Cocktail of bacteria-killing viruses prevents cholera infection

PATHFINDERS

Oral administration of a cocktail of three viruses, all of which specifically kill cholera bacteria, prevents infection and cholera-like symptoms in animal model experiments, report scientists from Tufts University School of Medicine (TUSM) and the Sackler School of Graduate Biomedical Sciences at Tufts in Nature Communications. The findings are the first to demonstrate the potential efficacy of bacteria-killing viruses known as bacteriophages, or phages—as an orally administered preventive therapy against an acute gastrointestinal bacterial disease.

“While phage therapy has existed for decades, our study is proof-of-principle that it can be used to protect against infection and intervene in the transmission of disease,” said senior study author Andrew Camilli, Ph.D., Howard Hughes Medical Institute Investigator and professor of molecular biology and microbiology at TUSM. “We are hopeful that phages can someday be a tool in the public health arsenal that helps decrease the global burden of cholera, which affects up to four million people around the world each year.”

In previous work, Camilli and colleagues searched for phages that are specific for Vibrio cholerae, the bacterium that causes cholera—a potentially lethal infectious disease marked by severe diarrhea and dehydration. While phages that kill V. cholerae are abundant in nature, the team identified three strains that uniquely retained the ability to kill V. cholerae within the small intestine, the site of infection in humans.

These phages function by targeting bacterial surface receptors normally involved in infectiousness, making them ideal therapeutic candidates—to develop resistance, cholera bacteria must acquire mutations in these receptors, which cause the bacteria to become less infectious.