|Organism||Microscopy||Culture and identification||Non-culture methods|
|General||Histopath PAS & silver stains etc.
K0H with Parker ink (skin scrapings/nails)
|SAB (Saborauds dextrose agar) medium +/- antibiotics +/- cycloheximide
For other media, see here.
Blue thymol blue sticky tape preparation from cultures for examining hyphae and fruiting structures
|MALDI-TOF for ID
Invasive fungal disease: 1-3 Beta-D-Glucan assay (serum) – broad spectrum but not incl. Cryptococcus
|Candida albicans and other similar species||Characteristic yeast shapes larger than bacteria; appear Gram positive||Colonies with ‘feet’ (C. albicans)
Chromogenic candida agar – usually sufficient for ID. Several types.
Yeast sugar assimilation panels e.g. API , VITEK etc
|India ink preparation for capsule (CSF)
NB. capsule production media dependent
|Presumptive: capsule+yeast= Cryptococcus (no other species has a capsule)
Bird seed agar – pigmented colonies = Cryptococcus
CGB medium- (L-Canavanine, glycine, 2 bromthymol blue agar) distinguishes C. gattii from C. neof.
|Crypto antigen lateral flow assay (serum/CSF)
IF serotyping of isolates- research only
|Aspergillus species||Histopath – narrow septate hyphae; acute angle branching||Culture appearance- pigmentation
Species ID by sticky tape preparation
|Galactomannan EIA (serum, BAL)
Serum precipitins used in ABPA Dx
|Pneumocystis jirovecii(PJP)||Bronchial lavage / induced sputum – IF / silver / Giemsa stains||Usually a clinical diagnosis
|PCR more sensitive than IF|
Histopathologic Diagnosis of Fungal Infections in the 21st Century : excellent overview- invasive fungal infections are often recognised only by histopathologists post mortem! Also this slide set : https://www.slideshare.net/appyakshay/fungus-in-histopathology
Cryptococcal serum antigen screening for HIV positive patients– previous posting. This ICT has excellent sensitivity and specificity for crypto antigen detection.
India ink preparation Gram stain of Candida species