Polysorbate, a safe additive found in everything from ice cream to cosmetics, has been proven to slow the toxic effects of E. coli poisoning. The findings, featured in the current issue of the journal Biofouling, show that polysorbates attack the protective biofilm in which E. coli lives and renders the deadly bacteria harmless, said Chris Waters, Michigan State University associate professor of microbiology and molecular genetics whose laboratory led the research.
Specifically, the team focused on the potent strain isolated from Germany that swept through Europe in 2011, causing thousands of infections and more than 50 deaths. This strain had been previously studied by Waters and Shannon Manning. Having samples of the bacteria at MSU helped the team, led by Rudolph Sloup, MSU microbiology and molecular genetics graduate student, isolate compounds that inhibited biofilms.
“During our animal infection studies, polysorbate 80 had no effect on the numbers of infecting E. coli. This was a little shocking, especially based on how promising our earlier tests had been,” Waters said. “Later, though, our pathology tests showed that polysorbate 80 essentially blocked all toxicity, even though it didn’t reduce the number of bacteria.”
The later confirmation of the successful in vivo experiment using mice models essentially showed that polysorbate 80 strips E. coli of its ability to cause disease allowing the bacteria to pass through the body’s intestinal tract without causing damage. So instead of killing the E. coli like traditional antibiotics, a strategy that works until the E. coli develops resistance to the treatment, this finding suggests an anti-virulence strategy can be quite effective.
Since polysorbate 80 is categorized as a GRAS (generally regarded as safe) compound, it doesn’t require FDA approval to be used as a treatment. Along with its potential for disarming the deadly German E. coli outbreak, polysorbate 80 could potentially help tackle more-common E. coli infections such as traveler’s diarrhea.
The next steps for this research will be to identify how polysorbate 80 inhibits biofilm formation and test its activity in other infection models.
Citation: Sloup, Rudolph E., Roberto J. Cieza, David B. Needle, Robert B. Abramovitch, Alfredo G. Torres, and Christopher M. Waters. “Polysorbates prevent biofilm formation and pathogenesis of Escherichia coli O104: H4.” Biofouling 32, no. 9 (2016): 1131-1140.
DOI: http://dx.doi.org/10.1080/08927014.2016.1230849
Research funding: National Institutes of Health
Adapted from press release by Michigan State University