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Updated: Sep 24, 2025
Isolation, Characterization, and Total DNA Extraction to Identify Endophytic Fungi in Mycoheterotrophic Plants
Published on: May 5, 2023
Isolation and molecular characterization of clinical and environmental dematiaceous fungi and relatives from Iran
Gholamreza Shokoohi1,2, Hamid Badali3,4, Bahram Ahmadi5
1Department of Parasitology and Mycology, Faculty of Medicine, Jahrom University of Medical Sciences, Jahrom, Iran.
Background And Purpose:
The frequency and genetic diversity of black fungi in environmental and clinical settings have not been fully studied in Iran. This study aimed to identify and evaluate intra- and inter-species DNA sequence variation and also understand the phylogenetic relationships of melanized fungi and relatives isolated from different geographical regions of Iran.
Materials And Methods:
In total, 111 clinical and environmental strains of dematiaceous fungi were isolated, and their internal transcribed spacer ribosomal DNA (rDNA) regions were sequenced and analyzed.
Results:
An inter-species nucleotide sequence diversity rate of 1 to 464 nucleotides was observed between the species. Intra-species differences were found in the strains of Alternaria alternata, Cladosporium cladosporioides, Alternaria tenuissima, Curvularia spicifera, Aureobasidium pullulans, Curvularia hawaiiensis, Neoscytalidium dimidiatum, Alternaria terricola, Alternaria chlamydospora, Didymella glomerata, and Drechslera dematioidea by 0-59, 0-22, 0-4, 0-4, 0-3, 0-2, 0-2, 0-2, 0-2, 0-1, and 0-1 nucleotide, respectively.
Conclusion:
The internal transcribed spacer rDNA is useful for the discrimination of several taxa of dematiaceous fungi. However, a better understanding of the taxonomy of species of Alternaria requires a larger rDNA region or a library of other gene sequences.
Insights
This study investigated the genetic diversity of black fungi in Iran, revealing significant intra- and inter-species DNA sequence variation. The internal transcribed spacer ribosomal DNA (rDNA) proved useful for discriminating dematiaceous fungi taxa.
Area of Science:
- Mycology
- Genetics
- Phylogenetics
Background:
- Limited studies exist on the frequency and genetic diversity of black fungi in Iranian environmental and clinical settings.
- Melanized fungi, also known as dematiaceous fungi, play roles in various ecosystems and can cause human infections.
Purpose of the Study:
- To identify and evaluate intra- and inter-species DNA sequence variation in dematiaceous fungi from Iran.
- To understand the phylogenetic relationships of these fungi using molecular data.
Main Methods:
- Isolation of 111 clinical and environmental strains of dematiaceous fungi.
- Sequencing and analysis of the internal transcribed spacer ribosomal DNA (rDNA) regions.
Main Results:
- Observed inter-species nucleotide sequence diversity ranging from 1 to 464 nucleotides.
- Identified intra-species differences in multiple fungal strains, including various species of *Alternaria*, *Cladosporium*, *Curvularia*, and others.
- Demonstrated variability within species like *Alternaria alternata* (0-59 nucleotides) and *Cladosporium cladosporioides* (0-22 nucleotides).
Conclusions:
- The internal transcribed spacer (ITS) rDNA is a valuable marker for discriminating between dematiaceous fungal taxa.
- Further taxonomic clarification, particularly for *Alternaria* species, may necessitate analysis of larger rDNA regions or additional gene sequences.
