Scientists from St. Jude Children’s Research Hospital have uncovered what gives Vibrio cholerae, the bacterium that causes cholera, the ability to colonize the human gut. The researchers found that a small RNA embedded within another gene controls where cholera thrives, a discovery that could improve prediction and prevention strategies. The study is published in the journal Nature Communications.

Infectious diseases remain the leading cause of pediatric mortality worldwide. V. cholerae causes a severe diarrheal disease leading to more than 143,000 deaths and millions of cases each year, primarily affecting young children. While there are many strains of the V. cholerae species, only one can infect humans. The reason for this has been unclear for 50 years, hampering efforts to predict and prevent outbreaks.

“For decades, we’ve been trying to understand what allows cholera to infect humans,” said corresponding author Salvador Almagro-Moreno, Ph.D., St. Jude Department of Host-Microbe Interactions. “The answer was right in front of us the whole time—this small RNA hiding inside another gene is the real culprit.”