Years ago, i read an article about how bacteriologists in the then USSR, were having some success against many bacterial diseases, by fishing out bacteria from sewerage treatment plants. They looked for bacteria, that more or less fed on the harmful bacteria. These were then cultivated and injected into patients, with a good rate of success.
It said this technique was far cheaper than developing new treatments.
unfortunately,i cannot for the life of me remember where i read it.
Edit: I was wrong, it was bacteriophages (viruses) they were fishing for. Heres an article that is quite similar to the one i read, though the one i read was earlier than this one....http://www.biotech-monitor.nl/3905.htm
"When humans yield up the privilege of thinking, the last shadow of liberty quits the horizon". Thomas Paine.