Genetically modified phages deliver bacterial toxins to combat multidrug-resistant E. coli

At the Vrije Universiteit Brussel (VUB) – Flanders Institute for Biotechnology (VIB), biologist Jessie Vandierendonck has been investigating new, alternative treatments to combat bacterial infections using (bacterio)phages, viruses that attack and destroy bacteria. The findings are published in the journal Microbiology Spectrum.

The phage may either exploit the bacterial "machinery" to produce new phages, which eventually burst the bacterial cell and kill it, or it may integrate its genetic material into the bacterial genome in a dormant state as a "temperate" phage.

The former makes bacteriophages a promising and natural tool to selectively eliminate bacteria as an alternative to antibiotics. Temperate phages, by contrast, do not necessarily kill the bacterial cells, and this is where Vandierendonck's research comes in.

In addition to phage therapy, she also explored the use of bacterial toxin–antitoxin systems, which consist of a toxin that induces cell death and an antitoxin that counteracts its effect. By combining phages and toxins, Vandierendonck developed an innovative approach to target pathogenic E. coli bacteria.

In her research, temperate phages were genetically engineered to deliver bacterial toxins to harmful bacteria. Once inside the bacterial cell, the toxin is expressed, effectively neutralizing the bacterium.

Image source: Vandierendonck et al. (2025), Microbiology Spectrum.