Drug resistant superbacteria – they’re what’s for dinner… or are they?

Posted on July 11, 2007


Finally, after years of mostly bad news in the competition between antibiotics developed by medical researchers and drug-resistance developed by bacteria, we have some good news. A class of drugs currently used to treat osteoporosis appears to stop conjugation, or the sharing of DNA between bacteria. It is conjugation that enables one bacteria that has developed drug resistance (say, XDR tuberculosis) to share the portions of its DNA that confer the drug resistance with another bacteria that hasn’t (say, e. coli). Not only that, but conjugation is disrupted in a way that tends to directly scramble the bacteria involved, killing them directly. (Scientific American story)

Obviously, if we can kill off drug-resistant bacteria, then this means we can turn back the bacterial evolutionary clock and use good-old-fashioned penicillin and it’s many derivatives again instead of dramatically more toxic drugs like Keflex. And because the osteoporosis drugs are already FDA approved, they could be used tomorrow “off label” to aid in the treatment of a drug-resistant bacterial infection. All in all, excellent news for medicine.

But I want to insert a note of caution into this discussion that I just haven’t seen in the media yet – bacteria have been evolving ways to survive for a very, very, very long time now, and it’s hardly inconceivable to think that they will eventually become resistant to this new class of drugs. After all, people evolved from something not too dissimilar to a bacterium long ago, ancient viral DNA is scattered throughout our own DNA, and even our mitochondria (the part of our cells that metabolizes our food with oxygen) may be an ancestral bacteria that developed a symbiotic relationship with the cell it invaded. And given that most of the biodiversity of the Earth is bacterial, not multicellular (like us, seals, even coral, insects, and algae), it’s safe to say that bacteria have been survived and prospered even in the face of radiation, heat, freezing, acids, etc. So, while we should certainly rejoice in this rare good news in the race to save lives from infections, we shouldn’t use this news as a justification for reducing medical research into new antibiotics or new methods to stop conjugation. It’s not a question of if we’ll need more new drugs, but a question of when.

But at least now we have an opportunity to catch up.

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