Shimadzu Corporation

Meijo University

Keio University

Keisuke Shima

Hiroto Tamura

Shinji Funatsu

Naomi Yamamoto

Teruyo Kato

Koretsugu Ogata

Noriyuki Ojima

Akifumi Hosoda

Yudai Hotta

Yosihiro Yamada

Miyuki Morozumi

Megumi Sakuma

Provided is a method of identifying a serovar ofbacteria including a step of subjecting a sample containing microorganisms to mass spectrometry to obtain a mass spectrum, a step of reading a mass-to-charge ratio m/z of a peak derived from a marker protein from the mass spectrum, and an identification step of identifying a serovar ofbacteria in the sample, based on the mass-to-charge ratio m/z, wherein the serovars ofbacteria are classified using cluster analysis using as an index the mass-to-charge ratio m/z derived from at least 12 types of ribosomal proteins S8, L15, L17, L21, L25, S7, SODa, peptidylprolyl isomerase, gns, YibT, YaiA and YciF as the marker proteins.

Microorganism identification method

An analysis method includes: acquiring data corresponding to a mass spectrum obtained by subjecting a sample containing a microorganism to mass spectrometry; and acquiring information on Group Aof emm type 1, based on the presence or absence, or magnitude of a peak in a first range of m/z of 10930 or more to 10945 or less in the mass spectrum.

Analysis method, analytical method and microorganism identification method

To provide a method for discriminating a microorganism by selecting and using a marker protein capable of reproducibly and quickly discriminating a bacterial species of the genus. The method for discriminating a microorganism according to the present invention includes: a step of subjecting a sample containing a microorganism to mass spectrometry to obtain a mass spectrum; a reading step of reading a mass-to-charge ratio m/z of a peak derived from a marker protein from the mass spectrum; and a discrimination step of discriminating which bacterial species ofbacteria the microorganism contained in the sample contains based on the mass-to-charge ratio m/z, in which at least one of 17 ribosomal proteins L3, L4, L23, L2, L24, L6, L18, S5, L15, S13, S11, L10, L21, L13, S9, L31, S16 is used as the marker protein and particularly at least one of 8 ribosomal proteins L24, L6, L18, L15, S9, L31, S16 among the 17 ribosomal proteins is used.

Method for discriminating a microorganism

A microorganism identification method according to the present invention includes a step of subjecting a sample containing microorganisms to mass spectrometry to obtain a mass spectrum, a step of reading a mass-to-charge ratio m/z of a peak derived from a marker protein from the mass spectrum, and an identification step of identifying which bacteria of serovar ofgenus bacteria the microorganisms contained in the sample contain, based on the mass-to-charge ratio m/z, in which at least one of two types of ribosomal proteins S8 and Peptidylpropyl isomerase is used as the marker protein.

When a user inputs samples per group, a sample tree and a peak matrix are generated. Peak lists per group are shown in the sample tree, and m/z values and signal strength values from the peak lists are coordinates in the peak matrix. A multivariate analysis is applied to the generated peak matrix. The sample tree, peak matrix, score plot, and loading plot are displayed. When the user clicks a plotted point on the loading plot, a row indicating a corresponding peak on the peak matrix is discriminated. When the user deletes a checkmark corresponding to the discriminated row, the multivariate analysis is applied to the peak matrix from which the peak has been excluded. The score plot and other data are updated. When separation between groups is known from the score plot as failure, the excluded peak may be visually determined as a marker contributing to the group separation.

Mass spectrometric data analyzer and mass spectrometric data analyzing program

To provide a method for discriminating a microorganism including: a step of subjecting a sample containing a microorganism to mass spectrometry to obtain a mass spectrum; a reading step of reading a mass-to-charge ratio m/z of a peak derived from a marker protein from the mass spectrum; and a discrimination step of discriminating which bacterial species ofbacteria, andthe microorganism contained in the sample contains based on the mass-to-charge ratio m/z, in which at least one of 13 ribosomal proteins S5, L15, S13, L31, L22, L19, L20, L13, S15, L25, HNS, HdeB, and L29 is used as the marker protein.

Method for discriminating microorganism

A microorganism identification method includes steps of: obtaining a mass spectrum through mass spectrometry of a sample including microorganisms; reading, from the mass spectrum, a mass-to-charge ratio m/z of a peak associated with a marker protein; and identifying which bacterial species of the genusare included in the microorganisms in the sample based on the mass-to-charge ratio m/z. The microorganism identification method is further characterized in that at least one of the following 18 marker proteins is used as the marker protein, S10, L23, S19, L22, L16, L29, S17, L14, L24, S14, L18, L15, L36, S13, S11 (Me), L32, and L7/L12.

An apparatus that identifies the type of a test cell based on a result obtained by performing mass spectrometry on the test cell includes a higher-level database, which contains mass lists that each list ion mass values of constituent components of a known cell, and a lower-level database, which contains partial mass lists that each list only strain-specific ion mass values out of the ion mass values. The higher-level database is first searched for a test mass list which is created from the result of the mass spectrometry performed on the test cell, and based on a result of the search, an organism species to be searched in the following search operation is determined. Mass values common to the organism species are subsequently deleted from the mass list for the test cell, and the mass list having undergone the deletion operation is used to search the lower-level database.

Growing community of inventors

Kyoto, Japan

Keisuke Shima