The main treatment for cholera involves oral rehydration therapy where the patient drinks water mixed with salts and glucose which can increase the toxicity of the cholera bacterium.Scientists have now shown that replacing glucose with rice powder can reduce its toxicity by almost 75 percent."The problem is that the infecting bacterium also consumes glucose and that increases the expression of its genes that make it toxic," said Melanie Blokesch from the Swiss Federal Institute of Technology (EPFL) in Lausanne.Blokesch and Andrea Rinaldo at EPFL correlated data from a recent cholera outbreak in Haiti with the effectiveness of oral rehydration therapy.
Blokesch's lab grew the cholera bacterium with different sugars and starch from potatoes and rice to see how each would affect the cholera toxin genes.The scientists found that both the activity of the genes, as well as the production of the cholera toxin itself were increased when the bacterium was fed with glucose but they were considerably decreased when it was fed with starch from rice."Although the explanation for this is complicated, one of the reasons is that the type of sugar available to the bacterium affects the mechanisms that regulate the activity of its toxin-producing genes. Ultimately, this effect influences the bacterium's ability to infect humans," Blokesch added.
"We are not saying stop doing oral rehydration therapy with glucose right away because it works so well," Blokesch added.But still, the data suggests that the regimen can be significantly improved, and that the community needs to start discussing this possibility again - especially in areas endemic to cholera, the authors concluded.The work was published in PLOS Neglected Tropical Diseases.