Identification of some human pathogenic fungi using four DNA extraction methods

Abstract

Dermatophytes being animal and human pathogenic fungi infect some human at one point or the other in their lifetime. For effective control of dermatophytes, accurate identification of the specific species/strain involved must be known. Stocks from pathogenic fungi isolated from infected areas on different patients, around Lagos-Nigeria were analysed using molecular methods (DNA extraction, PCR-RFLP and DNA sequencing). Four DNA extraction protocols were employed in the identification of the fungal isolates. Sixteen different fungal isolates were identified, and based on the molecular data these were classified into six species of dermatophytes belonging to the genera Microsporum, Trichophyton and Epidermaphyton, two species of systemic mycoses fungi and eight opportunistic human pathogenic fungi. The results also revealed that CTAB protocol, Modified CTAB protocol and the GNOME kit used in this work were only able to extract non-dermatophytes DNA. Only the Zymo DNA kit was able to isolate dermatophytes DNA. DNA extraction which is the first step in all molecular studies showed that one DNA extraction method might not be able to extract all fungal DNA for proper identification, diagnosis and treatment of fungal infections. 

Keywords: Dermatophytes, DNA extraction, Identification, Protocols.