Safety of sugar coated antibiotics- comparing Allison et al. (2011) and Zuroff et al. (2010)

Allison et al. (2011) claims that aminoglycosides given in combination with specific metabolites like glucose, fructose, mannitol or pyruvate can be used to treat biofilm-related infections. They found that 10 mM glucose, fructose, mannitol and 20 mM pyruvate given along with gentamicin could reduce the number of persisters in vitro by more than 99.9% than with gentamicin alone. This activity was found to be antibiotic specific (i.e. only with aminoglycosides, but not with other groups of antibiotics like β-lactam antibiotics or quinolones).

However, this finding is in stark contrast with Zuroff et al. (2010) who reported that addition of glucose to E.coli biofilms resulted in an increase in cfu/biofilm by an order of more than 6log₁₀ than without glucose when aminoglycoside was used but a decrease in cfu/biofilm of nearly the same magnitude when ampicillin was used. They also noticed the same effect with other metabolites like fructose, sorbitol and gluconate. This effect was found to be concentration dependent also.

This contrasting finding raises the question whether addition of glucose or other metabolites (probably with the exception of mannitol, which is discussed in the earlier blogposts) along with aminoglycosides (Allison et al. 2010) will be safe in the treatment of bacterial persisters and biofilm-related persistent infections.

Allison et al. (2011). Metabolite-enabled eradication of bacterial persisters by aminoglycosides. Nature 473: 216-220.

Zuroff et al. (2010). Robustness analysis of culturing perturbations on Escherichia coli biofilm beta-lactam and aminoglycoside antibiotic tolerance. BMC Microbiology 10:185