Bacterial defense islands limit viral attack

Abstract

In 1927, Felix d’Herelle attempted to treat cholera epidemics in India using viruses. Bacteriophages are viruses that infect bacteria, and d’Herelle was trying to use them as a natural weapon against the bacterial pathogen Vibrio cholerae—a strategy called phage therapy. Although d’Herelle had some success in treating cholera patients, he noted that the bacteria he studied could acquire resistance to the phages (1). Now, researchers are unraveling the complexity of the relationship between bacteria and phages using similar systems. Two studies, by Hussain et al. (2) on page 488 of this issue and by LeGault et al. (3), combine large ecological datasets, genomic analyses, and molecular genetics to clarify how phages and phage defenses coexist in the environment. Understanding these dynamics is important when considering the therapeutic use of phages and their major role in global biogeochemical cycles.