Time-kill studies of antibiotic combinations against penicillin-resistant and -susceptible Streptococcus pneumoniae.
Time-kill studies were conducted to evaluate antibiotic combinations against four strains of Streptococcus pneumoniae for which the MICs of penicillin were 0.03, 0.25, 1 and 4 mg/L, respectively. After 8 h of antibiotic exposure the combination of ceftriaxone and vancomycin showed enhanced activity against all four strains. Penicillin plus vancomycin and ceftriaxone plus gentamicin showed enhanced activity against the three penicillin-resistant strains. Combinations of vancomycin and rifampicin were indifferent. These results are similar to those found previously in the rabbit meningitis model suggesting that time-kill studies over 8 h may be useful in predicting in-vivo antibiotic interactions in resistant pneumococcal infections.
Friedland
I R
IR
Department of Pediatrics, University of Texas Southwestern Medical School, Dallas.
Paris
M
M
Shelton
S
S
McCracken
G H
GH
D002443:Ceftriaxone / Q000494:pharmacology; D004357:Drug Synergism; D004359:Drug Therapy, Combination / Q000494:pharmacology*; D005839:Gentamicins / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D010403:Penicillin Resistance / Q000502:physiology*; D010406:Penicillins / Q000494:pharmacology; D012293:Rifampin / Q000494:pharmacology; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000254:growth & development; D013752:Tetracycline / Q000494:pharmacology; D013997:Time Factors; D014640:Vancomycin / Q000494:pharmacology
D005839:Gentamicins; D010406:Penicillins; D014640:Vancomycin; D002443:Ceftriaxone; D013752:Tetracycline; D012293:Rifampin