Expression of the marA, soxS, acrB and ramA genes related to the AcrAB/TolC efflux pump in Salmonella entérica strains with and without quinolone resistance-determining regions gyrA gene mutations

Brazilian Journal of Infectious Diseases

Rafaela Gomes Ferrari²  Antonio Galiana¹  Rosa Cremades¹  Juan Carlos Rodríguez¹  Marciane Magnani²  Maria Cristina Bronharo Tognim¹  Tereza C.r.m. Oliveira²  Gloria Royo¹ 

[1] ,Universidade Estadual de Londrina Department of Food Science and Technology Agricultural Sciences CenterLondrina PR ,Brazil

关键词: Salmonella sp.;    Fluoroquinolone;    Efflux pump;    Antibiotic resistance;   

DOI  :  10.1016/j.bjid.2012.09.011

来源: SciELO

【 摘 要 】

Several studies have been conducted in recent years to elucidate the structure, function and significance of AcrB, MarA, SoxS and RamA in Salmonella enterica. In this study, the relative quantification of acrB, soxS, marA and ramA genes expression was evaluated in 14 strains of S. enterica, with or without accompanying mutations in the quinolone resistance-determining regions of the gyrA gene, that were exposed to ciprofloxacin during the exponential growth phase. The presence of ciprofloxacin during the log phase of bacterial growth activated the genes marA, soxS, ramA and acrB in all S. enterica strains analyzed in this study. The highest expression levels for acrB were observed in strains with gyrA mutation, and marA showed the highest expression in the strains without mutation. Considering only the strains with ciprofloxacin minimum inhibitory concentration values < 0.125 [1]g/mL (sensitive to ciprofloxacin), the most expressed gene in the strains both with and without mutations was acrB. In the strains with ciprofloxacin minimum inhibitory concentration values > 0.125 [1]g/mL (low susceptibility), with and without mutations in gyrA, the most expressed gene was marA. In this study, we observed that strains resistant to nalidixic acid may express genes associated with the efflux pump and the expression of the AcrAB-TolC pump genes seems to occur independently of mutations in gyrA.

【 授权许可】

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