Contamination And Genetic Diversity Analysis Of Clostridium Perfringens From Cattle Slaughterhouses In Parts Of Shaanxi Province

Clostridium perfringens(C.perfringens)is an important zoonotic pathogen that produces a variety of exotoxins.The enterotoxin(CPE)produced by this bacterium can cause human food and animal feed poisoning which has aroused more attention.At present,study on contamination of C.perfringens from the process of cattle slaughtering is still lacking.In this study,the contamination of C.perfringens has investigated from the cattle slaughtering process in some areas of Shaanxi Province,further,the gene diversity of C.perfringens isolates were detected by PFGE typing.Results are shown as follow:1.Total 607 samples were collected from 3 cattle slaughterhouses from Shaanxi Province,C.perfringens were isolated and identified then serotyped by multiplex PCR.Results showed 114 strains were isolated and isolation rate was 18.78%,of which 111 isolates were type A(97.37%)and 3 were type D(2.63%),it indicates that type A is the dominant epidemic serotype of the slaughthouse.2.Genotype of C.perfringens isolates were use analyzed by using PFGE method,results showed that 24 isolates were divided into 22 PFGE types and 12 gene clusters,and the similarity was from 50.6% to 100%,it indicates that the genotypes of C.perfringens were diverse.JCPBM190385 and JCPBM190384,JCPBM190312 and JCPBM190313 belong to the same genotype,respectively.The similarity was 90.2% between 9 strains isolated from the cutting-beef(7 isolates)and isolates from the tools of slaughteringcutting workshop,and which were the dominant gene cluster(9/24).The similarity of the 17 isolates was greater than 85%,and divided into 5 gene clusters,indicatinged high homology and epidemic correlationship between those isolates.3.The degree of contamination in the beef gradually increases with the slaughtering and cutting procedure.The air in the slaughtering workshop and tools and personnel sanitation of slaughteringcutting workshop are mainly source of carcass contamination.Moreover,the contamination of the carcass in traditional slaughter processing is higher than the modern slaughtering mode.In summary,in this study,the contamination status of C.perfringens in cattle slaughterhouses is investigated from parts of Shaanxi Province,and the PFGE genetic diversity of C.perfringens isolates and dominant serotypes are identifie.