Researchers at Intralytix have developed a spray to kill
harmful bacteria that can contaminate processed lunchmeat. This isn’t just your average poisonous antiseptic solution. It’s a cocktail of bacteriophages – viruses that attack and kill bacterial cells.
It’s a neat idea – biological control on a microscopic scale, very much like farmers releasing parasitoid wasps to control the crop-eating caterpillars in their fields. Just much, much smaller. Why does it work? Viruses are essentially cellular parasites. They can’t reproduce on their own because they don’t contain any of the structures that let cells build new proteins. So they make cells do the reproducing for them. When a virus infects a cell it hijacks its metabolic pathways, forcing it to make more viruses instead of cell-stuff. Eventually, the host cell gets so filled with new viruses that it explodes. The newly-freed viruses can move on and infect other cells. (1)
Sounds gruesome, doesn’t it? Bad for the bacteria, but what if the virus starts doing that to human cells? Don’t worry. Like many other parasites, these bacteriophages are specialists; they only attack bacteria of the genus Listeria. And if anyone out there is actually rooting for the bacterium, don’t. Listeria may only give healthy people some muscle aches and a little diarrhea, but it can cause septicemia and meningitis in pregnant women, newborns, the elderly, and other people with weakened immune systems. The company is still working on sprays targeted at E. coli and Salmonella bacteria, which cause much more widespread illness each year.
(1) Some viruses can also insert themselves into their host cell’s DNA and get copied into its daughter cells, only to emerge later, Alien-like, and force the cell to make new viruses. Intralytix doesn’t use this kind of bacteriophage, since it doesn’t kill bacteria quickly enough.
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