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Ingegerd Johansson, Anders Esberg, Linda Eriksson, Simon Haworth, Pernilla Lif Holgerson
Bovine milk intake has been associated with various disease outcomes, with modulation of the gastro-intestinal microbiome being suggested as one potential mechanism. The aim of the present study was to explore the oral microbiota in relation to variation in self-reported milk intake. Saliva and tooth biofilm microbiota was characterized by 16S rDNA sequencing, PCR and cultivation in 154 Swedish adolescents, and information on diet and other lifestyle markers were obtained from a questionnaire, and dental caries from clinical examination...
2018: PloS One
Gonzalo A Jaña, Fernanda Mendoza, Manuel I Osorio, Joel B Alderete, Pedro A Fernandes, Maria J Ramos, Verónica A Jiménez
In this work, QM/MM calculations were employed to examine the catalytic mechanism of the retaining glucosyltransferase GTF-SI enzyme, which participates in the process of caries formation. Our goal was to characterize, with atomistic details, the mechanism of sucrose hydrolysis and the catalytic factors that modulate this reaction. Our results suggest a concerted mechanism for sucrose hydrolysis in which the first event corresponds to the glycosidic bond breakage assisted by Glu515, followed by the nucleophilic attack of Asp477, leading to the formation of the Covalent Glycosyl Enzyme (CGE) intermediate...
March 20, 2018: Organic & Biomolecular Chemistry
Wen-Wen Zhao, Zan Ke, Jing-Yue Wu, Wei Gao, Yang Jie, Yin-Ying Ba, Xia Wu, Xiao-Qing Chen
One new triterpenoid (1) and seven known analogues (2-8) were isolated from the leaves of Ilex hainanensis Merr.. Their structures were established by analysis of their MS, 1D and 2D NMR spectroscopic data and comparison with those in the literature. The antibacterial activity of compounds 1-8 were evaluated by determination of minimum inhibitory concentration using twofold microdilution broth method against Streptococcus mutans ATCC 25175 (Gram-positive) and Fusobacterium nucleatum ATCC 10953 (Gram-negative)...
March 19, 2018: Natural Product Research
João Gabriel Silva Souza, Thamara Beline, Adaias Oliveira Matos, Bárbara Emanoele Costa Oliveira, Antônio Pedro Ricomini-Filho, Valentim Adelino Ricardo Barão
STATEMENT OF PROBLEM: Biofilms can reduce the corrosion resistance of titanium because of the bacterial metabolism of fermentable carbohydrates, including sucrose. However, studies evaluating whether biofilms exposed to higher sucrose concentrations can affect the electrochemical behavior of titanium are lacking. PURPOSE: The purpose of this in vitro study was to test the electrochemical behavior of titanium previously exposed to biofilm supplemented with different sucrose concentrations...
March 15, 2018: Journal of Prosthetic Dentistry
Josy Goldoni Lazarini, Janaina de Cássia Orlandi Sardi, Marcelo Franchin, Bruno Dias Nani, Irlan Almeida Freires, Juliana Infante, Jonas Augusto Rizzato Paschoal, Severino Matias de Alencar, Pedro Luiz Rosalen
The anti-inflammatory and antibiofilm activities as well as toxicity and chemical profile of Eugenia brasiliensis pulp extract (EBE), were evaluated. EBE chemical profile and phenolic content were determined by LC-MS/MS. EBE was tested for its in vitro and in vivo anti-inflammatory activity, including TNF-α release, NF-кB activation, neutrophil migration and paw edema. The MIC/MBC and antibiofilm activities were tested against methicillin sensitive and resistant Staphylococcus aureus, Escherichia coli, Pseudomona aeruginosa, Streptococcus mutans, and Lactobacillus acidophilus...
March 15, 2018: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Alejandro Avilés-Reyes, Irlan Almeida Freires, Richard Besingi, Sangeetha Purushotham, Champion Deivanayagam, L Jeannine Brady, Jacqueline Abranches, José A Lemos
Protein glycosylation has been described as the most abundant and complex post-translational modification occurring in nature. Recent studies have enhanced our view of how this modification occurs in bacteria highlighting the role of protein glycosylation in various processes such as biofilm formation, virulence and host-microbe interactions. We recently showed that the collagen- and laminin-binding adhesin Cnm of the dental pathogen Streptococcus mutans is post-translationally modified by the PgfS glycosyltransferase...
March 16, 2018: Scientific Reports
Stefanie Amend, Roland Frankenberger, Susanne Lücker, Eugen Domann, Norbert Krämer
OBJECTIVES: The present study aimed to establish Lactobacillus casei in a completely automated Streptococcus mutans-based artificial mouth model and to investigate secondary caries inhibiting properties of glass ionomer cements / resin composite groups in vitro. METHODS: Sixty extracted, caries-free human third molars were used for preparation of standardized class-V-cavities. Specimens were restored with a resin-modified (Photac Fil; PF) as well as a conventional glass ionomer cement (Ketac Molar; KM) and one resin composite bonded with and without conduction of etch-and-rinse technique (Prime&Bond NT, Ceram X mono; C+ERT, C)...
