Tracing of Salmonella spp. in two pork slaughter and cutting plants using serotyping and macrorestriction genotyping

Aims: The origin of Salmonella contamination of pork, products is not well established. In order to further this knowledge, the transmission of Salmon ella spp. from live pigs to pork cuts was investigated in two pork slaughte r and cutting plants. Methods and Results: Salmonella spp. were isolated from both pork (pigs, ca rcasses, cuts) and the environment before and during slaughterhouse activit ies. Eight serotypes were identified. XbaI and SpeI macrorestriction distin guished 20 genotypes of Salmonella Typhimurium and 16 genotypes of Salmonel la Derby. A major cluster of Salmonella Typhimurium genotypes was common to both plants and all pig-related genotypes, while a predominant pig-related Salmonella Derby genotype was common to both plants. Conclusions: None of the Salmonella strains persisted for long periods in t he pork-processing environments. Significance and Impact of the Study: This work shows that contaminated liv e pigs, because of bacterial spread due to the process and ineffective clea ning procedures, are involved in Salmonella contamination.