Purpose: The purpose of the current study was to determine the prevalence and serotype of Salmonella in common types of fresh ground meat available to consumers in regional grocery stores in eastern South Dakota.
Methods: Samples of fresh ground turkey, ground chicken, and ground pork were purchased from grocery stores one time per week for one year. The number of samples of each ground meat purchased each week was dependent on number of different products of each fresh ground meat that were available in the stores. The ground meat samples were tested for the presence of Salmonella using the USDA MLG method with BAX PCR as the primary screening assay. Once identified as a positive sample by BAX PCR, Salmonella were isolated using standard USDA MLG methods. The identity of the isolated bacteria as Salmonella was verified by MALDI-TOF MS biotyping. An Illumina MiSeq genome sequencer was then used to determine the serotypes of the isolates.
Results: For ground turkey, 1.4% (2 of 136) of the samples tested positive for Salmonella. For ground chicken, 11% (6 of 55) of the samples tested positive for Salmonella with the most common serotype (5 of 6 isolates) being Enteriditis. For ground pork, 37% (49 of 133) of the samples tested positive for Salmonella. Twenty different serotypes of Salmonella were detected among the ground pork isolates with the most common serotypes being the potential monophasic variant of Typhimurium (10%), Uganda (10%), Anatum (8%), Derby (8%), Infantis (6%), Johannesburg (6%) and London (6%).
Significance: Even though the sample size of this study was relatively small, the results of the study clearly show that retail fresh ground meats continue to be a potential source of Salmonella infections.