Exactly eight decades ago a Penicillium spore drifted through the air, landing on a Petri dish full of Staphylococcus in Dr Alexander Fleming’s lab and set in motion a chain of events that has changed medical history.

Now, a team of scientists has accidentally reversed the route taken by Fleming. Also through an accidental sequence of discoveries, they bumped into hundreds of soil-living germs that not only happened to be resistant to antibiotics – they actually had the ability to feed on them. Figuratively speaking, this is comparable to discovering a new zebra species that has developed not only a resistance to attacks by lions but began to find them tasty too!

The remarkable discovery occurred while a team of researchers led by Harvard Medical School geneticist George Church was looking for microorganisms in soil capable of breaking down certain chemicals, as part of a quest for developing biofuels from agricultural waste.

In the study, recently published in the journal Science, Church and colleagues describe bacteria able to feed on 18 different antibiotics (both natural and synthetic), including gentamicin, vancomycin and Cipro – all of them with wide clinical application.

One of the more disturbing aspects of the study was that some of the bacteria samples could survive antibiotic levels up to 100 times higher than the commonly administered clinical doses.

One of the next steps is to determine the genetic mechanisms that allow these soil bacteria to have such an unusual meal and also to check if they could manage to transfer their ‘anti-antibiotic’ genes to the most serious human pathogens.

At least in one respect, the antibiotic-eater bacteria strains that have just been discovered are good news: they are silently digesting all residual antibiotics released by us as pollution into the environment.

Reference
1. Dantas G, Sommer MOA, Rantimi D, Oluwasegun RD, Church GM. Bacteria subsisting on antibiotics. Science 320; 872, 100-103 doi: 10.1126/science.1155157.