Characterization of Salmonella species from poultry slaughterhouses in South Korea: carry-over transmission ofThompson ST292 in slaughtering process.

Abstract

IMPORTANCE: outbreaks linked to poultry meat have been reported continuously worldwide. Therefore,contamination of poultry meats in slaughterhouses is one of the critical control points for reducing disease outbreaks in humans. OBJECTIVE: This study examined the carry-over contamination ofspecies through the entire slaughtering process in South Korea. METHODS: From 2018 to 2019, 1,097 samples were collected from the nine slaughterhouses distributed nationwide. One hundred and seventeen isolates ofspecies were identified using thegene-specific polymerase chain reaction, as described previously. The serotype, phylogeny, and antimicrobial resistance of isolates were examined. RESULTS: Among the 117 isolates, 93 were serotyped intoMbandaka (n = 36 isolates, 30.8%),Thompson (n = 33, 28.2%), andInfantis (n = 24, 20.5%). Interestingly, allelic profiling showed that all. Mbandaka isolates belonged to the lineage of the sequence type (ST) 413, whereas all. Thompson isolates were ST292. Moreover, almost all. Thompson isolates (97.0%, 32/33 isolates) belonging to ST292 were multidrug-resistant and possessed the major virulence genes whose products are required for full virulence. Both serotypes were distributed widely throughout the slaughtering process. Pulsed-field gel electrophoretic analysis demonstrated that seven. Infantis showed 100% identities in their phylogenetic relatedness, indicating that they were sequentially transmitted along the slaughtering processes. CONCLUSIONS AND RELEVANCE: This study provides more evidence of the carry-over transmission ofspecies during the slaughtering processes. ST292. Thompson is a potential pathogenic clone ofspecies possibly associated with foodborne outbreaks in South Korea.