This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
[{'content': 'Sulphur granules are seen in - \nSelect and explain. \nA. Sulphur poisoning, B. Actinomycosis, C. H2SO4 poisoning, D. Staphylococcal infection', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Actinomycosis Laboratory diagnosis of actinomycosis* The diagnosis is most commonly made by microscopic identification of sulphur granules (an in-vivo matrix of bacteria calcium phosphate, and host material).* The sulfur granules are bacterial colonies and will be found to consist of a dense network of thin Gram positive filaments, surrounded by a peripheral zone of swollen radiating club shaped structures, presenting a sun ray appearance. The 'clubs' are believed to be antigen - antibody complexes. Colonies resemble a molor tooth.* Granules of actinomyces are yellow colored.* Diagnosis can also be made by isolation of actinomyces in culture. The culture media used are :# Thioglycollate liquid medium# Brain heart infusion agar* In thioglycollate:# A. bovis produces general turbidity# A. israelic grows as fluffy balls at the bottom of the tube.* On solid media :# A. isralii produces small spidery colonies.# A. isralii produces colonies which give a bread crumb appearance.", 'role': 'assistant'}]