This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic Bacteriology Pa 1 (Gram Positive Cocci, Gram Negative Cocci), Subject name: Microbiology
Which of the following organisms, when isolated in the blood, requires the synergistic activity of penicillin plus an aminoglycoside for appropriate therapy - 
Select and explain. 
A. Enterococcus faecalis, B. Staphylococcus aureus, C. Str. pneumoniae, D. Bacteroides fragilis
A: Enterococcus faecalis
Answer: A: Enterococcus faecalis 
Explanation: Organism Features Enterococcus faecalis Resistant to penicillins, aminoglycosides and sulfonamides. Intrinsic resistance to cephalosporins and cotrimoxazole. In c/o resistance -combine- Penicillin + Aminoglycoside as they act synergestically. Staphylococcus aureus Rx : Parenteral therapy for serious infections Oral therapy for skin and soft tissue infections Sensitive to penicillin- DOC: Penicillin G Sensitive to methicillin-DOC: Nafcillin or oxacillin Resistant to methicillin (MRSA)- DOC: Vancomycin Sensitive to methicillin- DOC: Dicloxacillin, cephalexin Resistant to methicillin (MRSA) - DOC: Clindamycin Streptococcus pneumoniae Rx DOC- Penicillin G Alternative : Cephalosporins(ceftriaxone) Bacteroides fragilis Obligately anaerobe, non-spore forming gram-negative bacilli C/F- Brain abscess, subdural empyema, epidural abscess, and meningitis Endocarditis, meningitis, septic ahritis and osteomyelitis Colonies- Brilliant red fluorescence Rx- Metronidazole