Genetic Exchange of Multidrug Efflux Pumps among Two Enterobacterial Species with Distinctive Ecological Niches

Abstract

AcrAB-TolC is the major multidrug efflux system in Enterobacteriaceae recognizing structurally unrelated molecules including antibiotics, dyes, and detergents. Additionally, in Escherichia coli it mediates resistance to bile salts. In the plant pathogen Erwinia amylovora AcrAB-TolC is required for virulence and phytoalexin resistance. Exchange analysis of AcrAB-TolC was conducted by complementing mutants of both species defective in acrB or tolC with alleles from either species. The acrB and tolC mutants exhibited increased susceptibility profiles for 24 different antibiotics. All mutants were complemented with acrAB or tolC, respectively, regardless of the taxonomic origin of the alleles. Importantly, complementation of E. amylovora mutants with respective E. coli genes restored virulence on apple plants. It was concluded that AcrAB and TolC of both species could interact and that these interactions did not yield in altered functions despite the divergent ecological niches, to which E. coli and E. amylovora have adopted.

Phytochemicals increase the antibacterial activity of antibiotics by acting on a drug efflux pump

“…According to our docking data, quercetin should be the best inhibitor of AcrB after PA β N. Cells lacking AcrB have also been shown to be hypersensitive to quercetin (Al-Karablieh et al. 2009 ). However, the E. coli strain we used was not susceptible to quercetin.…”

“…Quercetin has previously been reported as a substrate for AcrB as deletion of AcrB from E. coli resulted in a more than 8-fold reduction in the MIC of quercetin (Al-Karablieh et al. 2009 ). Nordihydroguaretic acid is bioactive compound from creosote bush, a plant which has long been used for its medicinal properties by North American Indians (Ross 2005 ) while antimicrobial effects of NDGA have recently been reported (Martins et al.…”

Characterization of genes required for the pathogenicity of Pectobacterium carotovorum subsp. carotovorum Pcc21 in Chinese cabbage

“…Changes in antimicrobial susceptibility were evaluated using a MIC assay (Al-Karablieh et al , 2009a; Barabote et al , 2003). The following plant-derived chemicals were purchased from Sigma-Aldrich: berberine, t -cinnamic acid, p -coumaric acid, esculetin, genistein, gossypol, plumbagin, pyrithione and rhein.…”

The population genetic test Tajima's D identifies genes encoding pathogen‐associated molecular patterns and other virulence‐related genes in Ralstonia solanacearum

“…Importantly, acrA has already been shown to contribute to virulence in R. solanacearum (Brown et al, 2007). Homologues of acrA and/or acrB in P. syringae (Fan et al, 2011;Stoitsova et al, 2008;Vargas et al, 2011Vargas et al, , 2013 and in Erwinia amylovora (Al-Karablieh et al, 2009;Burse et al, 2004) have also been shown to play important roles in plant-microbe interactions, probably by expelling a variety of different plant secondary metabolites toxic to bacteria. However, they may also confer resistance to agrochemicals in agricultural environments (Monteil et al, 2016).…”