title: Distribution of Streptococcus mutans strains with collagen-binding proteins in the oral cavity of IgA nephropathy patients.
abstract: BACKGROUND
  IgA nephropathy (IgAN) is the most common primary chronic glomerulonephritis; however, its precise initiating pathogenesis remains unclear. Streptococcus mutans is a major pathogen of human dental caries. S. mutans strains with the cnm gene encoding Cnm, a collagen-binding protein, have been reported to contribute to the development of systemic diseases. However, the contribution of S. mutans with Cnm in the development of IgAN has not been reported. The aim of this study was to investigate the prevalence of cnm-positive S. mutans in IgAN patients and clarify the effects of cnm-positive S. mutans on the histological pathology of IgAN.
  
  
  METHODS
  We identified the cnm gene in S. mutans isolated in saliva specimens, which were collected from IgAN patients (n = 53) and control subjects (n = 50). We evaluated the collagen-binding properties of S. mutans in IgAN patients and controls. The clinical parameters and histological scores were also assessed in IgAN patients.
  
  
  RESULTS
  The rates of S. mutans isolation in IgAN and control groups were 84.0 and 84.9 %, respectively, not significantly dfferent. cnm-positive strains were significantly more prevalent in the IgAN group than in controls (32.1 vs. 14.0 %, p < 0.05). With regard to collagen-binding assays, the binding rates of cnm-positive strains were significantly higher in the IgAN group than in controls (96.6 vs. 30.0, p < 0.05). In addition, the segmental glomerulosclerosis scores were significantly higher in cnm-positive patients with IgAN than in cnm-negative patients with IgAN (0.94 vs. 0.57, p < 0.05).
  
  
  CONCLUSIONS
  cnm-positive S. mutans strains are potentially associated with the pathogenesis of IgAN.
authors.affiliation: Division of Nephrology, Seirei Hamamatsu General Hospital, 2-12-12 Sumiyoshi, Naka-ku, Hamamatsu, Shizuoka, 430-8558, Japan. misakitar@sis.seirei.or.jp.
authors.forename: Taro
authors.initials: T
authors.lastname: Misaki
authors.affiliation: Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Naka
authors.affiliation: Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Kuroda
authors.affiliation: Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Nomura
authors.affiliation: Division of Nephrology, Seirei Hamamatsu General Hospital, 2-12-12 Sumiyoshi, Naka-ku, Hamamatsu, Shizuoka, 430-8558, Japan.
authors.forename: Tempei
authors.initials: T
authors.lastname: Shiooka
authors.affiliation: Division of Nephrology, Seirei Hamamatsu General Hospital, 2-12-12 Sumiyoshi, Naka-ku, Hamamatsu, Shizuoka, 430-8558, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Naito
authors.affiliation: Division of Nephrology, Seirei Hamamatsu General Hospital, 2-12-12 Sumiyoshi, Naka-ku, Hamamatsu, Shizuoka, 430-8558, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Yasuda
authors.affiliation: Division of Nephrology, Seirei Hamamatsu General Hospital, 2-12-12 Sumiyoshi, Naka-ku, Hamamatsu, Shizuoka, 430-8558, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Isozaki
authors.affiliation: Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakano
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism*; D000328:Adult; D002352:Carrier Proteins / Q000378:metabolism*; D024042:Collagen Type I / Q000378:metabolism; D024141:Collagen Type IV / Q000378:metabolism; D005260:Female; D005922:Glomerulonephritis, IGA / Q000382:microbiology* / Q000503:physiopathology; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000382:microbiology*; D012463:Saliva / Q000382:microbiology; D013295:Streptococcus mutans
chemical_list: D018829:Adhesins, Bacterial; D002352:Carrier Proteins; C488758:Cnm protein, Streptococcus mutans; D024042:Collagen Type I; D024141:Collagen Type IV
keywords: Collagen-binding protein; IgA nephropathy; Streptococcus mutans; cnm