血液来源表皮葡萄球菌生物被膜形成能力及agr基因多态性调查

Investigation on biofilm formation and gene polymorphism of the accessory gene regular(agr) in blood-derived Staphylococcus epidermidis

目的 探讨临床分离血液来源表皮葡萄球菌附属基因调节因子(agr)基因多态性,了解其分子特征与生物被膜形成能力。方法 收集2012年3月~2015年2月四川省人民医院临床分离血液来源的菌株,表皮葡萄球菌经过全自动微生物鉴定系统鉴定后通过分子生物学方法做进一步鉴定确认。采用半定量黏附实验检测生物被膜形成能力,采用多重PCR分析agr基因多态性。结果 实验期间收集到81株表皮葡萄球菌,并全部纳入了下一步的鉴定和分型实验中。血液来源的表皮葡萄球菌中,agrⅠ型51株(62.96%),agrⅡ型6株(7.41%),agrⅢ型7株(8.64%),agr未分型17株(20.99%)。生物被膜阳性菌株54株,占66.67%。结论 临床分离血液来源表皮葡萄球菌agr基因存在明显多态性,以agrⅠ型为主,agr未分型较普遍;血液来源表皮葡萄球菌具有较强的生物被膜形成能力,即具备强致病率,应引起临床重视。

Objective To investigate the gene polymorphism of the accessory gene regular(agr)in blood-derived Staphylococcus epidermidis from clinical isolates,and to understand the molecular characteristics and biofilm formation ability.Methods From March 2012 to February 2015,strains of clinical isolated blood source from Sichuan Province People′s Hospital were collected.Staphylococcus epidermidis was further identified and confirmed by molecular biology method after being identified by automatic microbial identification system.The semi-quantitative adhesion test was used to detect biofilm formation ability,the gene polymorphism of agr was analyzed by multiplex PCR.Results During the experiment,81 strains of Staphylococcus epidermidis were collected and all of them were included in the next identification and typing experiment.Among 81 strains of the epidermis Staphylococcus epidermidis in blood-derived,51(62.96%)agr strains were typeⅠ,6(7.41%)agr strains were typeⅡ,7(8.64%)agr strains were typeⅢ,17(20.99%)agr strains were not parting.There were 54 biofilm-positive strains,accounting for 66.67%.Conclusion The agr gene of in blood-derived from clinical isolated is significantly polymorphic.Blood-derived Staphylococcus epidermidis has a strong biofilm formation ability,that is,has a strong pathogenic rate.Clinicians should pay attention to this phenomenon.