Efficacy of the combination of tobramycin and a macrolide in an in vitro Pseudomonas aeruginosa mature biofilm model.
Antimicrob Agents Chemother
; 54(10): 4409-15, 2010 Oct.
Article
em En
| MEDLINE
| ID: mdl-20696878
ABSTRACT
Respiratory disease is the main cause of morbidity and mortality in patients with cystic fibrosis (CF). In particular, patients suffer from chronic infection due to biofilm formation by opportunistic Pseudomonas aeruginosa (32). Therefore, there is an urgent need to develop alternative ways to treat biofilm-associated clinical infections. The aim of this study was to compare the antimicrobial effects in vitro of the combinations tobramycin-clarithromycin and tobramycin-azithromycin against five P. aeruginosa biofilms and to establish the most effective combination. We performed a kinetic study over a period of 28 days of a twice-daily coadministration of the combinations tobramycin-clarithromycin and tobramycin-azithromycin on 12-day-old, mature P. aeruginosa biofilms formed on microplate pegs for 4 clinical isolates and one laboratory strain (PAO1) to simulate the treatment of CF patients with tobramycin inhalation solution (TOBI) through aerosolization. A synergy between tobramycin and clarithromycin was recorded for 3/5 biofilms, with a bacterial decrease of more than 5 log. Conversely, we found an antagonistic activity when 4 µg/ml tobramycin was administered with azithromycin at 2 µg/ml for P. aeruginosa PAO1 and with azithromycin at 2, 20, 50, 100, and 200 µg/ml for P. aeruginosa PYO1. Treatment with tobramycin at 4 µg/ml combined with clarithromycin at 200 µg/ml eradicated all five biofilms, while tobramycin-azithromycin at the same concentrations eradicated only three biofilms. Results of this study suggest that local administration of tobramycin and clarithromycin into the respiratory tract represents a better strategy than the combination tobramycin-azithromycin for the treatment of P. aeruginosa-associated pulmonary infections.
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Pseudomonas aeruginosa
/
Tobramicina
/
Biofilmes
/
Macrolídeos
/
Antibacterianos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Antimicrob Agents Chemother
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Bélgica