despite shifts in bacterial susceptibilities to commonly used antibacterial agents , penicillin , ampicillin and chloramphenicol remain effective therapy for the vast majority of cases , although newer cephalosporin derivatives may be required to avoid the toxicities of chloramphenicol and to effectively treat selected bacteria that have developed resistance to these more classical antibiotics .
C0279516
antibacterial agents
C0002680
ampicillin