不同浓度EDTA对产ESBL多重耐药大肠埃希菌抗菌药物敏感性的恢复作用

Drug susceptibility of multidrug-resistant ESBL-producing Escherichia coli to antimicrobial agents restored by different concentrations of EDTA

目的分析不同浓度乙二胺四乙酸(EDTA)对产超广谱β-内酰胺酶(ESBL)多重耐药大肠埃希菌抗菌药物敏感性的恢复作用。方法选取分离自临床样本的产ESBL大肠埃希菌240株,测定其添加低浓度(0.5 mg/mL)、标准浓度(1.0 mg/mL)、高浓度(2.0 mg/mL)EDTA前后最小抑菌浓度(MIC)的变化。结果对于产ESBL大肠埃希菌,使用单纯药物的MIC与联合应用EDTA的MIC存在明显差异,其中头孢哌酮、左氧氟沙星、头孢吡肟的MIC变化最明显,其次是阿米卡星、妥布霉素和庆大霉素,氨曲南变化较小,头孢噻肟无变化。抗菌药物联合标准浓度和高浓度EDTA时,其抗菌药物MIC变化较联合低浓度EDTA时更为显著,但联合标准浓度与高浓度EDTA之间无差异。3个浓度EDTA对头孢噻肟的MIC均无影响。结论不同浓度的EDTA对大多数产ESBL多重耐药大肠埃希菌有显著的协同抗菌作用,能明显提高其对抗菌药物的敏感性,具有重要的临床意义。

Objective To investigate the effect of different concentrations of ethylenediaminetetraacetic acid(EDTA)on the recovery of drug susceptibility of multidrug-resistant extended-spectrum beta-lactamase(ESBL)-producing Escherichia coli.Methods Totally,240 isolates of ESBL-producing Escherichia coli were collected.The minimum inhibitory concentrations(MIC)before and after adding EDTA with low(0.5 mg/mL),standard(1.0 mg/mL)and high(2.0 mg/mL)concentrations were determined.Results Among the isolates of ESBL-producing Escherichia coli,the difference between the MIC of pure antibiotics and the MIC of antibiotics with EDTA was obvious.The changes of MIC of cefoperazone,ofloxacin and cefepime were the most obvious,followed by amikacin,tobramycin and gentamicin.The change of MIC of aztreonam was small,and the MIC of cefotaxime did not change.In the 3 groups of combination of EDTA and antibiotics at different concentrations,the changes in the MIC of antibiotics were more significant when the antibiotics were combined with the standard concentration and the high concentration of EDTA than when the antibiotics were combined with the low concentration of EDTA,but there was no statistical significance between the standard concentration and the high concentration of EDTA.The MIC of cefotaxime did not change in the 3 groups.Conclusions EDTA of different concentrations has synergistic antibacterial effect on most determined isolates,and it can improve the drug susceptibility of antimicrobial agents,which has important clinical significance.