产碳青霉烯酶阴沟肠杆菌耐药特性及耐药基因分析

Drug resistance and genotype analysis of carbapenem-producing Enterobacter cloacae

目的调查某医院阴沟肠杆菌中产碳青霉烯酶菌株耐药性及基因型分布。方法分离鉴定2015年10月-2017年6月期间临床送检标本中阴沟肠杆菌,运用纸片扩散法(K-B法)检测抗菌药物敏感性;应用改良-Hodge试验检测阴沟肠杆菌产碳青霉烯酶表型,采用PCR方法检测阳性株携带相关酶基因情况。结果分离出的298株阴沟肠杆菌中33.2%来源于呼吸科,21.8%来源于重症医学科。共鉴定出26例产碳青霉烯酶的阴沟肠杆菌菌株。碳青霉烯酶阳性菌株对头孢拉定、头孢美唑等头孢类抗生素和亚胺培南、美罗培南等耐药率为100%;对哌拉西林/他唑巴坦复合制剂和阿米卡星耐药率较高,分别为88.5%和76.9%,对复方新诺明耐药率相对较低,为30.8%;26株产酶菌株携带的碳青霉烯酶基因以blaKPC为主,blaIMP和blaNDM-1也有检出。结论该院分离的产碳青霉烯酶阴沟肠杆菌主要为产KPC、VIM和NDM-1酶菌株,且耐药性较强,提示临床医生应重视抗菌药物合理应用,强化耐药菌监控。

Objective To investigate the drug resistance and genotypic analysis of carbapenemase in Enterobacter cloacae in the hospital. Methods 298 strains of Enterobacter cloacae were isolated from Oct,2015 to June,2017,and the antimicrobial susceptibility test was carried out by using the K-B method. The Carbapenemase phenotype was tested by modified-Hodge test. PCR was used to detect the related genes of Carbapenemase phenotype. Results 298 strains of Enterobacter cloacae were mostly from respiratory medicine（ 33. 2%） and severe medicine（ 21. 8%）. 26 strains were Carbapenemase phenotype positive,and the resistant rate of these strains to Cephalosporins（ e. g,Cefradine and Cefmetazole） and Carbapenems（ Meropenem and Imipenem） were almost 100%. The resistant rate to Piperacillin/Tazobactam,Amikacin and Compound Sulfamethoxazole was 88. 5%,76. 9% and 30. 8% respectively. The PCR results showed that the genotype was mainly blaKPC,and the presence of blaIMPand blaNDM-1 was also detected. Conclusion The Carbapenems-producing strains mainly produce KPC,VIM and NDM-1,and the problem of drug resistance is serious. So clinicians should pay attention to the rational use of antimicrobial agents and should strengthen the monitoring of drug-resistance.