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': 'Which of the following organisms, when isolated in the blood, requires the synergistic activity of penicillin plus an aminoglycoside for appropriate therapy- \nSelect and explain. \nA. Enterococcus faecalis, B. Staphylococcus aureus, C. Str. pneumoniae, D. Bacteroides fragilis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. is \'a\' i.e., Enterococcus faecalis "Unlike streptococci, enterococci are not reliably killed by penicillin or ampicillin alone. Because of synergistic action of Penicillin and aminoglycoside against enterococci combination therapy is recommended ".', 'role': 'assistant'}]