title: The well-coordinated linkage between acidogenicity and aciduricity via insoluble glucans on the surface of Streptococcus mutans.
abstract: Streptococcus mutans is considered the principal cariogenic bacterium for dental caries. Despite the recognition of their importance for cariogenesis, the possible coordination among S. mutans' main virulence factors, including glucan production, acidogenicity and aciduricity, has been less well studied. In the present study, using S. mutans strains with surface-displayed pH-sensitive pHluorin, we revealed sucrose availability- and Gtf functionality-dependent proton accumulation on S. mutans surface. Consistent with this, using a pH-sensitive dye, we demonstrated that both in vivo cell-produced and in vitro enzymatically synthesized insoluble glucans displayed proton-concentrating ability. Global transcriptomics revealed proton accumulation triggers the up-regulation of genes encoding functions involved in acid tolerance response in a glucan-dependent manner. Our data suggested that this proton enrichment around S. mutans could pre-condition the bacterium for acid-stress. Consistent with this hypothesis, we found S. mutans strains defective in glucan production were more acid sensitive. Our study revealed for the first time that insoluble glucans is likely an essential factor linking acidogenicity with aciduricity. The coordination of these key virulence factors could provide new insights on how S. mutans may have become a major cariogenic pathogen.
authors.affiliation: School of Dentistry, University of California, Los Angeles, CA90095, USA.
authors.forename: Lihong
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Periodontics, University of Washington, Seattle, WA, 98195, USA.|J. Crag Venter Institute, La Jolla, CA 92037, USA.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: McLean
authors.affiliation: School of Dentistry, University of California, Los Angeles, CA90095, USA.
authors.forename: Renate
authors.initials: R
authors.lastname: Lux
authors.affiliation: School of Dentistry, University of California, Los Angeles, CA90095, USA.
authors.forename: Xuesong
authors.initials: X
authors.lastname: He
authors.affiliation: School of Dentistry, University of California, Los Angeles, CA90095, USA.|C3-Jian Inc. Marina del Ray, CA 90292 USA.
authors.forename: Wenyuan
authors.initials: W
authors.lastname: Shi
mesh_terms: D000220:Adaptation, Biological; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D008040:Genetic Linkage; D005936:Glucans / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D050296:Microbial Viability; D011522:Protons; D012995:Solubility; D013295:Streptococcus mutans / Q000235:genetics* / Q000378:metabolism*; D013395:Sucrose / Q000378:metabolism; D059467:Transcriptome
chemical_list: D005936:Glucans; D011522:Protons; D013395:Sucrose