start-ver=1.4 cd-journal=joma no-vol=15 cd-vols= no-issue= article-no= start-page=1673581 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2026 dt-pub=20260107 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Binding of IgA1 and surface-expressed collagen-binding protein of Streptococcus mutans contributes to IgA nephropathy pathogenesis en-subtitle= kn-subtitle= en-abstract= kn-abstract=Background: The present study was conducted to examine the interaction between collagen-binding protein (Cnm) of Streptococcus mutans and immunoglobulin (IgA) to clarify the possible involvement in IgA nephropathy (IgAN) development.
Methods: The binding of Cnm to human immunoglobulins was examined using an enzyme-linked immunosorbent assay. A nephritis-induced rat model was employed to confirm the localization of Cnm.
Results: IgA1 showed significantly greater binding ability to Cnm than to other bacterial surface proteins, and Cnm showed significantly greater binding ability to IgA1 than to other immunoglobulins. In rats administered Cnm, IgA deposition was observed in the glomerular mesangial region. Furthermore, biotin-labeled Cnm was observed in the same region as IgA deposition in the Cnm group.
Conclusions: Taken together, it is considered that following invasion into the bloodstream, Cnm binds to and forms a complex with IgA1, leading to deposition of IgA1 in renal glomeruli. en-copyright= kn-copyright= en-aut-name=MatsuokaDaiki en-aut-sei=Matsuoka en-aut-mei=Daiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SueharaKana en-aut-sei=Suehara en-aut-mei=Kana kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NakaShuhei en-aut-sei=Naka en-aut-mei=Shuhei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MisakiTaro en-aut-sei=Misaki en-aut-mei=Taro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=NagasawaYasuyuki en-aut-sei=Nagasawa en-aut-mei=Yasuyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=ItoSeigo en-aut-sei=Ito en-aut-mei=Seigo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=SuehiroYuto en-aut-sei=Suehiro en-aut-mei=Yuto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=NomuraRyota en-aut-sei=Nomura en-aut-mei=Ryota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=NakanoKazuhiko en-aut-sei=Nakano en-aut-mei=Kazuhiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=Matsumoto-NakanoMichiyo en-aut-sei=Matsumoto-Nakano en-aut-mei=Michiyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= affil-num=1 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=2 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=3 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=4 en-affil=Division of Nephrology, Seirei Hamamatsu General Hospital kn-affil= affil-num=5 en-affil=Department of General Internal Medicine, Hyogo Medical University kn-affil= affil-num=6 en-affil=Department of Internal Medicine, Japan Self-Defense Force Iruma Hospital kn-affil= affil-num=7 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=8 en-affil=Department of Pediatric Dentistry, Graduate School of Biomedical and Health Sciences, Hiroshima University kn-affil= affil-num=9 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=10 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= en-keyword=bacterial surface proteins kn-keyword=bacterial surface proteins en-keyword=collagen-binding protein kn-keyword=collagen-binding protein en-keyword=human immunoglobulins kn-keyword=human immunoglobulins en-keyword=IgA nephropathy kn-keyword=IgA nephropathy en-keyword=Streptococcus mutans kn-keyword=Streptococcus mutans END start-ver=1.4 cd-journal=joma no-vol=135 cd-vols= no-issue= article-no= start-page=107077 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=202512 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Inhibitory effect of cyclodextran on the induction of dental caries by Streptococcus mutans en-subtitle= kn-subtitle= en-abstract= kn-abstract=Cyclodextrans (CIs) are cycloisomaltooligosaccharides that are known to function as dextran analogues and are possible inhibitors of dental plaque formation. CIs have a structure in which 7 to 12 glucose molecules are cyclically linked by α-1,6 bonds. We examined the inhibitory effects of CIs on the induction of dental caries by Streptococcus mutans. The inhibitory effects for bacterial growth, anti-enzymatic activity, and biofilm formation were analyzed. Additionally, the inhibitory effect