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Mutation design and strain background influence the phenotype of E scherichia coli luxS mutants
Author(s) -
Haigh Richard,
Kumar Brijesh,
Sandrini Sara,
Freestone Primrose
Publication year - 2013
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.12237
Subject(s) - mutant , biology , phenotype , mutation , virulence , escherichia coli , microbiology and biotechnology , genetics , gene
Summary Previous analyses of luxS in E scherichia coli have used different strain backgrounds and design formats to produce the luxS mutation, resulting in luxS mutants with confusingly dissimilar phenotypes. This study therefore investigates the roles that strain background and mutational design strategy have upon the phenotype of the pathogenic E . coli luxS mutant. We inactivated luxS in three E . coli backgrounds: enteropathogenic E . coli E 2348‐69, and enterohaemorrhagic strains S akai and NCTC 12900. To investigate the influence of mutational design strategy, four mutation formats were used: antibiotic resistance insertion methodologies as previously employed, using tetracycline and chloramphenicol resistance cassettes, and non‐polar strategies creating deletion and premature termination mutations. Our study showed that the E . coli luxS phenotype was markedly dependent on strain background: in some strains disruption of luxS caused significant metabolic stress or no stress at all. How the luxS mutation was constructed also shaped its phenotype: non‐polar mutants were very similar to wild type, while mutations made using the antibiotic insertion methodologies produced phenotypes defective in growth and virulence. Proteomic profiling of our luxS mutants showed only a few proteins were differentially expressed and those that were altered suggested a metabolic rather than communication role for the E . coli luxS gene product.