Isolation,identification and virulence gene distribution and pathogenicity of three Bacillus cereus strains / 中国生物制品学杂志

ABSTRACT

@#Objective To isolate and identify the pathogenic bacteria in Tongliao area,Inner Mongolia Autonomous Region,China in 2019 and determine the virulence gene distribution and pathogenicity.Methods Three Gram positive isolates,FL1,FL2 and FL3,from the clinical specimens in Tongliao area were subjected to biochemical test,drug sensitivity test,16S rDNA sequencing,virulence gene test and pathogenicity test.Results Bio-chemical test proved the three isolates as Bacillus cereus. The strains FL1 and FL2 from bovine origin were resistant to penicillin and carbamazillin,while the strain FL3 from horse origin to Cefradine. Strains FL1 and FL2 showed the closest relationship to the isolate(KR063181. 1)from Hunan,China,while strain FL3 to the isolate(HM104658. 1)from Shandong,China. However,strain FL3 showed relatively far relationship to strains FL1 and FL2. All the distributions of eight virulence genes of B.cereus were observed in the three strains,while the distributions of four virulence genes of B.anthracoides were different. All the three isolates showed pathogenicity.Conclusion All the three isolates were pathogenic B.cereus,which showed a certain drug resistance. However,there were differences in virulence gene distri-bution between bovine and equine B.cereus.