广州地区新生儿感染产超广谱β-内酰胺酶致病菌的基因和耐药分析

Analysis of Genotypes and Drug Resistance of Extended-Spectrum-Lactamases-Producing Strain in Pat-hogenic Gram-Negative Rod in Infection of Newborn in Guangzhou

目的了解广州地区新生儿感染致病性革兰阴性杆菌中产超广谱β-内酰胺酶(ESBLs)菌株的分布和耐药性特征及其基因分型。方法采用美国临床实验室标准化委员会2001年规定的药物敏感实验标准和ESBLs表型筛选标准进行分析。用聚合酶链反应(PCR)扩增法和DNA测序法对广州地区13家大型医院的新生儿的血液、脐拭子、眼分泌物、尿液、脑脊液、咽拭子等标本进行ESBLs基因序列分析。结果获得广州地区13家大型医院临床分离到的无重复的新生儿致病菌(革兰阴性杆菌)71株。其中ESBLs表型阳性42株,占59.2%。PCR扩增结果显示,多数新生儿感染致病菌中分离出2种或2种以上的ESBLs基因。TEM型占35.6%,SHV型占26.7%,CTX-M1型占10.9%,CTX-M9型占24.8%,OXA型占2.0%。耐药监测结果显示新生儿致病性革兰阴性杆菌大多为大肠埃希菌和肺炎克雷伯菌。对常用抗生素大部分耐药,且为多重耐药,敏感药物为亚胺培南(敏感率100%)、头孢哌酮/舒巴坦(87.3%)、哌拉西林/他唑巴坦(85.3%)、头孢他啶(82%)、氨曲南(82%)、头孢吡肟(81.8%)。结论广州地区新生儿感染致病性革兰阴性杆菌中产ESBLs菌株发生率较高,且为多重耐药,其基因型为TEM型和SHV、CTX-M1、CTX-M9、OXA型。

Objective To investigate the distribution, drug resistance characteristics and genotypes of extended - spectrum - lactamases （ESBLs） - producing strain in pathogenic gram - negative rod in infection of newborn in Guangzhou. Methods The standard was performed by the production for ESBLs by phenotypic screening and confirmatory test provided by the National Committee for Clinical Laboratory Standards in 2001. The method of polymerase chain reaction（PCR） amplification was perbonmed and DNA sequences were analyzed by ESBLs gene se- quencing. Results Total of 71 un -repicated and consecutive Gram -negative bacilli were isolated from 13 hospitals in Guangzhou, and the prevalence of ESBLs - producing clinical Gram - negative isolates was 59.2% （42/71 ）. The PCR results showed that most pathogenic bacilli which infected newborn could be separated two or more genes of ESBLs. The type of TEM, SHV, CTX - M1, CTX - M9, OXA was 35.6%, 26.7% , 10.9% ,24.8% ,2.0% ,respectively. The result of drug resistance monitoring showed that pathogenic gram - negative bacillui which infected newborn were Escherichia coli and Klebsiella pneumonia mostly. Most parts of them were drug fast and even muhidrug resistant to the commonly used antibiotics. The sensitive drugs were l mipenem（ the rate of sensitivty 100% ）, cefoperazone/sulbactam （87.3%）, piperacillin/ tazbatam（85.3% ） ,ceftazidime（82% ） ,aztreonam（82% ） ,cefepime（81.8% ）. Conclusions In Guangzhou,the incidence rate of ESBLs - producing strain are very high inpathogenic bacilli which infected in newborn and is muhidrug resistance. The genetypes of produced ESBLs are TEM ,SHV ,CTX - M1 ,CTX - M9,0XA.