In vitro susceptibility of Streptococcus bovis to six antibiotics.
A recent report of two isolates of Streptococcus bovis resistant to killing by low levels of penicillin G prompted this study of the in vitro susceptibility of 100 clinical isolates of S bovis to six antibiotics. Using a microdilution method, we found the minimum bactericidal concentrations for 99% of the isolates to be as follows: penicillin G, 0.5 microgram/ml; methicillin, 16 micrograms/ml; ampicillin, 0.5 microgram/ml; cephalothin, 2 micrograms/ml; clindamycin, 2 micrograms/ml; and vancomycin, 2 micrograms/ml. The high-level resistance of S bovis to penicillin G previously described was not seen. This study suggests that penicillin G can still prove effective in treating most infections caused by S bovis, including infective endocarditis, and that cephalothin and vancomycin are useful alternative agents.
D000667:Ampicillin / Q000627:therapeutic use; D002512:Cephalothin / Q000627:therapeutic use; D002981:Clindamycin / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004697:Endocarditis, Bacterial / Q000188:drug therapy*; D006801:Humans; D008712:Methicillin / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests; D010400:Penicillin G / Q000627:therapeutic use; D010406:Penicillins / Q000627:therapeutic use*; D013290:Streptococcal Infections / Q000188:drug therapy*; D013291:Streptococcus / Q000187:drug effects*; D014640:Vancomycin / Q000627:therapeutic use
D010406:Penicillins; D002981:Clindamycin; D014640:Vancomycin; D000667:Ampicillin; D010400:Penicillin G; D008712:Methicillin; D002512:Cephalothin