产ESBLs大肠埃希菌氨基糖苷类抗菌药耐药性及修饰酶基因的研究

Study on aminoglycosides resistance and aminoglycosides modifying enzymes genes of extended spectrum β-lactamases-producing strains in escherichia coli

目的了解本地产超广谱β-内酰胺酶(ESBLs)大肠埃希菌对氨基糖苷类抗菌药(AGs)的耐药情况,并分析其氨基糖苷类修饰酶(AMEs)基因的检出情况。方法对临床分离的75株大肠埃希菌用表型确证试验检测ESBLs,用KB纸片扩散法对6种AGs做药敏试验以及采用PCR技术检测AMEs基因。结果在临床分离的75株大肠埃希菌中共检出产ESBLs菌37株(49.33%)。产ESBLs菌耐药情况:依次为庆大霉素(78.38%)、链霉素(70.27%)、卡那霉素(62.16%)、妥布霉素(50.05%)、奈替米星(18.92%)、阿米卡星(10.81%)。与非产ESBLs菌株比较,除奈替米星和阿米卡星外差异均有统计学意义,且产ESBLs菌中耐多药模式明显,差异有统计学意义(P<0.05)。产ESBLs菌携带AMEs基因检出情况:共检出5种基因,其中以aac(3)-Ⅱ(64.86%)和aac(6′)-Ⅰ(45.95%)为主,未检出aac(6′)-Ⅱ。除ant(2")-Ⅰ和aac(3)-Ⅰ外,其余3种基因检出率高于非产ESBLs菌株,且两基因携带率也明显高于非产ESBLs菌株(P<0.05)。结论 ESBLs的产生可使大肠埃希菌对AGs的耐药情况加重。

Objective To study the resistance to aminoglyeosides（AGs） in Eseheriehia coli that produce extended spectrum β- lactamases（ESBLs） ,and analyze the aminoglycosides modifying enzymes（AMEs） genes in this area. Methods The ESBLs-producing strains were detected by confirmatory test from 75 strains of E. coli;the susceptibility of 75 strains to 6 kinds of AGs were detected by disk diffusion;and the genotypes of AMEs were detected by PCR. Results In 75 strains of E. coli,37（49.33% ） ESBLs- producing strains were confirmed. 1. The resistance to AGs in ESBLs-producing strains： Gentamiein （78. 38%）, Streptomycin （70.27 % ）, Kanamyein（ 62. 16 % ）, Tobramyein （ 50.05 % ）, Netilmiein（ 18.92% ）, Amikacin（ 10.81% ）. Compared with non-ESBLs- producing strains,there were obviously differences in these aminoglycosides except Netilmicin and Amikacin and also in the modes of resistance to three and more kinds of AGs（P〈0.05）. 2. Five kinds of AMEs genes were detected in the ESBLs-produeing strains and the more were aac（3）-II （64.86%） and aac（6＇）- I （45.95%）;aac（6＇）-II wasn＇t been detected. Compared with non-ESBLs- producing strains,the positive rates were obviously differences in aae（3）-II ,aac（6t）- I , ant（3＇＇）-I and double genes＇modes（P〈0.05）. Conclusion With the producing of ESBLs in E. coli,the resistance to AGs become more serious.