Evaluation of Vitek MS in identification of clinical filamentous fungi isolates

Abstract

Objective To evaluate the performance of Vitek MS, an automated mass spectrometry microbial identification system, in identification of clinical filamentous fungi isolates, which provide a new insight into filamentous fungi identification strategy. Methods Twenty-five isolates of filamentous fungi genetically confirmed by molecular sequencing method were inoculated in different culture conditions to analyze the potential influences of culture conditions on the identification of filamentous fungi with Vitek MS. Further evaluation of the performance of Vitek MS in filamentous fungi identification was carried out with 207 clinical isolates of filamentous fungi and the comparison of the results with those of morphology and sequencing analysis. Results The performance of Vitek MS in filamentous fungi identification was not significantly influenced by culture conditions. Vitek MS successfully identified 87.9% (182/207) of all tested filamentous fungi. Lacking of reference MS spectra in Vitek database was the main reason that the other isolates could not be identified. Vitek MS was superior to the traditional morphological method in identification of filamentous fungi especially non-Aspergillus molds at species level. Conclusion Vitek MS is an efficient approach for clinical filamentous fungi identification. Continuous enrichment of the species coverage in database will be of great importance for improving the performance of Vitek MS in identification of filamentous fungi. Key words: Vitek MS; Filamentous fungi; Identification