Inhibition of tobramycin diffusion by binding to alginate
(/sup 3/H)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)).
- Research Organization:
- John Radcliffe Hospital, Oxford (England)
- OSTI ID:
- 7126096
- Journal Information:
- Antimicrob. Agents Chemother.; (United States), Vol. 32:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
62 RADIOLOGY AND NUCLEAR MEDICINE
ANTIBIOTICS
BIOCHEMICAL REACTION KINETICS
PSEUDOMONAS
GROWTH
ALGINATES
DIFFUSION
INHIBITION
POLYSACCHARIDES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANTI-INFECTIVE AGENTS
BACTERIA
CARBOHYDRATES
DRUGS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MICROORGANISMS
ORGANIC COMPOUNDS
REACTION KINETICS
SACCHARIDES
550201* - Biochemistry- Tracer Techniques
550600 - Medicine