The resistance-nodulation-cell division family (RND) efflux pumps exemplify a unique phenomenon with drug resistance in different gram negative bacterial strains as a single mechanism causing resistance against several different classes of antibiotics. In Escherichia coli AG102 and Acinetobacter baumannii SBMox2 strains the well characterized RND efflux pumps are AcrAB-TolC and the AdeABC respe...

Tigecycline resistance in Klebsiella pneumoniae results from ramA upregulation that causes the overexpression of the efflux pump, AcrAB-TolC. Tigecycline mutants, derived from Ecl8ΔramA, can exhibit a multidrug resistance phenotype due to increased transcription of the marA, rarA, acrAB, and oqxAB genes. These findings support the idea that tigecycline or multidrug resistance in K. pneumoniae, ...

The Escherichia coli chromosome contains several operons encoding confirmed and predicted multidrug transporters. Among these transporters only the inactivation of components of the AcrAB-TolC complex leads to substantial changes in susceptibility to multiple drugs. This observation prompted a conclusion that other transporters are silent or expressed at levels insufficient to contribute to mul...