Molecular identification, phylogeny and antifungal susceptibilities of dematiaceous fungi isolated from human keratomycosis

Arumugam Mythili; Coimbatore Subramanian Shobana; Krisztina Krizsán; Anamangadan Shafeeq Hassan; Annanthode Balakrishnan Sangeetha; Mónika Homa; Tamás Papp; Raed Abdullah Alharbi; AyoubAl Othaim; Alaa Baazeem; Kanesan Panneer Selvam; Moorthy Kannaiyan; Csaba Vágvölgyi; László Kredics; Palanisamy Manikandan

doi:10.1016/j.jiph.2022.11.018

Molecular identification, phylogeny and antifungal susceptibilities of dematiaceous fungi isolated from human keratomycosis

J Infect Public Health. 2023 Jan;16(1):25-33. doi: 10.1016/j.jiph.2022.11.018. Epub 2022 Nov 21.

Authors

Arumugam Mythili¹, Coimbatore Subramanian Shobana², Krisztina Krizsán³, Anamangadan Shafeeq Hassan¹, Annanthode Balakrishnan Sangeetha², Mónika Homa⁴, Tamás Papp⁵, Raed Abdullah Alharbi⁶, AyoubAl Othaim⁷, Alaa Baazeem⁸, Kanesan Panneer Selvam⁹, Moorthy Kannaiyan¹⁰, Csaba Vágvölgyi⁴, László Kredics⁴, Palanisamy Manikandan¹¹

Affiliations

¹ Department of Microbiology, Dr. G.R. Damodaran College of Science, Coimbatore, India.
² Department of Microbiology, PSG College of Arts & Science, Coimbatore, India.
³ Synthetic and Systems Biology Unit, Institute of Biochemistry, BRC-HAS, 62 Temesvári krt, Szeged, Hungary.
⁴ Department of Microbiology, University of Szeged, Faculty of Science and Informatics, Közép fasor 52, H-6726 Szeged, Hungary.
⁵ ELKH-SZTE Pathomechanisms of Fungal Infections Research Group, University of Szeged, Faculty of Science andInformatics, Közép fasor 52, H-6726 Szeged, Hungary.
⁶ Department of Public Health, College of Applied Medical Sciences, Majmaah University, Al Majmaah, Saudi Arabia.
⁷ Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al Majmaah, Saudi Arabia.
⁸ Department of Biology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
⁹ Department of Microbiology, M.R Government Arts College, Mannargudi, Tamilnadu, India.
¹⁰ Department of Medical Laboratory Science, School of Pharmacy and Medical Laboratory Science, Institute of Health, Bule Hora University, Post Box Number - 144, Ethiopia.
¹¹ Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al Majmaah, Saudi Arabia; Greenlink Analytical and Research Laboratory India Private Limited, Coimbatore, India. Electronic address: m.palanisamy@mu.edu.sa.

PMID: 36459708
DOI: 10.1016/j.jiph.2022.11.018

Abstract

Purpose: To investigate the dematiaceous fungal profile of patients with ocular mycoses attending a tertiary eye care hospital in Coimbatore, India METHODS: The identification of dematiaceous fungus based on their morphology, their genotypes, and the measurement of the minimum inhibitory concentrations (MICs) using microdilution method of routinely used antifungal drugs were all compared.

Results: A total of 148 dematiaceous fungi were isolated during a study period of 27 months. Isolates were confirmed as Curvularia spp. (n = 98), Exserohilum spp. (n = 32), Alternaria spp. (n = 14), Exophiala spp. (n = 2), Cladosporium sp. (n = 1) and Aureobasidium sp. (n = 1). Out of 50 well grown isolates characterized genotypically based on the amplification and sequencing of the ITS region of the ribosomal RNA gene cluster and subsequent BLAST analysis, Curvularia lunata (n = 24), C. aeria (n = 1), C. spicifera (n = 8), C. hawaiiensis (n = 1), C. maydis (n = 2), C. papendorfii (n = 2), C. geniculata (n = 3), C. tetramera (n = 2) and Exs. rostratum (n = 7) were identified. In vitro antifungal susceptibilities of the most tested dematiaceous isolates showed that voriconazole had a MIC₅₀ of 0.25 μg ml^-1, while amphotericin B had a MIC₅₀ of 0.25 μg ml^-1 for Curvularia spp. and Alternaria spp.

Conclusion: Voriconazole proved to be the most effective drug against the pigmented filamentous fungi, followed by amphotericin B, itraconazole and econazole.

Keywords: Antifungal susceptibilities; Curvularia; Dematiaceous fungi; Keratomycosis; Molecular identification.

MeSH terms

Amphotericin B / pharmacology
Antifungal Agents* / pharmacology
Eye Infections, Fungal* / microbiology
Fungi
Humans
Microbial Sensitivity Tests
Phylogeny
Voriconazole / pharmacology
Voriconazole / therapeutic use

Substances

Antifungal Agents
Amphotericin B
Voriconazole