Bacteriophages

I was listening to the April 4th Science Friday Episode about Bacteriophages http://www.sciencefriday.com/program/archives/200804043.

These are viruses that kill a specific strain of bacteria. Work was done back in the early 1900's in Eastern Europe to cultivate them as a cure for certain diseases. This work was mostly forgotten over the years - particularly since the rise of antibiotics during WWII.

Since the antibiotic age seems to have come full circle, with many persistent strains of bacteria developing in response to the overuse and misuse of antibiotics, interested individuals are looking again at this technology.

If a strain of bacteriophage can be found that exactly works on a resistant strain of bacteria, this would be a great discovery. The phages are said to be completely safe in humans - as they will only attack the specific infectious agent and not the body. The trick is finding the right strain. Companies are starting to submit phages for approval to the FDA, and some have gotten GRAS (generally recognized as safe) status.

The question I have is how do they propagate the phage once they find it? The guest on Science Friday talked about delivering it in pill, spray, or patch form, and warned that exposure to light would kill the phages. Is it hard to keep a strain alive and grow a commercially useful amount? How does it kill the bacteria? Once a person is infected with a phage, does it stay after it has killed all the bacteria it targets? Does your immune system possibly learn from the action of the phage and have some immunity to the bacteria after the phage treatment is over?

I wrote an entry on June 11, 2007 http://atresfreq.blogspot.com/2007/06/civil-war-immunity.html about my speculation that the Civil War soldiers were infected with so many strains of various bacteria in their disease-ridden camps that they had some kind of immunity that lasted the rest of their lives. The soldiers that survived the war lived in great numbers into their 90's. While it is also true that marching the long distances and all the physical exertions put them in incredible shape, that can't be all there was to it. It stands to reason that nasty diseases with high mortality rates would also be the perfect breeding ground for viruses that lived on those bacteria. So maybe exposure to those filthy camps also brought the antidote for the diseases in the form of phages that could develop and get a foothold in an environment rich with bacteria. Like any good mystery, you just have to keep turning the pages until the answers reveal themselves.