of CIs on the induction of dental caries was investigated using a rat caries model. The presence of CIs resulted in reduced bacterial growth and biofilm formation. Kinetic analysis of the results showed that the inhibitory effect of CIs on anti-enzymatic activity is competitive. Furthermore, the caries scores with CIs were lower than those without CIs in both diet and drinking experiments. These results suggest that CIs possess strong anticaries activity and may be useful as a dietary supplement. en-copyright= kn-copyright= en-aut-name=AsaumiHaruka en-aut-sei=Asaumi en-aut-mei=Haruka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MatsuuraSakuya en-aut-sei=Matsuura en-aut-mei=Sakuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=GotoKana en-aut-sei=Goto en-aut-mei=Kana kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MatsuokaDaiki en-aut-sei=Matsuoka en-aut-mei=Daiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TabataKeiko en-aut-sei=Tabata en-aut-mei=Keiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=NakaShuhei en-aut-sei=Naka en-aut-mei=Shuhei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=Matsumoto-NakanoMichiyo en-aut-sei=Matsumoto-Nakano en-aut-mei=Michiyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=2 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=3 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=4 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=5 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=6 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=7 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= en-keyword=Streptococcus mutans kn-keyword=Streptococcus mutans en-keyword=glucosyltransferase kn-keyword=glucosyltransferase en-keyword=dental caries kn-keyword=dental caries en-keyword=cyclodextran kn-keyword=cyclodextran en-keyword=animal experiments kn-keyword=animal experiments END start-ver=1.4 cd-journal=joma no-vol=25 cd-vols= no-issue=1 article-no= start-page=1908 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=20251125 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Evaluation of Streptococcus mutans strains possessing genes encoding collagen-binding proteins in the Japanese population en-subtitle= kn-subtitle= en-abstract= kn-abstract=Background Streptococcus mutans harbors collagen-binding protein genes, namely cnm and cbm, which are implicated in its virulence and pathogenicity in both oral and extraoral infections. Although both genes were initially identified in S. mutans isolated from Japanese populations, their geographical prevalence, distribution, and genetic relatedness within Japan remain largely unexplored. This study investigates the prevalence of S. mutans strains carrying cnm and cbm genes across Japan, correlates these findings with clinical data, and analyzes the genetic relatedness of cnm-positive and cnm-negative strains using multilocus sequence typing (MLST).
Methods Dental plaque specimens were collected from 1248 individuals from eight Japanese cities (Hiroshima, Fukuoka, Nagasaki, Niigata, Okayama, Osaka, Tokushima, and Tokyo) and plated on selective medium for S. mutans isolation. S. mutans was confirmed in 523 subjects by colony morphology and PCR using species-specific primers, and the presence of the cnm and cbm genes was determined by PCR with gene-specific primers. Demographic (age, sex) and oral examination (caries prevalence, caries experience, number of teeth) data were recorded. MLST was employed to genotype selected cnm-positive and cnm-negative S. mutans strains to assess their clonal relationships.
Results Among 523 subjects possessing S. mutans (aged 3–90 years), we detected cnm-positive strains in all cities; specifically, the prevalence ranged from 5.5% in Okayama to 25.0% in Tokushima. In contrast, cbm-positive strains were less common and undetectable in some regions. Furthermore, subjects harboring cnm-positive S. mutans were significantly older (p = 0.002) and had higher caries prevalence and experience (p < 0.001). MLST revealed evolutionary relationships among cnm-positive strains across the cities but no discernible region-specific clustering. Clonal relationships partially reflected cnm gene distribution, particularly for exclusively cnm-positive or cnm-negative clonal complexes, but inconsistencies involving serotypes and cnm presence within some clonal complexes and sequence types were also noted.
