Wednesday, April 09, 2008

Germs that thrive on antibiotics

Wired reports: [edited]

Antibiotics are supposed to kill bacteria, not feed them. Yet Harvard researchers have discovered hundreds of germs in soil that are able to thrive with the potent drugs as their sole source of nutrition.

The work explains why the soil doesn't harbour big antibiotic buildups despite use of the drugs in livestock plus human disposal and excretion.

Bacteria prefer to eat sugars, like rotting fruit. Put in laboratory dishes to subsist only on antibiotics, the germs grew a little more slowly but the researchers found every drug tested could support growth of some bacteria.

A number of bacteria could withstand levels of antibiotics that were 50 to 100 times higher than would be given to a patient.

The next step is to identify the genes that let these bacteria devour and degrade antibiotics. Then the question becomes whether that genetic mechanism is something soil bacteria might be able to transfer to human pathogens, making them more drug-resistant.

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