Differentiation of clinically relevant Mucorales Rhizopus microsporus and R. arrhizus by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS).

摘要: This study addresses the usefulness of matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) MS for reliable identification two most frequently occurring clinical species Rhizopus, namely Rhizopus arrhizus with its varieties, and delemar, microsporus. The test-set comprised 38 isolates environmental origin previously identified by internal transcribed spacer (ITS) sequencing rDNA. Multi-locus sequence data targeting three gene markers (ITS, ACT, TEF ) showed monophylic clades microsporus (bootstrap values 99 %). Cluster analysis confirmed presence distinct within representing varieties delemar. MALDI Biotyper 3.0 Microflex LT platform (Bruker Daltonics) was used to confirm distinction between arrhizus. An in-house database 30 reference main spectra (MSPs) initially tested correctness using commercially available databases Bruker Daltonics. By challenging same strains which an created, automatic runs that MALDI-TOF is able recognize at variety level. Based on principal component analysis, MSP dendrograms were created concordance multi-locus tree; thus, a useful tool diagnostics mucoralean species.