pseudomonas aeruginosa is among the most important pathogens in the nosocomial infections. a genetic mobile element, the integron, is one of the major agents involved in dissemination of multi-drug resistance among gram negative bacteria. during a descriptive study from october 2009 to august 2010, some 130 p. aeruginosa clinical isolates were collected from different wards of three hospitals i...

background  and  objectives: pseudomonas  aeruginosa is responsible for devastating nosocomial infections among severely burn patients. class c of cephalosporinase (ampc-β-lactamases) is important cause of multiple β-lactam resistance in p. aeruginosa . the aim of this study was to detect the ampc-β-lactamases producing isolates among carbapenem resistant p.  aeruginosa isolated from burn patie...

AcrAB exports some beta-lactam antibiotics in the periplasm out of cells via an outer-membrane channel, TolC. It has been reported that eight drug transporters in Escherichia coli cooperate with TolC. In this study, the roles of the drug exporters of E. coli in beta-lactam resistance were examined. We found that five of five resistance-nodulation-cell division-type drug exporters confer beta-la...

BACKGROUND The addition of an aminoglycoside to a beta -lactam therapy regimen has been suggested to have a beneficial effect in delaying or preventing the development of antimicrobial resistance. We studied the effect of aminoglycoside/ beta -lactam combination therapy versus beta-lactam monotherapy on the emergence of resistance. METHODS We performed a meta-analysis of randomized, controlle...

To determine whether the widespread clinical use of -lactams has been selective for Citrobacter freundiiderived alleles of plasmid ampC genes, we generated a Bayesian consensus phylogeny of the published ampC sequences and compared the MICs of 16 -lactam antibiotics for Escherichia coli strains containing cloned copies of the C. freundii ampC alleles. We found that for the majority of compounds...

The beta-lactam antibiotics are the most widely used of all the groups of antimicrobials, but beta-lactam resistance is increasingly common among members of the Bacteroides fragilis group. Three major mechanisms are involved in beta-lactam resistance, and they act together in certain instances. In the present study, 2 resistant mutants (238m and 1186m) of Bacteroides thetaiotaomicron, obtained ...

The number of clinical specimens containing β-lactam-resistant Pseudomonas aeruginosa isolates is increasing. However, whether resistance is associated with reduced fitness is still uncertain in clinical Pseudomonas aeruginosa isolates. In this study, we aimed to determine whether β-lactam resistance conferred a fitness cost in Pseudomonas aeruginosa. Growth rate, extracellular slime production...

cage birds like canaries can potentially harbor human pathogens and contribute to transmission and spread of drug resistant infectious agents to human. considering many people's interests to keep canaries, present study was conducted in canaries from yazd to investigate the beta-lactam antibiotics resistant escherichia coli. 109 e. coli isolates from canary faeces in yazd were evaluated to...

Beta-lactam antibiotics are an important class of antibiotics for treating bacterial infections. Despite prevalent β-lactam resistance in Campylobacter jejuni, the leading bacterial cause of human diarrhea in developed countries, molecular mechanism of β-lactam resistance in C. jejuni is still largely unknown. In this study, C. jejuni 81-176 was used for random transposon mutagenesis. Screening...

Beta-lactam antibiotics form the backbone of treatment for Gram-negative pneumonia in mechanically ventilated patients in the intensive care unit. However, this beta-lactam antibiotic backbone is increasingly under pressure from emerging resistance across all geographical regions, and health-care professionals in many countries are rapidly running out of effective treatment options. Even in reg...