title: Natural mutations in a Staphylococcus aureus virulence regulator attenuate cytotoxicity but permit bacteremia and abscess formation.
abstract: Staphylococcus aureus is a major bacterial pathogen, which causes severe blood and tissue infections that frequently emerge by autoinfection with asymptomatically carried nose and skin populations. However, recent studies report that bloodstream isolates differ systematically from those found in the nose and skin, exhibiting reduced toxicity toward leukocytes. In two patients, an attenuated toxicity bloodstream infection evolved from an asymptomatically carried high-toxicity nasal strain by loss-of-function mutations in the gene encoding the transcription factor repressor of surface proteins (rsp). Here, we report that rsp knockout mutants lead to global transcriptional and proteomic reprofiling, and they exhibit the greatest signal in a genome-wide screen for genes influencing S. aureus survival in human cells. This effect is likely to be mediated in part via SSR42, a long-noncoding RNA. We show that rsp controls SSR42 expression, is induced by hydrogen peroxide, and is required for normal cytotoxicity and hemolytic activity. Rsp inactivation in laboratory- and bacteremia-derived mutants attenuates toxin production, but up-regulates other immune subversion proteins and reduces lethality during experimental infection. Crucially, inactivation of rsp preserves bacterial dissemination, because it affects neither formation of deep abscesses in mice nor survival in human blood. Thus, we have identified a spontaneously evolving, attenuated-cytotoxicity, nonhemolytic S. aureus phenotype, controlled by a pleiotropic transcriptional regulator/noncoding RNA virulence regulatory system, capable of causing S. aureus bloodstream infections. Such a phenotype could promote deep infection with limited early clinical manifestations, raising concerns that bacterial evolution within the human body may contribute to severe infection.
authors.affiliation: Biocenter, Chair of Microbiology, University of Würzburg, D-97074 Wuerzburg, Germany;
authors.forename: Sudip
authors.initials: S
authors.lastname: Das
authors.affiliation: Jenner Institute, Centre for Molecular and Cellular Physiology, Oxford OX3 7BN, United Kingdom;
authors.forename: Claudia
authors.initials: C
authors.lastname: Lindemann
authors.affiliation: Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom;
authors.forename: Bernadette C
authors.initials: BC
authors.lastname: Young
authors.affiliation: Jenner Institute, Centre for Molecular and Cellular Physiology, Oxford OX3 7BN, United Kingdom;
authors.forename: Julius
authors.initials: J
authors.lastname: Muller
authors.affiliation: Institute of Molecular Infection Biology, University of Würzburg, D-97080 Wuerzburg, Germany;
authors.forename: Babett
authors.initials: B
authors.lastname: Österreich
authors.affiliation: Jenner Institute, Centre for Molecular and Cellular Physiology, Oxford OX3 7BN, United Kingdom;
authors.forename: Nicola
authors.initials: N
authors.lastname: Ternette
authors.affiliation: Biocenter, Chair of Microbiology, University of Würzburg, D-97074 Wuerzburg, Germany;
authors.forename: Ann-Cathrin
authors.initials: AC
authors.lastname: Winkler
authors.affiliation: Biocenter, Chair of Microbiology, University of Würzburg, D-97074 Wuerzburg, Germany;
authors.forename: Kerstin
authors.initials: K
authors.lastname: Paprotka
authors.affiliation: Max Planck Genome Centre, D-50829 Cologne, Germany;
authors.forename: Richard
authors.initials: R
authors.lastname: Reinhardt
authors.affiliation: Institute of Molecular Infection Biology, University of Würzburg, D-97080 Wuerzburg, Germany;
authors.forename: Konrad U
authors.identifier: 0000-0002-1481-2996
authors.initials: KU
authors.lastname: Förstner
authors.affiliation: Jenner Institute, Centre for Molecular and Cellular Physiology, Oxford OX3 7BN, United Kingdom;
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Allen
