The incidence of oral Gram-negative bacteria in patients with Parkinson's disease

Background: Parkinson's disease is a common neurodegenerative disorder that affects an increasing number of older people every year. Dysphagia is not only a common feature, but one that results in poor nutrition and an increased risk of bronchopneumonia. Previous work has suggested that the oral flora is altered in patients with oral pathology. Methods: Fifty patients were assessed to quantify the incidence of oral Gram-negative bacteria. Results: Sixteen of the patients with Parkinson's disease were found to have six different Gram-negative bacilli in their oral cavities. The 20 different Gram-negative bacteria present were Escherichia coli (n=7), Klebsiella spp. (n=3), Kluyvera spp. (n=3), Serratia spp. (n=3), Proteus spp. (n=2) and Enterobacter spp. (n=2). We found that the oral cavity of 16 (32%) of the patients with Parkinson's disease was abnormally colonised with Gram-negative bacteria and that Gram-negative bacteria were more likely to occur in those patients in whom oromuscular dysfunction was present (88% vs. 21%; p<0.05). Conclusion: Further work is required to determine the association between oral flora and the pathogenic organisms found in aspiration pneumonia as well as work on innovative treatments to reduce oral Gram-negative bacteria in those patients at particular risk of aspiration pneumonia.

The effect of copper(II), iron(II) sulphate and vitamin C combinations on the weak antimicrobial activity of (+)-catechin against Staphylococcus aureus and other microbes

Few attempts have been made to improve the activity of plant compounds with low antimicrobial efficacy. (+)-Catechin, a weak antimicrobial tea flavanol, was combined with putative adjuncts and tested against different species of bacteria. Copper(II) sulphate enhanced (+)-catechin activity against Pseudomonas aeruginosa but not Staphylococcus aureus, Proteus mirabilis or Escherichia coli. Attempts to raise the activity of (+)-catechin against two unresponsive species, S. aureus and E. coli, with iron(II) sulphate, iron(III) chloride, and vitamin C, showed that iron(II) enhanced (+)-catechin against S. aureus, but not E. coli; neither iron(III) nor combined iron(II) and copper(II), enhanced (+)-catechin activity against either species. Vitamin C enhanced copper(II) containing combinations against both species in the absence of iron(II). Catalase or EDTA added to active samples removed viability effects suggesting that active mixtures had produced H2O2via the action of added metal(II) ions. H2O2 generation by (+)-catechin plus copper(II) mixtures and copper(II) alone could account for the principal effect of bacterial growth inhibition following 30 minute exposures as well as the antimicrobial effect of (+)-catechin–iron(II) against S. aureus. These novel findings about a weak antimicrobial flavanol contrast with previous knowledge of more active flavanols with transition metal combinations. Weak antimicrobial compounds like (+)-catechin within enhancement mixtures may therefore be used as efficacious agents. (+)-Catechin may provide a means of lowering copper(II) or iron(II) contents in certain crop protection and other products.