MRSA Notes

This is a nicely simplified “tale” of how phages work to destroy bacteria without destroying YOU, which is the big problem with finding antibiotics. It has become increasingly difficult to find drugs that kill these very tough, stubborn bacteria without harming you in the process. From Science News Forum:

Some doctors and researchers are trying to use an unlikely ally against stubborn bacteria: Phages - viruses that attack bacteria, but not humans. The idea of using microbes to fight microbes is anything but new. It spans an 80-year, checkered history. Science author Thomas Häusler now tells the intriguing story - past and present - of phage therapy in his book Viruses vs. Superbugs (Macmillan 2006).How does phage therapy work? The prototype of a phage looks a little bit like a lunar module from the Apollo program: It has a head sitting on a tail that has more or less long tail fibres sticking to it at the other end. Phages have only one objective: their reproduction. They are so poorly equipped, however, that they can’t do this on their own. Without the help of their victims, they aren’t much more than a dead piece of protein with a touch of genetic material. But if the phages do hit a suitable bacterium, they multiply in a chillingly efficient cycle.

It begins when the phage uses its tail fibres to attach itself to its victim. The details of what happens next vary according to the different phage types. But their aim is always the same: to get their genetic material, which is located in the head, inside the bacterium. T4, a well-studied phage infecting the Escherichia coli bacterium, then contracts its tail sheath which pushes a tube located within the tail through the membrane of the bacterial cell. The phage’s DNA is passed through the tube into the cell, where it takes control, brutally stops many of its vital functions and forces it to churn out new virus components - heads, tails, tail fibres - in production-line style. Then comes the final assembly. Finally, enzymes dissolve the wall of the bacterium from the inside and the newborn bacteriophages reach the exterior, ready to attack new victims. The viruses proceed very selectively as they do so. Most of them attack only a subgroup of a single bacterial species. Generally, they don’t touch animal or human cells, which is why they are harmless to human beings.

Just imagine this phage multiplication going on inside the mass of bacteria that fill a boil on human skin and you get the basic message: The phages will attack the bugs and multiply as long as there are bacteria left: The drug produces itself in the body until its food - the infection - is gone.

It’s as simple and intriguing as that.

Share This