Relationship between high expression of efflux pump AcrAB-TolC induced by quaternary ammonium compound and fluoroquinolones resistance in Escherichia coli
10.3760/cma.j.issn.0254-5101.2019.03.009
- VernacularTitle:季铵盐诱导大肠埃希菌外排泵AcrAB-TolC高表达与氟喹诺酮耐药性关系的研究
- Author:
Meng QI
1
;
Nan LI
;
Bingjie DAI
;
Yuchi JIA
;
Wei QI
Author Information
1. 天津医科大学第二医院感染性疾病研究所 300211
- Keywords:
Escherichia coli;
Quaternary ammonium compound ( QAC );
Disinfectant;
Efflux pump
- From:Chinese Journal of Microbiology and Immunology
2019;39(3):208-211
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the mechanism of efflux pump AcrAB-TolC involved in the cross-resistance between quaternary ammonium compounds ( QAC) and fluoroquinolones ( FQ) in Escherich-ia coli. Methods Seventy-eight Escherichia coli strains were isolated from clinical samples and then tested for the sensitivity to benzalkonium bromide by ager dilution method. Six strains were randomly selected and induced with benzalkonium bromide. Changes in the sensitivity of these strains to benzalkonium bromide and ciprofloxacin were analyzed after induction. Expression of the efflux pump genes acrA, acrB and tolC at mRNA level in the induced strains and their parent strains were detected by quantitative real-time PCR. Re-sults Among the 78 strains, the minimum inhibitory concentrations ( MIC) ranged from 8 μg/ml to 64μg/ml and 47. 4％ of strains have higher MIC than the standard strain. Compared with the parent strains, the induced strains showed higher expression of acrA and tolC genes, and the differences between the two groups were statistically significant. The MIC values of ciprofloxacin to the six induced strains were 4-8 times higher than those to their parent strains. Conclusions It was speculated that the increased expression of acrA and tolC genes at transcription level in the induced strains were related to the cross-resistance between quaternary ammonium compounds and fluoroquinolone antibiotics.
