Which medium isolates saprobic and pathogenic fungi from mixed flora specimen (i.e., sputum)?

Which medium isolates saprobic and pathogenic fungi from mixed flora specimen (i.e., sputum)?

• A. Dermatophyte Test Medium
• B. SABHI Agar
• C. Mycosel Agar
• D. Corn Meal Agar

Answer: (B)

The key idea is choosing a medium that suppresses bacteria but lets a wide range of fungi grow from a specimen with mixed flora. SABHI agar is designed for clinical fungal isolation because it includes antibiotics that inhibit bacteria, allowing fungal colonies to emerge from sputum without being overwhelmed by bacterial growth. Importantly, it doesn’t use strong antifungal agents that would restrict which fungi can grow, so both saprobic (environmental) and pathogenic fungi can be cultured from the same specimen. In contrast, Dermatophyte Test Medium is geared toward dermatophytes and can exclude other fungi; Mycosel agar contains cycloheximide to inhibit many saprophytic fungi and thus isn’t ideal for recovering the full spectrum of saprobic and pathogenic fungi; Corn Meal Agar is mainly for studying fungal morphology rather than broad isolation from mixed flora.

The key idea is choosing a medium that suppresses bacteria but lets a wide range of fungi grow from a specimen with mixed flora. SABHI agar is designed for clinical fungal isolation because it includes antibiotics that inhibit bacteria, allowing fungal colonies to emerge from sputum without being overwhelmed by bacterial growth. Importantly, it doesn’t use strong antifungal agents that would restrict which fungi can grow, so both saprobic (environmental) and pathogenic fungi can be cultured from the same specimen. In contrast, Dermatophyte Test Medium is geared toward dermatophytes and can exclude other fungi; Mycosel agar contains cycloheximide to inhibit many saprophytic fungi and thus isn’t ideal for recovering the full spectrum of saprobic and pathogenic fungi; Corn Meal Agar is mainly for studying fungal morphology rather than broad isolation from mixed flora.