THE viruses that attack bacteria may pose more of a threat to people than anyone thought.
Sequencing has shown that bacteriophages which integrate into the DNA of bacteria have occasionally picked up genes from one host and transferred them to another. Phages were probably to blame, for example, for making E. coli 0157:H7 dangerous to humans by transferring genes from Shigella bacteria.
Two years ago, Vincent Fischetti and Thomas Broudy at Rockefeller University in New York discovered that a chemical in human saliva can activate phages lurking within a bacterium’s genome, making them multiply and burst out of the cell.…
