abstract background: pseudomonas aeruginosa is one of the most common gram negative bacteria involved in nosocomial infections. presence of extended-spectrum beta-lactamases (esbls) genes, play an important role in induction of resistance in beta-lactamase producing species to beta lactam antibiotics. frequency of resistance to these antibiotics is increasing. in this study, antibiotic sensitiv...

The monobactam antibiotic aztreonam is used to treat cystic fibrosis patients with chronic pulmonary infections colonized by Pseudomonas aeruginosa strains expressing CTX-M extended-spectrum β-lactamases. The protonation states of active-site residues that are responsible for hydrolysis have been determined previously for the apo form of a CTX-M β-lactamase but not for a monobactam acyl-enzyme ...

background: resistance to contemporary broad-spectrum b-lactam antibiotics mediated by extended-spectrum b-lactamases (esbls) is increasing worldwide. klebsiella pneumoniae , an important cause of nosocomial and community acquired urinary tract infections has rapidly become the most common esbl producing organism. we examined esbl production in urinary isolates of k. pneumoniae in relation to t...

conclusions our study emphasized the increasing role of esbl genes, especially blactx-m15 in epec isolates. results of 42 epec, eight isolates carried the blactx-m1. none of the isolates carried blactx-m2 and blactx-m9. the blactx-m15 variant was identified in all of blactx-m1-positive isolates. furthermore, blashv and blatem genes were detected in 40.5% (n = 17) and 19% (n = 8) of all epec iso...

BACKGROUND Extended-spectrum β-lactamases (ESBLs) is one of the most important mechanisms of resistance to β-lactams especially among Enterobacteriaceae family including Klebsiella spp. Different types of extended-spectrum β-lactamases including CTX-M-type and PER enzymes are identified among gram negative bacteria. OBJECTIVES The current study aimed to determine the prevalence of CTX-M-type ...

BACKGROUND Extended spectrum β-lactamase (ESBL) are gram-negative bacteria that produce the enzyme, β-lactamase, which can break down commonly used antibiotics, such as penicillin and cephalosporins, making infections with ESBL producing bacteria more difficult to treat. Extended spectrum β-lactamase-producing Klebsiella pneumoniae were first reported in 1983 from Germany, and since then a stea...

We investigate random, discrete Schrödinger operators which arise naturally in the theory of random matrices, and depend parametrically on Dyson’s Coulomb gas inverse temperature β. They are similar to the class of “critical” random Schrödiner operators with random potentials which diminish as |x|− 12 . We show that as a function of β they undergo a transition from a regime of (power-law) local...

We studied the prevalence of ceftazidime resistance in Pseudomonas aeruginosa and the rates of extended-spectrum β-lactamase (ESBL), AmpC β-lactamase (AmpC) and metallo-β-lactamase (MBL) production among the ceftazidime resistant Pseudomonas aeruginosa. A very high rate of MBL production was observed, which suggested it to be an important contributing factor for ceftazidime resistance among Pse...