新生儿产超广谱β-内酰胺酶细菌的基因型与耐药性分析

Genotypes and drug resistance of ESBLs-producing bacteria isolated from neonatal unit

目的了解新生儿病房产ESBLs大肠埃希菌和肺炎克雷伯菌耐药性和ESBLs的基因型,为临床合理治疗提供理论依据。方法对2010-2012年住院新生儿送检标本进行菌株鉴定;ESBLs鉴定采用VITEK-2Compact鉴定及药敏系统,采用PCR方法对ESBLs基因型进行检测。结果 2010-2012年新生儿住院患者中共分离不重复肺炎克雷伯菌1 260株、大肠埃希菌755株,ESBLs产酶率分别为70.8%和57.4%,对亚胺培南、美罗培南、阿米卡星、环丙沙星、头孢哌酮/舒巴坦、哌拉西林/他唑巴坦等抗菌药物的敏感率高于65.0%;随机选取150株产ESBLs肺炎克雷伯菌、100株产EBSBLs大肠埃希菌进行PCR引物扩增;250株产ESBLs菌株中,TEM型引物扩增阳性176株,占70.4%;SHV型引物扩增阳性145株,占58.0%;CTX-M型引物扩增阳性227株,占90.8%;OXA型引物扩增阳性16株,占6.4%;PCR扩增阴性45株,占18.0%。结论在医院流行ESBLs的基因型主要是CTX-M型,加强ESBLs基因型监测、了解其基因型分布资料,对于产ESBLs菌株感染的治疗和控制具有重要指导意义。

OBJECTIVE To investigate the drug-resistance of Escherichia coli and Klebsiella pneumoniae and the genotype of extended-spectrum β-lactamase （ESBLs） isolated from the neonatal unit, so as to provide theoretical basis for rational clinical treatments. METHODS Identification of strains from 2010 to 2012 submitted by the neonatal unit was conducted. ESBLs were identified by VITEK-2 compact and antibiotic susceptibility system. The genotype of ESBLs was identified by polymerase chain reaction （PCR）. RESULTS A total of 1260 non-repeti- tive Klebsiella pneumoniae and 755 Escherichia coli were isolated from hospitalized neonates from 2010 to 2012. The ESBLs-producing rate reached 70.8 % and 57.4 % respectively. The susceptible rates to imipenem, meropen- em, amikaxin, ciprofloxacin, cefoperazone/sulbactam and piperacillin/tazobatan were higher than 65.0M. A total of 150 ESBLs-producing Klebsiella pneumoniae and 100 ESBLs-producing Escherichia coli were randomly selected to conduct PCR amplification. Among 250 ESBLs-producing strains, 176 strains showed TEM positive, account- ing for 70. 4%; 145 strains SHV positive, accounting for 58%% 227 strains CTX-M positive, accounting for 90.8% only 16 strains showed OXA positive, accounting for 6.4%. Meanwhile, 45 strains showed PCR nega- tive, accounting for 18.0%. CONCLUSION CTX-M is the main genotype of ESBLs in the neonatal unit. More intensified monitoring of ESBLs and full understanding of its genotype distribution present important reference for the treatment and control of the infection caused by ESBLs-producing strains.