Efflux-Mediated Antimicrobial Resistance

Beta-lactams resistance and presence of class 1 integron in Pseudomonas spp. isolated from untreated hospital effluents in Brazil

“…Species belonging to this genus can accumulate several resistance mechanisms, either acquired or intrinsic, to beta-lactams. Production of beta-lactamases is the most common one (Livermore 2002;Poirel et al 2009), although the resistance mediated by hyper expression of multidrug efflux pumps and loss or decrease of porin expression is also present (Poole 2005;Wolter et al 2007;Henrichfreise et al 2007;Jeannot et al 2008). Some beta-lactamases genes, most metallo-beta-lactamases and some oxacillinases, are found as gene cassettes in class 1 integrons (Walsh et al 2005;Strateva and Yordanov 2009).…”

In silico genetic correlations of multidrug efflux pump gene expression in Staphylococcus aureus

“…Multidrug resistance (MDR) efflux pumps (EPs) are cytoplasmic membrane proteins found both in Gram-positive and Gramnegative bacteria that are capable of expelling structurally diverse antimicrobial agents and biocides, resulting in relevant levels of resistance [1,2]. Minimum inhibitory concentration (MIC) increases provided by MDR EPs may also predispose an organism to highlevel target-based resistance, with a pertinent example being the occurrence of quinolone resistance-conferring mutations in topoisomerase genes that can be reduced by inhibition or elimination of MDR EP activity [3,4].…”

Emergence of antibiotic-resistant extremophiles (AREs)

“…RND pumps have made major contributions to the intrinsic and elevated resistance of clinically relevant pathogens (Poole 2005b). For example, fluoroquinoline resistance is mostly attributed to mutational alteration of the target topoisomerases; however, many strains have been found where the increased resistance has been caused by increased efflux (Mazzariol et al 2000).…”