A salmonellosis outbreak occurred at a California prison in April and May 2016. In a cohort study of 371 inmates, persons who consumed dishes from the prison kitchen made from ground meat had a higher attack rate (15%) than those who did not (4%) (risk ratio 3.4, 95% CI 1.1–10.6). The ground meat product was composed exclusively of beef, mechanically separated chicken (MSC) and textured vegetable protein; eight of eight lots of the product collected from the prison and processing facility were contaminated with Salmonella enterica of eight serotypes and 17 distinct PFGE patterns, including multidrug-resistant Salmonella Infantis. Either the MSC or the beef could have been the source of the particular strains of S. enterica isolated from patients or the product. The microbiological evidence is most consistent with MSC as the source of the high levels of S. enterica in the epidemiologically linked meat product.

Salmonella serotypes isolated in subsamples of the meat product included S. Typhimurium, S. Senftenberg, S. Infantis, S. Kentucky, S. Heidelberg, S. Schwarzengrund, S. Enteritidis and S. I 4,[5],12:d:-. All seven of the S. Infantis isolates were multidrug resistant.