致病性嗜水气单胞菌耐喹诺酮类药物菌株的分离鉴定

Isolation and Identification of Quinolone Resistant Strains of Pathogenic Aeromonas hydrophil

对吉林省内 12个水域采集和送检的 6 6尾病鱼进行了细菌分离鉴定 ,共检出 4 6株嗜水气单胞菌疑似菌 ,通过生化试验结合 PCR扩增气溶素基因 Aer,确定其中 2 2株为致病性嗜水气单胞菌。进一步采用纸片扩散法和双倍稀释法测定嗜水气单胞菌分离株对多种抗生素的耐药性 ,其中有 4株对喹诺酮类药物耐药 ,并且为交叉耐药 ,耐药菌检出率为 18.2 % ,纸片扩散法检测其对喹诺酮类药物的抑菌圈均小于 19mm。将病料中分离的 8株嗜水气单胞菌负染后电镜观察 ,耐药菌表面有许多大小不同的球形结构 。

Bacterial pathogens were isolated from fishes collected from 12 water regions in Jilin province.Biochemical tests and amplification of aer gene with PCR were utilized to identify the Aeromonas hydrophil(Ah.) isolates.Among forty six isolates tested,22 strains were identified as A.h and 4 drug resistant strains were identified by routine agar diffusion and disk diffusion test assays.Norfloxacin,ciprofloxacin and ofloxacin resistance were verified according to National Committee for Clinical Laboratory Standards.The identified strains,including 6 susceptible and 2 resistant strains were cultured in LB,washed with physiological saline,centrifugated at room temperature,dyed with phosphorus wolfram acid,observed on electron microscope and compared their surface structure.Many small globule,which were different in size,were observed on the surface of the 2 drug resistant strains,but not on the surface of the 6 susceptible strains.The isolation of quinolones resistant Aeromonas hydrophil strains in Northern China indicates that it is important to establish a system of identification of drug resistant strains in environment.