Isolation rate, genetic diversity, and toxinotyping of Clostridium perfringens isolated from French cattle, pig or poultry slaughterhouses

Clostridium perfringens is a major global pathogen responsible for foodborne infections. However, neither the source of contamination nor the risk associated with C. perfringens is yet fully understood. This study was designed to assess the presence, genetic diversity, and pathogenic potential of C. perfringens strains isolated from French slaughterhouses processing cattle, pig or poultry. A total of 1843 samples were collected and analyzed from nine slaughterhouses. C. perfringens was detected at various stages of the slaughter process, with overall isolation rates ranging from 19.7 % to 25.5 % depending on the sector. The positive rates in different sample types indicate that C. perfringens can spread and contaminate various parts of the slaughterhouse through cross-contamination and airborne transmission. In the pig sector, only type A strains were identified. While type A was the predominant toxinotype, 1.9 % of isolates from the cattle sector were confirmed as type D, and 4.2 % of isolates from the poultry sector were identified as type G. In addition, the genetic diversity—determined by M13-PCR and rarefaction curves—was high in all three sectors. These findings suggest that the presence of C. perfringens in the slaughter process could pose a risk to public health. Therefore, stringent hygiene and control measures should be closely monitored to mitigate the risk of the emergence of highly pathogenic strains in the food production chain. • Isolation rates range from 19.2 % to 25.5 % depending on the sector. • C. perfringens is present at all stages of the slaughter process. • Possible airborne dissemination along the slaughter and cutting process. • High strain diversity determined by M13-PCR and rarefaction curves in all sectors. • Toxinotype A isolates were predominantly found, with fewer types D and G.