携带耐药基因的大肠杆菌对消毒剂抗力研究

目的研究临床分离的大肠杆菌耐消毒剂基因携带情况及其对消毒剂抗力水平。方法采用PCR检测法与肉汤稀释法对临床分离大肠杆菌耐药基因和对消毒剂的最小抑菌浓度进行检测,同时与消毒试验标准菌株作平行比较。结果临床分离的7株大肠杆菌中,有4株耐药基因qacE△1-sulIPCR扩增阳性;该7株大肠杆菌基因qacA/B均为阴性。醋酸氯己定对7株大肠杆菌的最小抑菌浓度为1~2mg/L,对大肠杆菌标准株为2mg/L。对氯间二甲苯酚对7株临床分离大肠杆菌与标准株的最小抑菌浓度均为156mg/L。苯扎溴铵对7株大肠杆菌的最小抑菌浓度为19.5mg/L,与标准菌株相同。聚维酮碘和聚醇醚碘对7株临床分离大肠杆菌的最小抑菌浓度分别为1000mg/L与500mg/L,与标准株相同。结论临床分离大肠杆菌多数存在耐药基因,其对常用消毒剂的抗力与标准菌株相当。

STUDY ON DISINFECTANT RESISTANCE OF Escherichia coli CARRYING DISINFECTANT-RESISTANT GENE

Objectives To detect the disinfectant-resistant gene and disinfectant resistance in clinical isolates of Escherichia coli,to compare with the standard strain of E.coli and to evaluate the applicability of the standard strain. Methods The disinfectant-resistant genes qacE△-sul 1 and qacA/B were analyzed by polymerase chain reaction(PCR).The minimal inhibiting concentration(MIC) was measured to evaluate disinfectant resistance.Results The gene qacE△-sul 1 was detected in 4 of the 7 clinical isolates and qacA/B was not detected in all 7 strains.The range of the MIC of the disinfectant containing chlorhexidine acetate for the 7 clinical isolates was 1-2 mg/L and that for the standard strain of Escherichia coli was 2 mg/L.The MICs of the disinfectant containing p-chloro-m-xylenol,bromogeramine,povidone-iodine and polyoxinolum-iodine for both the 7 clinical isolates and the standard strain of E.coli were 156 mg/L,19.5 mg/L,1000 mg/L and 500 mg/L,respectively.Conclusion Most clinical isolates of E.coli have drug-resistant gene,but the levels of resistance of clinical isolates to disinfectants in common use were equal to those of the standard strain.