Improved performance of bacterium and yeast identification by a commercial matrix-assisted laser desorption ionization-time of flight mass spectrometry system in the clinical microbiology laboratory.

摘要

Bizzini et al. described the use of a commercial matrix-assisted laser desorption ionization-time of flight mass spec-trometry (MALDI-TOF MS) system as a reliable, fast, and efficient method for the identification (ID) of bacteria and yeasts (1). Among 1,371 isolates identified by conventional methods, 1,037 (75.6) isolates were identified by MALDI-TOF to.either the species or genus level by direct analysis of a colony. A small amount of colony was smeared onto a gridded steel plate, allowed to dry briefly, and overlaid with 1 fjil of HCCA (a-cyano-4-hydroxycinnamic acid) matrix before analysis in a Bruker Microflex MS system. For isolates which are not identified by this direct method, Bizzini et al. used an extraction method in which colonies were suspended in water and alcohol and centrifuged and bacterial proteins in the deposit were extracted with formic acid and acetonitrile before analysis (1).