Mutation induced by vibriophage PS166 infection changes biotype and phage type of Vibrio cholerae.

The effect of a newly isolated vibriophage, PS166, on Vibrio cholerae (E1 Tor) MAK757 was investigated. Two PS166-resistant mutants of strain MAK757 were isolated. These had undergone transition to the classical biotype with concomitant acquisition of new phage sensitivity. However, the parental Ogawa serotype remained unchanged. These mutant strains also showed a unique temperate phage-sensitivity profile, distinct from that of strain MAK757. The possible target of phage PS166 interaction is discussed.