title: Efficacy of macrolides used in combination with ethambutol, with or without other drugs, against Mycobacterium avium within human macrophages.
abstract: The activities of clarithromycin or roxithromicin used in combination with other antimicrobial drugs were tested in human macrophages experimentally infected with 23 strains of Mycobacterium avium. Overall, clarithromycin-ethambutol-rifampicin was the most active combination tested. The reduction in intracellular viable bacilli was found to be more than 1 log(10) for 95% and more than 2 logs(10) for 65% of the strains. The second most active combination was roxithromycin-ethambutol-rifampicin, which was found to be bactericidal for about 80% and highly bactericidal for 20% of the strains. Others combinations were only bacteriostatic or weakly bactericidal for many of the strains. The addition of a third drug did not necessarily promote enhanced bacterial killing inside the macrophage.
authors.affiliation: Institute of Hygiene, University of Urbino, 61029, Urbino, Italy.
authors.forename: G F
authors.initials: GF
authors.lastname: Schiavano
authors.forename: A G
authors.initials: AG
authors.lastname: Celeste
authors.forename: L
authors.initials: L
authors.lastname: Salvaggio
authors.forename: M
authors.initials: M
authors.lastname: Sisti
authors.forename: G
authors.initials: G
authors.lastname: Brandi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000995:Antitubercular Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D017291:Clarithromycin / Q000494:pharmacology; D004359:Drug Therapy, Combination / Q000494:pharmacology*; D004977:Ethambutol / Q000494:pharmacology*; D006801:Humans; D008264:Macrophages / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D009162:Mycobacterium avium / Q000187:drug effects* / Q000254:growth & development; D012293:Rifampin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000995:Antitubercular Agents; D004977:Ethambutol; D017291:Clarithromycin; D012293:Rifampin