リボソームタンパク質をバイオマーカーとしたMALDI-TOF MSによる細菌識別: S10-GERMS法による細菌の迅速識別

摘要

Previous bacterial identification methods based on ribosomal proteins as biomarkers have several weaknesses in phylogenetic analysis:(1)type strains must be genome-sequenced; (2) the ribosomal protein database constructed based on amino acid sequences of genome-sequenced bacteria includes some errors in the amino acid sequences; and (3) it is difficult to clarify the phylogenetic position at species level. To establish an accurate bacterial discrimination method by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) at strain level, the ribosomal proteins coded in the S10-spc-alpha operon, which encodes half of the ribosomal subunit proteins and is highly conserved in eubacterial genomes, were selected as reliable biomarkers. A newly developed method using those biomarkers, called the S10-GERMS(the S10-spc-alpha operon gene encoded ribosomal protein mass spectrum) method, overcomes those weaknesses and will be a powerful tool for rapid and reliable bacterial discrimination and successful phylogenetic characterization.%これまでのリボソームタンパク質をバイオマーカーとした微生物同定法は，系統解析をする上で次のような課題が存在した；1)基準株(Type strain)のゲノム解読情報が必要である；2)ゲノム解読されたリボソームタンパク質データベースにエラーが存在する；3)種レベルの系統学的距離を示すことが困難である。そこで細菌に共通に存在するS10-spc-alphaオペロンにコードされるリボソームタンパク質をバイオマーカーとしたMALDI-TOF MS(Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry)による細菌同定•識別法(S10-spc-alpha operon Gene Encoded Ribosomal protein Mass Spectrum:S10-GERMS法）を確立した。