Biofilms are biological structures that help bacteria survive in their environment. Researchers at the Institut Pasteur have shown that biofilms promote the emergence of antibiotic resistance in Escherichia coli bacteria exposed to antibiotics.
Bacteria are microorganisms that can assemble into transient communities. When this happens, they may form a biofilm, which is an ecosystem that can protect them from external threats. Biofilms that form on mucosal surfaces or certain medical devices are very difficult to remove, and this greatly increases the risk of infection. In this situation, the preferred solution is to administer several courses of antibiotics, but this has consequences.
In a study published on March 16, 2023 in the journal Communications biology, researchers from the Institut Pasteur and the University of Hokkaido measured the effect of this treatment on Escherichia coli bacteria. "We demonstrated that the repeated application of an antibiotic to the biofilm of these bacteria not only fails to eliminate them but instead induces resistance to the antibiotic" reports Jean-Marc Ghigo, Head of the Institut Pasteur's Genetics of Biofilms Laboratory and co-author of the study. Conversely, when the same treatment is applied to free-living bacteria, large numbers of them die and they do not develop antibiotic resistance.
This study highlights two issues. The first relates to antibiotic resistance, which has been a major problem since the invention of antibiotics, and the second relates to nosocomial diseases, which are spread in the hospital setting. "We are therefore convinced that efforts to eradicate biofilms could not only help to reduce the impact of associated infections but also make it less likely that antibiotic resistance will emerge" says Christophe Beloin, a unit researcher and leader of the study.
This study comes under the Antimicrobial resistance priority scientific area as part of the Institut Pasteur's 2019-2023 Strategic Plan.
Usui, M., Yoshii, Y., Thiriet-Rupert, S. et al. Intermittent antibiotic treatment of bacterial biofilms favors the rapid evolution of resistance. Communications Biology, 16 mars 2023. https://doi.org/10.1038/s42003-023-04601-y