耐甲氧西林凝固酶阴性葡萄球菌及糖肽类耐药的检测与分析

Meticillin Resistance and Glycopeptide Resistance in Clinical Coagulase-negative Staphylococci:Detection and Analysis

目的了解中日友好医院临床耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)糖肽类耐药的流行情况和耐药机制,为MRCNS医院感染的预防与控制提供可靠依据。方法头孢西丁纸片法、mecA基因PCR检测MRCNS;万古霉素耐药确证试验筛选对万古霉素敏感性下降的凝固酶阴性葡萄球菌(CNS),E-test法检测其MIC及多重PCR检测其van基因。结果CNS对头孢类、β-内酰胺类、氨基糖苷类、大环内酯类、克林霉素类抗菌药物耐药程度较高;52株CNS菌中头孢西丁纸片法与mecA基因检测MRCNS的符合率为96.2%,mecA基因阳性率为92.3%;256株CNS菌中筛选出4株异质性耐万古霉素葡萄球菌(VRS),均为MRCNS,未检出vanA、vanB、vanC1及vanC2基因。结论对VRS和MRCNS进行有效的实验室检测与院内监测并采取有效措施预防与控制其传播是非常重要的。

OBJECTIVE To provide laboratory evidence for the prevention and control of coagulase-negative staphylococci（CNS） and study the prevalence of meticillin resistance and vancomycin resistance in clinical CNS in our hospital. METHODS Meticillin-resistant coagulase-negative staphylococci （MRCNS） were detected with cefoxitin disk diffusion and mecA-PCR. CNS with reduced susceptibilities to vancomycin was detected with vancomycin agar screen test. Their MIC was determined with E-test and gene van was detected with multiplex PCR. RESULTS CNS was highly resistant to cephem, β-lactam, aminoglycoside, macrolide, and lincosamide. The confirm rate of cefoxitin disk diffusion to mecA-PCR was 96.2% and 92.3% of mecA in 52 CNS strains were detected. Four strains of staphylococci with heteroresistance to vancomycin （VRS） were screened in 256 CNS ones which were all MRCNS but without gene van detected. CONCLUSIONS It is important for clinical laboratory to detect VRS and MRCNS with suitable methods to prevent VRS infection and prevalence.