Coaggregation properties of trimeric autotransporter adhesins

Trimeric autotransporter adhesins (TAAs) comprise a group of virulence‐related proteins in Gram‐negative bacteria. Members of this family bind to extracellular matrix components such as collagen and fibronectin, but also they exhibit several other functions, such as conferring serum resistance and autoaggregation. Autoaggregation promoted by TAAs is homotypic and mediated by the sticky, globular head domains of these lollipop‐like molecules. However, whether TAAs mediate heterotypic interactions (i.e., coaggregation) has not been studied. To address this question, we investigated the coaggregation of two model TAA groups: YadA from the enteropathogenic Yersiniae and the immunoglobulin‐binding Eib proteins from Escherichia coli. To study TAA coaggregation, we coexpressed a fluorescent label together with a particular TAA and followed the aggregative interactions using fluorescence microscopy and quantified the interactions using a novel script implemented in Fiji. Our results show that there is coaggregation between some populations expressing different TAAs, which can be explained by relatively high sequence similarity between the interacting TAAs. Generally, the level of coaggregation correlated with the sequence similarity. However, some TAAs did not interact despite high sequence similarity, showing exclusion of bacteria producing a noncompatible TAA. These data demonstrate that TAAs can mediate bacterial coaggregation, but in some cases prevent coaggregation of bacteria with disparate TAAs. Our results have implications for the ecology of TAA‐producing bacteria, where coaggregation may promote co‐operation whereas exclusion might be an indication of competition

Microbial community succession on developing lesions on human enamel

Dental caries is one of the most common diseases in the world. However, our understanding of how the microbial community composition changes in vivo as caries develops is lacking.An in vivo model was used in a longitudinal cohort study to investigate shifts in the microbial community composition associated with the development of enamel caries.White spot lesions were generated in vivo on human teeth predetermined to be extracted for orthodontic reasons. The bacterial microbiota on sound enamel and on developing carious lesions were identified using the Human Oral Microbe Identification Microarray (HOMIM), which permits the detection of about 300 of the approximate 600 predominant bacterial species in the oral cavity.After only seven weeks, 75% of targeted teeth developed white spot lesions (8 individuals, 16 teeth). The microbial community composition of the plaque over white spot lesions differed significantly as compared to sound enamel. Twenty-five bacterial taxa, including Streptococcus mutans, Atopobium parvulum, Dialister invisus, and species of Prevotella and Scardovia, were significantly associated with initial enamel lesions. In contrast, 14 bacterial taxa, including species of Fusobacterium, Campylobacter, Kingella, and Capnocytophaga, were significantly associated with sound enamel.The bacterial community composition associated with the progression of enamel lesions is specific and much more complex than previously believed. This investigation represents one of the first longitudinally-derived studies for caries progression and supports microbial data from previous cross-sectional studies on the development of the disease. Thus, the in vivo experiments of generating lesions on teeth destined for extraction in conjunction with HOMIM analyses represent a valid model to study succession of supragingival microbial communities associated with caries development and to study efficacy of prophylactic and restorative treatments

Caries associated with orthodontic care part 2: management

It is recognized that wearing an orthodontic appliance increases the caries risk of the individual. The prevalence of demineralization has been reported to be as high as 73%. When demineralization occurs a number of treatments exist: fluoride application, acid microabrasion, casein phosphopeptide-amorphous calcium phosphate (CCP-ACP), resin infiltration and self-assembling peptides. Of these, topical fluoride has the most evidence to support its use. CPD/Clinical Relevance: Demineralization is the most common complication of orthodontic care. The clinician should understand how to manage this when it occurs

Standardizing Terminology and Assessment for Orofacial Conditions in Juvenile Idiopathic Arthritis : International, Multidisciplinary Consensus-based Recommendations

Objective. To propose multidisciplinary, consensus-based, standardization of operational terminology and method of assessment for temporomandibular joint (TMJ) involvement in juvenile idiopathic arthritis (JIA). Methods. Using a sequential expert group–defined terminology and methods-of-assessment approach by (1) establishment of task force, (2) item generation, (3) working group consensus, (4) external expert content validity testing, and (5) multidisciplinary group of experts final Delphi survey consensus. Results. Seven standardized operational terms were defined: TMJ arthritis, TMJ involvement, TMJ arthritis management, dentofacial deformity, TMJ deformity, TMJ symptoms, and TMJ dysfunction. Conclusion. Definition of 7 operational standardized terms provides an optimal platform for communication across healthcare providers involved in JIA-TMJ arthritis management.publishersversionPeer reviewe