Conclusions The cnm-positive S. mutans strains are widely distributed throughout Japan and are associated with increased age and caries burden. Although core genome analysis revealed some clonal patterns, the non-uniform distribution of the non-core cnm gene is likely influenced by horizontal gene transfer, providing S. mutans with adaptive advantages irrespective of its core genetic background or serotype. en-copyright= kn-copyright= en-aut-name=OkudaMakoto en-aut-sei=Okuda en-aut-mei=Makoto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SuehiroYuto en-aut-sei=Suehiro en-aut-mei=Yuto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=LapirattanakulJinthana en-aut-sei=Lapirattanakul en-aut-mei=Jinthana kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NakaShuhei en-aut-sei=Naka en-aut-mei=Shuhei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=Matsumoto-NakanoMichiyo en-aut-sei=Matsumoto-Nakano en-aut-mei=Michiyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=NomuraRyota en-aut-sei=Nomura en-aut-mei=Ryota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=OkawaRena en-aut-sei=Okawa en-aut-mei=Rena kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=NakanoKazuhiko en-aut-sei=Nakano en-aut-mei=Kazuhiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=2 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=3 en-affil=Department of Oral Microbiology, Faculty of Dentistry, Mahidol University kn-affil= affil-num=4 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=5 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=6 en-affil=Department of Pediatric Dentistry, Graduate School of Biomedical and Health Sciences, Hiroshima University kn-affil= affil-num=7 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=8 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= en-keyword=Collagen-binding protein gene kn-keyword=Collagen-binding protein gene en-keyword=cnm gene kn-keyword=cnm gene en-keyword=cbm gene kn-keyword=cbm gene en-keyword=Japan kn-keyword=Japan en-keyword=Multilocus sequence typing kn-keyword=Multilocus sequence typing en-keyword=Serotype kn-keyword=Serotype en-keyword=Streptococcus mutans kn-keyword=Streptococcus mutans END start-ver=1.4 cd-journal=joma no-vol=15 cd-vols= no-issue=1 article-no= start-page=27047 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=20250725 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Prevalence of Streptococcus mutans harboring the cnm gene encoding cell surface protein Cnm in Japanese children en-subtitle= kn-subtitle= en-abstract= kn-abstract=Dental caries is a highly prevalent infectious disease primarily caused by the pathogenic bacterium Streptococcus mutans, which has also been associated with systemic disease. A 120-kDa collagen-binding protein (Cnm) produced by S. mutans contributes to cardiovascular disease pathogenicity. Few studies have addressed the current prevalence of S. mutans and the cnm gene in Japanese children or examined caries pathology in relation to cnm presence. Here, we investigated the prevalence of S. mutans and the distribution of cnm-positive S. mutans among 490 children who visited two university hospitals in Japan. The caries experience index (dmft/DMFT) was calculated, and the collagen-binding ability of cnm-positive S. mutans strains was assessed. S. mutans was isolated from the oral cavities of 158 patients (36.8%); 10.1% (16/158) harbored cnm-positive S. mutans. When caries experience indices were compared across dentitions, patients harboring cnm-positive strains had significantly higher dmft/DMFT scores than those with cnm-negative strains (P < 0.05). Additionally, a positive correlation was observed between the collagen-binding capacity of cnm-positive S. mutans and the dmft/DMFT score (r = 0.601, P < 0.05). These findings suggest that cnm contributes to caries progression through collagen-mediated adherence to tooth surfaces. The presence of cnm-positive S. mutans may represent a risk factor for increased caries susceptibility in children. en-copyright= kn-copyright= en-aut-name=SuehiroYuto en-aut-sei=Suehiro en-aut-mei=Yuto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OkudaMakoto en-aut-sei=Okuda en-aut-mei=Makoto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=OtsuguMasatoshi en-aut-sei=Otsugu en-aut-mei=Masatoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=OchiaiMarin en-aut-sei=Ochiai en-aut-mei=Marin kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TakagiMisato en-aut-sei=Takagi en-aut-mei=Misato kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=TojoFumikazu en-aut-sei=Tojo en-aut-mei=Fumikazu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=MikasaYusuke en-aut-sei=Mikasa