[Objective]The study aimed to identify the pathogen responsible for the recent outbreak of severe diarrhea,characterized by yellow watery stool,some with blood,and symptoms like depression and loss of appetite among calves in a cattle farm near Changji City,Xinjiang Province,and to provide a basis for treatment.[Methods]The research involved bacterial identification and classification from the diarrheic fecal samples of calves,as well as an analysis of drug resistance.[Results]The findings indicated that the pathogenic bacterium was identified as Escherichia coli.PCR analysis confirmed the presence of E.coli,and the staining microscopy was consistent with its morphology,including the presence of the K99 adhesive gene in the isolated strain.Drug susceptibility testing revealed that the bacteria were resistant to polymyxin B but susceptible to other tested antimicrobial agents.Pathogenicity tests on mice resulted in death within 15 hours,thereby proving the strain's pathogenic capacity.[Conclusion]The isolated strain from the diarrheic feces of calves was determined to be enterotoxigenic E.coli(ETEC),harboring the K99 virulence factor,and demonstrated pathogenicity,particularly showing resistance to polymyxin B.This discovery is critical for guiding effective treatment strategies.
NETL
NSTL
维普
万方数据
