临床标本分离表皮葡萄球菌的耐药性与脉冲场电泳分型研究

Drug resistance of Staphylococcus epidermidis isolates from clinical specimens and pulsed-field gel electrophoresis typing

目的探讨ICU表皮葡萄球菌感染的耐药性及分子流行病学特点,以防多药耐药菌感染发生。方法于2010年9月-2013年12月采用药物敏感性检测技术对ICU分离出的43株表皮葡萄球菌进行药物敏感性检测,同时用限制性内切酶XbaI进行酶切,在脉冲场凝胶电泳仪上进行DNA分子分型,应用沙门菌属H9812作为脉冲场凝胶电泳的分子量标准,使用BioNumerics(Version4.0)分析软件,计算试验菌株相互之间的相似性关系。结果 43株表皮葡萄球菌分9型,分别命名为A、B、C、D、E、F、G、H和I型,其中A型和C型为优势菌株,A型共20株占46.51%,C型12株占27.90%,E型3株占6.97%,D型和B型各2株,分别占4.65%,其余型别各有1株分别占2.33%;另对13种抗菌药物共产生相同的耐药表型为23种,各型之间存在表型的重叠;多药耐药菌的检出率高达62.79%。结论脉冲场凝胶电泳分型技术可以准确和快速地用于表皮葡萄球菌菌株引起医院感染溯源分型,同时ICU表皮葡萄球菌多药耐药菌发生率较高,必须加强耐药监测与合理使用抗菌药物。

OBJECTIVE To explore the drug resistance of the Staphylococcus epidermidis causing infections in the ICU and analyze the molecular epidemiology so as to prevent the multidrug‐resistant bacteria infections .METHODS From Sep 2010 to Dec 2013 ,the drug susceptibility of 43 S .epidermidis isolates from the ICU was detected by u‐sing drug susceptibility testing techniques ,meanwhile ,the restriction endonuclease XbaI was used in chipping DNA extracted from all the strains ,which then were typed by the standardized pulsed‐field gel electrophoresis ap‐paratus ,and then the similarity was calculated among the studied strains with the PFGE molecular standards of Salmonella H9812 and BioNumerics （Version 4 .0）analysis software .RESULTS Totally nine PFGE types （A ,B , C ,D ,E ,F ,G ,H ,and I ）were identified from the 43 S .epidermidis strains .Type A （20 strains ,46 .51% ）and type C （12 strains ,27 .90% ） were the prevalent types ,three （6 .97% ）strains were type E ;there were two （4 .65% ） strains of type D and two （4 .65% ） strains of type B ;there was 1 （2 .33% ） strain of another type and 1 （2 .33% ） strain of another type .The S .epidermidis strains showed various levels of resistance to the 13 antibiotics ,invol‐ving 23 drug resistance phenotypes ,with overlaps among them .The incidence of multidrug‐resistant organisms was as high as 62 .79% .CONCLUSION The pulsed‐field gel electrophoresis typing technique can be used to accu‐rately and rapidly trace the sources of nosocomial infections due to S .epidermidis strains .At the same time ,the incidence of multidrug‐resistant S .epidermidis is high in the ICU ,and it is necessary to strengthen the surveil‐lance of drug resistance and reasonably use antibiotics .