A later study showed the prevalence of S. aureus in retail beef in Fargo, ND to be 9/36 and in retail pork to be 25/37 with slightly higher detection when realtime PCR was used [23]. An older study showed the prevalence of staphylococci to be 42% in beef liver and 27% in pork chops [30]. There are many factors that make the comparisons between different studies difficult and also these factors may contribute to the variety of positive percentages. Factors like different processing facilities, sampling, geographic locations, brand, isolation methods, and collection time can explain the variable prevalence of S. aureus among different studies in the literature.