title: Pharmacodynamic properties of HMR 3004, a novel ketolide, on respiratory pathogens, enterococci and Bacteroides fragilis demonstrated by studies of time kill kinetics and postantibiotic effect.
abstract: OBJECTIVE: The pharmacodynamic properties of the novel ketolide (a new class of macrolide) antibiotic, HMR 3004, were investigated by studying time-kill kinetics and postantibiotic effect. METHODS: The time-kill kinetics were studied at two inocula against three strains each of Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, Streptococcus pyogenes, Enterococcus faecalis, Enterococcus faecium and Bacteroides fragilis. The postantibiotic effects of HMR 3004 were also investigated on these organisms at concentrations equivalent to 1, 4 and 10 x MIC. RESULTS: The time kill-kinetic data demonstrated that HMR 3004 is inoculum dependent and predominantly bacteriostatic being only slowly bactericidal at higher concentrations. HMR 3004 exhibited a significant postantibiotic effect with all strains studied, ranging from 1.9--6.2 h at 10 x MIC. CONCLUSIONS: The bacteriostatic activity and significant postantibiotic effect demonstrated by HMR 3004 are similar to those previously obtained with other macrolides.
authors.affiliation: Department of Medical Microbiology, City Hospital NHS Trust, Dudley Road, Birmingham, UK.
authors.forename: F.J.
authors.initials: FJ
authors.lastname: Boswell
authors.forename: J.M.
authors.initials: JM
authors.lastname: Andrews
authors.forename: R.
authors.initials: R
authors.lastname: Wise