Mutation design and strain background influence the phenotype of Escherichia coli luxS mutants. Issue 5 (7th May 2013)

• Record Type: Journal Article
• Authors: Haigh, Richard; Kumar, Brijesh; Sandrini, Sara; Freestone, Primrose
• Is Part Of: Molecular microbiology. Volume 88:Issue 5(2013)
• Page Start: 951
• Page End: 969
• Publication Date: 2013-05-07
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.12237
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>Previous analyses of <italic>luxS</italic> in <italic>Escherichia coli</italic> have used different strain backgrounds and design formats to produce the <italic>luxS</italic> mutation, resulting in <italic>luxS</italic> 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 <italic>E. coli</italic> <italic>luxS</italic> mutant. We inactivated <italic>luxS</italic> in three <italic>E. coli</italic> backgrounds: enteropathogenic <italic>E. coli</italic> E2348‐69, and enterohaemorrhagic strains Sakai and NCTC12900. 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 <italic>E. coli</italic> <italic>luxS</italic> phenotype was markedly dependent on strain background: in some strains disruption of <italic>luxS</italic> caused significant metabolic stress or no stress at all. How the <italic>luxS</italic> 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 <italic>luxS</italic> mutants showed only a few proteins were differentially expressed and those that were altered suggested a metabolic rather than communication role for the <italic>E. coli</italic> <italic>luxS</italic> gene product.</p> </abstract>