In vitro and in vivo activities of antimicrobials against Nocardia brasiliensis.
In Mexico mycetomas are mostly produced by Nocardia brasiliensis, which can be isolated from about 86% of cases. In the present work, we determined the sensitivities of 30 N. brasiliensis strains isolated from patients with mycetoma to several groups of antimicrobials. As a first screening step we carried out disk diffusion assays with 44 antimicrobials, including aminoglycosides, cephalosporins, penicillins, quinolones, macrolides, and some others. In these assays we observed that some antimicrobials have an effect on more than 66% of the strains: linezolid, amikacin, gentamicin, isepamicin, netilmicin, tobramycin, minocycline, amoxicillin-clavulanic acid, piperacillin-tazobactam, nitroxolin, and spiramycin. Drug activity was confirmed quantitatively by the broth microdilution method. Amoxicillin-clavulanic acid, linezolid, and amikacin, which have been used to treat patients, were tested in an experimental model of mycetoma in BALB/c mice in order to validate the in vitro results. Linezolid showed the highest activity in vivo, followed by the combination amoxicillin-clavulanic acid and amikacin.
Servicio de Dermatología, Hospital Universitario "José E. González," Centro de Investigación Biomédica del Noreste, IMSS, Monterrey, N.L., México.
Alejandra
A
Gomez-Flores
Oliverio
O
Welsh
Salvador
S
Said-Fernández
Gerardo
G
Lozano-Garza
Roman Erick
RE
Tavarez-Alejandro
Lucio
L
Vera-Cabrera
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D004359:Drug Therapy, Combination / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D005528:Foot / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008826:Microbial Sensitivity Tests; D009615:Nocardia / Q000187:drug effects*; D009617:Nocardia Infections / Q000188:drug therapy* / Q000473:pathology; D012874:Skin Diseases, Infectious / Q000188:drug therapy / Q000473:pathology
D000900:Anti-Bacterial Agents