This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mycology, Subject name: Microbiology
Hair perforation test is positive in infection with? 
Select and explain. 
A. Trichophyton, B. Exophila werneckii, C. Epidermophyton, D. All of the above
A: Trichophyton
Answer: A: Trichophyton 
Explanation: Hair perforation test: This test is performed to differentiate T. rubrum from T. mentagrophytes and M. canis from Microsporum equinus. T. mentagrophytes shows a positive hair perforation test characterized by a wedge-shaped perforation of the hair. This test is negative for T. rubrum in which only surface eruption of hair shaft is demonstrated. figure :-Perforation test positive Exophila/Hoaea werneckii is the causative agent of Tinea nigra (brown or black patches on the soles of the feet)