A Point Mutation in <i>carR</i> Is Involved in the Emergence of Polymyxin B-Sensitive Vibrio cholerae O1 El Tor Biotype by Influencing Gene Transcription

Abstract

Antimicrobial peptides play an important role in host defense against Vibrio cholerae . Generally, the V. cholerae O1 classical biotype is polymyxin B (PB) sensitive and El Tor is relatively resistant. Detection of classical biotype traits like the production of classical cholera toxin and PB sensitivity in El Tor strains has been reported in recent years, including in the devastating Yemen cholera outbreak during 2016-2018. To investigate the factor(s) responsible for the shift in the trend of sensitivity to PB, we studied the two-component system encoded by carRS , regulating the lipid A modification of El Tor vibrios, and found that only carR contains a single nucleotide polymorphism (SNP) in recently emerged PB-sensitive strains.