Rapid evolutionary turnover of mobile genetic elements drives bacterial resistance to phages

Fatima Aysha Hussain (1) , Javier Dubert (1, 2) , Joseph Elsherbini (1) , Mikayla Murphy (1) , David Vaninsberghe (1) , Philip Arevalo (1) , Kathryn Kauffman (1) , Bruno Kotska Rodino-Janeiro (1, 3) , Hannah Gavin (1) , Annika Gomez (1) , Anna Lopatina (3) , Frédérique Le Roux (4, 5) , Martin F Polz (3, 1)

1 MIT - Massachusetts Institute of Technology
2 USC - Universidade de Santiago de Compostela [Spain]
3 University of Vienna [Vienna]
4 IFREMER - Institut Français de Recherche pour l'Exploitation de la Mer
5 LBI2M - Laboratoire de Biologie Intégrative des Modèles Marins

Although it is generally accepted that phages drive bacterial evolution, how these dynamics play out in the wild remains poorly understood. We found that susceptibility to viral killing in marine Vibrio is mediated by large and highly diverse mobile genetic elements. These phage defense elements display exceedingly fast evolutionary turnover, resulting in differential phage susceptibility among clonal bacterial strains while phage receptors remain invariant. Protection is cumulative, and a single bacterial genome can harbor 6 to 12 defense elements, accounting for more than 90% of the flexible genome among close relatives. The rapid turnover of these elements decouples phage resistance from other genomic features. Thus, resistance to phages in the wild follows evolutionary trajectories alternative to those predicted from laboratory-based evolutionary experiments.

Domaines: Microbiologie et Parasitologie

Fatima Aysha Hussain, Javier Dubert, Joseph Elsherbini, Mikayla Murphy, David Vaninsberghe, et al.. Rapid evolutionary turnover of mobile genetic elements drives bacterial resistance to phages. Science, 2021, 374 (6566), pp.488-492. ⟨10.1126/science.abb1083⟩. ⟨hal-03406805⟩