Method for identifying marker for discriminating microorganism

A method for identifying a marker for discriminating a microorganism, comprising steps 1 to 8 below:

• step 1:
• select a microorganism whose entire genome has been decoded,
• step 2:
• perform mass spectrometry on protein possessed by the microorganism selected in step 1 above to obtain molecular weight-related ion peaks of the protein,
• step 3:
• obtain an actual m/z value of each peak from the molecular weight-related ion peaks obtained in step above,
• step 4:
• for the microorganism selected in step 1 above, obtain protein information of the protein possessed by the microorganism and amino acid sequence information thereof from a genetic database, and calculate a theoretical m/z value of the protein from the obtained amino acid sequence information,
• step 5:
• compare the theoretical m/z value calculated in step with the actual m/z value obtained in step 3 above, and assign the actual m/z value to a protein and an amino acid sequence thereof that have theoretical m/z values that match the actual m/z values,
• step 6:
• obtain an amino acid sequence information similar to the protein assigned in step 5 above from the genetic database,
• step 7:
• among microorganisms having similar amino acid sequences based on the amino acid sequence information obtained in step 6 above, select a microorganism according to discrimination and classification, and calculate the theoretical m/z value of the amino acid sequence of the protein possessed by the microorganism, and
• step 8:
• compare the theoretical m/z values of the amino acid sequence calculated in step 7 for each classification, and identify the protein with different theoretical m/z values for each classification as a marker for discrimination.