title: Polymyxin B resistance and biofilm formation in Vibrio cholerae are controlled by the response regulator CarR.
abstract: Two-component systems play important roles in the physiology of many bacterial pathogens. Vibrio cholerae's CarRS two-component regulatory system negatively regulates expression of vps (Vibrio polysaccharide) genes and biofilm formation. In this study, we report that CarR confers polymyxin B resistance by positively regulating expression of the almEFG genes, whose products are required for glycine and diglycine modification of lipid A. We determined that CarR directly binds to the regulatory region of the almEFG operon. Similarly to a carR mutant, strains lacking almE, almF, and almG exhibited enhanced polymyxin B sensitivity. We also observed that strains lacking almE or the almEFG operon have enhanced biofilm formation. Our results reveal that CarR regulates biofilm formation and antimicrobial peptide resistance in V. cholerae.
authors.affiliation: Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, California, USA.
authors.forename: Kivanc
authors.initials: K
authors.lastname: Bilecen
authors.affiliation: Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, California, USA.
authors.forename: Jiunn C N
authors.initials: JC
authors.lastname: Fong
authors.affiliation: Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, California, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Cheng
authors.affiliation: Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, California, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Jones
authors.affiliation: Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, California, USA.
authors.forename: David
authors.initials: D
authors.lastname: Zamorano-Sánchez
authors.affiliation: Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, California, USA fyildiz@ucsc.edu.
authors.forename: Fitnat H
authors.initials: FH
authors.lastname: Yildiz
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D024881:Drug Resistance, Bacterial; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator; D005998:Glycine / Q000378:metabolism; D006033:Glycylglycine / Q000378:metabolism; D008050:Lipid A / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D009876:Operon; D011112:Polymyxin B / Q000494:pharmacology*; D014734:Vibrio cholerae / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D008050:Lipid A; D006033:Glycylglycine; D011112:Polymyxin B; D005998:Glycine