Which of the following organisms, when isolated in the blood, requires the synergistic activity of penicillin plus an aminoglycoside for appropriate therapy-

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 ".