This may be possible as tolC from Ty21a strains unable to dock with AcrAB
in acute strain.
The acrAB gene operates within the complex MAR system.
Paratek projects that products related to its work on the mar operon and now the acrAB locus, could be used to enhance the potency of currently marketed antibiotics, such as fluoroquinolones, penicillins and cephalosporins.
However, no synergy was seen between trimethoprim and ciprofloxacin for strains of Salmonella Typhimurium in which acrA, acrB, acrAB or tolC were inactivated.
AcrAB multidrug efflux pump regulation in Salmonella enterica serovar Typhimurium by RamA in response to environmental signals.
The MarA and SoxS proteins can activate acrAB expression.
13) Bacteria overexpressing ramA may exhibit the MDR phenotype by inducing expression of acrAB and tolC.
There are reports that AcrAB pump expression in Escherichia coli can increase the MIC for ciprofloxacin and norfloxacin up to five times.
3) have reported a reduction of up to 64-fold in CipMIC values after inhibition of the AcrAB operon in strains of S.
In clinical isolates, increased levels of AcrAB pump gene expression may arise due to changes in marA or to bactericidal protection generated by the regulators of this gene.
Effect of transcriptional activators ramA and soxS on expression of multidrug efflux pumps acrAB and acrEF in fluoroquinolone-resistant Salmonella Typhimurium.
Multidrug pump AcrAB
of Salmonella Typhimurium excretes only those b-lactam antibiotics containing lipophilic side chains.