Molecular basis of virulence in Staphylococcus aureus mastitis
2011
Le Maréchal, Caroline | Seyffert, Nubia | Jardin, Julien | Hernandez, David | Jan, Gwénaël | Rault, Lucie | Azevedo, Vasco | François, Patrice | Schrenzel, Jacques | van de Guchte, Maarten | Even, Sergine | Berkova, Nadia | Thiéry, Richard | Fitzgerald, J.R. | Vautor, Eric | Le Loir, Yves | Science et Technologie du Lait et de l'Oeuf (STLO) ; Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST | Laboratoire de Sophia-Antipolis, Unité pathologie des ruminants ; Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES) | Instituto de Ciencias Biologicas [Minas Gerais] (ICB) ; Universidade Federal de Minas Gerais = Federal University of Minas Gerais [Belo Horizonte, Brazil] (UFMG) | Genomic Research Laboratory, Service of infectious diseases ; Hôpitaux Universitaires de Genève (HUG) | MICrobiologie de l'ALImentation au Service de la Santé (MICALIS) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Laboratoire de Sophia-Antipolis, Unité pathologique des ruminants ; Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES) | The Roslin Institute and Centre for Infectious Diseases, Royal dick school of veterinary studies ; The University of Edinburgh
Background: S. aureus is one of the main pathogens involved in ruminant mastitis worldwide. The severity of staphylococcal infection is highly variable, ranging from subclinical to gangrenous mastitis. This work represents an in-depth characterization of S. aureus mastitis isolates to identify bacterial factors involved in severity of mastitis infection. Methodology/Principal Findings: We employed genomic, transcriptomic and proteomic approaches to comprehensively compare two clonally related S. aureus strains that reproducibly induce severe (strain O11) and milder (strain O46) mastitis in ewes. Variation in the content of mobile genetic elements, iron acquisition and metabolism, transcriptional regulation and exoprotein production was observed. In particular, O11 produced relatively high levels of exoproteins, including toxins and proteases known to be important in virulence. A characteristic we observed in other S. aureus strains isolated from clinical mastitis cases. Conclusions/Significance: Our data are consistent with a dose-dependant role of some staphylococcal factors in the hypervirulence of strains isolated from severemastitis. Mobile genetic elements, transcriptional regulators, exoproteins and iron acquisition pathways constitute good targets for further research to define the underlying mechanisms of mastitis severity.
显示更多 [+] 显示较少 [-]