Which specific medium is selected for culturing the yeast phase of dimorphic fungi? _________________?
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Answer: C. Sabouraud’s plus antibiotics
Explanation
Sabouraud agar supplemented with antibacterial agents selectively inhibits fast-growing bacteria while isolating fungi. Dimorphic fungi grow as molds at lower environmental temperatures and as yeasts at human body temperature. Adding antibiotics prevents contaminating bacteria from overgrowing clinical fungal cultures during incubation. Sabouraud dextrose agar provides an acidic environment that favors fungal growth over competing bacterial flora. Dimorphic fungal pathogens present significant occupational hazards and require careful laboratory handling precautions. Selective media formulations ensure that slow-growing pathogens are successfully recovered from mixed clinical specimens.
Mycology laboratories use selective media to diagnose systemic fungal infections in immunocompromised patients. Identifying the yeast phase of dimorphic fungi confirms systemic pathogenicity and guides antifungal treatment regimens. Proper incubation temperatures are critical for observing the characteristic morphological phase transitions of these fungi. Brain-heart infusion medium supports fastidious organisms but lacks specific antibacterial supplements for routine primary fungal isolation. Unsupplemented Sabouraud agar allows rapid bacterial growth which frequently obscures slow-growing clinical fungal isolates. Incubating any medium at thirty-five to thirty-seven degrees without antibiotics leads to overwhelming bacterial contamination.
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