Differentiation of banding patterns between Streptococcus mutans and Streptococcus sobrinus isolates in rep-PCR using ERIC primer

Streptococcus mutans and Streptococcus sobrinus are considered to be important bacterial species in the initiation of human dental caries. Therefore, the establishment of a reliable genotyping method to distinguish S. mutans from S. sobrinus is of central importance.We assessed the usefulness of repetitive extragenic palindromic polymerase chain reaction (rep-PCR) using ERIC primer banding patterns in differentiating S. mutans and S. sobrinus.Five S. mutans and two S. sobrinus prototype strains and 50 clinical isolates (38 S. mutans serotype c, 4 S. sobrinus serotype d, and 8 S. sobrinus serotype g) were examined. The banding patterns of amplicons generated were compared among the prototype strains and clinical isolates, to find common bands that distinguish S. mutans and S. sobrinus.Multiple banding patterns were seen with all strains tested. The representative strains of S. mutans tested revealed six unique, strong bands at 2,000 bp, 1,700 bp, 1,400 bp, 1,100 bp, 850 bp, and 250 bp, whereas S. sobrinus had seven strong bands at 2,000 bp, 1,800 bp, 1,100 bp, 900 bp, 800 bp, 600 bp, and 550 bp. The band at 1,100 bp was the only band that was observed in both S. mutans and S. sobrinus. Furthermore, most clinical S. mutans isolates revealed identical banding patterns. All S. mutans had amplicons at 1,700 bp, 850 bp, and 250 bp, whereas those of S. sobrinus were at 1,100 bp, 900 bp, and 800 bp.These results indicate that using rep-PCR with the ERIC primers can distinguish between S. mutans and S. sobrinus

Reporting stAndards for research in PedIatric Dentistry (RAPID):an expert consensus-based statement

Abstract Background Reporting guidelines for different study designs are currently available to report studies with accuracy and transparency. There is a need to develop supplementary guideline items that are specific to areas within Pediatric Dentistry. This study aims to develop Reporting stAndards for research in PedIatric Dentistry (RAPID) guidelines using a pre-defined expert consensus-based Delphi process. Methods The development of the RAPID guidelines was based on the Guidance for Developers of Health Research Reporting Guidelines. Following a comprehensive search of the literature, the Executive Group identified ten themes in Pediatric Dentistry and compiled a draft checklist of items under each theme. The themes were categorized as: General, Oral Medicine, Pathology and Radiology, Children with Special Health Care Needs, Sedation and Hospital Dentistry, Behavior Guidance, Dental Caries, Preventive and Restorative Dentistry, Pulp Therapy, Traumatology, and Interceptive Orthodontics. A RAPID Delphi Group (RDG) was formed comprising of 69 members from 15 countries across six continents. Items were scored using a 9-point rating Likert scale. Items achieving a score of seven and above, marked by at least 70% of RDG members were accepted into the RAPID checklist items. Weighted mean scores were calculated for each item. Statistical significance was set at p < 0.05 and one-way ANOVA was used to calculate the difference in the weighted mean scores between the themes. Results The final RAPID checklist comprised of 128 items that were finalized and approved by the RDG members in the online consensus meeting. The percentage for high scores (scores 7 to 9) ranged from 69.57 to 100% for individual items. The overall weighted mean score of the final items ranged from 7.51 to 8.28 (out of 9) and the difference was statistically significant between the themes (p < 0.05). Conclusions The RAPID statement provides guidance to researchers, authors, reviewers and editors, to ensure that all elements relevant to particular studies are adequately reported

Mechanistic insights into GPCR–G protein interactions

G protein-coupled receptors (GPCRs) respond to extracellular stimuli and interact with several intracellular binding partners to elicit cellular responses, including heterotrimeric G proteins. Recent structural and biophysical studies have highlighted the dynamic nature of GPCRs and G proteins and have identified specific conformational changes important for receptor-mediated nucleotide exchange on Gα. While domain separation within Gα is necessary for GDP release, opening the inter-domain interface is insufficient to stimulate nucleotide exchange. Rather, an activated receptor promotes GDP release by allosterically disrupting the nucleotide-binding site via interactions with the Gα N- and C-termini. Highlighting the allosteric nature of GPCRs, recent studies suggest that agonist binding alone poorly stabilizes an active conformation of several receptors. Rather, full stabilization of the receptor in an active state requires formation of the agonist-receptor-G protein ternary complex. In turn, nucleotide-free Gα is able to stabilize conformational changes around the receptor’s agonist-binding site to enhance agonist affinity