Identification of filamentous Fungi Isolated from Clinical Specimens by MALDITOF Mass Spectrometry in A Tertiary Health Care Centre
DOI:
https://doi.org/10.21276/apalm.2264Keywords:
MALDI-TOF Vitek MS, Filamentous fungi, Ethanol-Formic acid-Acetonitrile extraction, macromorphological, identificationAbstract
Background: Matrix Assisted Laser Desorption Ionisation- Time of Flight Mass Spectrometry (MALDI-TOF MS) has revolutionized the identification of microorganisms particularly bacteria and yeasts in terms of rapidity, cost-effectiveness, automation and enhanced discriminatory power. Its utility for the identification of filamentous fungi lags due to certain challenges like effective protein extraction method and limited databases. The conventional methods for the identification of filamentous fungi are time consuming and may not establish the definitive species identification. Keeping this in mind, we planned this study to evaluate MALDI-TOF Vitek MS (Biomerieux, France) for the identification of filamentous fungi, to standardize the mould identification protocol and to correlate the identification results by MALDI TOF MS with the conventional phenotypic methods.
Methods: The identification of clinically significant filamentous fungi isolated from various clinical specimens was done by both conventional method and MALDITOF Vitek MS using Ethanol-Formic acid –Acetonitrile protocol. The unidentified fungi by both the methods were identified in the reference Mycology laboratory.
Result: Out of 50 clinically significant moulds isolated from various clinical specimens during study period, 35 (70%) could be identified using MALDI-TOF Vitek MS and all the identification results corroborated with the phenotypic method for identification with no misidentification. In addition to Aspergillus species, the identification of Zygomycetes and Phaeoid fungi could also be possible using MALDI TOF Vitek MS.
Conclusion: MALDITOF MS was found to be a rapid and reliable method for the species identification of filamentous fungi. We could standardize two extraction protocols using Ethanol-Formic acid -Acetonitrile at our institute for the identification of filamentous fungi by MALDI TOF Vitek MS. We also emphasize on the creation of own in-house library for the optimum utilization of MALDI TOF Vitek MS for the identification of filamentous fungi.
References
2. Becker PT, de Bel A, Martiny D, et al. Identification of filamentous fungi isolates by MALDI-TOF mass spectrometry: clinical evaluation of an extended reference spectra library. Med Mycol 2014;8:826-34.
3. Iriart X, Laverne RA, Fillaux J, et al. Routine identification of medical fungi by the new Vitek MS Matrix assisted laser desorption ionisation –time of flight system with a new time effective strategy. J Clin Microbiol 2012;50:2107-10.
4. Chakrabarti A, Singh R. The emerging epidemiology of mould infections in developing countries. Curr Opin Infect Dis 2011;24:521-6.
5. Marr KA, Carter RA, Crippa F, Wald A, Corey L. Epidemiology and outcome of mould infections in hematopoietic stem cell transplants recipients. Clin Infect Dis 2002;34:909-17.
6. Gautier M, Ranque S, Normand AC, et al. Matrix Assisted Laser Desorption Ionisation- Time of Flight Mass Spectrometry: revolutionizing clinical laboratrory diagnosis of mould infection. Clin Microbiol Infect 2014;20:1366-71.
7. Lau FA, Drake SK, Calhoun LB, Henderson CM and Zelanzy AM. Development of a clinically comprehensive database and a simple procedure for identification of moulds from solid media by Matrix Assisted Laser Desorption Ionisation -Time of Flight Mass Spectrometry. J Clin Microbiol 2013;51:828-34.
8. Vidal CG, Upton A, Kirby KA, Marr KA. Epidemiology of invasive mould infections in allogenic stem cell transplant recipients: biological risk factors associated for infection according to time after transplantation. Clin Infect Dis 2008;47:1041-50.
9. Pagano L, Akova M, Dimopoulos G, Herbrecht R, Drgona L, Blijlevens N. Risk assessment and prognostic factors for mould related diseases in immunocompromised patients. J Antimicrob Chemother 2011;66:i5-i14.
10. Normand AC, Cassagne C, Ranque S ,et al. Assessment of various parameters to improve MALDI -TOF MS reference spectra libraries constructed for the routine identification of filamntous fungi. BMC Microbiol 2013;13:pg76.
11. Schulthess B, Lendermann R, Mouttet F, et al. Use of the Bruker MALDI Biotyper for the identification of molds in the clinical mycology laboratory. J Clin Microbiol 2014;52:2797-803
12. Levesque S, Dufresne PJ, Soualhine H, et al. A side by side comparison of Bruker Biotyper and Vitek MS:Utility of MALDI-TOF MS technology for microorganisms identification in a public health reference laboratory. PLOS ONE 2015 ;10(12):e0144878.
13. Cassagne C, RanqueS, Normand AC, et al. Mould routine identification in the clinical laboratory by Matrix Assisted Laser Desorption Ionisation –Time Of Flight Mass Spectrometry. PLOS ONE 2011;6:2.
14. Rahi P, Prakash O, Shouche YS. Matrix Assisted Laser Desorption /Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) Based microbial identifications: Challenges and scopes for microbial ecologists. Front Microbiol 2016; 7:1359.
15. Singh A, Singh PK, Kumar A, et al. Molecular and matrix-assisted laser desorption ionization–time of flight mass spectrometry based characterization of clinically significant melanized fungi in India. J Clin Microbiol 2017;55:1090 –103.
16. De Carolis E, Posteraro B ,Vella A, etal. Species identification of Aspergillus, Fusarium and Mucorales with direct surface analysis by matrix assisted laser desorption ionization- time of flight mass spectrometry. Clin Microbiol Infect 2012;18:475-84.
17. L’Ollivier C, Ranque S. MALDI-TOF-Based Dermatophyte Identification. Mycopathologia 2017;182:183-92.
18. Ranque S, Normand AC, Cassagne C, et al. MALDI-TOF MS mass spectrometry identification of filamentous fungi in the clinical laboratory. Mycoses 2013;57:135-40.
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Copyright (c) 2019 Hena Butta, Raman Sardana, Ashmita Grover, Leena Mendiratta, Sudha Kansal, Neerav Goyal
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