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...

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...

A variety of novel tetrazole derivatives attached to the β-lactam ring was made utilizing heptanitrile in a reaction with generated azide-β-lactam derivatives, and these compounds were then studied using IR NMR spectroscopy. Biological testing showed that most final good antibacterial antifungal activity, particularly derivative (b3), which shown efficacy on par or even superior reference drugs...

The activity of daptomycin (DAP) against methicillin-resistant Staphylococcus aureus (MRSA) is enhanced in the presence of subinhibitory concentrations of antistaphylococcal β-lactam antibiotics by an undefined mechanism. Given the variability in the penicillin-binding protein (PBP)-binding profiles of different β-lactam antibiotics, the purpose of this study was to examine the relative enhance...

The enzymatic ring-opening copolymerization of ε-caprolactone (ε-CL) and β-lactam by using Candida antarctica lipase B (CAL-B) as catalyst was studied. Variation of the feed ratios of 25:75, 50:50, and 75:25 of ε-CL/β-lactam was performed. The products contain poly(ε-CL-co-β-lactam) and the homopolymers of poly(ε-CL) and poly(β-lactam). The structure of the copolymers was determined by MALDI-To...

Novel enantiopure pseudopeptide models containing a central -(β-lactam)-(Aa)- scaffold characterized by the combined presence of an α-alkyl-α-amino-β-lactam (i+1) residue and a α-substituted (i + 2) amino acid have been readily synthesized from α-alkyl serines. The conformational analysis of such β-lactam pseudopeptides conducted in CDCl(3) and DMSO-d(6) solutions using 1D- and 2D-NMR technique...

OBJECTIVE Skin testing with penicilloyl-polylysine (PPL) and a minor determinant mixture (MDM) were previously recommended for evaluating β-lactam hypersensitivity. However, PPL and MDM have not been commercially available. This study was to determine the negative predictive value (NPV) of skin testing with β-lactam antibiotics for the diagnosis of β-lactam hypersensitivity. METHOD Patients a...

As a novel strategy to remove β-lactam antibiotic residues from fish tissues, utilization of β-lactamase, enzyme that normally degrades β-lactam structure-containing drugs, was explored. The enzyme (TEM-52) selectively degraded β-lactam antibiotics but was completely inactive against tetracycline-, quinolone-, macrolide-, or aminoglycosidestructured antibacterials. After simultaneous administra...

BACKGROUND AND OBJECTIVE Administration of carbapenems to β-lactam-allergic patients has always been considered potentially harmful because of a 47.4% rate of cross-reactivity to imipenem reported in a single study. Nevertheless, recent studies have shown that the rate of cross-reactivity of imipenem and meropenem with penicillins is lower than 1%. The aim of this study was to evaluate the poss...