en-aut-mei=Yusuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=NakaShuhei en-aut-sei=Naka en-aut-mei=Shuhei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=Matsumoto-NakanoMichiyo en-aut-sei=Matsumoto-Nakano en-aut-mei=Michiyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=LapirattanakulJinthana en-aut-sei=Lapirattanakul en-aut-mei=Jinthana kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=OkawaRena en-aut-sei=Okawa en-aut-mei=Rena kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=NomuraRyota en-aut-sei=Nomura en-aut-mei=Ryota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=NakanoKazuhiko en-aut-sei=Nakano en-aut-mei=Kazuhiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 ORCID= affil-num=1 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=2 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=3 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=4 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=5 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=6 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=7 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=8 en-affil=Department of Pediatric Dentistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=9 en-affil=Department of Pediatric Dentistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=10 en-affil=Department of Oral Microbiology, Faculty of Dentistry, Mahidol University kn-affil= affil-num=11 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=12 en-affil=Department of Pediatric Dentistry, Graduate School of Biomedical and Health Sciences, Hiroshima University kn-affil= affil-num=13 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= en-keyword=Streptococcus mutans kn-keyword=Streptococcus mutans en-keyword=Collagen-binding protein kn-keyword=Collagen-binding protein en-keyword=Cnm kn-keyword=Cnm en-keyword=Prevalence kn-keyword=Prevalence en-keyword=Dental caries kn-keyword=Dental caries en-keyword=Japanese population kn-keyword=Japanese population END start-ver=1.4 cd-journal=joma no-vol=7 cd-vols= no-issue=1 article-no= start-page=1141 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20240914 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Contribution of collagen-binding protein Cnm of Streptococcus mutans to induced IgA nephropathy-like nephritis in rats en-subtitle= kn-subtitle= en-abstract= kn-abstract=IgA nephropathy (IgAN), the most common primary glomerulonephritis, is considered an intractable disease with unknown pathogenic factors. In our previous study, Streptococcus mutans, the major causative bacteria of dental caries, which expresses Cnm, was related to the induction of IgAN-like nephritis. In the present study, the Cnm-positive S. mutans parental strain, a Cnm-defective isogenic mutant strain, its complementation strain, and recombinant Cnm (rCnm) protein were administered intravenously to Sprague Dawley rats, and the condition of their kidneys was evaluated focusing on the pathogenicity of Cnm. Rats treated with parental and complement bacterial strains and rCnm protein developed IgAN-like nephritis with mesangial proliferation and IgA and C3 mesangial deposition. Scanning immunoelectron microscopy revealed that rCnm was present in the electron-dense deposition area of the mesangial region in the rCnm protein group. These results demonstrated that the Cnm protein itself is an important factor in the induction of IgAN in rats. en-copyright= kn-copyright= en-aut-name=NakaShuhei en-aut-sei=Naka en-aut-mei=Shuhei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MatsuokaDaiki en-aut-sei=Matsuoka en-aut-mei=Daiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MisakiTaro en-aut-sei=Misaki en-aut-mei=Taro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NagasawaYasuyuki en-aut-sei=Nagasawa en-aut-mei=Yasuyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=ItoSeigo en-aut-sei=Ito en-aut-mei=Seigo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=NomuraRyota en-aut-sei=Nomura en-aut-mei=Ryota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=NakanoKazuhiko en-aut-sei=Nakano en-aut-mei=Kazuhiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=Matsumoto-NakanoMichiyo en-aut-sei=Matsumoto-Nakano en-aut-mei=Michiyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=2 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=3 en-affil=Division of Nephrology, Seirei Hamamatsu General Hospital kn-affil= affil-num=4 en-affil=Department of General Internal Medicine, Hyogo College of Medicine kn-affil= affil-num=5 en-affil=Department of Internal Medicine, Japan Self-Defense Force Iruma Hospital kn-affil= affil-num=6 en-affil=Department of Pediatric Dentistry, Graduate School of Biomedical and Health Sciences, Hiroshima University