Catabolite repression and virulence gene expression in Listeria monocytogenes.
Previous studies have suggested that carbohydrates may affect expression of virulence genes in Listeria monocytogenes. Which carbohydrates influence virulence gene expression and how carbohydrates mediate expression, however, is not clear. The goal of this work was to examine how carbohydrates affect virulence gene expression in L. monocytogenes 10403S. Growth studies were conducted in medium containing glucose and various sugars. Metabolism of arbutin, arabitol, cellobiose, mannose, maltose, trehalose, and salicin were repressed in the presence of glucose. Only when glucose was consumed were these sugars fermented, indicating that catabolite repression by glucose had occurred. To determine whether virulence gene expression was also influenced by catabolite repression, we performed primer extension experiments, using primers for hly and prfA, which encode for a hemolysin and the regulator protein PrfA, respectively. In the presence of cellobiose and arbutin, transcription of hemolysin was reduced. However, none of the sugars affected transcription of prfA. The results demonstrate that catabolite repression occurs in L. monocytogenes and suggests that, at least in strain 10403S, cellobiose and arbutin repress expression of hemolysin.
Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE 68583-0919, USA.
Stefanie Evans
SE
Gilbreth
Andrew K
AK
Benson
Robert W
RW
Hutkins
D001104:Arbutin / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics; D001427:Bacterial Toxins / Q000235:genetics; D001592:Benzyl Alcohols / Q000378:metabolism; D050260:Carbohydrate Metabolism; D002475:Cellobiose / Q000378:metabolism; D005285:Fermentation; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism; D005960:Glucosides; D006360:Heat-Shock Proteins / Q000235:genetics; D006460:Hemolysin Proteins; D008089:Listeria monocytogenes / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D008320:Maltose / Q000378:metabolism; D008358:Mannose / Q000378:metabolism; D010454:Peptide Termination Factors; D013402:Sugar Alcohols / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics; D014158:Transcription, Genetic; D014199:Trehalose / Q000378:metabolism; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism*
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D001592:Benzyl Alcohols; D005960:Glucosides; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D010454:Peptide Termination Factors; D013402:Sugar Alcohols; D015534:Trans-Activators; D037521:Virulence Factors; D002475:Cellobiose; C005696:salicin; D008320:Maltose; D014199:Trehalose; D001104:Arbutin; D005947:Glucose; D008358:Mannose; C038705:hlyA protein, Listeria monocytogenes; C014999:arabitol