This combined approach not only prevented Salmonella infection in mice, but also eliminated established pathogenic E.coli infections. For this approach to work, the harmless bacteria must be able to thrive in the same environment as the pathogenic bacteria, with similar nutrient, oxygen and acidity requirements. The researchers used genetic engineering to develop a competitive harmless bacteria strain, though naturally selected E. coli strains were also effective.
“Although we can decimate pathogenic bacteria with a vaccine, we need harmless microorganisms to fill the resulting niche in the intestinal ecosystem in order to achieve long-term success,” explained Professor Slack. “It’s like gardening. If you want to avoid weeds in an area of the garden, you must plant other plants there after weeding. If you leave the soil empty, the weeds will just grow back.”
Read the full story on the Sir William Dunn School of Pathology website.