norA基因mRNA表达水平与表皮葡萄球菌氟喹诺酮耐药性的关系

The Relationship between mRNA Expression Levels of norA Gene in Staphylococcus epidermidis and Fluoquinolones Resistance

目的:探讨表皮葡萄球菌多药转运蛋白norA基因表达水平与氟喹诺酮耐药性的关系。方法:收集临床分离表皮葡萄球菌菌株,用纸片扩散法(Kirby-Bauer)检测50株表皮葡萄球菌对抗菌药物的敏感性,筛选出耐药和敏感菌株,以标准菌株ATCC12228作为对照;提取表皮葡萄球菌的总RNA,应用荧光实时定量RT-PCR检测表皮葡萄球菌多药转运蛋白norA基因mRNA表达水平。结果:所有菌株均检测到norA基因,临床分离耐药菌株norA基因mRNA表达水平明显高于敏感菌株,统计学分析差异有显著性(P<0.05)。结论:对氟喹诺酮类耐药的表皮葡萄球菌norA基因过度表达,其可能是表皮葡萄球菌耐药的原因之一。

Objective： To investigate the relationship between the expression level of multi-drug transporter norA gene and fluoro- quinolones resistance of Staphylococcus epidermidis. Methods： Firstly, clinical strains of Staphylococcus epidermidis were collected, conducted for drug sensitive test by disc diffusion method （Kirby-Bauer）, and resistant strains and sensitive strains were selected, standard strains ATCC 12228 were regarded as control. The total RNA were extracted from Staphylococcus epidermidis, and the levels of transcription of norA gene was detected by fluorescent quantitation RT-PCR. Results： The norA gene was detected in all Staphylococcus epidermidis strains. The expression levels of norA gene in resistant strains was obviously higher than those in sensitive strafns with significant difference （P〈0.05）. Conclusions： S. epidermidis over-expressed the norA gene, which may be associated with the resistance characteristics of the bacteria.