title: Analysis of two-component sensor proteins involved in the response to acid stimuli in Streptococcus pyogenes.
abstract: The virulence of Streptococcus pyogenes depends on proteins that are produced by this bacterium. The production of virulence proteins depends on environmental factors, and two-component regulatory systems are considered to be involved in sensing these factors. One of the environmental factors is acid stimuli. We established knockout strains in all speculated two-component regulatory sensor proteins of the M1 clinical strain of S. pyogenes and examined their relevance to acid stimuli. The parental strain and its derived knockout strains were cultured in a medium adjusted to pH 7.6 or 6.0, and their growth in broth was compared. The spy1622 sensor knockout strain showed significant growth reduction compared with the parental strain in broth at pH 6.0, suggesting that the Spy1622 two-component sensor protein is involved in sensing acid stimuli. To further examine the role of the Spy1622 two-component sensor protein in virulence, blood bactericidal assays and mouse infection model experiments were performed. We found that the spy1622 knockout strain was less virulent than the parental strain, which suggests that the Spy1622 two-component sensor protein could play an important role in virulence.
authors.affiliation: Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Ichikawa
authors.affiliation: Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Minami
authors.affiliation: Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Isaka
authors.affiliation: Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Tatsuno
authors.affiliation: Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan.
authors.forename: Tadao
authors.initials: T
authors.lastname: Hasegawa
mesh_terms: D000143:Acids / Q000378:metabolism*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001770:Blood Bactericidal Activity; D003470:Culture Media; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D055786:Gene Knockout Techniques; D005816:Genetic Complementation Test; D006801:Humans; D006863:Hydrogen-Ion Concentration; D051379:Mice; D008813:Mice, Inbred ICR; D013297:Streptococcus pyogenes / Q000235:genetics / Q000254:growth & development* / Q000472:pathogenicity; D014774:Virulence
chemical_list: D000143:Acids; D001426:Bacterial Proteins; D003470:Culture Media