一起 MRSA 感染流行病学调查

摘要

Objective To investigate transmission routes of healthcare-associated infection(HAI)caused by methi-cillin-resistant Staphylococcus aureus (MRSA),and make effective measures for preventing and controlling the oc-currence and epidemic of HAI caused by multidrug-resistance bacteria.Methods From February 24 to March 29, 2012,12 MRSA-infected patients were performed epidemiological study,these patients underwent bronchoscopy be-cause of tracheal stenosis,strains were identified by amplifying the sequences of 16S rRNA ,femA and mecA with real-time quantitative polymerase chain reaction (PCR),homology analysis of strains were performed by Spa geno-typing.Results All 12 MRSA-infected patients were susceptible to multidrug-resistance bacterial infection,5 cases of MRSA infection occurred during this hospitalization.Detection of specimens from health care workers and envi-ronment were all negative;Spa gene of all 12 MRSA isolates was type t 030 ,which was the main epidemic strain in Asia;Spa gene of Staphylococcus aureus isolated from nurses’noses was type t1425 .Conclusion The assumption of MRSA spread among health care workers aren’t supported by the epidemiological investigation results,genotypes of 12 MRSA isolates are identical,but the result of gene typing can’t be as the evidence of homology of infection ;patients at high risk for MRSA infection should be screened as early as possible,early contact isolation should be performed,so as to prevent and control the occurrence of HAI.%目的：探讨耐甲氧西林金黄色葡萄球菌（MRSA）医院感染的传播途径，为防控多重耐药菌医院感染及流行制定有效措施。方法对2012年2月24日-3月29日某院肿瘤内科因气管狭窄而收入院行支气管镜检查治疗的12例 MRSA 感染患者进行流行病学调查，采用实时荧光定量 PCR 方法扩增，检测16S rRNA 、femA、mecA 和 Spa 基因，前三者进行菌株鉴定，后者进行菌株同源性分析。结果12例 MRSA 感染患者均为多重耐药菌的易感人群，其中5例为此次住院发生的医院感染，7例可排除此次住院发生的医院感染。医务人员及环境卫生学采样检测结果为阴性；12株 MRSA 的 Spa 基因分型结果显示均为t030型，为亚洲医院主要流行株；分离自护士鼻腔的普通金黄色葡萄球菌 Spa 基因型为 t1425型。结论此次流行病学调查结果不支持医护间传播，12株MRSA 基因型相同，但基因分型结果不能作为此次感染同源的依据；同时，医院应主动对 MRSA 感染高危患者进行筛查，尽早实施接触隔离，预防和控制医院感染的发生。