This episode returns to the laboratory, focusing on diagnostic strategies specific to fungi. Drawing from Murray’s Chapter 60, it explores how identification relies heavily on morphology, growth characteristics, and targeted antigen detection.
Unlike many viral diagnoses, fungal identification frequently begins with direct microscopy:
* Potassium hydroxide (KOH) preparations
* Calcofluor white staining
* Histopathology with special stains
Culture remains central. Fungi often grow more slowly than bacteria, requiring specialised media and extended incubation. Colony morphology, hyphal branching patterns, and spore formation aid identification.
Serologic and antigen-based assays assist in diagnosing invasive infections, particularly when culture is slow or difficult.
Conceptually, fungal diagnosis relies on structural recognition. Clinically, early detection is crucial in immunocompromised patients, where delay may lead to invasive disease.
Key Takeaways
* Direct microscopy is foundational in mycology
* Fungal culture requires specialised media and patience
* Morphology guides identification
* Antigen detection supports invasive disease diagnosis
* Early diagnosis improves outcomes in vulnerable hosts
