Coordinate regulation of virulence genes in Listeria monocytogenes requires the product of the prfA gene.
The prfA gene of Listeria monocytogenes encodes a protein that activates transcription of the listeriolysin gene (lisA). In order to explore the role of the prfA gene product in the pathogenesis of listerial infection, we constructed a site-directed insertion mutation in prfA by the chromosomal integration of a novel suicide vector containing a portion of the prfA coding region. This mutation not only transcriptionally silenced the listeriolysin (lisA) gene but also abrogated production of specific RNA transcripts corresponding to the phosphatidylinositol-specific phospholipase C (pic) and metalloprotease (mpl) genes, two further virulence gene products expressed only by pathogenic Listeria strains. The strain was also found to be avirulent when tested in a mouse model of listerial infection. The concomitant loss of multiple characteristics such as production of LisA, Pic, Mpl, and loss of virulence in a mouse infection model is the result of a mutation in a single gene and demonstrates that the prfA gene product is a positive regulator of multiple virulence determinants in L. monocytogenes.
Chakraborty
T
T
Medizinische Universitäts Klinik, Klinische Biochemie, Würzburg, Federal Republic of Germany.
Leimeister-Wächter
M
M
Domann
E
E
Hartl
M
M
Goebel
W
W
Nichterlein
T
T
Notermans
S
S
D000818:Animals; D001681:Biological Assay; D005798:Genes, Bacterial; D008089:Listeria monocytogenes / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D008088:Listeriosis / Q000235:genetics / Q000382:microbiology; D051379:Mice; D016254:Mutagenesis, Insertional; D010957:Plasmids; D013154:Spleen; D014774:Virulence