title: A Rapid, simple method for demonstrating synergy of amikacin and penicillin against various microorganisms.
abstract: A simple disk diffusion technique with use of triple-layer agar and enzymatic inactivation of penicillin demonstrated synergy between penicillins and aminoglycosides. The method was applied to measurement of the synergistic activity of amikacin and penicillin G against a strain of Streptococcus faecalis sensitive to both drugs, amikacin and ampicillin against a strain of S. faecalis sensitive to amplicillin but resistant to amikacin, and amikacin and carbenicillin against a strain of Proteus mirabilis sensitive to both drugs. The degree of synergy was related to the specific organism tested. For example, syngery of penicillin G and amikacin for S. faecalis could be demonstrated only when the organism was subjected first to the action of penicillin G alone. In addition to providing useful clinical information, the triple-layer technique appears to be a promising tool for the study and understanding of synergy between antimicrobial agents.
mesh_terms: D000583:Amikacin / Q000494:pharmacology*; D000667:Ampicillin / Q000494:pharmacology; D002228:Carbenicillin / Q000494:pharmacology; D004357:Drug Synergism; D013293:Enterococcus faecalis / Q000187:drug effects*; D007612:Kanamycin / Q000031:analogs & derivatives*; D008826:Microbial Sensitivity Tests; D010400:Penicillin G / Q000494:pharmacology; D010406:Penicillins / Q000494:pharmacology*; D011513:Proteus mirabilis / Q000187:drug effects*
chemical_list: D010406:Penicillins; D007612:Kanamycin; D000667:Ampicillin; D000583:Amikacin; D002228:Carbenicillin; D010400:Penicillin G