大肠埃希菌耐药性变化及其DNA多态性分析

目的了解某院2001-2005年大肠埃希菌耐药性变化趋势并对其DNA多态性进行分析。方法采用VITEK全自动微生物鉴定仪对大肠埃希菌临床分离株进行鉴定；Kirby-bauer（K-B）法进行药敏试验；对分离菌株中的10株敏感株和10株耐药株进行随机引物聚合酶链反应（PCR）扩增。结果大肠埃希菌对除亚胺培南、阿莫西林／克拉维酸以外的其他抗菌药物敏感率均呈下降趋势。10株敏感菌呈9种基因型；10株耐药菌仅呈3种基因型，其中6株菌为同一谱型。结论大肠埃希菌对常用抗菌药物耐药率高，耐药范围广，并且其耐药表型与其基因型之间具有一定的相关性。

Analysis on change in drug-resistance and DNA polymorphism of Escherichia coli

Objective To investigate the trend of antimicrobial resistance of Escherichia coli from 2001 to 2005,and analyse the DNA polymorphism.Methods Escherichia coli isolates from clinic were identified by VITEK-automated microbial identification system.Antimicrobial susceptibility test was carried out by Kirby-Bauer method.The genes of Escherichia coli were amplified by randomly amplified polymorphic DNA(RAPD)in 10 antimicrobial susceptible and 10 multidrug-resistant isolates.Results There was an elevated tendency of the resistance rates to other antimicrobial agents except imipenem and amoxicillin/clavulanic acid.10 susceptible strains were classified into 9 genotypes and 10 multidrug-resistant strains were classified into 3 genotypes by RAPD,6 of 10 multidrug-resistant strains were the same pattern.Conclusion The resistant rates of Escherichia coli to common antimicrobial agents are high and the resistant patterns are wide.There is correlation between antimicrobial resistant phenotypes and genotypes of Escherichia coli.