agr RNAIII divergently regulates glucose-induced biofilm formation in clinical isolates of Staphylococcus aureus

• Published in: Microbiology (Society for General Microbiology) 2008-11, Vol.154 (11), p.3480-3490
• Main Authors: Coelho, Leonardo Rocchetto, Souza, Raquel Rodrigues, Ferreira, Fabienne Antunes, Guimaraes, Marcia Aparecida, Ferreira-Carvalho, Bernadete Teixeira, Figueiredo, Agnes Marie Sa
• Format: Article
• Language: English
• Subjects: Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Base Sequence; Biofilms - growth & development; Biogenesis of cell structures, supramolecular organization; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Bacterial; Glucose - metabolism; Humans; Methicillin-Resistant Staphylococcus aureus - genetics; Methicillin-Resistant Staphylococcus aureus - isolation & purification; Methicillin-Resistant Staphylococcus aureus - pathogenicity; Methicillin-Resistant Staphylococcus aureus - physiology; Microbiology; Molecular Sequence Data; RNA, Bacterial - genetics; RNA, Bacterial - metabolism; Sequence Alignment; Staphylococcal Infections - microbiology; Staphylococcus aureus; Staphylococcus aureus - genetics; Staphylococcus aureus - isolation & purification; Staphylococcus aureus - pathogenicity; Staphylococcus aureus - physiology; Trans-Activators - genetics; Trans-Activators - metabolism; Virulence Factors - genetics; Virulence Factors - metabolism
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.2007/016014-0

Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Professor Paulo de Góes, Av. Carlos Chagas Filho 373 – CCS – Bl I, Cidade Universitária, 21941590 Rio de Janeiro, Brazil Correspondence Agnes Marie Sá Figueiredo agnes{at}micro.ufrj.br Staphylococcus aureus is an important nosocomial and community-acquired pathogen. Hospital infections are frequently complicated by the ability of bacteria to form biofilms on different surfaces. The development of bacterial films on medical indwelling devices, such as prostheses, often requires surgical procedures to remove the contaminated implant. Indeed, biofilm formation on central endovenous catheters is a major cause of primary bacteraemia in hospitals. The modulation of virulence factors in S. aureus is orchestrated by a number of global regulators including agr RNAIII. To improve our understanding of the role of the agr quorum-sensing system in biofilm formation by S. aureus , we constructed a number of agr -null mutants, derived from contemporary clinical isolates. Analysis of these mutants indicates that agr has a significant impact on biofilm development for most of the isolates tested. Our data show that RNAIII can control both biofilm formation and accumulation. The agr effect included both up- and downregulation of biofilms, even for isolates within the same lineage, corroborating the hypothesis that the mechanisms involved in S. aureus biofilms are complex and probably multifactorial. Abbreviations: AIP, Agr autoinducing peptide; BEC, Brazilian epidemic clone; BU, biofilm unit; CLSM, confocal laser scanning microscopy; CS, conditioned supernatant; MRSA, meticillin-resistant S. aureus ; MSSA, meticillin-susceptible S. aureus ; WT, wild-type These authors contributed equally to this work.