A man developed a pustule after striking by a thorn in the garden. Laboratory examination of the tissue specimen shows cigar-shaped budding yeasts. Most probable causative agent is:

Sporothrix schenckii, is a dimorphic fungus. The mold form lives on plants and the yeast form occurs in human tissue. When spores of the mold are introduced into the skin, typically by a thorn, it causes a local pustule or ulcer with nodules along the draining lymphatics. In the clinical laboratory, round or cigar-shaped budding yeasts are seen in tissue specimens. In culture at room temperature, hyphae occur bearing oval conidia in clusters at the tip of slender conidiophores (resembling a daisy). The drug of choice for skin lesions is itraconazole. Ref: Levinson W. (2012). Chapter 48. Cutaneous & Subcutaneous Mycoses. In W. Levinson (Ed), Review of Medical Microbiology & Immunology, 12e.