Antimicrobial synergism against Mycobacterium avium complex strains isolated from patients with acquired immune deficiency syndrome.
AUTOR(ES)
Yajko, D M
RESUMO
Pairs of 11 antimicrobial agents were tested in vitro for their ability to act synergistically against three strains of Mycobacterium avium complex isolated from patients with acquired immune deficiency syndrome. From the combinations tested, four drugs (ethambutol, rifampin, ciprofloxacin, and erythromycin) were selected for more extensive study against 20 strains of M. avium complex. The inhibitory and killing synergism obtained with combinations of two, three, or four drugs was assessed by determining the fractional inhibitory concentration index and fractional bactericidal concentration index. Inhibitory synergism occurred against 90 to 100% of the strains for all drug combinations in which ethambutol was included. Killing synergism occurred against 85 to 95% of the strains when ethambutol was used in combinations which included either rifampin or ciprofloxacin. However, killing synergism occurred against only 45% of the strains when drugs were tested at concentrations that can be obtained in patient serum. In other experiments, rifabutin (Ansamycin) gave results that were comparable to those obtained with rifampin. Clofazimine did not show synergistic killing activity at a concentration that is achievable in serum for any of the drugs tested. Our results indicate that there is considerable variability in the antimicrobial susceptibility of M. avium isolates obtained from patients with acquired immune deficiency syndrome. This variability could have significant impact on the clinical response to various therapies.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=175874Documentos Relacionados
- Broth microdilution testing of susceptibilities to 30 antimicrobial agents of Mycobacterium avium strains from patients with acquired immune deficiency syndrome.
- Characterization and growth in human macrophages of Mycobacterium avium complex strains isolated from the blood of patients with acquired immunodeficiency syndrome.
- Geographic distribution, frequency, and specimen source of Mycobacterium avium complex serotypes isolated from patients with acquired immunodeficiency syndrome.
- Mycobacterium simiae and Mycobacterium avium-M. intracellulare mixed infection in acquired immune deficiency syndrome.
- Rapid identification using a specific DNA probe of Mycobacterium avium complex from patients with acquired immunodeficiency syndrome.