Which feature is characteristic of dermatophytes when viewed in lactophenol cotton blue mounts?

Which feature is characteristic of dermatophytes when viewed in lactophenol cotton blue mounts?

• A. Branching hyphae, occasional arthrospores
• B. Short, stubby hyphal elements and grape-like clusters of spores
• C. Pseudohyphae & chlamydospores/blastospores
• D. Hyphae do not grow geometrically (e.g., sharp acute or right angles)

Answer: (A)

In lactophenol cotton blue mounts, dermatophytes show septate hyphae that branch in a regular, often acute-angle pattern and, along the hyphae, you can see arthroconidia (arthrospores) forming as the hyphae fragment. This combination—branching hyphae with occasional arthrospores—is the hallmark you look for under the microscope. The other descriptions don’t fit dermatophytes as well: pseudohyphae with chlamydospores are characteristic of Candida, not dermatophytes; short, stubby hyphae with grape-like clusters of spores aren’t the typical dermatophyte presentation; and hyphae that don’t grow geometrically contradict the common, orderly branching seen in dermatophyte hyphae.

In lactophenol cotton blue mounts, dermatophytes show septate hyphae that branch in a regular, often acute-angle pattern and, along the hyphae, you can see arthroconidia (arthrospores) forming as the hyphae fragment. This combination—branching hyphae with occasional arthrospores—is the hallmark you look for under the microscope.

The other descriptions don’t fit dermatophytes as well: pseudohyphae with chlamydospores are characteristic of Candida, not dermatophytes; short, stubby hyphae with grape-like clusters of spores aren’t the typical dermatophyte presentation; and hyphae that don’t grow geometrically contradict the common, orderly branching seen in dermatophyte hyphae.