title: Listeria monocytogenes response regulators important for stress tolerance and pathogenesis.
abstract: Environmental sensing by two-component signal transduction systems is likely to play a role for growth and survival of Listeria monocytogenes both during transmission in food products and within a host organism. Two-component systems typically consist of a membrane-associated sensor histidine kinase and a gene regulatory protein, the response regulator (RR). We have identified seven putative RR genes in L. monocytogenes LO28 by PCR using degenerate oligonucleotide primers. By insertional inactivation we obtained data suggesting that three of the putative RRs contribute to the pathogenicity of L. monocytogenes in mice. Strikingly, the mutants that were attenuated in virulence also had a decreased ability to grow in the presence of various stress conditions potentially encountered in an infection process. Thus, our data point to a connection between the ability of the putative two-component systems to sense and respond to certain environmental stimuli, and the virulence of L. monocytogenes.
authors.affiliation: Department of Veterinary Microbiology, The Royal Veterinary and Agricultural University, Stigbøjlen 4, DK-1870 Frederiksberg C, Denmark.
authors.forename: B H
authors.initials: BH
authors.lastname: Kallipolitis
authors.forename: H
authors.initials: H
authors.lastname: Ingmer
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005809:Genes, Regulator; D018869:Heat-Shock Response; D006801:Humans; D008089:Listeria monocytogenes / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D008088:Listeriosis / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D014157:Transcription Factors