry farms.
Technical Abstract: A collection of Salmonella enterica subspecies I isolates obtained from mice caught on 32 poultry farms in the Northeast US between 1995 to 1998 was assessed for serotype distribution to provide reference material for whole genome analysis. Spleens and intestines were cultured. Of 821 mice cultured, 157 were positive (19.1%). Total samples isolated after culturing 5 colonies per positive sample were 164, because 2 serotypes were obtained from 7 mice. Nine serotypes were detected, 8 of which have been associated with foodborne illness. The three most prevalent serotypes were Enteritidis (genovars 2994G and 2850), Heidelberg (genovar 15835), and Typhimurium (genovars 10909 and 2717), which together accounted for 84.8% of the 164 isolates. Both Enteritidis and Typhimurium were obtained similarly from spleens and intestines, whereas Heidelberg was isolated most often from intestines and Schwarzengrund most often from spleens. Serotypes Enteritidis and Typhimurium were the only serotypes isolated from both spleens and intestines within the same mouse. Analysis of the adenylate cyclase gene of serotype Schwarzengrund was required to differentiate it from serotype Bredeney. These results confirm that the house mouse Mus musculus was an important risk factor for egg contamination by serotype Enteritidis in the Northeast United States as well as other foodborne serotypes.