The efflux pump AcrAB is important in the antibiotic resistance and virulence of several pathogenic bacteria. We report that deletion of the Yersinia pestis AcrAB-TolC homolog leads to increased susceptibility to diverse substrates, including, though unlike in Escherichia coli, the aminoglycosides. Neither is the Y. pestis pump affected by the efflux pump inhibitor phenylalanine-arginine beta-n...

background and objectives: pseudomonas aeruginosa (pa) is one of the most important causes of nosocomial infections and has an intrinsic resistance to many antibiotics. among all the resistance-nodulation-division (rnd) pumps of p. aeruginosa, mexab-oprm is the first efflux pump found to target multiple classes of antibiotics. this study was aimed to evaluate the expression level of genes expre...

OBJECTIVES The oxazolidinone class of antibiotics such as linezolid have a narrow spectrum of activity that targets Gram-positive bacteria. We hypothesized that the poor activity of linezolid in Gram-negative bacteria is in part caused by relatively low intracellular concentration due to efflux. METHODS Using whole cell accumulation assays we estimated the intracellular concentration of linez...

BACKGROUND Acinetobacter baumannii is an important human pathogen with increasing notoriety in the recent years, as a causative organism of drug resistant nosocomial infections, particularly in immunocompromised patients hospitalized in burn centers. OBJECTIVES The aim of this study was to determinate the role of efflux pump(s) in ciprofloxacin resistance of A. baumannii strains isolated from...

background: shigella spp. are gram negative bacteria, which are of global public health importance. the growing of multidrug-resistant shigella isolates are a major problemaround the world. methods: overall, 50 isolates of shigella spp. from children diarrheic stools were studied. the isolates were identified and confirmed using biochemical, serological and molecular methods (ipah, wbgz and rfc...

BACKGROUND Acinetobacter baumannii has emerged as a highly troublesome pathogen and a leading cause of mortality and morbidity among hospitalized burn patients. OBJECTIVES The aims of this study were to determine the frequency of the AdeABC genes and the role of the efflux pump (s) in the imipenem resistance of A. baumannii strains isolated from burn patients. MATERIALS AND METHODS This stu...

legionella pneumophila is the pathogen responsible for severe pneumonia known as legionnaires’ disease. legionella can live under varied stress conditions, especially in cold environments, and is common in many artificial environments. in this study, the antimicrobial activity of biogenic silver nanoparticles, prepared using the culture supernatant of klebsiella pneumoniae, was evaluated agains...