Format: MS WORD | Chapter: 1-5 | Pages: 65-80 | .
EPIDEMIOLOGICAL STUDIES AND MOLECULAR CHARACTERISATION OF DERMATOPHYTES
ABSTRACT
Dermatophytes are fungi that have the capacity to invade keratinised tissues of humans and animals to produce an infection. The study was conducted to determine the epidemiology and molecular characterisation to identify of the dermatophytes associated with almajirai in Makarfi Local Government Area (L. G. A.) of Kaduna State. Samples were collected from the almajirai that had lesions on their scalps. The sites of infection were cleaned with 70% alcohol and followed by the collection of scalp scrapings using sterile scalpel blades. Sabouraud‘s dextrose agar (DibenDiagnostics, U.K) containing cycloheximide and chloramphenicol was used. Identification of isolates was through observation of colonial morphology and microscopic appearance of lactophenol cotton blue stained fungal specimen obtained from culture. Molecular identification was carried out using primers which contained the ITS1-2, 18S rRNA and 28S rRNA regions. A total of 408 almajirai were selected and examined, out of which 153 (37.5%) were found to be infected with different species of dermatophytes. From the 153 samples collected 119 (78.1%) were culture positive while no growth was observed in 34 samples (21.9%). Dermatophytes identified were members of Trichophyton (T.) and Microsporum (M.) genera. The species isolated include Trichophyton rubrum45 (29.4%), Trichophyton mentagrophytes 16 (10.5%), Trichophyton violaceum 3 (2.0%), Trichophyton soudanense 2 (1.3%), Trichophyton tonsurans 17 (11.1%) Trichophyton concentricum 4 (2.6%), Trichophyton quickeanum 01 (0.7%), Trichophyton megninii 01(0.7%), Trichophyton verrucosum 01 (0.7%), Microsporum canis 05 (3.3%), Microsporum fulvum 07 (4.6%), Microsporum gallinae 10 (6.5%), Microsporum audouinii 01 (0.7%), Microsporum equinum 05 (3.3%), and Microsporum nanum 01 (0.7%). Highest rate of infection occurred in the almajirai of 5 – 7years (54.67%) and the least infection was found among 17-19 age group (P< 0.05). Those that reside with their parents or guardians had low infection rate (29.17%) compared to those that reside in the tsangaya. Based on the number of rooms in a house, rate of infection was higher among almajirai that live in houses that have one or two rooms (31.25%). Participants that share beddings had higher infection rate (31.17%) than those that do not share beddings (31.12%). The almajirai that shaved at the Barber‘s shop had the less infection (27.45%) than those that barb at home (31.37%). Contact with pets and livestock accounted for 29.35% infection while those that were not in contact with pets and livestock had an infection rate of 28.70%. From PCR result, regions of amplification consisting of expected sizes of between 200 and 500 base pairs were obtained for Microsporum canis, Microsporum audouinii, Trichophyton rubrum, Trichophyton tonsurans and Trichophyton mentagrophytes using a dermatophyte specific primer (ITS1-2). Using 18S ribosomal RNA primer, approximately 500 base pairs band on ITS1-2 was observed in M. canis, T. rubrum, and T. tonsurans while band patterns of 560 base pairs band on ITS1-2 were observed in M. audoinii and T. mentagrophytes. M. canis, M. audouinii, T. violaceum, T. rubrum, T. mentagrophytes and T. verrucosum were visible around 200 base pair long band. A 300 base pair long band was identified with the 28S ribosomal RNA primer PCR on M. canis, T. violaceum, T. mentagrophytes T. tonsurans, T. verrucosum and M. gypseum. A 300 base pair-long was observed in M. audouinii, T. rubrum and M. fulvum on the 18S ribosomal RNA primer. It is therefore necessary that the Mallams, parents/guardians as well as the almajirai are educated on maintaining adequate personal, community and environmental hygiene through general sanitation. Contact with pets and livestock should be minimised and also there is need for provision of good infrastructure and upgrading of the informal settlements by the government so as to improve the living conditions of the almajirai