非表皮葡萄球菌mecA基因的检测及耐药性分析  

Detection of mecA gene and drug-resistance analysis

作　　者：高振祥[1] 陶凤蓉[2] 骈亚亚 聂晶晶 胡继红[1] Gao Zhenxiang;Tao Fengrong;Pian Yaya;Nie Jingjing;Hu Jihong(National Center for Clinical Laboratories,Beijing Hospital,National Center of Gerontology,Beijing 100730,China;Department of Laboratory Medicine,Beijing Hospital,Beijing 100730,China)

机构地区：[1]北京医院,国家老年医学中心,卫健委临床检验中心,100730 [2]北京医院检验科,国家老年医学中心,100730

出　　处：《中华老年医学杂志》2019年第5期574-577,共4页Chinese Journal of Geriatrics

摘　　要：目的当苯唑西林最小抑菌浓度(MIC)介于0.5~2.0mg/L,探讨凝固酶阴性非表皮葡萄球菌是否是甲氧西林凝固酶阴性葡萄球菌需做mecA基因检测。方法采用头孢西丁纸片扩散法、浓度梯度扩散法(E-test)、最新一代全自动细菌鉴定仪器(CompactVITEK-2)及PCR扩增检测分析mecA基因。结果从4032例患者中筛选到300株凝固酶阴性葡萄球菌(7.4%),CompactVITEK-2鉴定300株凝固酶阴性葡萄球菌中有腐生葡萄球菌45株和溶血葡萄球菌80株,腐生葡萄球菌mecA基因阳性率与溶血葡萄球菌mecA基因阳性率之间差异有统计学意义(P<0.05);头孢西丁(抑菌环直径≥25mm)、E-test(MIC介于0.5~2.0mg/L)及CompactVITEK-2(MIC介于0.5~2.0mg/L)结果显示凝固酶阴性非表皮葡萄球菌共81株;PCR结果发现mecA基因阳性的菌株有10株。结论当苯唑西林MIC介于0.5~2.0mg/L的凝固酶阴性非表皮葡萄球菌,临床微生物实验室应严格执行美国临床实验室标准化研究所(CLSI)指南,一定要做mecA基因检测,若mecA基因检测结果阴性则报告为MSCNS,反之则报告为MRCNS。Objective To determine whether coagulase-negative non-epidermal staphylococcus is methicillin-resistant coagulase-negative staphylococcus by mecA gene test, when the minimal inhibitory concentration(MIC)of oxacillin is between 0.5-2.0 mg/L. Methods The mecA gene was detected and analyzed by the cefoxitin disk diffusion, E-test, VITEK-2 Compact and polymerase chain reaction(PCR)purification. Results A total of 300 strains of coagulase-negative staphylococci were screened from 4032 patients(7.4%), of which 45 strains of Staphylococcus saprophyticus and 80 strains of Staphylococcus hemolyticus were identified by Compact VITEK-2.There was a statistically significant difference in the positive rate of mecA gene detection between Staphylococcus saprophyticus and Staphylococcus hemolyticus(P<0.05). The results of detection of cefoxitin disk diffusion(inhibitory zone diameter ≥25 mm), E-test(MIC of oxacillin between 0.5-2.0 mg/L)and Compact VITEK-2(MIC of oxacillin between 0.5-2.0 mg/L)showed that there were 81 strains of coagulase-negative non-Staphylococci, of which 10 strains with positive mecA gene were confirmed by PCR. Conclusions When the minimal inhibitory concentration(MIC)of oxacillin against coagulase-negative non-Staphylococci stains is between 0.5-2.0 mg/L, the guidelines of the American clinical laboratory standardization institute(CLSI)should be strictly implemented in clinical microbiology laboratory and the mecA gene must be tested.Based on the wide dissemination of the mecA gene in Staphylococcus aureus population, if the mecA gene test is negative, it is reported as methicillin-susceptible coagulase-negative Staphylococcus(MSCNS), and the reverse result is reported as methicillin-resistant coagulase-negative staphylococcus(MRCNS).

关 键 词：凝固酶 甲氧西林抗药性 葡萄球菌属 MECA基因 

分 类 号：R446.5[医药卫生—诊断学]