Which of the following organisms, when isolated in the blood, requires the synergistic activity of penicillin plus an aminoglycoside for appropriate therapy -
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
Enterococcus faecalis
Staphylococcus aureus
Str. pneumoniae
Bacteroides fragilis
Systemic Bacteriology Pa 1 (Gram Positive Cocci, Gram Negative Cocci)