MALDI-TOF MS, a useful instrument for differentiating metallo-β-lactamases in Enterobacteriaceae and Pseudomonas spp.

Autor: Hoyos-Mallecot Y; Department of Microbiology, University Hospital Virgen de las Nieves, Granada, Spain; Clinical Medicine and Public Health, Postgraduate programme, University of Granada, Granada, Spain., Cabrera-Alvargonzalez JJ, Miranda-Casas C, Rojo-Martín MD, Liebana-Martos C, Navarro-Marí JM
Jazyk: angličtina
Zdroj: Letters in applied microbiology [Lett Appl Microbiol] 2014 Apr; Vol. 58 (4), pp. 325-9. Date of Electronic Publication: 2013 Dec 18.
DOI: 10.1111/lam.12203
Abstrakt: Unlabelled: We have evaluated a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) method for the identification of carbapenemases and for distinguishing metallo-β-lactamases (MBLs). A total of 49 noncarbapenemase-producing and 14 carbapenemase-producing Enterobacteriaceae and Pseudomonas aeruginosa clinical strains, previously characterized by PCR, were included in the study. With MALDI-TOF MS, the presence of carbapenemases was confirmed by the detection of ertapenem hydrolysis (lost of molecular peaks: 476·5 Da, 498·5 Da, 520·5 Da and presence of degradation products) in the mixture of the bacteria with the antibiotic, and classification was achieved by selective inhibition of carbapenemase activity (the ertapenem molecular peak was maintained) with ethylenediaminetetraacetic acid (EDTA). We obtained a good concordance among the results of PCR and MALDI-TOF MS. This method appears to be simple, fast and reliable for distinguishing in few hours different classes of carbapenemases, which can be very useful for epidemiological studies or to establish a specific antimicrobial therapy.
Significance and Impact of the Study: MALDI-TOF mass spectrometry is increasingly present in microbiology laboratories due to its increasing use for bacterial identification. This study describes a method for detection of carbapenemase activity using MALDI-TOF, which is similar to the reference method: the detection of imipenem hydrolysis using UV spectrometry.
(© 2013 The Society for Applied Microbiology.)
Databáze: MEDLINE
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