This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': 'A farmer presents with multiple discharging sinuses in the leg not responding to antibiotics. Most likely diagnosis is - \nSelect and explain. \nA. Madurella, B. Actinomycetoma, C. Nocardia, D. Sporothrix', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Multiple discharging sinuses not responding to antibiotics suggest the diagnosis of mycetoma.\n\n\nActinomycetoma may respond to antibiotic therapy. eg. combination of streptomycin and dapsone or combination of streptomycin and trimethoprim-sulfamethoxazole.\nActinomycetoma is caused by Actinomadura, Nocardia and Streptomyces.\nEumycetoma rarely responds to antibiotics, some cases caused by madurella mycetoma have appeared to respond to ketoconazole or itraconazole.', 'role': 'assistant'}]