How do environmental bacteria evolve into human pathogens? Our recent study reveals that a unique, bimodular small RNA called OueS drives the evolution of toxigenic Vibrio cholerae from environmental strains. We show that allelic variations in OueS dictate the emergence of virulence phenotypes while introducing key fitness trade-offs in natural reservoirs – shedding new light on how environmental microbes acquire critical pathogenic traits under changing conditions.
