The use of bacterial luciferase for monitoring the environmental regulation of expression of genes encoding virulence factors in Listeria monocytogenes.
A promoter probe vector, which utilized the lux AB genes from Vibrio fischeri as reporters of gene expression, was constructed for use in Listeria monocytogenes. Using this system gene expression can be monitored non-destructively and in real-time, simply by measuring cellular bioluminescence. Derivatives of the promoter probe were constructed that contained the cloned promoters from the hlyA and plcA genes of L. monocytogenes. The activity of these promoters was dependent on the transcriptional activator PrfA. Accordingly, in a strain containing an intact copy of the prfA gene, expression from both the hlyA and plcA promoters was 25-45-fold higher than in prfA mutants. Heat shock was identified as an environmental signal which induced expression of hlyA and plcA. Conversely, oxidative stress had no effect upon the expression of the virulence factors. In addition, the composition of the growth media was found to have a dramatic effect upon the expression of hlyA and plcA, suggesting the presence of an unidentified signal which may regulate induction of expression of virulence genes in L. monocytogenes.
Park
S F
SF
Department of Microbiology, AFRC Institute of Food Research, Reading, UK.
Stewart
G S
GS
Kroll
R G
RG
D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D015342:DNA Probes / Q000235:genetics; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005798:Genes, Bacterial / Q000235:genetics*; D006360:Heat-Shock Proteins / Q000096:biosynthesis; D006460:Hemolysin Proteins / Q000096:biosynthesis / Q000235:genetics*; D008089:Listeria monocytogenes / Q000235:genetics* / Q000472:pathogenicity; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D014157:Transcription Factors / Q000494:pharmacology; D014774:Virulence
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D015342:DNA Probes; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; C036507:Hlya protein, E coli; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D008156:Luciferases