Mycoses: Molecular Characterization and Phylogenetic Analysis of Some Human Pathogenic Fungi Associated with School Pupils' Scalp in Lagos

Abstract

This study investigated the molecular characterization of the non-dermatophytes and phylogenetic analysis of the fungi causing dermatomycoses among primary school children in Bariga, Lagos, Nigeria. The study ran from April to October 2019. The study population was drawn using a multi stage sampling technique. Three primary schools were first purposively selected, while the pupils were randomly selected from all grades of the selected primary schools. A cluster random sampling method was used to screen a total sample of 45 pupils for the study. Samples were obtained by scraping the infected scalp area with a sterile toothed comb and collected into a sterile paper, folded in an envelope to avoid exposure to moisture and to prevent the growth of contaminants. Sabouraud Dextrose Agar (SDA) culturing and morphological identification of samples were carried out at the Mycology Botany Laboratory, UNILAG, while the molecular characterization analysis was done at the Federal Institute of Industrial Research, Oshodi, Lagos (FIIRO).  Results of the morphological identification of the cultured samples showed colonies of white, cream, and yellow club-shaped microconidia with septate hyphae under the microscope among twelve samples, while the molecular characterization of the isolates revealed that the purity of the extracted DNA was within the range of 1.8 - 2.0, as expected for pure DNA. Agarose gels of PCR amplicons showed products ranging from 500 base pairs to 600 base pairs, as expected for a successful amplification of the internally transcribed spacer regions of fungal species. Based on these results, it is recommended that school-based hygiene education, routine screening, and improved sanitation infrastructure be prioritized among primary and secondary schools.