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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Extracellular matrix influence in Streptococcus mutans gene expression in a cariogenic biofilm

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Author(s):
Salamanca, E. J. Florez [1] ; Klein, M. I. [1]
Total Authors: 2
Affiliation:
[1] Sao Paulo State Univ Unesp, Sch Dent, Dept Dent Mat & Prosthodont, Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Molecular Oral Microbiology; v. 33, n. 2, p. 181-193, APR 2018.
Web of Science Citations: 2
Abstract

Caries etiology is biofilm-diet-dependent. Biofilms are highly dynamic and structured microbial communities enmeshed in a three-dimensional extracellular matrix. The study evaluated the expression dynamics of Streptococcus mutans genes associated with exopolysaccharides (EPS) (gtfBCD, gbpB, dexA), lipoteichoic acids (LTA) (dltABCD, SMU\_775c) and extracellular DNA (eDNA) (lytST, lrgAB, ccpA) during matrix development within a mixed-species biofilm of S.mutans, Actinomyces naeslundii and Streptococcus gordonii. Mixed-species biofilms using S.mutans strains UA159 or gtfB formed on saliva-coated hydroxyapatite discs were submitted to a nutritional challenge (providing an abundance of sucrose and starch). Biofilms were removed at eight developmental stages for gene expression analysis by quantitative polymerase chain reaction. The pH of spent culture media remained acidic throughout the experimental periods, being lower after sucrose and starch exposure. All genes were expressed at all biofilm developmental phases. EPS- and LTA-associated genes had a similar expression profile for both biofilms, presenting lower levels of expression at 67, 91 and 115hours and a peak of expression at 55hours, but having distinct expression magnitudes, with lower values for gtfB (eg, fold-difference of 382 for gtfC and 16 for dltB at 43hours). The eDNA-associated genes presented different dynamics of expression between both strains. In UA159 biofilms lrgA and lrgB genes were highly expressed at 29hours (which were 13 and 5.4 times vs gtfB, respectively), whereas in gtfB biofilms an inverse relationship between lytS and lrgA and lrgB expression was detected. Therefore, the deletion of gtfB influences dynamics and magnitude of expression of genes associated with matrix main components. (AU)

FAPESP's process: 14/05423-0 - Role of extracellular DNA and lipoteichoic acid in the matrix of cariogenic biofilm
Grantee:Marlise Inêz Klein Furlan
Support Opportunities: Research Grants - Young Investigators Grants