Listeria typically doesn't get as much press as E. coli or salmonella, but it causes listeriosis, a leading--and potentially deadly--food-borne illnesses. You can get listeriosis from raw meats, pre-cooked meats (lunch meats, hot dogs), and sometimes vegetables. In fact, the CDC recommends that if you're in the "high risk" group (pregnant, seriously ill, weakened immune system, elderly, etc.), that you cook your cold cuts!

So, this new listeria-eater sounds like a great idea, right? Kill the suckers before they kill me? Reduce the overall number of listeriosis outbreaks?

It does sound cool, but the concern is that it would be used as a band-aid to mask a major problem, rather than tackle its causes head-on. We should encourage and enforce livestock-raising practices that reduce the spread of disease, and discourage the over-use of antibiotics in livestock. Slaughterhouses and meat-processing plants should be kept as clean as possible. Spraying something on the meat after it comes out of a filthy or unsafe plant isn't the solution.

I have seen conflicting reports on whether or not meats treated with the bacteriophage will be required to say so on their labels. Hopefully they will, as you should always have a choice in what you eat. As for myself, I'm going to wait and see before I enjoy a hot dog soaked in this stuff.

(Just to be clear, this virus doesn't actually eat the bacteria, even though "phage" derives from the Greek word for eat. It basically injects its DNA into the bacteria, where it reproduces using the hosts machinery. Eventually, the copies of itself are released, rupturing the host and killing it.)