Proteus mirabilis PM13 is a well-characterized chloramphenicol-sensitive isolate which spontaneously gives rise to resistant colonies on solid media containing chloramphenicol (50 micrograms ml-1) at a plating efficiency of 10(-4) to 10(-5). Such chloramphenicol-resistant colonies exhibit a novel phenotype with respect to chloramphenicol resistance. When a single colony grown on chloramphenicol...

The inhibitory effect of chloramphenicol on human cytochrome P450 (CYP) isoforms was evaluated with human liver microsomes and cDNA-expressed CYPs. Chloramphenicol had a potent inhibitory effect on CYP2C19-catalyzed S-mephytoin 4'-hydroxylation and CYP3A4-catalyzed midazolam 1-hydroxylation, with apparent 50% inhibitory concentrations (inhibitory constant [K(i)] values are shown in parentheses)...

Plasmid-mediated chloramphenicol resistance in Staphylococcus aureus has been shown to involve acetylation of chloramphenicol by an enzyme induced by growth in the presence of the antibiotic and certain analogues. Analysis of the kinetics of induction has been complicated by (i) the intrinsic inhibitory effects of chloramphenicol on induced enzyme synthesis and (ii) the rapid disappearance of i...

367 children with cerebrospinal-fluid findings suggestive of bacterial meningitis were randomised to receive either chloramphenicol alone by intramuscular injection, or chloramphenicol plus penicillin by intravenous injection. Sequential analysis showed no difference in mortality between the two treatments. 48 (26%) of the 183 children in the chloramphenicol alone group died, and 49 (27%) of th...

Analogs of chloramphenicol were prepared for the first time in which the nitro group was replaced by hydroxylamine, nitroso, hydroxamic acid, methyl hydroxamate, and O-acetyl hydroxamate functional groups. These compounds were tested for antibiotic activity in order to determine whether the antibiotic activity of chloramphenicol is mediated by one or more of these potential metabolites of chlor...

The effect of a series of puromycin analogues and aminoacyl chloramphenicol derivatives on poly(U,C)-directed polyphenylalanine synthesis in an Escherichia coli cell-free system was examined. A comparison between the structures and activities of the puromycin and chloramphenicol analogues was made to examine the proposal that ribosomal binding sites for both antibiotics overlap. Our results sug...

A spontaneously occurring, noninducible, chloramphenicol-resistant mutant of Bacillus subtilis 168 has a mutation (cam-2) which maps in the ribosomal protein region of the chromosome near dal. Its presence does not confer dependence on chloramphenicol. Ribosomes of the cam-2 strain remained sensitive to chloramphenicol in in vitro protein synthesis. No chloramphenicol acetyltransferase activity...

Two infants with meningitis who were treated with phenobarbitone and high-dose chloramphenicol showed progressive falls in the peak blood levels of chloramphenicol. A standard chloramphenicol dose of 50 mg/kg daily would have produced subtherapeutic blood levels after only a few days. The importance of measuring serial blood chloramphenicol concentrations is stressed.