Question

In mid-December, a woman with insulin-dependent diabetes who had been on prednisone fell and received an abrasion on the dorsal side of her right hand. She was placed on penicillin. By the end of January, the ulcer had not healed, and she was referred to a plastic surgeon. On January 30, a swab of the wound was cultured at 35°C on blood agar. On the same day, a smear was made for Gram staining. The Gram stain showed large (10 µm) cells. Brownish, waxy colonies grew on the blood agar. Slide cultures set up on February 1 and incubated at 25°C showed septate hyphae and single conidia. The most likely cause of the infection is a _____________________?

a. Green algae--prokaryotic
b. Fungal spores
c. Dimorphic fungus
d. Lichens

Answer 1

c. Dimorphic fungus

Step-by-step explanation:

Many fungal species have structures such as septate hyphae and conidia at their ends. In addition, brownish and waxy colonies represent yeast fungi.

The 35 ° C temperature to which the cultures were exposed, however, are most supported by dimorphic fungi, which generally withstand temperatures between 35 and 37 degrees celsius in the yeast phase and their infectious forms are found in the tissues(as the woman's wound).

Given the above, the most likely cause of infection is a dimorphic fungus.