肠杆菌科细菌对多黏菌素的敏感性分析

Analysis of polymyxin susceptibility in Enterobacteriaceae

目的了解上海华山医院2014年临床分离肠杆菌科细菌构成及其对多黏菌素的药物敏感性。方法收集该院2014年1-8月临床分离的肠杆菌科细菌,药敏试验采用琼脂稀释法,PCR扩增blaKPC基因并行DNA测序分析,用WHONET 5.6软件对数据进行统计分析。结果 719株肠杆菌科细菌中,主要为克雷伯菌属(315/719,43.8%)和大肠埃希菌(219/719,30.4%)。克雷伯菌属、大肠埃希菌和枸橼酸杆菌属细菌对多黏菌素B和多黏菌素E的耐药率均较低(<3%);肠杆菌属细菌对多黏菌素B和多黏菌素E的耐药率分别为10.9%和11.1%;沙雷菌属细菌对多黏菌素B和多黏菌素E的耐药率分别为47.5%和44.7%;摩根菌属和变形杆菌属细菌对多黏菌素B和多黏菌素E的耐药率均超过90%。碳青霉烯类耐药菌株主要见于克雷伯菌属,其对美罗培南、厄他培南耐药率均高于40%,但对多黏菌素B、E耐药率分别为2.9%、2.6%;枸橼酸杆菌属和沙雷菌属细菌对厄他培南的耐药率分别为27.8%和17.9%;其他肠杆菌科细菌对碳青霉烯类的耐药率小于10%。20.7%(149/719)的菌株blaKPC基因呈阳性,主要见于克雷伯菌属(129/315,41.0%);7株黏质沙雷菌和2株肺炎克雷伯菌同时对碳青霉烯类和多黏菌素耐药。结论克雷伯菌属、大肠埃希菌、肠杆菌属、枸橼酸杆菌属等对多黏菌素仍保持着较高的敏感性。

Objective To investigate the distribution and antimicrobial susceptibility of clinical strains of Enterobacteriaceae isolated from Huashan Hospital in 2014. Methods Enterobacteriaceae were isolated from January to August 2014. Antimicrobial susceptibility testing was performed by agar dilution method. The blanc gene was screened by PCR and DNA sequencing. Results were analyzed by WHONET 5.6 software. Results A total of 719 strains of Enterobacteriaceae were collected, of which Klebsiella spp., and E .coli accounted for 43.8% （315/719） and 30.4% （219/719）, respectively. Resistance rates of Klebsiella spp., E. coli, and Citrobacter spp., to polymyxin B and polymyxin E were low （〈3%）. The percentage of the Enterobacter strains resistant to polymyxin B and polymyxin E was 10.9% and 11.1%, respectively. About 47.5% and 44.7% of the Serratia strains were resistant to polymyxin B and polymyxin E, respectively. More than 90% of the Morganella and Proteus isolates were resistant to polymyxin B or polymyxin E. The carbapenem-resistant Enterobacteriaceae strains were mainly identified in Klebsiella isolates, more than 40% of which were resistant to meropenem and ertapenem, but only 2.9% and 2.6% were resistant to polymyxin B and polymyxin E, respectively. Ertapenem resistance was identified in 27.8% of the Citrobacter isolates and 17.9% of the Serratia isolates. Less than 10% of the other Enterobacteriaceae strains were resistant to carbapenem. Overall, 20.7% （149/719） of the isolateswere blaKPc positive, mainly in K. pneumoniae （129/315, 41.0%）. Seven strains of Serratia marcescens and 2 strains of K. Pneumoniae were resistant to both carbapenems and polymyxin. Conclusions The clinical isolates of Klebsiella, E. coil Enterobacter and Citrobacter in 2014 were still highly susceptible to polymyxin antibiotics.