Bacteriophage-host interaction: from splendid isolation into a messy reality

In the reductionist era T-type coliphage research became one of the foundations for molecular biology. The technological progress in systems biology makes it now possible to study T-type phage-Escherichia coli interaction in the natural ecological niche, the gut of warm blooded animals. This development gives a second chance to phages as anti-microbial agents ('phage therapy'). Bacteria growing in biofilms are difficult to treat with antibiotics while many phages express naturally depolymerases which attack the polysaccharide matrix that enmesh bacteria in biofilms. Phages were already used successfully to reduce contamination levels with medical catheters and might likewise be of use against infections frequently forming bacterial biofilms.