kn-affil= affil-num=7 en-affil=Department of Pediatric Dentistry, Graduate School of Dentistry, The University of Osaka kn-affil= affil-num=8 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= END start-ver=1.4 cd-journal=joma no-vol=12 cd-vols= no-issue= article-no= start-page=994014 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2022 dt-pub=20220913 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Cnm of Streptococcus mutans is important for cell surface structure and membrane permeability en-subtitle= kn-subtitle= en-abstract= kn-abstract=Streptococcus mutans, a Gram-positive facultative anaerobic bacterium, is a major pathogen of dental caries. The protein Cnm of S. mutans is involved in collagen binding, but its other biological functions are unknown. In this study, a Cnm-deficient isogenic mutant and a complementation strain were generated from a Cnm-positive S. mutans strain to help determine the properties of Cnm. Initially, comparison of the cell surface structure was performed by electron microscopy, which demonstrated that Cnm appears to be localized on the cell surface and associated with a protruding cell surface structure. Deep RNA sequencing of the strains revealed that the defect in Cnm caused upregulated expression of many genes related to ABC transporters and cell-surface proteins, while a few genes were downregulated. The amount of biofilm formed by the Cnm-defective strain increased compared with the parental and complemented strains, but the biofilm structure was thinner because of elevated expression of genes encoding glucan synthesis enzymes, leading to increased production of extracellular polysaccharides. Particular antibiotics, including bacitracin and chloramphenicol, had a lower minimum inhibitory concentration for the Cnm-defective strain than particular antibiotics, including bacitracin and chloramphenicol, compared with the parental and complemented strains. Our results suggest that S. mutans Cnm is located on the cell surface, gives rise to the observed protruding cell surface, and is associated with several biological properties related to membrane permeability. en-copyright= kn-copyright= en-aut-name=NakaShuhei en-aut-sei=Naka en-aut-mei=Shuhei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MatsuokaDaiki en-aut-sei=Matsuoka en-aut-mei=Daiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=GotoKana en-aut-sei=Goto en-aut-mei=Kana kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MisakiTaro en-aut-sei=Misaki en-aut-mei=Taro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=NagasawaYasuyuki en-aut-sei=Nagasawa en-aut-mei=Yasuyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=ItoSeigo en-aut-sei=Ito en-aut-mei=Seigo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=NomuraRyota en-aut-sei=Nomura en-aut-mei=Ryota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=NakanoKazuhiko en-aut-sei=Nakano en-aut-mei=Kazuhiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=Matsumoto-NakanoMichiyo en-aut-sei=Matsumoto-Nakano en-aut-mei=Michiyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= affil-num=1 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=2 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=3 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=4 en-affil=Division of Nephrology, Seirei Hamamatsu General Hospital kn-affil= affil-num=5 en-affil=Department of General Internal Medicine, Hyogo College of Medicine kn-affil= affil-num=6 en-affil=Department of Internal Medicine, Japan Self-Defense Iruma Hospital kn-affil= affil-num=7 en-affil=Department of Pediatric Dentistry, Division of Oral infection and Disease Control, Osaka University Graduate School of Dentistry kn-affil= affil-num=8 en-affil=Department of Pediatric Dentistry, Division of Oral infection and Disease Control, Osaka University Graduate School of Dentistry kn-affil= affil-num=9 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= en-keyword=Streptococcus mutans kn-keyword=Streptococcus mutans en-keyword=collagen-binding protein kn-keyword=collagen-binding protein en-keyword=membrane permeability kn-keyword=membrane permeability en-keyword=cell structure kn-keyword=cell structure en-keyword=RNA-seq kn-keyword=RNA-seq END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=e13312 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=202153 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Roles of Porphyromonas gulae proteases in bacterial and host cell biology en-subtitle= kn-subtitle= en-abstract= kn-abstract=Porphyromonas gulae, an animal-derived periodontal pathogen, expresses several virulence factors, including fimbria, lipopolysaccharide (LPS) and proteases. We previously reported that its