Type

Journal Article

Authors

Colin Hill
Cormac G M Gahan
Rosemarie B. Rea

Subjects

Biochemistry

Topics
pharmacology sigma factor metabolism esculetin iron physiology transcription factors hydrogen peroxide animals sigh protein bacteria bacterial proteins ferric uptake regulating proteins bacterial repressor proteins listeria monocytogenes genetics pathogenicity mice inbred balb c virulence mice mutation umbelliferones peroxide repressor proteins

Disruption of putative regulatory loci in Listeria monocytogenes demonstrates a significant role for Fur and PerR in virulence. (2004)

Abstract The ability to adapt to adverse environmental conditions encountered in food and during host infection is a sine qua non for a successful Listeria monocytogenes infection. This ability is likely to depend on complex regulatory pathways controlled by a number of key regulators. We utilized the pORI19 plasmid integration system to analyze the role of six putative regulatory loci in growth under suboptimal environmental conditions and during murine infection. Disruption of loci encoding a topoisomerase III (lmo2756), a putative methyltransferase (lmo0581), and a regulator of the MarR family (lmo1618) revealed roles for the methyltransferase and the MarR regulator in growth under environmental stress conditions. However, plasmid integration into these loci had no impact on virulence potential in the murine model of infection. Disruption of the alternative sigma factor Sigma-H resulted in a mutant that demonstrated reduced growth potential in minimal medium. Murine studies indicated a minor role for this sigma factor in the infectious process. Strikingly, disruption of both perR and fur loci resulted in mutants that are significantly affected in virulence for mice, with the fur mutant demonstrating the greatest reduction in virulence potential. Both perR and fur mutants demonstrated increased resistance to hydrogen peroxide and the fur mutant was sensitive to low-iron conditions. The virulence defect of both fur and perR mutants could be rescued by iron-overload after esculetin treatment of mice, suggesting that the in vivo role of these gene products is to procure iron for bacterial growth.
Collections Ireland -> University College Cork -> PubMed

Full list of authors on original publication

Colin Hill, Cormac G M Gahan, Rosemarie B. Rea

Experts in our system

1
Colin Hill
University College Cork
Total Publications: 351
 
2
Cormac G M Gahan
University College Cork
Total Publications: 109