March 12, 2018: Dental Materials: Official Publication of the Academy of Dental Materials
Amo Dal Piva, Lpc Contreras, F C Ribeiro, L C Anami, Sea Camargo, Aoc Jorge, M A Bottino
INTRODUCTION: This study evaluated the morphology, biofilm formation, and viability of human gingival fibroblasts in contact with two monolithic ceramics after two different finishing techniques: polishing or glazing. For this, 92 blocks (4.5 × 4.5 × 1.5 mm) of each ceramic were made using high translucency zirconia partially stabilized by yttrium (YZHT) and lithium silicate reinforced by zirconium (ZLS). METHODS AND MATERIALS: Blocks were sintered and then divided into glazing (g) or polishing (p) surface finish...
March 13, 2018: Operative Dentistry
A Almståhl, C Finizia, A Carlén, B Fagerberg-Mohlin, T Alstad
OBJECTIVE: To analyse mucosal and major salivary secretion rates, caries and plaque microflora in connection with treatment for cancer in the head and neck region. METHODS: Thirty-three patients were included and the number of teeth, filled surfaces and caries lesions registered. The labial and buccal gland secretion and stimulated whole salivary secretion rates were determined. Supragingival plaque microflora was analysed using cultivation technique. Data were collected pretreatment, during treatment and 6 months, 1 year and 2 years post-treatment...
March 13, 2018: International Journal of Dental Hygiene
Pei Lin Zhuang, Li Xia Yu, Juan Kun Liao, Yan Zhou, Huan Cai Lin
BACKGROUND: The VicRK two-component signalling system regulates virulence and cariogenicity in Streptococcus mutans (S. mutans). The purpose of this study was to explore the genetic polymorphisms of the vicR and vicK genes, which are associated with dental caries in children with S. mutans. METHODS: In this study, 121 (from each group) clinical S. mutans strains were isolated from caries-free children and children with high-severity caries to sequence the vicR and vicK genes...
March 12, 2018: BMC Oral Health
Thamires Priscila Cavazana, Juliano Pelim Pessan, Thayse Yumi Hosida, Douglas Roberto Monteiro, Alberto Carlos Botazzo Delbem
OBJECTIVE: This study aimed to standardize an in vitro experimental model able to reproduce the pH changes that occur in dental biofilm under in vivo conditions, using a mixed biofilm of Streptococcus mutans and Candida albicans. DESIGN: Biofilms were developed for 96 h, and exposed to three different concentrations of sucrose (10, 20 or 30%) during 1, 3 or 5 min. The pH was measured before exposure to sucrose, immediately after its removal from the biofilms, and at 1, 3, 5 and 10 min after removal...
March 6, 2018: Archives of Oral Biology
Alejandro Avilés-Reyes, Irlan Almeida Freires, Jessica K Kajfasz, Dicler Barbieri, James H Miller, José A Lemos, Jacqueline Abranches
We report the whole genome sequence (WGS) of the serotype e Cbm+ strain LAR01 of Streptococcus mutans, a dental pathogen frequently associated with extra-oral infections. The LAR01 genome is a single circular chromosome of 2.1 Mb with a GC content of 36.96%. The genome contains 15 PTS gene clusters, 7 cell wall-anchored (LPxTG) proteins, all genes required for the development of natural competence and genes coding for mutacins VI and K8. Interestingly, the cbm gene is genetically linked to a putative type VII secretion system that has been found in Mycobacteria and few other gram-positive bacteria...
March 9, 2018: Molecular Oral Microbiology
Nancy J Lin, Courtney Keeler, Alison M Kraigsley, Jing Ye, Sheng Lin-Gibson
OBJECTIVE: Resin-based composites are known to elute leachables that include unincorporated starting materials. The objective of this work was to determine the effect of common dental monomers and initiators on Streptococcus mutans biofilm metabolic activity and biomass. METHODS: S. mutans biofilms were inoculated in the presence of bisphenol A glycerolate dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), camphorquinone (CQ), and ethyl 4-(dimethylamino)benzoate (4E) at 0...
