Transcription and translation products of the cytolysin gene psm-mec on the mobile genetic element SCCmec regulate Staphylococcus aureus virulence

• Published in: PLoS pathogens Vol. 7; no. 2; p. e1001267
• Main Authors: Kaito, Chikara, Saito, Yuki, Nagano, Gentaro, Ikuo, Mariko, Omae, Yosuke, Hanada, Yuichi, Han, Xiao, Kuwahara-Arai, Kyoko, Hishinuma, Tomomi, Baba, Tadashi, Ito, Teruyo, Hiramatsu, Keiichi, Sekimizu, Kazuhisa
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.02.2011; Public Library of Science (PLoS)
• Subjects: Animals; Bacteriology; Base Sequence; Female; Genes; Genetic aspects; Genetics and Genomics/Gene Expression; Genetics and Genomics/Gene Function; Health aspects; Infectious Diseases/Bacterial Infections; Interspersed Repetitive Sequences - genetics; Interspersed Repetitive Sequences - physiology; Methicillin-Resistant Staphylococcus aureus - genetics; Methicillin-Resistant Staphylococcus aureus - pathogenicity; Mice; Microbiology; Microbiology/Cellular Microbiology and Pathogenesis; Microbiology/Medical Microbiology; Microbiology/Microbial Evolution and Genomics; Microbiology/Microbial Growth and Development; Models, Biological; Molecular Sequence Data; Open Reading Frames - genetics; Organisms, Genetically Modified; Perforin - genetics; Perforin - metabolism; Perforin - physiology; Physiological aspects; Protein Biosynthesis - physiology; Proteins; Staphylococcus aureus; Staphylococcus aureus - genetics; Staphylococcus aureus - pathogenicity; Staphylococcus infections; Transcription, Genetic - physiology; Transformation, Bacterial - physiology; Virulence (Microbiology); Virulence - genetics; Japan
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1001267

The F region downstream of the mecI gene in the SCCmec element in hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) contains two bidirectionally overlapping open reading frames (ORFs), the fudoh ORF and the psm-mec ORF. The psm-mec ORF encodes a cytolysin, phenol-soluble modulin (PSM)-mec. Transformation of the F region into the Newman strain, which is a methicillin-sensitive S. aureus (MSSA) strain, or into the MW2 (USA400) and FRP3757 (USA300) strains, which are community-acquired MRSA (CA-MRSA) strains that lack the F region, attenuated their virulence in a mouse systemic infection model. Introducing the F region to these strains suppressed colony-spreading activity and PSMα production, and promoted biofilm formation. By producing mutations into the psm-mec ORF, we revealed that (i) both the transcription and translation products of the psm-mec ORF suppressed colony-spreading activity and promoted biofilm formation; and (ii) the transcription product of the psm-mec ORF, but not its translation product, decreased PSMα production. These findings suggest that both the psm-mec transcript, acting as a regulatory RNA, and the PSM-mec protein encoded by the gene on the mobile genetic element SCCmec regulate the virulence of Staphylococcus aureus.