The factors influencing the oligomerization state of OXA-10 and OXA-14 class D beta-lactamases in solution have been investigated. Both enzymes were found to exist as an equilibrium mixture of a monomer and dimer, with a K(d) close to 40 microM. The dimeric form was stabilized by divalent metal cations. The ability of different metal ions to stabilize the dimer was in the following order: Cd(2+...

This work is a report on the development of a method of hybridization analysis on DNA microarrays for the simultaneous identification and typing of carbapenemase-encoding genes. These enzymes are produced by the microorganisms that are responsible for causing infectious diseases. The method involves several steps, including DNA extraction from clinical samples and amplification of carbapenemase...

Acinetobacter sp. has emerged as a major hospital pathogen (8). The greatest concern has been the emergence of carbapenem resistance in Acinetobacter baumannii by the acquisition of OXA-type carbapenemase or metallo-lactamases, since few effective antimicrobial agents exist. Several mechanisms can underlie carbapenem resistance in A. baumannii (1), but less is known about carbapenem resistance ...

Sir, Carbapenem resistance in Acinetobacter baumannii is now increasingly reported. The most prevalent mechanism of carbapenem resistance in A. baumannii corresponds to the production of acquired carbapenem-hydrolysing class D b-lactamases (CHDLs) encoded by blaOXA-23-like, blaOXA-40-like or blaOXA-58-like genes. Whereas the blaOXA-40 gene has been detected in Portugal, Spain and the USA, blaOX...

Extended-spectrum ?-lactamase-producing Enterobacteriaceae (ESBL-E) and carbapenemase-producing (CPE) are widespread. Here we used the ‘One Health’ approach to determine knowledge gaps on ESBL-E CPE in West Central Africa. We searched all articles these African regions published PubMed, Journals Online Google Scholar from 2000 onwards. Among 1201 retrieved, selected 165 studies (West Africa, 11...

In 2000, at the Université d'Auvergne teaching hospital in Clermont-Ferrand, France, 44 (6.2%) strains of Pseudomonas aeruginosa were found to be resistant to ceftazidime. After genotyping, 34 strains were selected. Nine had an additional beta-lactamase: OXA-21 (n = 6), PSE-1 (CARB-2) (n = 2), or PER-1 (n = 1). Ceftazidime resistance was related solely to the overproduction of the cephalosporin...

ChromID extended-spectrum beta-lactamase (ESBL) culture medium is routinely used for screening ESBL producers. This medium was tested for detecting carbapenemase-producing Enterobacteriaceae isolates from a collection of reference strains and compared to the CHROMagar KPC culture medium previously evaluated for detecting KPC-producing isolates. Producers of IMP-, VIM-, and KPC-type carbapenemas...

This descriptive study was accomplished on 83 K. pneumoniae strains isolated from two hospitals in Tehran, Iran. Antibiotic susceptibility tests were performed by disc diffusion and broth microdilution methods. ESBLs, MBL, Amp-C, and KPC producing strains were detected by phenotypic confirmatory test, combination disk diffusion test (CDDT), Amp-C detection kit, and modified Hodge test, respecti...

In this surveillance study, we identified the genotypes, carbapenem resistance determinants, and structural variations of AbaR-type resistance islands among carbapenem-resistant Acinetobacter baumannii (CRAB) isolates from nine Asian locales. Clonal complex 92 (CC92), corresponding to global clone 2 (GC2), was the most prevalent in most Asian locales (83/108 isolates; 76.9%). CC108, or GC1, was...