West African–South American pandemic Vibrio cholerae encodes multiple distinct phage defence systems (Nature Microbiology)

Adams and colleagues report in Nature Microbiology that the two genetic signatures defining the West African–South American (WASA) lineage of Vibrio cholerae, responsible for the 1991-2001 Latin American cholera epidemic, encode multiple anti-phage defence systems. The WASA-1 prophage encodes an abortive-infection system, WonAB, that makes the lineage resistant to the predatory vibriophage ICP1, and genes on Vibrio seventh pandemic island II encode a modification-dependent restriction system and a new Shedu-family member active against vibriophage X29; the authors propose these defences contributed to the lineage's success.