Isolation,Identification and Drug Resistance Analysis of Clostridium perfringens from Broiler Chickens
[Objective]The study was aimed to identify the pathogens of the death of broiler chickens suspected to be infected by Clostridium perfringens in a farm in Nantong,Jiangsu.[Method]The livers,spleens,lungs,kidneys and contents of intestines of the dead chickens were collected aseptically.Bacterial isolation and purification were carried out through anaerobic cultivation,and the isolated strains were preliminarily identified by Gram staining microscopy.Genus and evolutionary relationship were determined by 16S rRNA gene sequence analysis,toxin type was determined by PCR amplification of toxin genes,pathogenicity and drug resistance phenotypes were determined by animal pathogenicity test and drug susceptibility test,and drug resistance genes were detected.[Result]9 suspected strains were isolated from different organs of 4 dead chickens,and the isolates were black on the identification medium of Clostridium perfringens.16S rRNA analysis showed that the similarity between the 9 isolates and Clostridium perfringens was up to 99.60％.The 16S rRNA gene phylogenetic tree showed that 4 isolates were closely related to chicken-derived Clostridium perfringens of Pakistan(GenBank accession No.:MN365136.1),and 5 isolates were closely related to chicken-derived Clostridium perfringens of South Africa(GenBank accession No.:OR494055).The results of toxin typing showed that 5 strains were type A,2 strains were type F and others were type E.The results of pathogenicity test showed that the bacteria were lethal.The drug sensitivity tests showed that 9 strains were sensitive to cephalosporin antibiotics.Resistance genes analysis showed that macrolide erm(B)(77.8％),tetracycline tetA(P)(55.6％),tetB(P)(66.7％)genes were the main resistance genes.[Conclusion]In this study,different toxin-type Clostridium perfringens were isolated from the same dead chicken,and the drug resistance of the isolated bacteria was serious.This result provided a new idea for the prevention and treatment of chicken Clostridium perfringens in veterinary clinic.
万方数据
维普
