Activities of telithromycin (HMR 3647, RU 66647) compared to those of erythromycin, azithromycin, clarithromycin, roxithromycin, and other antimicrobial agents against unusual anaerobes

The comparative activity of telithromycin (HMR 3647) against 419 human anae robic isolates was determined by the agar dilution method. At concentration s of less than or equal to 0.5 mu g/ml, telithromycin was active against Ac tinomyces israelii,Actinomyces odontolyticus, Bacteroides tectum, Bacteroid es ureolyticus, Bacteroides gracilis (now Campylobacter gracilis), Porphyro monas spp. (including Porphyromonas gingivalis and Porphyromonas macacae), Prevotella intermedia, Prevotella heparinolytica, and almost all Peptostrep tococcus species. Clostridia showed species and strain variability, often,v ith a biphasic pattern. Fusobacterium species, except Fusobacterium russii, were relatively resistant.