Great post! And I just knew the old man was going to be named Reynolds.... Re the great "cross-breed" controversy. Bacteria do have viruses that attack them. They're called bacteriophages, or phages for short. There are millions of them, and they're very specific. There is a fascinating antibacterial treatment invented in Georgia (when it was still the Soviet Union) that involves isolating phages lethal to a given pathogenic bacterium, say typhoid. The stuff works like a charm--the same sort of Omigod! effect that penicillin had when it was first invented. Bacteria can't evolve resistance because the phages evolve too. We haven't heard much about it because the doctors there realized what they had and wanted to work together with better-funded Westerners to carry it forward. Some Americans expressed interest, but this was at the beginning of the biotech boom, the Americans wanted to own all the patents, the Georgians wouldn't sign them over, and the Americans lost interest when they couldn't make a killing. (Sorry about the pun. Couldn't resist.) Drug companies haven't pursued it because they really don't like tailored drugs. The Georgian phage method would require libraries of hundreds of phages adapted to kill different bacterial strains, as well as the need to select for new phages on a continuous basis. Much more profitable to have a single blockbuster drug you can sell to absolutely everyone. (More fodder for Tom's file of things that don't work when profit is primary.) All that said, a flu virus is not a phage, could not attack a bacterium, and when I got to that sentence, I must admit I chuckled, which was probably not the desired effect. (If you want to be scary, although still only faintly plausible, cross Marburg and rabies viruses. They're at least slightly related, although how you'd ever get them to cross is problematic. One person would have to have both infections and survive long enough for them to cross-over and then to pass the crossed version on to somebody else. Bacteria are easier, but I can't think of a well-known scary one that would go well with MRSA.)