1株犬源大肠杆菌的分离鉴定与耐药性分析

Isolation,Identification and Drug Resistance Analysis of a Canine Escherichia coli

为检测北京市某动物医院1例宠物犬顽固性腹泻的原因,通过采集肛门拭子进行细菌分离鉴定试验,分离出1株大肠杆菌,命名为37-Canine株。通过细菌形态学观察、生化鉴定、16S rDNA序列分析、大肠杆菌荧光PCR致泻型检测等方法对该病原菌进行分析,并采用K-B药敏纸片法及耐药基因PCR检测测定其耐药情况。结果表明:37-Canine株经PCR电泳试验,16S rDNA测序分析,与GenBank中大肠杆菌参考株16S rDNA基因序列的同源性达到99%,进化树显示与AP018488.1参考株被划为一支;经大肠杆菌致泻型荧光PCR检测为EIEC-EPEC-EHEC的杂合型菌株,具有致泻性;对临床常用药物头孢曲松钠、头孢噻肟、诺氟沙星3种药物敏感,对多黏菌素B、庆大霉素2种药物中度敏感,对阿莫西林、磺胺嘧啶、氨苄西林3种药物耐药;经耐药基因PCR检测显示,37-Canine株携带氨基糖苷类、四环素类、氯霉素类耐药基因,出现多重耐药。本试验为临床宠物犬顽固性腹泻病例合理使用抗生素及犬源大肠杆菌的防治提供了参考依据。

In order to detect the causes of intractable diarrhea in a pet dog in an animal hospital in Beijing,a strain of Escherichia coli named 37-Canine strain was isolated by collecting anal swabs for bacterial isolation and identification.The pathogenic bacteria were analyzed by morphological observation,biochemical identification,16S rDNA sequence analysis and fluorescent PCR laxative detection of E.coli.The drug resistance of the bacteria was determined by K/B drug sensitive disk method and drug resistance gene PCR detection.The results showed that the homology of 37-Canine strain with the 16S rDNA gene sequence of E.coli reference strain in genbank was 99%by PCR electrophoresis test and 16S rDNA sequencing analysis.The evolutionary tree analysis showed that it was classified as a hybrid strain with AP018488.1 reference strain by PCRr electrophoresis test and 16S rDNA sequencing analysis,and the strain with cathartic fluorescence PCR was detected as a hybrid strain of E.coli,which was cathartic.The strain was sensitive to ceftriaxone sodium,cefotaxime and norfloxacin,moderately sensitive to polymyxin b and gentamicin,and resistant to amoxicillin,sulfadimidine and ampicillin.PCR test showed that 37-Canine strain carried aminoglycosides,tetracycline and chloramphenicol resistant genes.This study provides a reference for the rational use of antibiotics and the prevention and treatment of canine Escherichia coli in clinical pet dogs with intractable diarrhea.