coagulase negative staphylococci community in the processing environment of dry sausages
Some Coagulase Negative Staphylococci (CNS) are naturally present or used as starters in sausage manufacture and are involved in the typical properties of these products. The diversity of this microbiota isolated from the products and the environment of units manufacturing sausages fermented without starter is few known, due to the difficulty to identify the CNS species. We have developed and validated a specific PCR to identify S. xylosus, the major species naturally present in meat products. To extend this PCR-based method, a multiplex PCR targeting the Staphylococcus genus, S. xylosus and three opportunistic food-borne pathogens Staphylococcus species has been developed. These methods and others based on strain characterization by DNA macro-restriction PFGE, sodA gene sequencing and specific probes hybridization allowed the study of the CNS diversity through units manufacturing sausages fermented with or without starter. We showed that, in dry sausages fermented without starter, S. equorum and S. succinus mainly colonized the products and the environment whereas the S. carnosus and S. xylosus species usually used as starters were found in minority and were not isolated in the final products. The monitoring of the starters S. carnosus and S. xylosus in artisanal and industrial units revealed, that these species did not colonized their environment and that S. xylosus quickly dominated in the products. It could be interesting to develop new starters with the species S. equorum or S. succinus, which seemed to be well-adapted to the meat environment.