Abstract: A method for identifying by mass spectrometry an unknown microorganism subgroup among a set of reference subgroups, including a step of constructing one knowledgebase and one classifying model per associated subgroup on the basis of the acquisition of at least one set of learning spectra of microorganisms identified as belonging to the subgroups of a group and including: constructing an adjusting model allowing mass-to-charge offsets of the acquired spectra to be corrected on the basis of reference masses-to-charges that are common to the various subgroups; adjusting the masses-to-charges of all of the lists of peaks of the learning spectra and constructing one classifying model per subgroup and the associated knowledgebase on the basis of the adjusted learning spectra.

Abstract: A method for identifying by mass spectrometry an unknown microorganism subgroup among a set of reference subgroups, including a step of constructing one knowledgebase and one classifying model per associated subgroup on the basis of the acquisition of at least one set of learning spectra of microorganisms identified as belonging to the subgroups of a group and including: constructing an adjusting model allowing mass-to-charge offsets of the acquired spectra to be corrected on the basis of reference masses-to-charges that are common to the various subgroups; adjusting the masses-to-charges of all of the lists of peaks of the learning spectra and constructing one classifying model per subgroup and the associated knowledgebase on the basis of the adjusted learning spectra.

Abstract: A method for characterizing at least one microorganism from a sample includes identifying the at least one microorganism and determining the properties of typing, potential resistance to at least one antimicrobial, and virulence factor. The properties of typing, resistance to at least one antimicrobial, and virulence factor for the at least one microorganism are determined by implementing mass spectrometry using proteins, peptides and/or metabolites as markers of the properties of typing, resistance to at least one antimicrobial, and virulence factor.

Abstract: The present invention is directed to a method for inactivation and/or extraction of acid-fast bacteria (e.g., mycobacteria or nocardia), the method comprising the following sequential steps: (a) acquiring a test sample known to contain or that may contain acid-fast bacteria and suspending the test sample in a container containing ethanol and beads; (b) bead beating and/or vortexing the container to break up clumps and/or disrupt acid-fast bacteria cells in the container; and (c) subsequently incubating the suspension for at least about 3 minutes at room temperature to inactivate any acid-fast bacteria contained in the test sample. In accordance with the present invention, the test sample can subsequently be pelleted by centrifugation, resuspended with formic acid, acetonitrile added, and subjected to mass spectrometry for characterization and/or identification of the acid-fast bacteria.

Abstract: The present invention is directed to a method for inactivation and/or extraction of fungus samples (e.g., mold or yeast samples), the method comprising the following sequential steps: (a) acquiring a test sample known to contain or that may contain fungus and suspending the test sample in a container containing water and/or suspension medium; (b) adding ethanol to the suspension; (c) centrifuging the container to pellet the fungus and removing and discarding the supernatant; (d) resuspending the fungus in formic acid; (e) adding acetonitrile to the sample; (f) centrifuging the sample; and (g) recovering the supernatant. In accordance with the present invention, the recovered supernatant can be subjected to mass spectrometry analysis for characterization and/or identification of the unknown fungus.

Abstract: The present invention is directed to a method for inactivation and/or extraction of acid-fast bacteria (e.g., mycobacteria or nocardia), the method comprising the following sequential steps: (a) acquiring a test sample known to contain or that may contain acid-fast bacteria and suspending the test sample in a container containing ethanol and beads; (b) bead beating and/or vortexing the container to break up clumps and/or disrupt acid-fast bacteria cells in the container; and (c) subsequently incubating the suspension for at least about 3 minutes at room temperature to inactivate any acid-fast bacteria contained in the test sample. In accordance with the present invention, the test sample can subsequently be pelleted by centrifugation, resuspended with formic acid, acetonitrile added, and subjected to mass spectrometry for characterization and/or identification of the acid-fast bacteria.

Abstract: The present invention relates to a method for characterizing at least one microorganism from a sample, said method including identifying said at least one microorganism and determining the properties of typing, potential resistance to at least one antimicrobial, and virulence factor, characterized in that determining the properties of typing, resistance to at least one antimicrobial, and virulence factor for said at least one microorganism is implemented by means of mass spectrometry through the use of proteins, peptides and/or metabolites as markers of said properties of typing, resistance to at least one antimicrobial, and virulence factor.