authors.affiliation: Jenner Institute, Centre for Molecular and Cellular Physiology, Oxford OX3 7BN, United Kingdom;
authors.forename: Amy
authors.initials: A
authors.lastname: Flaxman
authors.affiliation: Jenner Institute, Centre for Molecular and Cellular Physiology, Oxford OX3 7BN, United Kingdom;
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yamaguchi
authors.affiliation: Oxford Vaccine Group, University of Oxford, Oxford, United Kingdom;
authors.forename: Christine S
authors.initials: CS
authors.lastname: Rollier
authors.affiliation: Jenner Institute, Centre for Molecular and Cellular Physiology, Oxford OX3 7BN, United Kingdom;
authors.forename: Pauline
authors.initials: P
authors.lastname: van Diemen
authors.affiliation: Biocenter, Chair of Microbiology, University of Würzburg, D-97074 Wuerzburg, Germany;
authors.forename: Sebastian
authors.initials: S
authors.lastname: Blättner
authors.affiliation: Biocenter, Chair of Bioinformatics, University of Würzburg, D-97074 Wuerzburg, Germany;
authors.forename: Christian W
authors.initials: CW
authors.lastname: Remmele
authors.affiliation: Institute of Molecular Infection Biology, University of Würzburg, D-97080 Wuerzburg, Germany;
authors.forename: Martina
authors.initials: M
authors.lastname: Selle
authors.affiliation: Biocenter, Chair of Bioinformatics, University of Würzburg, D-97074 Wuerzburg, Germany; Institute of Human Genetics, University of Würzburg, D-97074 Wuerzburg, Germany;
authors.forename: Marcus
authors.initials: M
authors.lastname: Dittrich
authors.affiliation: Biocenter, Chair of Bioinformatics, University of Würzburg, D-97074 Wuerzburg, Germany;
authors.forename: Tobias
authors.initials: T
authors.lastname: Müller
authors.affiliation: Institute of Molecular Infection Biology, University of Würzburg, D-97080 Wuerzburg, Germany;
authors.forename: Jörg
authors.initials: J
authors.lastname: Vogel
authors.affiliation: Institute of Molecular Infection Biology, University of Würzburg, D-97080 Wuerzburg, Germany;
authors.forename: Knut
authors.initials: K
authors.lastname: Ohlsen
authors.affiliation: Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom;
authors.forename: Derrick W
authors.initials: DW
authors.lastname: Crook
authors.affiliation: Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, United Kingdom;
authors.forename: Ruth
authors.initials: R
authors.lastname: Massey
authors.affiliation: Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom; Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom thomas.rudel@biozentrum.uni-wuerzburg.de daniel.wilson@ndm.ox.ac.uk.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Wilson
authors.affiliation: Biocenter, Chair of Microbiology, University of Würzburg, D-97074 Wuerzburg, Germany; thomas.rudel@biozentrum.uni-wuerzburg.de daniel.wilson@ndm.ox.ac.uk.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rudel
authors.affiliation: Jenner Institute, Centre for Molecular and Cellular Physiology, Oxford OX3 7BN, United Kingdom;
authors.forename: David H
authors.initials: DH
authors.lastname: Wyllie
authors.affiliation: Biocenter, Chair of Microbiology, University of Würzburg, D-97074 Wuerzburg, Germany;
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Fraunholz
mesh_terms: D000038:Abscess / Q000209:etiology* / Q000473:pathology; D000818:Animals; D017209:Apoptosis; D016470:Bacteremia / Q000209:etiology* / Q000473:pathology; D001426:Bacterial Proteins / Q000235:genetics*; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D006367:HeLa Cells; D006461:Hemolysis; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation / Q000235:genetics*; D040901:Proteomics; D012333:RNA, Messenger / Q000235:genetics; D022661:RNA, Untranslated / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000150:complications* / Q000382:microbiology / Q000473:pathology; D013211:Staphylococcus aureus / Q000472:pathogenicity; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D012333:RNA, Messenger; D022661:RNA, Untranslated; D037521:Virulence Factors
keywords: SSR42; Staphylococcus aureus; bloodstream infection; rsp; toxicity regulator