Publication Type : Journal Article
Publisher : J Clin Microbiol,
Source : J Clin Microbiol, Volume 55, Issue 4, p.1090-1103 (2017)
Keywords : aged, Antifungal Agents, Biodiversity, child, DNA, Fungal, DNA, Ribosomal Spacer, Fungi, Humans, India, male, Microbial Sensitivity Tests, Microbiological Techniques, Molecular Diagnostic Techniques, Mycoses, Sequence Analysis, DNA, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
Campus : Bengaluru
School : School of Engineering
Department : Chemistry
Year : 2017
Abstract : Melanized or black fungi are a heterogeneous group of fungi causing cutaneous to systemic diseases with high mortality. These fungi are rarely reported as agents of human infections, primarily due to difficulties in their classical identification. In this study, we examined, using molecular methods and matrix-assisted laser desorption ioniazation-time of flight mass spectrometry (MALDI-TOF MS), the diversity of melanized fungi (MF) isolated from patients in 19 medical centers in India. Overall, during a 4-year period, 718 (5.3%) clinical specimens yielded MF. Of these, 72 (10%) isolates had clinical significance and were identified primarily by sequencing the internal transcribed spacer and large subunit (LSU) regions. MF represented 21 genera comprising 29 species, the majority of them belonging to the orders Pleosporales (50%) and Chaetothyriales (22%). Among the 29 fungal species identified in this study, only 6 (20%) species were identified by the MALDI-TOF MS due to the limited commercial database of Bruker Daltonics for MF. However, a 100% identification rate of 20 additional species identified in this study was obtained by constructing an in-house database using 24- to 96-h-old liquid cultures. Further, the CLSI broth microdilution method revealed low MICs for posaconazole (≤1 μg/ml) and voriconazole (≤2 μg/ml) in 96% and 95% of isolates, respectively. Skin/subcutaneous and sino-nasal and pulmonary phaeohyphomycosis due to MF were diagnosed in 21.4% ( = 15) and 28.5% ( = 20) of cases. Also, 10% of patients had central nervous system involvement ( = 7), and 3 cases of fungal osteomyelitis due to and spp. were observed.
Cite this Research Publication : A. Singh, Singh, P. Kumar, Kumar, A., Chander, J., Khanna, G., Roy, P., Meis, J. F., and Chowdhary, A., “Molecular and Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry-Based Characterization of Clinically Significant Melanized Fungi in India.”, J Clin Microbiol, vol. 55, no. 4, pp. 1090-1103, 2017.