Isolation and Identification of Wagyu-Originated pathogenicity Escherichia coli
To investigate the cause of Wagyu calf diarrhea mortality,this study collected ten fresh fecal samples from diarrheic Wagyu calves in Longjiang County Qiqihar City,for bacterial isolation and culture,biochemical identification,and 16S rRNA gene sequencing.A single purified bacterial strain isolated from a diarrhea sample,was selected for pathogenicity tests,antimicrobial susceptibility testing,virulence gene detection,phylogenetic tree construction,and homology analysis.The results showed that all 10 pathogenic strains isolated from the samples were consistent with the growth morphology and biochemical characteristics of Escherichia coli,with an isolation rate of 100%.The test strain is named Wagyu.1,virulence gene detection revealed that K88,CS31A,BfpA,EAST1,and hlyA were positive.The 16S rRNA sequence showed 93.6%～99.9%homology with E.coli in GenBank.The phylogenetic tree indicated that Wagyu.1 and the human-derived E.coli strain 62-b pink(GenBank accession number:MN208129)in the same branch,exhibiting the closest phylogenetic relationship.The in vitro antimicrobial susceptibility test showed that the strain was most sensitive to cefotaxime and ceftazidime,The findings suggest that the isolate Wagyu.1 is a highly virulent pathogenic E.coli strain.The close phylogenetic relationship and homology with human-derived E.coli for Human-animal separation management and reduce disease incidence.
Wagyupathogenicity E.coliisolation and identificationphylogenetic treevirulence gene
国家科技期刊平台
NSTL
万方数据