invasive efficiency was dependent on fimbriae types. In addition, P. gulae LPS increased inflammatory responses via toll-like receptors. The present study was conducted to investigate the involvement of P. gulae proteases in bacterial and host cell biology. Porphyromonas gulae strains showed an ability to agglutinate mouse erythrocytes and also demonstrated co-aggregation with Actinomyces viscosus, while the protease inhibitors antipain, PMSF, TLCK and leupeptin diminished P. gulae proteolytic activity, resulting in inhibition of haemagglutination and co-aggregation with A. viscosus. In addition, specific proteinase inhibitors were found to reduce bacterial cell growth. Porphyromonas gulae inhibited Ca9-22 cell proliferation in a multiplicity of infection- and time-dependent manner. Additionally, P. gulae-induced decreases in cell contact and adhesion-related proteins were accompanied by a marked change in cell morphology from well spread to rounded. In contrast, inhibition of protease activity prevented degradation of proteins, such as E-cadherin, beta-catenin and focal adhesion kinase, and also blocked inhibition of cell proliferation. Together, these results indicate suppression of the amount of human proteins, such as gamma-globulin, fibrinogen and fibronectin, by P. gulae proteases, suggesting that a novel protease complex contributes to bacterial virulence. en-copyright= kn-copyright= en-aut-name=UrmiAlam Saki en-aut-sei=Urmi en-aut-mei=Alam Saki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=InabaHiroaki en-aut-sei=Inaba en-aut-mei=Hiroaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NomuraRyota en-aut-sei=Nomura en-aut-mei=Ryota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YoshidaShoko en-aut-sei=Yoshida en-aut-mei=Shoko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=OharaNaoya en-aut-sei=Ohara en-aut-mei=Naoya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=AsaiFumitoshi en-aut-sei=Asai en-aut-mei=Fumitoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=NakanoKazuhiko en-aut-sei=Nakano en-aut-mei=Kazuhiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=Matsumoto‐NakanoMichiyo en-aut-sei=Matsumoto‐Nakano en-aut-mei=Michiyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=2 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=3 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=4 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=5 en-affil=Department of Oral Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and the Advanced Research Center for Oral and Craniofacial Sciences, Dental School, Okayama University kn-affil= affil-num=6 en-affil=Department of Pharmacology, School of Veterinary Medicine Azabu University kn-affil= affil-num=7 en-affil=Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry kn-affil= affil-num=8 en-affil=Department of Pediatric Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= en-keyword=coaggregation kn-keyword=coaggregation en-keyword=haemagglutination kn-keyword=haemagglutination en-keyword=P. gulae kn-keyword=P. gulae en-keyword=protease kn-keyword=protease en-keyword=protein degradation kn-keyword=protein degradation END start-ver=1.4 cd-journal=joma no-vol=12 cd-vols= no-issue=1 article-no= start-page=1797320 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200804 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Identification and functional analysis of glutamine transporter inStreptococcus mutans en-subtitle= kn-subtitle= en-abstract= kn-abstract=Background
Streptococcus mutans, a biofilm-forming bacterium, possesses several transporters that function as import/export molecules. Among them, the PII protein family is composed of members that regulate glutamine synthesis in bacterial species.
Objective
In this study, we characterized the function of the glutamine transporter in S. mutans MT8148.
Methods
The SMU.732 gene, corresponding to glnP in S. mutans, is homologous to the glutamine transporter gene in Bacillus subtilis. We constructed a glnP-inactivated mutant strain (GEMR) and a complement strain (comp-GEMR) and evaluated their biological functions.
Results
Growth of GEMR was similar in the presence and absence of glutamine, whereas the growth rates of MT8148 and comp-GEMR were significantly lower in the presence of glutamine as compared to its absence. Furthermore, biofilms formed by MT8148 and comp-GEMR were significantly thicker than that formed by GEMR, while the GEMR strain showed a significantly lower survival rate in an acidic environment than the other strains. Addition of n-phenyl-2-naphthylamine, used to label of the membrane, led to increased fluorescence intensity of MT8148 and GEMR, albeit that was significantly lower in the latter.