Effect of silver nanoparticles on the physicochemical and antimicrobial properties of an orthodontic adhesive

ABSTRACT Orthodontic treatment with fixed brackets plays a major role on the formation of white spot lesions. Objective This study aimed to incorporate silver nanoparticle solutions (AgNP) in an orthodontic adhesive and evaluate its physicochemical and antimicrobial properties. Material and Methods Silver nanoparticle solutions were added to a commercial adhesive in different concentrations (w/w): 0%, 0.11%, 0.18%, and 0.33%. Shear bond strength (SBS) test was performed after bonding metal brackets to enamel. Raman spectroscopy was used to analyze in situ the degree of conversion (DC) of the adhesive layer. The surface free energy (SFE) was evaluated after the measurement of contact angles. Growth inhibition of Streptococcus mutans in liquid and solid media was determined by colony-forming unit count and inhibition halo, respectively. One-way ANOVA was performed for SBS, DC, SFE, and growth inhibition. Results The incorporation of AgNP solution decreased the SBS (p<0.001) and DC in situ (p<0.001) values. SFE decreased after addition of 0.18% and 0.33% AgNP. Growth inhibition of S. mutans in liquid media was obtained after silver addition (p<0.05). Conclusions The addition of AgNP solutions to Transbond&#8482; XT adhesive primer inhibited S. mutans growth. SBS, DC, and SFE values decreased after incorporation up to 0.33% AgNP solution without compromising the chemical and physical properties of the adhesive

Relationship between disease course in the temporomandibular joints and mandibular growth rotation in patients with juvenile idiopathic arthritis followed from childhood to adulthood

<p>Abstract</p> <p>Objective</p> <p>To investigate the relationship between radiographic JIA disease course in the TMJs and mandibular growth rotation, compared with growth in healthy individuals.</p> <p>Methods</p> <p>From a larger series of JIA patients followed from childhood to adulthood, 26 were included; 11 without and 15 with bilateral radiographic TMJ involvement. Joint morphology and function were assessed at baseline, 2-, 4-, 6- and 27 years follow-up. Mandibular growth rotation (anterior, posterior or none) was assessed from cephalometric evaluations at childhood and adulthood, with observations from 16 healthy individuals as controls. TMJ disease course and mandibular growth rotation were assessed independently and their relationship analysed. Non-parametric statistical methods were applied to test differences between groups.</p> <p>Results</p> <p>In the normal TMJ group of JIA patients the joint morphology was similar at the follow-ups and all patients had good function both in childhood and in adulthood. The mandibular growth rotation was similar to that of healthy controls, i.e. predominantly in anterior direction. In the abnormal TMJ group different JIA TMJ disease courses were observed and associated with changes in the mandibular growth rotation (p = 0.007).</p> <p>Progressing JIA TMJ disease course was related to posterior mandibular growth rotation and improving disease course to anterior mandibular growth rotation.</p> <p>Conclusion</p> <p>A relationship was found between JIA disease course in the TMJs and mandibular growth rotation, suggesting that a favourable growth could be regained in patients with improvement in TMJ morphology and/or TMJ function. To confirm this, further research on larger patient series is needed.</p

Validation of the Comprehensive Feeding Practices Questionnaire with parents of 10-to-12-year-olds

Abstract Background: There is a lack of validated instruments for quantifying feeding behavior among parents of older children and adolescents. The Comprehensive Feeding Practices Questionnaire (CFPQ) is a self-report measure to assess multiple parental feeding practices. The CFPQ is originally designed for use with parents of children ranging in age from about 2 to 8 years. It is previously validated with American and French parents of children within this age range. The aim of the present study was to adapt and test the validity of this measure with parents of older children (10-to-12-year-olds) in a Norwegian setting. Methods: A sample of 963 parents of 10-to-12-year-olds completed a Norwegian, slightly adapted version of the CFPQ. Scale analyses were performed to test the validity of the instrument in our sample. Results: Although a few problematic items and scales were revealed, scale analyses showed that the psychometric properties of the slightly adapted, Norwegian version of the CFPQ were surprisingly similar to those of the original CFPQ. Conclusions: Our results indicated that the CFPQ, with some small modifications, is a valid tool for measuring multiple parental feeding practices with parents of 10-to12-year-olds