Phylogenetic Diversity and In Vitro Susceptibility Profiles of Human Pathogenic Members of the Fusarium fujikuroi Species Complex Isolated from South India
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Availability of molecular methods, gene sequencing, and phylogenetic species recognition have led to rare fungi being recognized as opportunistic pathogens. Fungal keratitis and onychomycosis are fairly common mycoses in the tropics, especially among outdoor workers and enthusiasts. The frequently isolated etiological agents belong to genera Candida, Aspergillus, and Fusarium. Within the genus Fusarium, known to be recalcitrant to prolonged antifungal treatment and associated with poor outcome, members of the Fusarium solani species complex are reported to be most common, followed by members of the Fusarium oxysporum SC and the Fusarium fujikuroi SC (FFSC). Morphological differentiation among the various members is ineffective most times. In the present study, we describe different species of the FFSC isolated from clinical specimen in south India. All twelve isolates were characterized up to species level by nucleic acid sequencing and phylogenetic analysis. The molecular targets chosen were partial regions of the internal transcribed spacer rDNA region, the panfungal marker and translation elongation factor-1α gene, the marker of choice for Fusarium speciation. Phylogenetic analysis was executed using the Molecular Evolutionary Genetics Analysis software (MEGA7). In vitro susceptibility testing against amphotericin B, voriconazole, posaconazole, natamycin, and caspofungin diacetate was performed following the CLSI M38-A2 guidelines for broth microdilution method. The twelve isolates of the FFSC were F. verticillioides (n = 4), F. sacchari (n = 3), F. proliferatum (n = 2), F. thapsinum (n = 1), F. andiyazi (n = 1), and F. pseudocircinatum (n = 1). To the best of our knowledge, this is the first report of F. andiyazi from India and of F. pseudocircinatum as a human pathogen worldwide. Natamycin and voriconazole were found to be most active agents followed by amphotericin B. Elderly outdoor workers figured more among the patients and must be recommended protective eye wear.
KeywordsFusarium fujikuroi species complex F. andiyazi F. pseudocircinatum Antifungal susceptibility patterns TEF-1α Phylogeny
This study has been funded by the Indian Council of Medical Research (ICMR), New Delhi, India, through the ICMR-TSS MD-PhD Fellowship awarded to Dr. Ananya Tupaki-Sreepurna.
- 16.Kvas M, Marasas WF. Diversity and evolution of Fusarium species in the Gibberella fujikuroi complex. Fungal Divers. 2009;34:1–21.Google Scholar
- 21.Moroti RV, Gheorghita V, Al-Hatmi AMS, de Hoog GS, Meis JF, Netea MG. Fusarium ramigenum, a novel human opportunist in a patient with common variable immunodeficiency and cellular immune defects: case report. BMC Infect Dis. 2016;16:79. https://doi.org/10.1186/s12879-016-1382-9.CrossRefPubMedPubMedCentralGoogle Scholar
- 27.Rzhetsky A, Nei M. A simple method for estimating and testing minimum evolution trees. Mol Biol Evol. 1992;9:945–67.Google Scholar
- 29.Rex JH, Ghannoum MA, Alexander BD, Knapp CC, Andes D, Motyl MR, et al. Reference method for broth dilution antifungal susceptibility testing of filamentous fungi; approved standard-CLSI document M38-A2. Wayne, PA: Clinical and Laboratory Standards Institute (CLSI); 2008. p. 52.Google Scholar
- 30.Espinel-Ingroff A, Fothergill A, Ghannoum M, Manavathu E, Ostrosky-Zeichner L, Pfaller MA, et al. Quality control and reference guidelines for CLSI broth microdilution method (M38-A document) for susceptibility testing of anidulafungin against molds. J Clin Microbiol. 2007;45(7):2180–2.CrossRefPubMedPubMedCentralGoogle Scholar
- 38.Espinel-Ingroff A, Colombo AL, Cordoba S, Dufresne PJ, Fuller J, Ghannoum M, Gonzalez GM, Guarro J, Kidd SE, Meis JF, Melhem TM. International evaluation of MIC distributions and epidemiological cutoff value (ECV) definitions for Fusarium species identified by molecular methods for the CLSI broth microdilution method. Antimicrob Agents Chemother. 2016;60(2):1079–84.CrossRefPubMedPubMedCentralGoogle Scholar
- 40.Dornbusch HJ, Buzina W, Summerbell RC, Lass-Flörl C, Lackner H, Schwinger W, Sovinz P, Urban C. Fusarium verticillioides abscess of the nasal septum in an immunosuppressed child: case report and identification of the morphologically atypical fungal strain. J Clin Microbiol. 2005;43(4):1998–2001.CrossRefPubMedPubMedCentralGoogle Scholar
- 42.Cocchi S, Codeluppi M, Venturelli C, Bedini A, Grottola A, Gennari W, Cavrini F, Di Benedetto F, De Ruvo N, Rumpianesi F, Gerunda GE. Fusarium verticillioides fungemia in a liver transplantation patient: successful treatment with voriconazole. Diagn Microbiol Infect Dis. 2011;71(4):438–41.CrossRefPubMedGoogle Scholar
- 47.Kebabcı N, Diepeningen AD, Ener B, Ersal T, Meijer M, Al-Hatmi A, Özkocaman V, Ursavaş A, Çetinoğlu ED, Akalın H. Fatal breakthrough infection with Fusarium andiyazi: new multi-resistant aetiological agent cross-reacting with Aspergillus galactomannan enzyme immunoassay. Mycoses. 2014;57(4):249–55.CrossRefPubMedGoogle Scholar