LuxS Affects Flagellar Phase Variation Independently of Quorum Sensing inSalmonella entericaSerovar Typhimurium

LuxS catalyzes the synthesis of the quorum-sensing signaling molecule autoinducer 2. We show that in Salmonella enterica serovar Typhimurium, deletion of the luxS gene polarizes flagellar phase variation toward the more immunogenic phase 1 flagellin. This phenotype is complementable by luxS in trans but is independent of quorum-sensing signals.