Inhibition of tobramycin diffusion by binding to alginate.
AUTOR(ES)
Nichols, W W
RESUMO
[3H]tobramycin bound to sodium alginate and to exopolysaccharide prepared from two mucoid strains of Pseudomonas aeruginosa. Binding to sodium alginate was similar to binding to exopolysaccharide, both in the dependence on tobramycin concentration and in the maximum binding observed at saturation. Incorporation of sodium alginate into agar plates reduced the zone sizes of growth inhibition caused by tobramycin. The reductions in zone sizes were quantitatively accounted for by the binding of tobramycin to sodium alginate during diffusion of the antibiotic away from the well in which it had been placed at the start of the experiment. However, the binding of tobramycin to the exopolysaccharide of P. aeruginosa, and the resulting inhibition of diffusion of the antibiotic, did not significantly increase the penetration time of a spherical microcolony with a radius of 125 micron, such as might be found in the respiratory tract of a patient with cystic fibrosis (from a 90% penetration time of 12 s in the absence of exopolysaccharide to one of 35 s with an exopolysaccharide concentration of 1.0% [wt/vol]).
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=172213Documentos Relacionados
- Hypochlorite scavenging by Pseudomonas aeruginosa alginate.
- Protection of Pseudomonas aeruginosa against ciprofloxacin and beta-lactams by homologous alginate.
- Anaerobic production of alginate by Pseudomonas aeruginosa: alginate restricts diffusion of oxygen.
- Binding of tobramycin leads to conformational changes in yeast tRNAAsp and inhibition of aminoacylation
- Cloning and expression in Pseudomonas aeruginosa of a gene involved in the production of alginate.