Expression of multidrug active efflux system acrAB-tolC genes in clinical isolated strains of Shigella
YANG Haiyan, DUAN Guangcai,XI Yuanlin Department of Epidemiology, College of Public Health, Zhengzhou University, Zhengzhou 450052
Aim: To study the multiple-antibiotic-resistance mechanism in clinical isolated strains of Shigella. Methods: Accumulation of ciprofloxacin in clinical isolates of Shigella was measured by fluorometry. acrAB-tolC genes were detected using PCR-SSCP. The mRNA levels of acrAB-tolC expression were measured using Northern-blot.Results: The concentration of ciprofloxacin in sensitive strains was significantly higher than that in the multiple-antibiotic-resistance (Mar) strains (P0.000 1). acrAB-tolC was found in all the strains, and the lack of genes was not found. The mutation of acrA gene was found in four Mar strains of Shigella and the mutation of tolC gene, in one susceptible strains, while the mutation of acrB gene was not found. The expression level of acrA gene in the Mar strains was significantly higher than that in sensitive strains (P0.05), acrB gene and tolC gene had not significant difference(P0.05). Conclusion: High expression of acrA gene leads to multiple-antibiotic-resistance in clinical isolated strdin of Shigella, and Mar operon may contribute to the regulation of acrAB-tolC gene expression.
【CateGory Index】： R378