Conclusions
These results suggest that glnP is associated with glutamine transport in S. mutans, especially the import of glutamine involved in biofilm formation. en-copyright= kn-copyright= en-aut-name=MorikawaYuko en-aut-sei=Morikawa en-aut-mei=Yuko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MorimotoSetsuyo en-aut-sei=Morimoto en-aut-mei=Setsuyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YoshidaEri en-aut-sei=Yoshida en-aut-mei=Eri kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NakaShuhei en-aut-sei=Naka en-aut-mei=Shuhei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=InabaHiroaki en-aut-sei=Inaba en-aut-mei=Hiroaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=Matsumoto-NakanoMichiyo en-aut-sei=Matsumoto-Nakano en-aut-mei=Michiyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Department of Pediatric Dentistry, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=2 en-affil=Department of Pediatric Dentistry, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=3 en-affil=Department of Pediatric Dentistry, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=4 en-affil=Department of Pediatric Dentistry, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=5 en-affil=Department of Pediatric Dentistry, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=6 en-affil=Department of Pediatric Dentistry, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= en-keyword=Streptococcus mutans kn-keyword=Streptococcus mutans en-keyword=glutamine transporter kn-keyword=glutamine transporter en-keyword=biofilm kn-keyword=biofilm en-keyword=membrane protein kn-keyword=membrane protein en-keyword=glnP kn-keyword=glnP END start-ver=1.4 cd-journal=joma no-vol=14 cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2014 dt-pub=20140102 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Cross-cultural validity of a dietary questionnaire for studies of dental caries risk in Japanese en-subtitle= kn-subtitle= en-abstract= kn-abstract=Background: Diet is a major modifiable contributing factor in the etiology of dental caries. The purpose of this paper is to examine the reliability and cross-cultural validity of the Japanese version of the Food Frequency Questionnaire to assess dietary intake in relation to dental caries risk in Japanese. Methods: The 38-item Food Frequency Questionnaire, in which Japanese food items were added to increase content validity, was translated into Japanese, and administered to two samples. The first sample comprised 355 pregnant women with mean age of 29.2 +/- 4.2 years for the internal consistency and criterion validity analyses. Factor analysis (principal components with Varimax rotation) was used to determine dimensionality. The dietary cariogenicity score was calculated from the Food Frequency Questionnaire and used for the analyses. Salivary mutans streptococci level was used as a semi-quantitative assessment of dental caries risk and measured by Dentocult SM. Dentocult SM scores were compared with the dietary cariogenicity score computed from the Food Frequency Questionnaire to examine criterion validity, and assessed by Spearman's correlation coefficient (r(s)) and Kruskal-Wallis test. Test-retest reliability of the Food Frequency Questionnaire was assessed with a second sample of 25 adults with mean age of 34.0 +/- 3.0 years by using the intraclass correlation coefficient analysis. Results: The Japanese language version of the Food Frequency Questionnaire showed high test-retest reliability (ICC = 0.70) and good criterion validity assessed by relationship with salivary mutans streptococci levels (r(s) = 0.22; p < 0.001). Factor analysis revealed four subscales that construct the questionnaire (solid sugars, solid and starchy sugars, liquid and semisolid sugars, sticky and slowly dissolving sugars). Internal consistency were low to acceptable (Cronbach's alpha = 0.67 for the total scale, 0.46-0.61 for each subscale). Mean dietary cariogenicity scores were 50.8 +/- 19.5 in the first sample, 47.4 +/- 14.1, and 40.6 +/- 11.3 for the first and second administrations in the second sample. The distribution of Dentocult SM score was 6.8% (score = 0), 34.4% (score = 1), 39.4% (score = 2), and 19.4% (score = 3). Participants with higher scores were more likely to have higher dietary cariogenicity scores (p < 0.001; Kruskal-Wallis test). Conclusions: These results provide the preliminary evidence for the reliability and validity of the Japanese language Food Frequency Questionnaire. en-copyright= kn-copyright= en-aut-name=Shinga-IshiharaChikako en-aut-sei=Shinga-Ishihara en-aut-mei=Chikako kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakaiYukie en-aut-sei=Nakai en-aut-mei=Yukie kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MilgromPeter en-aut-sei=Milgrom en-aut-mei=Peter kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MurakamiKaori en-aut-sei=Murakami en-aut-mei=Kaori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=Matsumoto-NakanoMichiyo en-aut-sei=Matsumoto-Nakano en-aut-mei=Michiyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Pediat Dent affil-num=2 en-affil= kn-affil=Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Pediat Dent affil-num=3 en-affil= kn-affil=Univ Washington, Dept Oral Hlth Sci affil-num=4 en-affil= kn-affil=Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Pediat Dent affil-num=5 en-affil= kn-affil=Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Pediat Dent en-keyword=Food frequency questionnaire kn-keyword=Food frequency questionnaire en-keyword=Cariogenic food kn-keyword=Cariogenic food en-keyword=Diet kn-keyword=Diet en-keyword=Reliability kn-keyword=Reliability en-keyword=Validity kn-keyword=Validity en-keyword=Mutans streptococci kn-keyword=Mutans streptococci END