Corneal scrapings from a suspected fungal corneal ulcer are sent for culture. Which culture medium must be specifically requested because the standard formulation inhibits fungal growth?
- A Blood agar incubated anaerobically
- B Sabouraud dextrose agar without cycloheximide ✓
- C Chocolate agar enriched with IsoVitalex
- D Non-nutrient agar seeded with Escherichia coli
Correct answer: B. Sabouraud dextrose agar without cycloheximide
Explanation
Fungal corneal cultures are set up on Sabouraud dextrose agar without cycloheximide, since cycloheximide suppresses saprophytic fungi including many ocular pathogens such as Aspergillus and Fusarium. Blood and chocolate agar support bacteria, and non-nutrient agar with E. coli is the enrichment medium for Acanthamoeba, not fungi. In practice, specimens are plated onto blood agar, chocolate agar, and Sabouraud agar together.
Reference: American Academy of Ophthalmology Basic and Clinical Science Course, External Disease and Cornea, BCSC Section 8 ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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