Isolation,Identification and Pathogenicity Analysis of a Strain of Swine-derived Clostridium perfringens Type A
[Objective]The experiment was aimed to investigate the pathogenicity of Clostridium perfringens type A in piglet diarrhoea and provide experimental data and reference for the diagnosis and treatment of diarrhea caused by Clostridium perfringens type A infection.[Method]Preliminary identification was carried out by culture characteristics and staining microscopy,suspicious strains were further identified by biochemical tests,PCR amplification of toxin genes,16S rRNA sequence alignment and phylogenetic tree construction.Drug sensitivity and animal regression tests were conducted to assess drug resistance and pathogenicity of the isolated strain.[Result]The isolated strain displayed black colonies on TSN agar plates,a and βhemolytic zones on blood agar plates,and appeared as large purple rods in Gram staining.The results of biochemical tests showed that glucose,maltose,sucrose,lactose,reductive nitrate test,H2S test and gelatin liquefaction were positive,while mannitol,indole test and salicylic acid test were negative.The 16S rRNA sequence alignment showed more than 99％identity with the 16S rRNA gene sequences of Clostridium perfringens in the NCBI database,the strain was identified as Clostridium perfringens.The plc and cpb2 genes were amplified by PCR,indicating that the strain was Clostridium perfringens type A carrying the β2 toxin.Drug sensitivity test revealed the isolate was resistant to penicillin G,gentamicin,lincomycin,sulfafurazole,ciprofloxacin,and norfloxacin.Animal regression test results showed that the strain could cause diarrhea in piglets,with a mortality rate of 50％.A significant amount of Clostridium perfringens was detectable in the feces post-infection.Necropsy of deceased piglets revealed congestion,hemorrhage,and distension in the small intestine,and Clostridium perfringens type A with high load was isolated from the severely injured jejunal segment.[Conclusion]This study successfully isolated a strain of Clostridium perfringens type A that could induce disease in neonatal piglets.It exhibited strong pathogenicity,and the results of this study provided a reference for the diagnosis,epidemiological investigation,and treatment of Clostridium perfringens type A infections in piglets.
Clostridium perfringens type Aneonatal pigletsisolation and identificationpathogenicity
万方数据
维普
