儿童感染MRCNS的药敏分析及SCCmec基因分型研究  

On antibiotic resistance and SCCmec molecular epidemiology of methicillin resistant coagulase negative Staphylococci in Children

作　　者：熊玉玲[1] 夏小荣[1] 朱玉林[1] 李长春[1] 王亚亭[1] Xiong Yuling Xia Xiaorong Zhu Yulin et al(Dept of Paediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei 23002)

机构地区：[1]安徽医科大学第一附属医院儿科,合肥230022

出　　处：《安徽医科大学学报》2016年第10期1430-1435,共6页Acta Universitatis Medicinalis Anhui

基　　金：安徽省自然科学基金(编号:1408085QH157)

摘　　要：目的了解安徽地区儿童感染耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）的耐药现状和葡萄球菌盒式染色体（SCCmec）基因型分布及各基因型的耐药特点。方法对安徽地区近6年临床分离的儿童感染凝固酶阴性葡萄球菌（CNS）进行表型筛选,并利用聚合酶链反应（PCR）扩增mec A的方法收集MRCNS菌株。采用标准琼脂倍比稀释法测定MRCNS 16种抗菌药物的最低抑菌浓度（MIC）值,同时利用PCR对MRCNS进行SCCmec基因分型。结果经表型筛选及mec A基因检测双重方法共收集MRCNS 186株,包括耐甲氧西林表皮葡萄球菌、耐甲氧西林溶血葡萄球菌、耐甲氧西林人葡萄球菌及少数其他类型MRCNS,分别为45.7%（85/186）、24.7%（46/186）、18.8%（35/186）及10.8%（20/186）。耐药分析显示MRCNS对青霉素、头孢哌酮、头孢噻肟、头孢曲松、亚胺培南、美罗培南耐药率达100%,红霉素和阿奇霉素的耐药率大多在90%以上,对环丙沙星、克林霉素耐药率为80%左右,对庆大霉素、左氧氟沙星的耐药率为40%左右,对利福平的耐药率为20%左右,对氯霉素的耐药率为10%左右,对替考拉宁、万古霉素的耐药率分别为2.2%（4/186）、0.5%（1/186）。186株MRCNS的SCCmec分型共有Ⅰ～Ⅴ5种型别,以Ⅲ型为主,Ⅳ型检出Ⅳa、Ⅳc、Ⅳd3种亚型,并有较多的混合型存在。各基因型对多种抗菌药物呈不同程度的耐药。结论安徽地区临床分离的儿童MRCNS对多种常用抗菌药物不敏感,具有多重耐药性,其中出现万古霉素表型耐药菌株,应予警惕。不同类型的MRCNS所携带的SCCmec型别不同,SCCmecⅢ型为主要流行菌株。SCCmec基因型与耐药谱有着密切的关系。Objective To learn the drug resistance of methicillin resistant coagulase negative Staphylococcus （ MRC- NS） and to investigate the distribution and antimicrobial resisitanee of different MRCNS SCCmec genotyping from children in Anhui. Methods Resistance phenotype screening and Polymerase Chain Reaction （PCR） mecA gene detection were conducted in clinical strains of coagulase negative Staphylococcus, in order to collect MRCNS in re- cent six years from children in Anhui. Minimal inhibitory concentrations of 16 antibiotics were determined by agar dilution method, then SCCmec types were determined by PCR methods. Results A total of 186 MRCNS were de- tected by resistance phenotype screening and PCR mecA gene detection methods. There were 45.7% （85/186） me- thicillin resistant Staphylococcus epidermidis, 24.7% （ 46/186 ） methicillin resistant Staphylococcus haemolyticus, 18.8 % （ 35/186 ） methicillin resistant Staphylococcus hominis, 10. 7 % （ 20/186 ） other types of MRCNS. Drug re- sistance analysis showed the resisitance rates to penicillin, cefoperazone, cefotaxime, ceftriaxone, imipenem, and meropenem were 100% , to erythromycin and azithromycin were about 90% , to ciprofloxacin and clindamycin were about 80% , to gentamicin and levofloxacin were about 40% , to rifampincin was about 20% , to ehloramphenieol, teicoplanin and vancomyein were 10% , 2. 2% and 0.5%. Ⅰ to V SCCmec genotypes were detected in 186 MRC- NS, the major type was SCCmec type Ⅲ. Three subtypes of IV genotype were identified, including Ⅳ a, Ⅳ c and Ⅳd, the second type was hybrid type. Each genotype showed varying degrees of resistance to several antibiotics. Conclusion Clinical strains of children infected MRCNS isolated from Anhui have multiple resistances to common- ly used antibiotics. It should be on alert that vancomycin phenotypic drug resistant strain appears. Different types of MRCNS carry different types of SCCmec, SCCmec m genotype is the major epidemic isolates. SCCmec genotype and drug resistance sp

关 键 词：儿童 耐甲氧西林凝固酶阴性葡萄球菌 耐药性 聚合酶链反应 SCCmec基因型 

分 类 号：R446.5[医药卫生—诊断学]