Lab diagnosis of fungal infection The diagnosis relies upon combination of clinical observation and lab investigations. The successful lab diagnosis of fungal infection depends in major part on the collection of adequate clinical specimens for investigations. It is important that clinician indicate the suspect case and provide sufficient background information to the lab. In addition to specify the sources of specimen.

Lab methods Microscopically detection of the causative agent Isolation and identification of the causative agent Detection of a serologic response. Procedures based on the detection of fungal DNA in clinical materials are presently based nowadays.

Direct microscopic examination of clinical specimens In many cases the definitive diagnosis of fungal infection can be made by the direct microscopic detection. Skin scraping reveals → fungi in matter of minutes. Keratinized tissues → pre treatment → dissolve the materials → examination. Warm 10- 20 % KOH (dekeratiniazation) A drop of lactophenol cotton blue is used for diagnosis. Calcofluor white stain the fungal cell wall Indian ink is negative stain of capsulated fungi.

Histopathological studies. It is one of the most reliable methods of establishing the diagnosis of subcutaneous and systemic mycoses. Hematoxylin and Eosin (H & E) stains. Methamine silver stain, periodic acid shift (PAS).

Culture Very important method for the diagnosis of the causative agent, its genus and species. Almost are not fastidious Sabouraud agar and malt agar are used widely to isolate almost fungi. B.H.I.A is used for fastidious forms of fungi →yeast form of H. capsulated. CHROM agar → candida species (chromogenic medium). Antibacterial agents must add to the medium. Optimum growth temperature 28 – 30 C for 2 – 4 weeks.

Oral candidiasis (thrush)). Cryptococcosis neoformans

Rhizopus oryzae Aspergillus species