Isolation,identification and drug resistance analysis of Escherichia coli that causes mastitis in dairy cows
Ding Ying
Zhang Wei
Wei Mingqing
Liu Feifan
Zhang Qian
Zhou Xia
Wang Zhen
Zhang Hui
Abstract：The experiment aimed to investigate the antibiotic resistance and pathogenicity of Escherichia coli causing bovine mastitis in the Shihezi region.The experiment involved bacterial isolation and purification from milk samples of dairy cows with mastitis in the surrounding areas of Shihezi.The isolated strains underwent biochemical identification,Gram staining and microscopic examination,16S rDNA identification,as well as pathogenicity tests and antimicrobial susceptibility testing.The results showed that a suspected Escherichia coli strain was isolated,exhibiting an oval or rod-shaped morphology with Gram-negative staining(red coloration).Biochemical identification yielded a characteristic profile code of A070,and 16S rDNA sequencing confirmed it as Escherichia coli.Antimicrobial susceptibility testing revealed resistance to β-lactams,aminoglycosides,and quinolones.Pathogenicity tests demonstrated that the isolate caused mortality in mice,with deceased subjects exhibiting hepatomegaly and congestion spots in the liver,spleen,and heart.This study successfully isolated a pathogenic Escherichia coli strain from raw milk sample showing partial antibiotic resistance.The findings provide a reference for clinical treatment strategies against bovine mastitis in dairy farms.
Keywords：Escherichia coliIsolation and identificationDrug susceptibility testingPathogenicity testing
Publication Date：2025-03-15
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 16-20 )