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': 'All of the following organisms are known to survive intracellularly except - \nSelect and explain. \nA. Neisseria meningitidis, B. Salmonella typhi., C. Streptococcus pyogenes, D. Legionella pneumophila', 'role': 'user'}, {'content': "Answer: C \nExplanation: Facultative intracellular organisms \n\n\nBesides obligate intracellular organisms, some other organisms can live intracellularly → Facultative intracellular organisms.\n\n\n\nThese bacteria also have the capability of synthesis their own ATP, So they usually live extracellularly (in contrast obligate intracellular organisms).\nThese bacteria are phagocytosed by the host's macrophages and neutrophils yet survived within these WBCs by inhibiting phagosome-lysosome fusion, thus escaping host's toxic H2O2 and superoxide radicals.\nImportant examples :-\n\n\nListeria monocytogenes\xa0 - Yersinia\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0 - Brucella\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0 - Mycobacterium\nNeisseria\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0 - Salmonella typhi\xa0\xa0\xa0\xa0\xa0\xa0 - Legionella\xa0\xa0\xa0\xa0 - Francisella tularensis", 'role': 'assistant'}]