Telithromycin is active against Mycobacterium avium in mice despite lacking significant activity in standard in vitro and macrophage assays and is associated with low frequency of resistance during treatment.

TitleTelithromycin is active against Mycobacterium avium in mice despite lacking significant activity in standard in vitro and macrophage assays and is associated with low frequency of resistance during treatment.
Publication TypeJournal Article
Year of Publication2001
AuthorsBermudez LE, Inderlied CB, Kolonoski P, Wu M, Aralar P, Young LS
JournalAntimicrobial agents and chemotherapy
Volume45
Issue8
Pagination2210-4
Date Published2001 Aug
ISSN0066-4804
KeywordsAnimals, Anti-Bacterial Agents, Dose-Response Relationship, Drug, Drug Resistance, Female, Humans, Ketolides, Macrolides, Macrophages, Mice, Mice, Inbred C57BL, Microbial Sensitivity Tests, Mycobacterium avium Complex, Mycobacterium avium-intracellulare Infection
Abstract

The activity of telithromycin, a new ketolide, was evaluated in vitro and in vivo against Mycobacterium avium complex (MAC) strains. The MIC of telithromycin for several M. avium isolates obtained from the blood of AIDS patients ranged from 16 to >128 microg/ml (MIC at which 90% of isolates are inhibited, >128 microg/ml), and the compound did show activity in the macrophage system at concentrations greater than 8 or 16 microg/ml, but this was dependent on the MAC strain used. Telithromycin was then administered to mice infected with MAC strain 101 for 4 weeks at doses of 100, 200, or 400 mg/kg of body weight/day. Treatment with 100 and 200 mg/kg/day was bacteriostatic, but at 400 mg/kg/day telithromycin was bactericidal for MAC strains. The frequency of the emergence of resistance to telithromycin was low despite prolonged usage (12 weeks). This study demonstrates that telithromycin is active in vivo against MAC and warrants further evaluation.

DOI10.1128/AAC.45.8.2210-2214.2001
Alternate JournalAntimicrob. Agents Chemother.