Multi-centre evaluation of real-time multiplex PCR for detection of carbapenemase genes OXA-48, VIM, IMP, NDM and KPC

Background: Resistance to carbapenem antibiotics is emerging worldwide among Enterobacteriaceae. To prevent hospital transmission due to unnoticed carriage of carbapenemase producing micro-organisms in newly admitted patients, or follow-up of patients in an outbreak setting, a molecular screening method was developed for detection of the most prevalent carbapenemase genes; blaOXA-48, blaVIM, blaIMP, blaNDM and blaKPC.Methods: A real-time multiplex PCR assay was evaluated using a collection of 86 Gram negative isolates, including 62 carbapenemase producers. Seven different laboratories carried out this method and used the assay for detection of the carbapenemase genes on a selection of 20 isolates.Results: Both sensitivity and specificity of the multiplex PCR assay was 100%, as established by results on the strain collection and the inter-laboratory comparisons.Conclusions: In this study, we present a multiplex real-time PCR that is a robust, reliable and rapid method for the detection of the most prevalent carbapenemases blaOXA-48, blaVIM, blaIMP, blaNDM and blaKPC, and is suitable for screening of broth cultured rectal swabs and for identification of carbapenemase genes in cultures

Reaction of the diimine pyridine ligand with aluminum alkyls: An unexpectedly complex reaction

Item does not contain fulltextThe diimine pyridine ligand 2,6-{2,6-(Pr2C6H3N)-Pr-i=CMe}(2)C5H3N (1) was reacted with a series of aluminum alkyls (Me3Al, Et3Al, (Bu3Al)-Bu-i, (Bu2AlH)-Bu-i, Et2AlCl). Depending on the choice of alkyl, addition to the imine carbon and the pyridine C2 and C4 positions was observed. Addition to C2 usually dominates but is reversible; the C4 alkylation product eventually dimerizes via double C-C coupling. Reaction of 1 with AlCl3 gave the ionic complex [1 center dot AlCl2](+)[AlCl4](-). DFT calculations were used to support NMR assignments of the various addition products and also to study alkyl transfer from Et2AlCl to simplified model ligand 1'. Direct alkyl transfer from coordinated Et2AlCl to the ligand C4 position is not possible. Introduction of a second molecule of Et2AlCl results in formation of the ion pair [1'center dot AlEtCl](+)[Et3AlCl](-), from which alkyl transfer to any position of the ligand is relatively easy. The dimerization of the C4-alkylated product is symmetry-forbidden and was calculated to follow a stepwise biradical path with an unusually low barrier

Reaction of AlEt2Cl with the diiminepyridine ligand: an unexpected product

Item does not contain fulltextReaction of AlEt2Cl with 2,6-bis(1-(2,6-diisopropylphenylimino)ethyl)pyridine offered an unexpected tricyclic complex, which was characterized by X-ray diffraction. The dimerisation reaction leading to this product has been studied by DFT calculations. This symmetry-forbidden cyclisation reaction was found to follow a biradical pathway with an unusual low energy barrier. (C) 2004 Academie des sciences. Published by Elsevier SAS. All rights reserved

Schrijfonderwijs van twee pabo-docenten beschreven

Item does not contain fulltextVelon congres 2003, 7 april 200