A Klebsiella pneumoniae isolate was identified that had reduced susceptibility to several expanded-spectrum cephalosporins and imipenem. That isolate produced a chromosome-encoded SHV-type beta-lactamase, SHV-38, that had an alanine to valine substitution in position Ambler 146 compared to beta-lactamase SHV-1. The kinetic parameters for purified beta-lactamases SHV-38 and SHV-1 showed that the...

The stability of meropenem in the presence of renal dehydropeptidase I (DHP-I) varied extremely with the animal source of the enzyme. Meropenem, compared with imipenem, was rather easily hydrolyzed by DHP-Is from mice, rabbits, and monkeys, while it showed a higher resistance to guinea pig and beagle dog DHP-Is. In addition, meropenem was four times more resistant than imipenem to human DHP-I. ...

We investigated the synergism of colistin and imipenem against a multidrug-resistant K. pneumoniae isolate which was recovered from a severe hip infection. PCR and DNA sequencing were used to characterize the outer membrane porin genes and the resistance genes mediating the common β-lactamases and carbapenemases. Synergism was evaluated by time-kill studies. The bla SHV-31, bla CMY-2, and bla D...

Multiple antibiotic resistance threatens successful treatment of Acinetobacter baumannii infections worldwide. Increasing interest in the well-known activity of sulbactam against the genus Acinetobacter has been aroused. The purpose of this study was to compare the outcomes for patients with Acinetobacter bacteremia treated with cefoperazone/sulbactam versus imipenem/cilastatin. Forty-seven pat...

Background: Resistant strains of Pseudomonas aeruginosa to imipenem was medical treatment problem, especially in burnt units of hospitals. Objectives: This study was conducted to evaluate the antimicrobial effect of Fe2O3 nanoparticles alone and functionalized with imipenem on P. aeruginosa starins producing metallo b-lactamases (MBL). Materials and Methods: A disk diffusion method was used to...

Introduction of the Vitek GNS-506 susceptibility testing cards in the Hippokration General Hospital, Thessaloniki, Greece, resulted in an apparently high prevalence of imipenem-resistant Acinetobacter baumannii. When 35 of these isolates were further tested by disk diffusion, broth microdilution, and agar dilution assays, 32 were imipenem sensitive by all tests and three were sensitive or inter...

Prompt detection of metallo-beta-lactamase (MBL) producing isolates is necessary to prevent their dissemination. Frequency of MBLs producing strains among multidrug resistant (MDR) Acinetobacter species and Pseudomonas aeruginosa was evaluated in critical care patients using imipenem-EDTA disk method. One hundred MDR Acinetobacter spp. and 42 Pseudomonas aeruginosa were checked for MBL producti...

A total of 87 Acinetobacter baumannii nonrepetitive consecutive clinical isolates were tested for the presence of metallo-beta-lactamases (MBLs). Results of phenotypic assays (MBL Etest, imipenem/imipenem-EDTA combined-disk test, and imipenem/EDTA double-disk synergy test) were negative in all cases, but molecular testing revealed the presence of two bla(VIM-1)-carrying isolates. One isolate ha...

Background & objective Beta-lactam antibiotics resistance specifically Imipenem and Meropenem, the last choices of treatment, causes fatal events in patients with P.aeruginosa infection. The aim of this study was to detect the VIM and IMP of metallo-beta-lactamase genes in 103 isolates of P. aeruginosa in two Iranian hospitals. Methods In this study, we evaluated the susceptibility of P. aeru...