March 6, 2018: Dental Materials: Official Publication of the Academy of Dental Materials
Josiane de Almeida, Andrea L Pimenta, Ulisses A Pereira, Luiz C A Barbosa, Michel A Hoogenkamp, Suzette V van der Waal, Wim Crielaard, Wilson T Felippe
This study evaluated the inhibitory effects of lactams on Streptococcus mutans, Enterococcus faecalis, and Candida glabrata multispecies biofilm formation. γ-Alkylidene-γ-lactams 1, 2, and 3 [solubilized in 3.5% dimethyl sulfoxide (DMSO)] were tested. Glass coverslips were conditioned with either the lactams or 3.5% DMSO (control) for 1 h, inoculated with microbial cultures, and incubated for 48 h. To assess the effect of the lactams on biofilm formation, the following parameters were determined: the biofilm biomass (by both crystal violet staining and protein determination); the amount of insoluble polysaccharides of the extracellular matrix; and the number of viable and total cells [by both colony-forming unit counting and quantitative real-time PCR (qPCR)]...
March 8, 2018: European Journal of Oral Sciences
Sofia B Mohamed, Atif Alagib, Tahani B AbdElkareim, Mohamed M Hassan, Wendell C Johnson, Hala E Hussein, Naomi S Taus, Massaro W Ueti
Tropical theileriosis is a serious animal disease transmitted by tick vectors. The agents of theileriosis are obligate intracellular parasites that cause mild to severe disease in the mammalian host. Tropical theileriosis has been recognized as a burden to the development of the dairy industry in Sudan and causes major economic losses. However, knowledge about the distribution of Theileria spp. in Sudan and the extent of sequence variation within the 18S rRNA gene is currently unknown. The aim of this study was to determine the diversity of Theileria spp...
March 7, 2018: Parasitology Research
Fei-Long Li, Ying Shi, Jiu-Xun Zhang, Jian Gao, Ye-Wang Zhang
A novel nicotinamide adenine dinucleotide (NADH) oxidase from Streptococcus mutans ATCC 25175 (SmNox) was cloned and overexpressed in Escherichia coli BL21 (DE3). Sequence analysis revealed an open reading frame of 1374 bp, capable of encoding a polypeptide of 457 amino acid residues. The molecular mass of the purified SmNox was estimated to be ∼49.9 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified SmNox had the highest specific activity of 281.2 U·mg-1 at optimal pH and temperature of 7...
March 4, 2018: International Journal of Biological Macromolecules
Jonatas Rafael de Oliveira, Kely Karina Belato, Felipe Eduardo de Oliveira, Antonio Olavo Cardoso Jorge, Samira Esteves Afonso Camargo, Luciane Dias de Oliveira
This study evaluated the in vitro antibiofilm effect of 5 different commercial mouthwashes (Cepacol Traditional, Colgate Plax Fresh Mint, Listerine Cool Mint, Oral-B Complete, and Sensodyne) on Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans, Escherichia coli, and Pseudomonas aeruginosa. The cytotoxic effect of the mouthwashes on gingival fibroblasts was also analyzed. A colorimetric assay with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was used to investigate the viability of biofilms after 48 hours and gingival fibroblasts after 24 hours...
March 2018: General Dentistry
Meng-Ying Mao, Meng Li, Lei Lei, Jia-Xin Yin, Ying-Ming Yang, Tao Hu
Streptococcus mutans is an important factor in the etiology and pathogenesis of dental caries, largely owing to its ability to form a stable biofilm. Previous animal studies have indicated that rnc could decrease the amount of sulcal caries, and that the downregulation of cariogenicity might be due to its capacity to disrupt biofilm formation. However, the biofunctions by which rnc is involved in biofilm formation remain to be elucidated. In this study, we further investigate the role of rnc based on the study of mature biofilm...
March 6, 2018: Caries Research
Pratick Khara, Saswat Sourav Mohapatra, Indranil Biswas
Streptococcus mutans, the primary aetiological agent of dental caries, is one of the major bacteria of the human oral cavity. The pathogenicity of this bacterium is attributed not only to the expression of virulence factors, but also to its ability to respond and adapt rapidly to the ever-changing conditions of the oral cavity. The two-component signal transduction system (TCS) CovR/S plays a crucial role in virulence and stress response in many streptococci. Surprisingly, in S. mutans the response regulator CovR appears to be an orphan, as the cognate sensor kinase, CovS, is absent in all the strains...
March 5, 2018: Microbiology
Yufei Wang, Xiuqing Wang, Wentao Jiang, Kun Wang, Junyuan Luo, Wei Li, Xuedong Zhou, Linglin Zhang
Cariogenic virulence factors of Streptococcus mutans include acidogenicity, aciduricity, and extracellular polysaccharides (EPS) synthesis. The de novo designed antimicrobial peptide GH12 has shown bactericidal effects on S. mutans , but its interaction with virulence and regulatory systems of S. mutans remains to be elucidated. The objectives were to investigate the effects of GH12 on virulence factors of S. mutans , and further explore the function mechanisms at enzymatic and transcriptional levels. To avoid decrease in bacterial viability, we limited GH12 to subinhibitory levels...
2018: Journal of Oral Microbiology
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