医院获得性尿路感染大肠埃希菌ESBLs基因型与耐药性分析

目的了解医院获得性尿路感染大肠埃希菌(HA-UPEC)的耐药与超广谱β-内酰胺酶(ESBLs)基因型特征,指导尿路感染的临床用药与控制医院感染。方法收集住院患者尿路感染分离的168株大肠埃希菌,应用PCR扩增检测ESBLs主要基因型,分析这些菌株对常见16种抗菌药物的耐药特征。结果 168株HA-UPEC对复方磺胺甲噁唑、氨苄青霉素、头孢唑啉、头孢呋辛、头孢噻肟、头孢曲松、环丙沙星的耐药率高达70%以上。16种常见抗菌药物中,头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、丁胺卡那与亚胺培南的耐药率较低。与non-ESBLs大肠埃希菌相比,产ESBLs的大肠埃希菌对青霉素类、头孢菌素类、氟喹诺酮类的耐药率高。根据药敏谱,168株HAUPEC分为5个大组(A~E组),产ESBLs的大肠埃希菌主要分布在A、B、C组。CTX-M是主要的基因型(109株),其次是TEM(48株);59株产大于或等于2种ESBLs,3株未检测到ESBLs。耐药性聚类分组与ESBLs基因型关系分析发现,TEM在D组的分布率最高,为65.2%;SHV在C组未检测到,SHV在A组与B组间的分布不同;CTX-M在4个组的分布差异无统计学意义(P0.05),OXA在B组未检测到,OXA在A组与B组间的分布不同。结论产ESBLs大肠埃希菌的耐药情况比较严重,4种ESBLs基因型在不同组别的分布差异可能是产ESBLs的HA-UPEC耐药不同的原因之一,TEM基因型较敏感,CTX-M与SHV基因型较耐药;临床上应严格合理使用抗菌药物,及时掌握HA-UPEC ESBLs基因型与耐药性的变化,有利于减少多重耐药尿路感染大肠埃希菌的出现。

Analysis on ESBLs genotypes and drug resistance of hospital-acquired uropathogenic E .coli

Objective To understand the characteristics of drug resistance and ESBLs genotypes of hospital-acquired uropathogenic E .coli(HA-UPEC) for guiding clinical antibacterial drug use of urinary tract infection and controlling hospital-acquired infections .Methods A total of 168 HA-UPEC strains isolated from the inpatients were collected .The PCR amplification was used to detect the main ESBLs genotypes and their resistance characteristics to common 16 kinds of antibiotics were analyzed .Results The resistance rates of 168 strains of HA-UPEC to com-pound sulfamethoxazole ,ampicillin ,cefazolin ,cefuroxime ,cefotaxime ,ceftriaxone ,and ciprofloxacin were up to more than 70% .Among 16 kinds of common antibacterial drugs ,cefoperazone/sulbactam ,piperacillin/tazobactam ,amikacin and imipenem had lower resistance rate .Compared with non-ESBLs producing E .coli ,ESBLs-producing E .coli showed higher resistance to penicillins ,cephalosporins and fluoroquinolones .According to the drug susceptibility spectrum ,168 strains of HA-UPEC were divided into five supergroups group A-E ,and ESBLs producing E .coli strains were mainly distributed in the group A ,B and C .CTX-M was main ESBL genotype(109 strains) ,followed by TEM (48 strains) .59 strains produced ≥ 2 kinds of ESBLs and ESBLs was not detected in 3 strains .The relation a-nalysis between drug resistance cluster grouping and ESBLs genotypes displayed that TEM had the highest distribu-tion rate in the group D(65 .2% ) ;SHV was not detected in the group C ,SHV had different distribution in the group A and B ;the CTX-M distribution difference among 4 groups had no statistical significance(P> 0 .05) ,OXA was not detected in the group B and differently distributed between A and B groups .Conclusion The drug resistance of ES-BLs-producing E .coli is serious .The different distribution of four ESBLs genotypes may be one of causes for UPES-BLs drug resistance difference ,and TEM genotype is more sensitive .The CTX-M and SHV genotypes are more drug resistant ;so clinic should strictly and rationally use antibiotics ,timely master the change of ESBLs genotypes and drug resistance ,which is conducive to reduce the generation of E .coli strains causing multi-drug resistant urinary tract infection .