社区获得性泌尿系感染大肠埃希菌的耐药性及β-内酰胺酶基因分析  

Antibiotic resistance and β-Lactamase genotype of Escherichia coli from community-acquired urinary tract infections

作　　者：常燕子[1] 李巧云[2,3] 裘莉佩[1] 徐炜烽[1] 张顺[2] 蔡挺[2] 

机构地区：[1]浙江省宁波市医疗中心李惠利医院检验科,浙江宁波315041 [2]浙江省宁波市第二医院,浙江宁波315000 [3]宁波大学医学院,浙江宁波315000

出　　处：《中国卫生检验杂志》2010年第6期1319-1321,1511,共4页Chinese Journal of Health Laboratory Technology

基　　金：浙江省医药卫生科学研究基金(2009A184)

摘　　要：目的:分析引起社区获得性泌尿系感染大肠埃希菌的耐药性及常见β-内酰胺酶基因携带情况。方法:收集39株从社区泌尿系感染病人分离的大肠埃希菌,体外测试其对常用抗生素的敏感情况,用PCR方法扩增CTX-M、TEM、SHV、DHA、EBC、CIT等6种β-内酰胺酶基因,并进行相应的序列测定。结果:在39株大肠埃希菌中,产ESBL菌株有21株(53.8%)。ESBL阳性菌株除对常用β-内酰胺类抗生素耐药外,对庆大霉素、环丙沙星、左氧氟沙星的耐药率均超过70%,约为ESBL阴性菌株的2倍。所有菌株均未发现对哌拉西林/他唑巴坦、头孢替坦、亚胺培南和卡那霉素耐药。在受试菌株中,TEM基因的检出率最高(64.1%),其次为CTX-M(28.2%),SHV、CIT、EBC、DHA的检出率分别为2.6%、10.3%、7.7%、5.1%。CTX-M基因只见于ESBL阳性菌株(11/21,52.4%),而TEM基因在ESBL阳性和阴性菌株的检出率无差异(13/21,61.9%和12/18,66.7%,P>0.05),且均为TEM-1亚型。另外,ESBL阳性和阴性菌株的β-内酰胺酶基因型分布有所不同,ESBL阳性菌株以单TEM阳性(4/21,19%)、单CTX-M阳性(3/21,14.3%)或TEM、CTX-M双阳性(4/21,19%)基因型为主,而ESBL阴性菌株则以单TEM阳性(11/18,61.1%)为主。结论:在引起社区获得性泌尿系感染的大肠埃希菌中,产ESBL菌株所占比例已超过一半,TEM和CTX-M基因则是这些菌株携带的主要β-内酰胺酶基因型。Objective：To investigate the antibiotic resistance and β-Lactamase genotype of Escherichia coli（E.coli） from community-acquired urinary tract infections.Methods：A total of 39 E.coli isolates from community-acquired urinary tract infections were collected.The antimicrobial susceptibility was tested in vitro.Six β-Lactamase genes（CTX-M,TEM,SHV,DHA,EBC and CIT） screened by PCR,and gene subtype was confirmed by direct sequencing.Results：Of 39 E.coli isolates,21（53.8%） were ESBL producer.All ESBL-producing isolates were resistant to common β-lactam antibiotics and more than 70% were resistant to Gentamicin,Ciprofloxacin and Levofloxacin,Which was two-times as compared to ESBL non-producer.No isolates were found resistant to Piperacillin-tazobactam,Cefotetan,Imipenem and Amikacin.The β-Lactamase genes screening test showed that the TEM prevalence was highest than other genes（25/39,64.1%）,followed by CTX-M（11/39,28.2%）.SHV（1/39,2.6%）,CIT（4/39,10.3%）,EBC（2/39,5.1%） and DHA（3/39,7.7%） prevalence is lower than CTX-M and TEM.Nevertheless,CTX-M were only found in ESBL producers（11/21,52.4%）,but not in ESBL non-producer.However,TEM prevalence in ESBL-positive isolates was similar to ESBL-negative ones [13/21（61.9%） versus 12/18（66.7%）,P〉0.05],and these isolates all harbored TEM-1 subtype.Genotype analysis showed that TEM（4/21,19%）,CTX-M（3/21,14.3%） and TEM＋CTX-M（4/21,19%） were the main types in ESBL producers,and single TEM was the main type in ESBL non-producers（11/18,61.1%）.Conclusion：The ESBL-producing isolates account for more than half of E.coli from community-acquired urinary tract infections,which need to be given more attention.TEM and CTX-M are the main β-Lactamase gene type in these E.coli isolates.

关 键 词：社区获得性 泌尿系感染 大肠埃希菌 耐药性 Β-内酰胺酶基因 

分 类 号：R691.3[医药卫生—泌尿科学]