【摘要】 目的研究耐甲氧西林金黄色葡萄球菌(MRSA)对临床常用抗生素万古霉素(VAN)和替考拉宁(TEC)的异质性耐药情况及分子分型,为临床合理应用抗菌药物提供实验依据,为MRSA的异质性耐药机制研究奠定基础。方法收集2016年1月至2020年12月间中山大学附属第一医院临床分离的305株MRSA,采用多重PCR进行SCCmec分型,用菌群谱型分析微量滴定法(MPAP)初筛、群体谱型分析法(PAP)确认MRSA对VAN和TEC的异质性耐药情况。结果 SCCmec分型中Ⅳa型占35.7%(109/305),Ⅳb型2.0%(6/305),Ⅳc型0.3%(1/305),Ⅳd型0.7%(2/305),Ⅱ型25.9%(79/305),Ⅲ型10.2%(31/305),Ⅴ型5.6%(17/305),未能分型19.7%(60/305)。血液和脓液标本中分离的MRSA主要为SCCmecⅣ型,分别占47.9%(45/94)和43.0%(43/100);痰液标本中分离的MRSA主要为SCCmecⅡ型,占50.5%(35/111)。PAP法显示MRSA对VAN和TEC的异质性耐药阳性率分别为35.5%(104/293)和59.9%(163/272)(P<0.05)。不同SCCmec型别的MRSA对TEC的异质性耐药率分别为:Ⅳ型69.7%(76/109),Ⅴ型56.3%(9/16),Ⅲ型48.1%(13/27),Ⅱ型44.6%(29/65),未能分型65.5%(36/55),差异有统计学意义(P<0.05),SCCmec分型与MRSATEC-HR有一定相关性(r=0.22)。不同SCCmec型别的MRSA对VAN的异质性耐药率分别为:Ⅳ型40.7%(48/118),Ⅴ型29.4%(5/17),Ⅱ型29.2%(21/72),Ⅲ型23.3%(7/30),未能分型41.1%(23/56),差异无统计学意义(P>0.05),SCCmec分型与MRSA-VAN-HR不存在相关性。结论临床分离的MRSA SCCmec型别以SCCmecⅣ型为主,其次是Ⅱ型。MRSA对VAN与TEC有较高的异质性耐药率,对TEC的异质性耐药率高于VAN。MRSA的SCCmec型别与其对TEC的异质性耐药有一定的相关性。更多还原

【Abstract】 Objective To study the heteroresistance(HR)of methicillin-resistant Staphylococcus aureus(MRSA)to vancomycin(VAN)and teicoplanin(TEC),and the corresponding molecular typing,and to provide a basis for guiding clinical treatment and lay a foundation for further investigation of the mechanism of HR in MRSA. Methods A total of 305 MRSA isolates were collected from the First Affiliated Hospital of Sun Yat-sen University from January 2016 to December 2020. The Multiplex PCR was used for SCCmec typing. The HR of MRSA resistance to VAN and TEC were primary screened by microtitration population analysis profiling(MPAP)and confirmed by population analysis profiling(PAP). Results In SCCmec classification,typeⅣa accounted for 35.7%(109/305),typeⅣb 2.0%(6/305),typeⅣc 0.3%(1/305),typeⅣd 0.7%(2/305),typeⅡ25.9%(79/305),typeⅢ10.2%(31/305),type V 5.6%(17/305),and19.7%(60/305)could not be classified. MRSA isolated from blood and pus specimens are mainly SCCmec typeⅣ,accounting for 47.9%(45/94)and 43.0%(43/100)respectively. The MRSA isolated from sputum samples was mainly SCCmec typeⅡ,accounting for 50.5%(35/111). PAP method showed that the positive rates of MRSA to VAN and TEC were 35.5%(104/293) and 59.9%(163/272)(P<0.05). The heteroresistance rates of different SCCmec types of MRSA to TEC are:typeⅣ69.7%(76/109),typeⅤ56.3%(9/16),typeⅢ48.1%(13/27),typeⅡ44.6%(29/65),65.5%(36/55)failed to be typed,the difference was statistically significant(P<0.05),SCCmec typing has a certain correlation with MRSA-TEC-HR(r=0.22). The heteroresistance rates of different SCCmec types of MRSA to VAN are:typeⅣ40.7%(48/118),typeⅤ29.4%(5/17),typeⅡ29.2%(21/72),typeⅢ23.3%(7/30),41.1%(23/56)failed to type,the difference was not statistically significant(P>0.05),there was no correlation between SCCmec typing and MRSA-VAN-HR. Conclusion The clinically isolated MRSA SCCmec type is mainly SCCmec typeⅣ,followed by typeⅡ. MRSA has a higher rate of heterogeneous resistance to VAN and TEC,and the rate of heterogeneous resistance to TEC is higher than that of VAN. The SCCmec type of MRSA is related to its heterogeneous resistance to TEC.更多还原