Molecular Identification of Mycetoma Causative Organisms:

Most of the fungi that cause mycetoma grow slowly and culture plates should be incubated for at least four weeks before being discarded as negative. Identification of the isolated fungus is based on thegross morphology of fruit bodies and conidia, if present. Conventional mycological identification is difficult in some species such as T. grisea, Madurella mycetomatis, Neotestudina rosatii, Pyrenochaeta mackinnonii, and Pyrenochaeta romeroi. Most of these species donot sporulate readily, and identification is based on molecular techniques, particularly sequencing of the rDNA Internal Transcribed Spacer (ITS) region.

The molecular diagnosis of a number of eumycetoma causing agents has been developed. The black yeast Exophiala jeanselmei and Phaeoacremonium are recognisable by sequence data of the rDNA Internal Transcribed Spacer (ITS) region.  SEQ CHAPTER \h \r 1rDNA Restriction Fragment Length Polymorphism and specific ITS-PCR were used for species identification of Madurella mycetomatis. Although Scedosporium apiospermum cultures can be identified by culture morphology, PCR-based assays for rapid diagnosis of infections from infected tissue was found useful.

Ahmed SA, van de Sande WW, Desnos-Ollivier M, Fahal AH, Mhmoud NA, de Hoog GS. Application of Isothermal Amplification Techniques for the Identification of Madurella mycetomatis, the Prevalent Agent of Human Mycetoma. J Clin Microbiol. 2015 Aug 5. pii: JCM.01544-15.

Ahmed AO, Mukhtar MM, Kools-Sijmons M, Fahal AH, de Hoog S, van den Ende BG, Zijstara, ED, Verburgh H, Abugroun ESA, EL Hassan AM, van Beklkum A. Development of a species-specific PCR RFLP procedure for the identification of Madurella mycetomatis. J Clin Microbiol. 1999; 37(10):3175-8.