“Turning the Phage” — The Discovery Files

The virus called a bacteriophage, found in Dodge Pond in East Lyme, attacks a common multi-drug resistant bacterial pathogen called Pseudomonas aeruginosa, which can lethally infect people with compromised immune systems. In a neat evolutionary trick, the virus attaches to the cell membrane where bacteria pump out antibiotics, a system that had originally evolved to resist antibiotics. The presence of the virus in turn leads to evolutionary changes in the bacterial membrane that makes this pumping mechanism less efficient. This makes bacteria once more susceptible to existing antibiotics.