The development and verification of "Chinese Pathogenic Mycobacteria Mass Spectrometry Database" / 中华检验医学杂志

ABSTRACT

Objective@#To establish the domestic matrix assisted laser desorption/ionisation time of flight mass spectrometry database for identification of clinical mycobacteria and evaluate its accuracy with foreign counterpart. @*Methods@#The establishment of "Chinese Pathogenic Mycobacteria Mass Spectrometry Database" : nineteen American type culture collection strains from 19 species and 183 "standardized" isolates from 42 species were selected and extracted by modified ultrasonic extraction method for spectral acquisition and database establishment based on microTyper MS. Each extract was dropped onto 12 spots and tested twice to generate 24 spectrum, then at least 20 qualified spectrum according to the standard were selected. Subsequently they were composed into one main spectra (MSP) by setting peak number maximum, peak frequency minimum and mass tolerance. Verification of database: Totally 305 mycobacteria from different regions were used for comparison of accuracy and spectral features between microTyper MS based on domestic database and imported MALDI TOF MS base on Mycobacteria Library 3.0 database. @*Results@#The database composed of 202 stains from 42 species was constructed, with an average of 4.8 in each species. The top ten were M. Kansasii(16), M. intracellulare(16), M. gordonae(16), M. fortuitum(16), M. avium(16), M. abscessus(16), M. tuberculosis(15), M. marseillense(11), M. arupense(10), M. yongongens(8). A total of 305 isolates were confirmed belonging to 22 species by sequencing. The accuracy based on this database was 99.67% (304/305), which was better than the Mycobacteria Library 3.0 database (χ2=4.06, P<0.05). @*Conclusion@#The construction of the "Chinese Pathogenic Mycobacteria Mass Spectrometry Database" meets the requirement of routine clinical application and was more accurate than its counterpart in terms of domestic comment strains.(Chin J Lab Med, 2018, 41: 519-526)