犊牛肺源致病性大肠杆菌分离鉴定、耐药性及耐药基因检测

Isolation,Identification and Detection of Drug Resistance and Drug Resistance Gene of Pulmonary Pathogenic Escherichia coli from Calves

本试验旨在确定新疆石河子地区某牛场因呼吸系统疾病导致犊牛死亡的细菌性病原,并对分离病原进行系统进化分类、耐药表型和耐药基因分析。采用细菌常规分离结合全自动生化分析系统对分离株进行分离鉴定,采用纸片法和PCR方法对分离株进行系统分群、药敏表型及耐药基因的分析。从患病犊牛肺脏、肝脏及淋巴结组织分离鉴定出6株致病性大肠杆菌,6株分离株均呈多重耐药现象,其中对青霉素、阿莫西林、头孢唑啉、头孢拉定、链霉素、庆大霉素、氟苯尼考、替考拉宁、克林霉素、美罗培南、四环素和妥布霉素的耐药率高达100%。氨基糖苷类耐药基因aacC 2、β-内酰胺类耐药基因bla CTX-M和bla TEM、四环素类耐药基因tetA、喹诺酮类耐药基因gyrA、磺胺类耐药基因sul 2携带率分别为66.67%、83.3%、66.7%、100%、100%和100%。结果表明,新疆石河子某牛场发生呼吸道感染死亡犊牛细菌性病原是大肠杆菌,且表现较强的多重耐药现象,分离株携带更为丰富的耐药基因。

The purpose of this study was to identify the bacterial pathogens that cause the death of calves due to respiratory diseases in a cattle farm in Shihezi,Xinjiang,and to analyze the phylogenetic classification,drug resistance phenotype and drug resistance gene of the isolated pathogens.The routine isolation of bacteria combined with automatic biochemical analysis system was used to isolate and identify the isolates.The paper and PCR methods were used to analyze the systematic grouping,drug sensitive phenotype and drug resistance genes of the isolates.Six strains of pathogenic E.coli were isolated and identified from the lung,liver and lymph nodes of infected calves.All of the six strains were multidrug resistant.The drug resistance rates of penicillin,amoxicillin,cefazolin,cefradine,streptomycin,gentamicin,florfenicol,teicoplanin,clindamycin,meropenem,tetracycline and tobramycin were 100%.The carrying rates of aminoglycoside resistance genes aacC 2,β-lactam resistance genes bla CTX-M and bla TEM,tetracycline resistance gene tetA,quinolone resistance gene gyrA,and sulfonamide resistance gene sul 2 were 66.67%,83.3%,66.7%,100%,100%and 100%,respectively.E.coli was the bacterial pathogen causing respiratory tract infections in dead calves in a cattle farm in Shihezi,Xinjiang.It showed strong multi-drug resistance,and the isolates carried more abundant drug resistance genes.