Recent cases of antibiotic resistance have prompted epidemiologists to speculate that various strains, or even species, of bacteria can swap genes. In a serendipitous bolstering of this theory, researchers at the National Institute of Allergy and Infectious Diseases have discovered surreptitious gene ferries—bacteriophages.
James Musser, MD, PhD, and colleagues made the find while teasing out genetic variation in Group A Streptococcous strains, which can cause, among other illnesses, strep throat and scarlet and rheumatic fevers. Comparing whole-genome scans of a strain isolated from a patient with toxic shock syndrome with a harmless variety, the researchers found genetic markers of bacteriophage invasion. The bacterial viruses "have imported crucial new toxin genes to create new virulent strains," said Musser.
Vastag B. Viruses Arm Bacteria. JAMA. 2002;288(7):823. doi:10.1001/jama.288.7.823-JHA20008-3-1