TWiV 1321: Phage cross talk and cross reactions

This Week in Virology episode 1321 explores two groundbreaking topics in phage biology: cross-reactive antibodies in phage therapy and inter-phage communication via peptide signaling. The episode begins with a somber discussion of a recent hantavirus outbreak on a cruise ship, where an elderly couple died from Andes hantavirus, with evidence of person-to-person transmission raising concerns about pandemic preparedness. The main scientific focus shifts to a case report of a 22-year-old cystic fibrosis patient whose phage therapy failed due to pre-existing cross-reactive antibodies against a prophage in his chronic Bordetella infection, combined with bacterial heteroresistance. This highlights critical challenges in personalized phage therapy, including immune responses and microbial diversity. The second major segment dives into a Nature paper on phage 'cross talk' using the Arbitrium system—a quorum-sensing-like mechanism where temperate phages communicate via small peptides to decide between lytic and lysogenic lifestyles. Remarkably, some phages can eavesdrop on signals from related phages, altering their behavior and influencing microbial ecosystem dynamics. The episode concludes with listener emails on political attacks on scientists, a NASA discovery of a resilient Earth microbe capable of surviving Mars-like conditions, and creative student projects on virology communication, underscoring the importance of science outreach and resilience in the face of adversity.