三种消毒剂对ESBL阳性和阴性大肠杆菌杀灭效果的观察

EXPERIMENTAL OBSERVATION ON BACTERICIDAL EFFECT OF THREE KINDS OF DISINFECTANTS ON E. coli ESBL-POSITIVE AND NEGATIVE STRAINS

产超广谱β-内酰胺酶(ESBL)大肠杆菌是医院内常见耐药菌株,为了解其对常用消毒剂的抗力,采用悬液定量试验对戊二醛、碘伏、含氯消毒剂(921消毒剂)杀灭ESBL阳性和阴性大肠杆菌的效果进行了比较。结果,用含有效碘500mg/L碘伏作用3min对ESBL阴性大肠杆菌杀灭率为99.95％,含3000mg/L戊二醛和1:100倍稀释的921消毒剂作用3min对ESBL阴性大肠杆菌杀灭率达100％;用同样含量和作用时间,三种消毒剂对ESBL阳性大肠杆菌杀灭率依次分别为82.75％、100％和91.46％;但将作用时间延长至5min,上述剂量的三种消毒剂对两种菌杀灭率均可达到100％,对表面擦拭3遍消毒亦得到同样的效果。结果说明,ESSL阳性大肠杆菌对碘伏和含氯消毒剂抗力比ESBL阴性者强;二者对戊二醛抗力基本一致。

Escherichia coli producing extended-spectrum β-lactamase (ESBL) is a common drug-resistant bacterial strain in hospitals. In order to know its resistance to commonly used disinfectants, suspension quantitative test was used to compare the efficacy of glutaraldehyde, iodophor and chlorine-containing disinfectant (921 disinfectant) in killing ESBL-positive and negative Escherichia coli. The results showed that iodophor containing available iodine 500 mg/ L with a 3 min contact time killed 99.95% of ESBI-negative E. coli. The disinfectant containing 3 000 mg/ L glutaraldehyde and 1:100 diluted 921 disinfectant with a 3 min contact time killed 100% of ESBL-negative E. coli. The three disinfectants at same concentrations and with same contact time killed 82.75%, 100% and 91.46% of ESBL-positive E. coli respectively. When the contact time was increased to 5 min, the three disinfectants at above doses could kill 100% of both bacterial strains. Wiping the surface with the three disinfectants at above doses for 3 times also gave the same efficacy. The results indicate that the resistance of ESBL-positive E. coli to iodophor and chlorine-containing disinfectant is higher than that of ESBL-negative strain, while the resistance of the two strains to glutaraldehyde is essentially identical.