In fluoroquinolone-resistant clinical and veterinary isolates of E. coli, a number of mutations were found in soxR as well as marR and acrR (Wang et al.2001 Webber and Piddock 2001; Komp Lindgren et al.2003).2003
Mutations in marR or soxR were suggested to enhance the expression level of the AcrAB-TolC efflux pump (Okusu et al.1996 Aono 1998 Randall and Woodward 2002; Komp Lindgren et al.2003).2003
On the other hand, the mutation frequency was significantly increased by exposure to SMF of 9 T in soxR and sodAsodB mutants, which are defective in defense mechanisms against oxidative stress.
The limitations forced a mutation in forms.
She told me that she carried a mutation in the BRCA-1 gene a mutation that she had likely inherited from her father.
In this study, we isolated organic solvent-tolerant E. coli mutants and identified mutations in regulatory genes (marR, soxR, acrR).
In the present study, we isolated cyclohexane-tolerant mutants from cyclohexane-sensitive E. coli K-12 strain JA300 and investigated whether or not these mutants carried mutations in regulatory genes marR, soxR, and acrR.
Mutations in acrR, marR and soxR, which are the repressor genes of operons acrRAB, marRAB and soxSR, respectively, cause the overexpression of the multidrug efflux pump AcrAB and its direct activators MarA and SoxS.
Expression of these genes is regulated by the adjacent acrR gene (KP03628), as well as by marR, ramR and soxR genes; mutations in these genes may result in acrAB overexpression, thus contributing to the MDR phenotype [ 55].
