大肠埃希菌对喹诺酮类药物的耐药机制分析

发布时间：2018-06-22 17:53

本文选题：喹诺酮类药物 + 大肠埃希菌　；参考：《中华医院感染学杂志》2017年20期

【摘要】：目的分析大肠埃希菌对喹诺酮类药物的耐药机制。方法菌株来源于2013年1月-2016年12月医院患者分离的大肠埃希菌348株,排除同一患者同一部位分离出的重复病原菌,采用琼脂稀释法,按照《美国临床实验室标准协会》(CLSI)2007年标准计算分离菌株的最低抑菌浓度值(MIC)。筛选出耐药菌株,加入7种常用抗菌药物,测定其他抗菌药物对喹诺酮类耐药菌株的药敏情况。提取耐药大肠埃希菌株的DNA,加入适宜引物,进行扩增,并进行比对分析。结果在分离的大肠埃希菌中为喹诺酮类非敏感菌株87株占25.00%,87株喹诺酮类非敏感菌株对庆大霉素、阿米卡星、头孢噻肟、头孢吡肟、头孢曲松、头孢他啶6种抗菌药物的耐药率均超过50.00%。大肠埃希菌中gryA耐药基因的突变主要发生于低水平的MIC耐药菌株,而parC和PMQR的耐药基因均主要发生在MIC值在4~8μg/ml、16~64μg/ml两个浓度区间的耐药菌株。gryA基因S83L、D87N两个位点,及gryC基因的S80I、A108V两个位点的突变情况在MIC值各个范围内突变发生情况无显著性差异。结论喹诺酮类抗菌药物非敏感的大肠埃希菌对很多其他的抗菌药物也具有耐药性,大肠埃希菌中的耐药基因同喹诺酮类抗菌药物的MIC值分布上具有一定的相关性。
[Abstract]:Objective to analyze the resistance mechanism of Escherichia coli to quinolones. Methods A total of 348 strains of Escherichia coli were isolated from hospital patients from January 2013 to December 2016. Repeated pathogens isolated from the same site were excluded and Agar dilution method was used. The minimum inhibitory concentration (MIC) of isolated strains was calculated according to the 2007 CLSI standard. Drug resistant strains were screened and seven common antimicrobial agents were added to determine the susceptibility of other antibiotics to quinolone-resistant strains. The DNA of drug-resistant Escherichia coli was extracted and amplified by adding suitable primers. Results among the isolated Escherichia coli, 87 quinolone-insensitive strains accounted for 25.00 and 87 quinolone-insensitive strains to gentamicin, amikacin, cefotaxime, cefepime, ceftriaxone. The resistance rates of ceftazidime and ceftazidime were higher than 50.00cm. The mutation of gryA resistance gene in Escherichia coli was mainly found in the low level of MCI resistant strains, while the resistant genes of parc and PMQR were mainly at the two sites of S83LnD87N in the concentration range of 4 渭 g / ml ~ 1664 渭 g/ml. There was no significant difference in the occurrence of mutations between the two loci in the MIC value of the S80Igna A108V and the gryC gene. Conclusion Escherichia coli, which is insensitive to quinolones, is also resistant to many other antibiotics, and the resistance genes in Escherichia coli are correlated with the distribution of MIC values of quinolones.
【作者单位】：甘肃省人民医院药剂科;
【基金】：甘肃省科技厅资助项目(1606RJAZ/38)
【分类号】：R446.5

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