Bacteria-killing Viruses Could Make Medical Implants Safer

Medical implants like catheters and pacemakers can be a hotspot for bacteria, which grow in hard-to-treat films on the surface of such devices. Scientists and engineers are taking different approaches to changing the surface of implants so bacteria can’t take hold. For example, some groups are developing polymer films with structures that prevent bacterial growth (see “Pillowy Antibacterial Polymers”), while others are developing coatings that slowly release antibiotic compounds over time (see “Safer Joint Replacements” and “Innovators Under 35, 2007: Christopher Loose”). And now, researchers from Clemson University in South Carolina and the University of Southern Mississippi have described how a layer of bacteria-killing viruses could help prevent bacterial infections.

In a study published in Biomacromolecules, the investigators describe a new method for attaching bacteria-busting viruses, also known as bacteriophages, to plastic and Teflon-type materials. When a bacterium gets too close to these enemy-coated surfaces, a tethered bacteriophage can grab on and inject its genetic material into the bacterial cell where it is copied and turned into many more bacteriophage. Eventually, these virus copies burst open the bacteria, killing it. Each newly freed bacteriophage can then go on to infect more bacteria (the authors note that this “amplification effect” could make it hard to control the population size of the bacteria killers).

The researchers show that E. coli and the species of bacteria that causes staph infections can both be killed by tethered bacteriophages. The team writes that their method could work with almost any surface, and add that beyond fighting infections, their idea could also be used as a “technological platform for the development of bacteria sensing and detecting devices.”