Molecular Typing of Dermatophytes Isolated from Pupils and Staff Members of Some Selected Schools in Anambra State, Nigeria

Abstract

Dermatophytes are the fungal pathogens of human and animals infecting the keratinized tissues of the body namely skin, hair and nails. They include species of Trichophyton, Microsporum and Epidermophyton. This study was aimed at molecular typing  of dermatophytes isolated from school pupils and staff members of some selected Schools in Anambra East and Ayamelum L.G.As of Anambra State in Nigeria. One thousand (1000) samples  (scalp/hair, nail, feet, glabrous skin and groin/perianal) were collected from pupils and staff members of both gender and age bracket of  (1 to 10, 11 to 20, 21 to 30 etc ) years that showed visible signs of skin infection located in these two Local Government Areas. Standard procedures were employed in processing of test samples and inoculation on dermatophyte test medium. The plates were incubated at room temperature (25 – 270C) for 7 – 10days for observation of fungal growth. Colonial, morphology, and molecular studies and sequencing were used for identification. Sensitivity was performed using sterilized discs (6mm) prepared from whatman No. 1 filter paper, impregnanted with different concentrations (25mg, 50mg, 100mg and 200mg) of terbinafine, itraconazole, ketoconazole, fluconazole and griseofulvin dissolved in 2% dimethylsuphuroxide (DMSO). Molecular studies were used as confirmatory tests on dermatophytic isolates using Sanger sequencing method. The results show that the dermatophytic isolates includes: Trichophyton tonsurans, Microsporum audounii, Trichophyton rubrum, Microsporum canis, Trichophyton violaceum, Trichophyton verrucosum, Trichophyton mentagrophytes, and Epidermorphyton flocossum. Results also revealed the nucleotide sequences of the dermatophytes and genetic relationships between isolated dermatophytes from different pupils and schools. PCR-RFLP was used as gold standard for the diagnosis and Confirmation of Source of infection of dermatophytes and can aid in initiating prompt and appropriate antifungal therapy. Phylogenetic tree was drawn to show the relationships between the isolates.