×î×¼µÄÁùºÏ²ÊÂÛ̳

XClose

×î×¼µÄÁùºÏ²ÊÂÛ̳ Research Domains

Home
Menu

What is a phage?

Bacteriophages (or phages) are viruses that infect and kill bacteria.

What areÌýthe differences betweenÌýviruses andÌýbacteria?

Bacteria and viruses are two different kinds of organism. Bacteria are microscopic, single-celled organisms that exist almost everywhere. They survive and replicate by metabolising different substances depending on the particular strain of bacteria. Viruses are generally even smaller entities that are the most abundant entities on the planet, existing everywhere you find bacteria. They consist of a package of DNA (or RNA) contained inÌýprotein armour. Viruses have to infect host cells with their DNAÌýto replicate, usually killing the host cells in the process.

Are bacteria bad?

Not necessarily. The human microbiome consists of many typesÌýof bacteria that help regulate variousÌýfunctions of the human body, from digestion to skin condition. ButÌýsome bacteria do produce toxins that are harmful to humans - and these are the bacteria we want to kill.

Why not use antibiotics to kill the bad bacteria?

Antibiotics are used widely to kill bad bacteria. However, antibiotics kill bacteria fairly indiscriminately, so have the potential to kill good bacteria as well. The inappropriate use of antibiotics (overprescription or not completing a prescribed course) is driving the increase in antibiotic resistance - the rise of 'superbugs'. Phages could be a solution to both these problems. Specific phages only attack specific bacteria, so the bad bacteria can be targeted while the good bacteria areÌýleft alone. In addition, as phages are not antibiotics, bacteria that have evolved antibioticÌýresistance are still vulnerable to phage attack.

If phages are so good at killing bad bacteria, why are they not in wider use?

This is a very good question, and one that theÌýHouse of Commons Science, Innovation and TechnologyÌý(SI&T) Select Committee have been looking into through their . The resulting report can be accessed .

The short answer to this question is that much more research needs to be done to allow scientists and clinicians a better understanding of how phages and bacteria interact, and how to ensure any phage therapies developed in future are safe and effective. On a visit to a number of laboratories at ×î×¼µÄÁùºÏ²ÊÂÛ̳, Birkbeck, University of London and the Zayed Centre for Research into Rare Disease in Children,ÌýSI&T Select Committee members saw first-hand the potential of phages as a solution to antimicrobial resistance, but also the research and infrastructure challenges that need to be overcome to develop phage therapies for clinical use.