1株牛源腹泻大肠杆菌耐药基因检测

Detection of antibiotic resistance genes in a bovine diarrhea Escherichia coli strain

试验旨在分析牛源腹泻大肠杆菌耐药原因,并获悉16S rRNA甲基化酶基因携带情况。采用药敏试纸对腹泻大肠杆菌进行体外药物敏感试验,通过PCR检测分离株16S rRNA甲基化酶基因携带情况,给昆明小白鼠腹腔注射稀释菌液观测,发病死亡情况。结果显示,该株大肠杆菌携带rmtB耐药基因,对头孢他啶、头孢噻肟、多黏菌素、头孢吡肟敏感,对其余8种不同种类抗生素均表现耐药。试验小鼠在注射稀释菌液5 h后开始发病,48 h内全部死亡。研究表明,该牛源腹泻大肠杆菌对阿米卡星、卡那霉素等氨基糖苷类药物耐药,提示要合理规范使用抗生素。

The experiment aimed to analyze the reasons for antimicrobial resistance in Escherichia coli causing diarrhea in cattle and to determine the carriage of 16S rRNA methyltransferase genes.The susceptibility of the diarrhea-causing Escherichia coli to antimicrobial agents was tested using antibiotic sensitivity test strips,and the carriage of 16S rRNA methyltransferase genes in the isolated strains was detected by PCR.Additionally,Kunming white mice were injected intraperitoneally with diluted bacterial solution to observe the onset and death from the infection.The results showed that the Escherichia coli strain carried the rmtB resistance gene and was sensitive to ceftazidime,cefotaxime,colistin,and cefoperazone,but resistant to other eight types of antibiotics.The test mice began to show symptoms five hours after injection with the diluted bacterial solution and all died within 48 hours.The study indicates that this bovine diarrhea Escherichia coli strain is resistant to aminoglycoside drugs such as amikacin and kanamycin,suggests the need for rational and standardized use of antibiotics.