OBJECTIVES To determine the mechanisms of resistance to β-lactam antibiotics in clinical isolates of Haemophilus parainfluenzae. METHODS Twenty clinical isolates of H. parainfluenzae with decreased susceptibility to aminopenicillins were examined and compared with a control group of 20 fully susceptible isolates. In this collection, the presence of amino acid substitutions in the transpeptida...

A clinical isolate of Pseudomonas aeruginosa was found to produce a clavulanic acid-inhibited extended-spectrum beta-lactamase with a pI of 6.4. PCR, cloning, and sequencing experiments showed that the corresponding bla(TEM-21) gene was part of a chromosomally located Tn801 transposon disrupted by an IS6100 element and adjacent to an aac(3)-II gene.

BACKGROUND Quinolone resistance in Enterobacteriaceae species has increased over the past few years, and is significantly associated to beta-lactam resistance. The aim of this study was to evaluate the prevalence of chromosomal- and plasmid-mediated quinolone resistance in acquired AmpC β-lactamase and/or carbapenemase-producing Enterobacteriaceae isolates. METHODS The presence of chromosomal...

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...

Background & Aims: The production of extended-spectrum-β-lactamases (ESBLs) is the main mechanism of resistance to β-lactam antibiotics. The outbreak of isolates simultaneously possessing several resistance mechanisms to β-lactam antibiotics caused a decrease in sensitivity of the confirmatory tests for ESBL. The aim of this study was the evaluation of the β-lactamase disk test method in the de...

Published Ahead of Print 17 November 2008. 10.1128/AAC.00785-08. 2009, 53(1):331. DOI: Antimicrob. Agents Chemother. and Arnfinn Sundsfjord Christian G. Giske, Nils O. Hermansen, Timothy R. Walsh Ørjan Samuelsen, Liselotte Buarø, Mark A. Toleman, from Ghana Isolate of Sequence Type 233 Imported Pseudomonas aeruginosa Transposon in a Norway Is Associated with a TniC-Like -Lactamase Identified in...

An Escherichia coli strain exhibiting decreased susceptibility to carbapenems was isolated from a hospitalized patient in Greece. The strain carried a self-transferable plasmid coding for metallo-beta-lactamase VIM-1. bla(VIM-1), along with aacA7, dhfrI, and aadA, was included as a gene cassette in a novel class 1 integron. A Citrobacter freundii ampC-derived gene, not associated with the integ...

An environmental isolate of Serratia fonticola resistant to carbapenems contains a gene encoding a class A beta-lactamase with carbapenemase activity. The enzyme was designated SFC-1. The bla(SFC-I) gene is contained in the chromosome of S. fonticola UTAD54 and is absent from other S. fonticola strains.

BACKGROUND Emergence of extended-spectrum beta-lactamases (ESBLs) in Shigella species imparting resistance to third-generation cephalosporins is a growing concern worldwide. The aim of this study is to molecularly characterize the newly emerging beta-lactam resistant Shigella sonnei, specifically ESBLs in Lebanon, and compare them to beta-lactam sensitive isolates. METHODOLOGY We compared fiv...

Resistance to extended-spectrum cephalosporins (ESC) among members of the family Enterobacteriaceae occurs worldwide; however, little is known about ESC resistance in Escherichia coli strains from companion animals. Clinical isolates of E. coli were collected from veterinary diagnostic laboratories throughout the United States from 2008 to 2009. E. coli isolates (n = 54) with reduced susceptibi...