MRSA对6种消毒剂耐药性及相关抗性基因的比较研究

目的观察医院分离的2株耐甲氧西林金黄色葡萄球菌(MRSA)和金黄色葡萄球菌标准株(ATCC 6538)对6种消毒剂的抗性与耐药基因变化。方法选择最小抑菌浓度(MIC)试验、悬液定量杀菌试验和耐消毒剂基因PCR检测。结果 MIC检测,医院分离的2株MRSA,对6种消毒剂的MIC,明显高于标准菌株。只有醋酸氯己定对MRSA-1的MIC值与标准菌株相同。PCR检测,2株MRSA均未携带耐消毒剂基因qacA/B。定量杀菌实验,苯扎氯铵、过氧乙酸、双癸基二甲基氯化铵对MRSA-1菌株的杀灭对数值低于标准菌株;苯扎氯铵、过氧乙酸、有效氯对MRSA-2菌株的杀灭对数值低于标准株。结论医院分离的2株MRSA对消毒剂的抗性普遍高于标准菌株,PCR检测未发现qacA/B基因。

COMPARATIVE STUDY ON RESISTANCE TO SIX DISINFECTANTS IN MRSA AND RESISTANCE-RELATED GENES

Objective To observe the resistance to six disinfectants in two methicilin resistance Staphylococcus aureus strains isolated from clinical samples and the change of resistance genes.Methods Minimum inhibitory concentration(MIC) test and suspension quantitative germicidal test are used to study the resistance to disinfectants.Disinfectant resistance genes were amplified by PCR.Results The MIC of the other disinfectants for the two isolates unharbered the qacA/B gene were higher than the ATCC 6538 standard strain.But there wasn′t difference between the MRSA and the standard strain to the MIC of chlorhexidine acetate.The average killing logarithm values of MRSA-1 strain in the suspension exposed to the disinfectant solution containing didecyl dimethy ammonium chloride,benzalkonium chloride,peracetic acid were lower than control.The same applies to MRSA-2 strains about the disinfectants such as benzalkonium chloride,peracetic acid,active chlorine.Conclusions The two clinic isolated MRSAs displayed generally more antibiotic resistance than standard strain.The MRSA isolates were not confirmed through the presence of qacA/B gene by PCR.