New insight into multi-drug resistance

Researchers have found that two strains of E. coli bacteria, each resistant to one antibiotic, can protect each other in an environment where both drugs are present.

The findings demonstrate that mutualism, a phenomenon in which different species benefit from their interactions with each other, can help bacteria form drug-resistant communities. This is the first experimental demonstration in microbes of a type of mutualism known as cross-protection, which is more commonly seen in larger animals.

The researchers focused on two strains of E. coli, one resistant to ampicillin and the other resistant to chloramphenicol. These bacteria and many others defend themselves from antibiotics by producing enzymes that break down the antibiotics. As a side effect, this also protects cells that don't produce those enzymes, by removing the antibiotic from the environment.

For further details, see:

Saurabh R. Gandhi, Eugene Anatoly Yurtsev, Kirill S. Korolev, and Jeff Gore. Range expansions transition from pulled to pushed waves as growth becomes more cooperative in an experimental microbial population. PNAS, 2016 DOI: 10.1073/pnas.1521056113

Posted by Dr. Tim Sandle