大肠埃希菌中Ⅰ类整合子耐药基因的分析

目的 对临床分离大肠埃希菌株携带的Ⅰ类整合子及相关耐药基因进行筛选和分析.探讨Ⅰ类整合子在大肠埃希菌耐药中的作用.方法 对43株大肠埃希菌临床分离株做药敏试验;采用PCR扩增、DNA测序、DNA序列比对的方法 对其携带的Ⅰ类整合子相关耐约基因进行分析.结果 43株大肠埃希菌分离株对10种抗菌药物的耐药率依次为亚胺培南4.7%、阿米卡星18.6%、头孢他啶、27.9%、头孢吡肟37.2%、头孢呋辛55.8%、复方磺胺甲嗯唑58.1%、妥布霉素74.4%、庆大霉素79.1%、头孢噻肟81.4%和哌拉两林83.7%.在43株大肠埃希菌分离株中有25株含有Ⅰ类整合子,其中18株携带整合子相关耐药基因,如介导对磺胺类和氨基糖苷类约物的耐药基因等;某些菌株携带的整合子相关耐药基因相同.结论 Ⅰ类整合子在大肠埃希菌中广泛存在,整合子相关耐约基因在该菌耐药性的形成和播散中发挥作用.

Analysis of drug resistance genes integrated by class 1 integron in clinical Escherichia coli isolates

Objective To study distribution of the class 1 integron in clinical Escherichia coil isolates and explore the relationship between integron and their drug resistance. Methods The class 1 integron and drug resistance gene cassettes integrated by class 1 integron among the E. coli isolates were analyzed by PCR screening, DNA sequencing and sequence analysis, and the antibiotic sensitivity tests were performed. Results Twenty five of 43 E. coil isolates were observed in class 1 integron, 18 of which carried the integrated drug resistance gene. Susceptibility test showed their resistance as follows 4.7% of imipenem, 18.6% of amikacin,27.9% of ceftazidime,37.2% of cefepime, 55.8% of cefuroxime,58.1% of sulfamethoxazole,74.4% of tobramycin,79.9% of gentamicirt,81.4% of cefotaxime and 83.7% of piperacillin. Conclusion Drug resistance genes integrated by class 1 integron were widespread in E. coli isolates.