海南耐碳青霉烯类肠杆菌科细菌的耐药基因分析

目的 检测海南省5家综合医院临床送检微生物标本中的耐碳青霉烯类肠杆菌科细菌，了解其耐药基因及流行现状。方法 收集2014年6月—2016年6月期间住院患者各种培养标本中耐碳青霉烯类肠杆菌科细菌菌株，对其进行菌种鉴定和药敏分析试验；然后对筛选出的菌株进行blaKPC-2、blaNDM-1和blaIMP耐药基因PCR特异性扩增，扩增产物进行琼脂糖凝胶电泳和测序分析，经BLAST比对，确定耐药基因的基因型。结果 从5家医院的临床各种标本中，收集到75株耐碳青霉烯类肠杆菌科细菌(CRE)，主要为肺炎克雷伯菌45株占60.0%，阴沟肠杆菌13株占17.3%；科室分布主要为ICU占43.9%，儿科占10.7%；通过药敏实验表明75株CRE除对替加环素(10.6%)、阿米卡星(23.3%)、左氧氟沙星(37.3%)、环丙沙星(40.0%)的耐药率较低外，第一到第三代头孢及氨苄西林、氨苄西林/舒巴坦的耐药率均为100%；第四代头孢头孢吡肟也达到89.3%，复方磺胺甲噁唑的耐药率78.7%，哌拉西林/三唑巴坦耐药率也达到64%；75株CRE细菌中11株blaKPC-2基因阳性占14.6%；25株为blaNDM-1基因阳性占33.3%和12株blaIMP基因阳性占16%。结论 NDM-1型金属酶为海南省CRE菌株的主要耐药基因型，KPC-2型为首次发现占12%。未检测出目的基因的CRE菌株的耐药机制有待于进一步的研究。

Analysis of drug resistance genes of carbapenem resistantEnterobacteriaceae in Hainan province

Objective To collect carbapenem-resistant Enterobacteriaceae (CRE) strains from five hospitals inHainan and analyze their drug resistance genes and prevalence features. Methods CRE strains were collected frominpatients clinical samples from June 2014 to June 2016. Bacteria identification and drug resistance were analyzedby Bio-Merieux VITEK-2 Compact identification system. The drug resistance genes of KPC-2, NDM-1and IPMwere amplified by PCR, and then the products were analyzed by agarose gel electrophoresis and sequenced. The drugresistance genotypes of CRE strains were determined by BLAST. Results 75 CRE strains were collected from thefive hospitals. In 75 CRE strains, 45 were Klebsiella pneumoniae (60%), 13 were Enterobacter cloacae (17.3%).43.9% collected samples were from ICU and 10.7% were from pediatric. The resistance rates of 75 CRE strainswere listed as follows: prostacyclin (10.6%), amikacin (23.3%), levofloxacin (37.3%), ciprofloxacin (40%), the firstto third generation cephalosporins (100%), ampicillin (100%), ampicillin/shubatan (100%), the fourth generationcephalosporin cefepime (89.3%), SMZ-TMP (78.7%), and piperacillin/tazobactam (64%). Among the 75 CRE strains, 11 were blaKPC-2 positive (14.6%), 25 were blaNDM-1 positive (33.3%), and 12 were blaIMP positive (16%). ConclusionblaNDM-1 is the major genotype of CRE in Hainan, and blaKPC-2 is firstly reported in this study. The drug resistancemechanism of CRE should be further studied for strains without the three