耐喹诺酮类铜绿假单胞菌的耐药分子机制研究

Study on molecular mechanism of resistance to quinolone-resistant Pseudomonas aeruginosa

目的探讨耐喹诺酮类铜绿假单胞菌的耐药分子机制。方法选取我院2013年1月-2015年7月收集的100例耐喹诺酮类铜绿假单胞菌株,采用PCR技术培养,并将培养收集的菌株点状种植在平板培养基上,培养基是由制备的耐喹诺酮类药物组成。对耐药铜绿假单胞菌株中的gyrA、gyrB、parC和parE基因的表达情况进行检测;将100例培养的铜绿假单胞菌株培养液,每份分为等量两份(每份100例),并将所有的铜绿假单胞菌株接种在含有耐喹诺酮类药物的平板培养基上,其中一份接受常规培养,为对照组,一份放入含有羰基氢氯苯腙(carbonyl hydroch lorophenylhydrazone,CCCP)培养基中进行培养,为观察组,对其耐药性进行分析。结果 gyrA的基因表达率为75.00%,parC的基因表达率为74.00%,明显高于gyrB的基因表达率(23.00%)和parE的基因表达率(22.00%),差异有统计学意义(P<0.05)。观察组中存活菌株数48例(48.00%),明显低于对照组[70例(70.00%)],差异有统计学意义(P<0.05)。结论铜绿假单胞菌耐喹诺酮类药物的主要机制是gyrA、parC两种基因的表达,其次铜绿假单胞菌的主动泵出系统也是其耐药性的一个重要机制。在临床中应熟悉菌株的耐药机制,选择合理的抗菌药物,可降低临床用药的不良事件的危险性,提高治疗疗效,延长抗菌药物的使用寿命。

Objective To study the molecular mechanism of resistance to quinolone-resistant Pseudomonasaeruginosa.Methods From January2013to July2015in Banfu Hospital of Zhongshan City,100strainsof quinolone-resistant Pseudomonas aeruginosa were cultured by PCR and the collected strains were planted onplate culture medium.The medium was composed of quinolones.The expressions of gyrA,gyrB,parC and parEgenes in resistant Pseudomonas aeruginosa strains were detected.The resistant strains were analyzed by addingcarbonyl hydrochlorophenylhydrazone(CCCP).Results The gene expression rate of gyrA was75.00%;the geneexpression rate of parC was74.00%,which was significantly higher than that of gyrB gene(23.00%)and parE gene(22.00%),with significant differences(P<0.05).The number of viable strains in the observation group(48.00%)was significantly lower than that in the control group(70.00%),and the difference was statistically significant(P<0.05).Conclusion The main mechanism of quinolones is the expression of gyrA and parC,and the activepumping system of Pseudomonas aeruginosa is also an important mechanism of drug resistance.Therefore,be familiarwith the drug resistance mechanism and a reasonable antimicrobial drugs selection could reduce the riskof adverse events and improve the clinical efficacy.