Whole-cell matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for rapid identification of bacteria cultured in liquid media
- 634 Downloads
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been used for many years to rapidly identify whole bacteria. However, no consistent methodology exists for the rapid identification of bacteria cultured in liquid media. Thus, in this study we explored the use of MALDI-TOF MS analysis for rapid identification of cells cultured in liquid media. We determined that 2,5-dihydroxybenzoic acid (50 mg mL−1, 50% acetonitrile, 0.1% trifluoroacetic acid) was the best matrix solution for MALDI-TOF MS for this type of study. Moreover, the tested strains were successfully differentiated by principal component analysis, and the main characteristics of the mass peaks for each species were found in mixed culture samples. In addition, we found that the minimum number of cells for detection was 1.8×103. In conclusion, our findings suggest that MS-based techniques can be developed as an auxiliary method for rapidly and accurately identifying bacteria cultured in liquid media.
KeywordsMALDI-TOF MS bacteria PCA identification
- 2.Widjojoatmodjo M N, Fluit A C, Verhoef J. Rapid identification of bacteria by PCR-single-strand conformation polymorphism. Clin Microbiol, 1994, 32: 3002–3007, 1:CAS:528:DyaK2MXivFWnu78%3DGoogle Scholar
- 3.Pershing D H, Tenover F C, Versalovic J, et al. Molecular microbiology: Diagnostic principles and practice, 8th ed. Washington DC: American Society for Microbiology Press, 2003Google Scholar
- 7.Warscheid B, Fenselau C. A targeted proteomics approach to the rapid identification of bacterial cell mixtures by matrix-assisted laser desorption/ionization mass spectrometry. Proteomics, 2004, 4: 2877–2892, 1:CAS:528:DC%2BD2cXovVynsbw%3D, 10.1002/pmic.200400911, 15378756PubMedCrossRefGoogle Scholar
- 8.Pribil P A, Patton E, Black G, et al. Rapid characterization of Bacil lus spores targeting species-unique peptides produced with an atmospheric pressure matrix-assisted laser desorption/ionization source. J Mass Spectrom, 2005, 40: 464–474, 1:CAS:528:DC%2BD2MXktFKjtbk%3D, 10.1002/jms.816, 15712356PubMedCrossRefGoogle Scholar
- 10.Carbonnelle E, Beretti J L, Cottyn S, et al. Rapid identification of Staphylococci isolated in clinical microbiology laboratories by matrix-assisted laser desorption ionization-time of flight mass spectrometry. J Clin Microbiol, 2007, 45: 2156–2161, 1:CAS:528:DC%2BD2sXptFGltr4%3D, 10.1128/JCM.02405-06, 17507519PubMedPubMedCentralCrossRefGoogle Scholar
- 11.Mellmann A, Cloud J, Maier T, et al. Evaluation of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry in comparison to 16S rRNA gene sequencing for species identification of nonfermenting bacteria. J Clin Microbiol, 2008, 46: 1946–1954, 1:CAS:528:DC%2BD1cXotFGhs7c%3D, 10.1128/JCM.00157-08, 18400920PubMedPubMedCentralCrossRefGoogle Scholar
- 14.Hoben H J, Somasegaran P. Comparison of the pour, spread and drop plate methods for enumeration of Rhizobium spp. in inoculants made from presterilized peat. Appl Environ Microbial, 1982, 44: 1246–1247, 1:STN:280:DC%2BC3crnvFKltg%3D%3DGoogle Scholar
This article is published under license to BioMed Central Ltd. Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.