[The use in routine of mass spectrometry in a hospital microbiology laboratory].
OBJECTIVE
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently been introduced in diagnostic microbiology laboratories for the identification of microorganisms. The mass fingerprint obtained by analyzing the ribosomal proteins and proteins associated with membranes is compared to spectra and superspectra of database. Microbiological Laboratory of Mulhouse acquired this system 1 year ago.


METHODS
The MALDI-TOF MS analyses of all strains were performed on Axima(®) (Shimadzu), data analysis with Saramis(®) software (Anagnostec) and integration with SirWeb(®) software (I2A society).


RESULTS
Rapidly, laboratory technicians and biologists are able to turn the system after a few days of training. The data prospectively gathered in the present study demonstrated that MALDI-TOF mass spectrometry identification is an efficient method included fastidious bacteria. Exactly 98.8 % of 10,000 isolates were identified in genus and species levels. Use of identification techniques was seldom necessary for a few clinical relevant isolates. The database is in constant evolution. The superspectra contain characteristic signals of genus, species allowing reliable microorganism identifications with high confidence.


CONCLUSIONS
In conclusion, our results show that MALDI-TOF MS is a fast and reliable technique for identification of most bacterial strains routinely isolated in a clinical microbiology. Identification and susceptibility testing with a single cell colony are more often possible. The simple tests, such as Gram staining and oxidase and catalase tests are usually performed in our laboratory.
Gravet
A
A
Laboratoire de microbiologie, centre hospitalier de Mulhouse, hôpital Emile-Muller, 20, avenue du Docteur-Laennec, 68070 Mulhouse cedex, France. graveta@ch-mulhouse.fr
Camdessoucens-Miehé
G
G
Gessier
M
M
Peluso
A-R
AR
Vogelsperger-Fuchs
B
B
Lohmann
C
C
Schmitt
F
F
Delarbre
J-M
JM
D001419:Bacteria / Q000737:chemistry / Q000302:isolation & purification; D001424:Bacterial Infections / Q000382:microbiology*; D001426:Bacterial Proteins / Q000032:analysis*; D015373:Bacterial Typing Techniques / Q000379:methods*; D005656:Fungal Proteins / Q000032:analysis; D005658:Fungi / Q000737:chemistry / Q000302:isolation & purification; D006801:Humans; D066298:In Vitro Techniques; D007755:Laboratories, Hospital; D008565:Membrane Proteins / Q000032:analysis*; D009181:Mycoses / Q000382:microbiology; D012269:Ribosomal Proteins / Q000032:analysis*; D012984:Software; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D001426:Bacterial Proteins; D005656:Fungal Proteins; D008565:Membrane Proteins; D012269:Ribosomal Proteins