汉中地区某猪场仔猪腹泻性大肠埃希氏菌的分离鉴定及耐药性检测

Isolation,Identification and Drug Resistance Detection of Escherichia coli in Piglets in Hanzhong

为明确汉中某猪场仔猪腹泻的病原菌及其耐药情况,试验无菌采集腹泻仔猪病料,分离培养后经生化试验、16S rRNA PCR鉴定、药物敏感性试验以及小鼠致病性试验等研究进行探索。试验结果显示该分离株在各培养基上的菌落特征、革兰氏染色镜检结果及生化特性与大肠埃希氏菌相吻合;分离菌株16S rRNA序列与GenBank中登录的大肠埃希氏菌同源性达99%以上;分离菌株对氨苄西林、多黏菌素B、氯霉素、头孢曲松、头孢噻吩、头孢唑林等耐受,对头孢他啶、米诺环素、阿米卡星3种药物敏感,同时对多种抗生素产生耐药性;在小鼠致病性试验中发现48 h内试验组小鼠全部死亡且对照组无死亡,并从死亡小鼠组织中得到该菌株,说明分离菌有较强的致病力。结果表明,本试验所分离的病原菌为多重耐药致病性大肠埃希氏菌。本研究结果可为该猪场仔猪腹泻性大肠埃希氏菌病的临床防治提供科学依据。

To clarify the pathogenic bacteria and drug resistance of diarrhea in piglets at a farm in Hanzhong,piglets were collected using sterile techniques.They were isolated and cultured using biochemical tests,16S rRNA PCR identification,drug sensitivity tests,and mouse pathogenicity tests.The results showed that the colony characteristics,Gram stain microscopic results,and biochemical characteristics of the isolate coincided with E.coli;the sequence of the isolate's 16S rRNA was 99%identical to E.coli strains registered in GenBank.The isolate was sensitive to ceftazidime,minocycline,and amikacin,but resistant to ampicillin,polymyxin B,chloramphenicol,ceftriaxone,cefothiophene,and cefazolin.All mice in the experimental group died,whereas the control group survived;the strain was isolated from the tissues of the deceased mice,indicating high pathogenicity.The pathogens isolated in this experiment were identified as multidrug-resistant pathogenic E.coli.This study provides a scientific basis for the clinical prevention and treatment of Escherichia coli in piglets.