target modification and reduced drug accumulation are the main resistance mechanisms against fluoroquinolone antibiotics in pseudomonas aeruginosa. we performed a genotypic characterization of three major mex multidrug efflux pumps (mexab-oprm, mexxy-oprm and mexcd-oprj) in ciprofloxacin resistant clinical isolates of p. aeru­ginosa, collected from tehran, iran this was followed by sequencing a...

background: the importance of this research was to determine the prevalence of efflux pump genes among acinetobacter baumannii isolates from hospitalized patients in imam reza hospital in tabriz, iran. materials and methods: this descriptive study was conducted in the imam reza hospital, tabriz, ir iran during june 2013 to march 2014. twenty-six strains were isolated from female patients (42.6%...

Ouabain-sensitive 22Na efflux from right-side-out membrane vesicles prepared from dog kidney has been examined with a time resolution of 30 msec. The vesicles are preloaded with 22Na and caged ATP [P3-1-(2-nitro)phenylethyl adenosine triphosphate], so that transport by the Na pump can be initiated by light. After a brief illumination, which releases less ATP than the number of catalytic sites, ...

Drug resistant tuberculosis continues to increase and new approaches for its treatment are necessary. The identification of M. tuberculosis clinical isolates presenting efflux as part of their resistant phenotype has a major impact in tuberculosis treatment. In this work, we used a checkerboard procedure combined with the tetrazolium microplate-based assay (TEMA) to study single combinations be...

Calcium efflux was studied in monolayers of HeLa cells. The fast phase of exchange was studied in an open system by continuous washout. Its half-time was 1.58 min which is practically identical to the fast phase of calcium influx previously found to be 1.54 min. This suggests that the fast component of efflux represents calcium exchange from an extracellular compartment probably from calcium bo...

conclusions pmf-dependent efflux mechanism appears to play an important role in the mdr phenotype of a. baumannii clinical strains. background multidrug-resistant (mdr) strains of acinetobacter baumannii have been increasingly reported as a major cause of nosocomial infections, and have created major therapeutic problems worldwide. objectives the aim of the present study was to evaluate the rol...

We examined the roles of diffusion, convection and capillary transporters in solute removal from extracellular space (ECS) of the brain. Radiolabeled solutes (eight with passive distribution and four with capillary or cell transporters) were injected into the brains of rats (n=497) and multiple-time point experiments measured the amount remaining in brain as a function of time. For passively di...

To evaluate the importance of phenylalanine residues for substrate transport in the Escherichia coli efflux pump protein AcrB, we subjected Phe-to-Ala binding pocket mutants to a real-time efflux assay with the novel near-infrared lipophilic membrane probe 1,2'-dinaphthylamine (1,2'-DNA). All mutations, with the exception of F617A, led to considerable retardation of efflux. F610A was the point ...