Glucose Decreases Virulence Gene Expression of Escherichia coli O157:H7

• Published in: Journal of food protection Vol. 75; no. 4; pp. 748 - 752
• Main Authors: DELCENSERIE, V, LAPOINTE, G, CHARASLERTRANGSI, T, RABALSKI, A, GRIFFITHS, M. W
• Format: Journal Article Web Resource
• Language: English
• Published: Des Moines, IA International Association for Food Protection 01.04.2012; Elsevier Limited
• Subjects: Biological and medical sciences; Dose-Response Relationship, Drug; E coli; Enterocytes; Escherichia coli; Escherichia coli O157 - genetics; Escherichia coli O157 - metabolism; Escherichia coli O157 - pathogenicity; Food industries; Food microbiology; Food safety; Food science; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation, Bacterial - drug effects; Genetics; Glucose; Glucose - pharmacology; Hemolytic uremic syndrome; Hemolytic-Uremic Syndrome - prevention & control; Humans; Intestine; LEE gene; Lesions; Life sciences; LuxS protein; Motility; Nutrients; Operons; pathogenicity islands; Pathogens; Polymerase chain reaction; Quorum Sensing; Reverse transcription; Sciences des denrées alimentaires; Sciences du vivant; Shiga toxin; Shiga Toxin - metabolism; Toxins; Virulence; Virulence - drug effects; Virulence - genetics; Decrease; Escherichia coli; Virulence; Bacteria; Carbohydrate; Glucose; Gene expression; Enterobacteriaceae
• ISSN: 0362-028X; 1944-9097; 1944-9097
• DOI: 10.4315/0362-028X.JFP-11-384

Escherichia coli O157:H7 is responsible for a human toxico-infection that can lead to severe complications such as hemolytic uremic syndrome. Inside the intestine, E. coli O157:H7 forms typical attaching-effacing lesions and produces Shiga toxins. The genes that are responsible for these lesions are located in a pathogenicity island called the locus of enterocyte effacement (LEE). LEE gene expression is influenced by quorum sensing through the luxS system. In this study, the effect of glucose on the expression of several genes from LEE, on the expression of Shiga toxin genes, and on the expression of luxS was assessed with real-time, reverse transcription PCR. All concentrations of glucose (from 0.1 to 1%) were able to down-regulate genes from the LEE operon. A slight down-regulation of genes implicated in Shiga toxin expression was also observed but was significant for low doses of glucose (0.1 to 0.5%) only. A slight but significant increase in luxS expression was observed with 1% glucose. This confirms that in addition to quorum sensing, the presence or absence of nutrients such as glucose has an impact on the down- or upregulation of LEE-encoded virulence genes by the bacterium. The influence of glucose on the virulence of E. coli O157:H7 has received little attention, and these results suggest that glucose can have an important effect on the virulence of E. coli O157:H7.