The scientists found that some of the bacteria have the potential to become much nastier than others, a result that has implications for averting outbreaks among humans and animals, they write in a study published April 12 in the journal PLoS Pathogens.
Led by Douglas Heithoff of the University of California, Santa Barbara, they used a technique called animal passage, in which a pathogen is weakened or strengthened by infecting an animal with it. In recent research that created a more transmissible version of the H5N1 flu virus, scientists passed it between ferrets. In this case, the scientists created more virulent forms of the bacteria by infecting mice.
