Microorganism identification method

Abstract

Provided is a microorganism identification method involving the selection and use of a marker protein that makes it possible to quickly identify bacterial species of the genus Listeria with good reproducibility. The microorganism identification method comprises: a step in which a sample containing microorganisms is subjected to mass spectrometry and a mass spectrum is obtained; a reading step in which the mass-to-charge ratio m / z of peaks derived from a marker protein is read from the mass spectrum; and an identification step in which the mass-to-charge ratio m / z is used as a basis to identifywhether the microorganisms included in the sample include any bacterial species of the genus Listeria. The microorganism identification method is characterized in that one or more of the following seventeen types of ribosomal proteins is used as the marker protein: L3; L4; L23; L2; L24; L6; L18; S5; L15; S13; S11; L10; L21; L13; S9; L31; and S16. The microorganism identification method is also characterized in that among the seventeen types of ribosomal proteins, particularly one or more of the following eight types of ribosomal proteins is used: L24; L6; L18; L15; S9; L31; and S16.

Description

technical field [0001] The present invention relates to a method for identifying microorganisms using mass analysis. Background technique [0002] Homology analysis based on DNA base sequences has been known as one of the methods for identifying the type of microorganisms, and has been widely used in the classification and identification of microorganisms (for example, refer to Patent Document 1). In this method, first, DNA is extracted from a microorganism to be examined, and the DNA base sequence of a region such as an rRNA gene, which exists at a high degree of preservation in all organisms, is determined. Then, using the DNA base sequence, a large number of databases containing DNA base sequences of known microorganisms are searched, and a base sequence showing a high similarity to the DNA base sequence of the microorganism to be examined is selected. Next, the species from which the nucleotide sequence is derived is judged to be the same species or a closely related sp...

AI Technical Summary

Problems solved by technology

[0005] However, in the identification of microorganisms by the fingerprint method using the above-mentioned mass analysis, even if identification can be performed at the genus level or at the level of more distant species, it is generally difficult to identify between closely related species or more closely related species. The lower taxonomic level is the identification in the level of subspecies, pathogenic type, or strain, etc.

Furthermore, in the fingerprinting method, it is not determined which protein each of the peaks appearing on the mass spectrum is derived from, so there are technical problems in the theoretical basis and reliability of the identification

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