No abstract

No abstract

The acquisition of drug resistance and virulence by staphylococcal species colonizing humans is a growing public health concern. The present study was conducted to investigate the prevalence, antimicrobial resistance and genetic characteristics of Staphylococcus isolates from the oral cavity and skin (hand) of systemically healthy subjects with dental disease and dental staff in northern Japan. Among a total of 133 subjects (91 patients and 42 staff), 87 coagulase-positive Staphylococcus (83 S. aureus/4 S. argenteus) and 162 coagulase-negative Staphylococcus (CoNS) isolates were recovered from 59 (44.4%) and 95 (71.4%) subjects, respectively. Three oral isolates were methicillin-resistant S. aureus (MRSA) (3.6%, 3/83) that were genotyped as ST8-SCCmec-IVl, ST4775(CC1)-SCCmec-IVa and ST6562(CC8)-SCCmec-IVa. Remarkably, the ST6562 isolate harbored PVL genes on ΦSa2usa and type I ACME (arginine catabolic mobile element). Four methicillin-susceptible isolates were identified as S. argenteus belonging to ST1223 and ST2250, which harbored enterotoxin genes egc-2 and sey, respectively. Among the fourteen CoNS species identified, methicillin-resistant (MR) isolates were detected in five species (11 isolates, 13.3% of CoNS), with S. saprophyticus and S. haemolyticus being the most common. ACME was prevalent in only S. epidermidis and S. capitis. These findings indicated the potential distribution of USA300 clone-like MRSA, toxigenic S. argenteus and MR-CoNS in the oral cavity of dental patients.

The spread of methicillin resistance and virulence among staphylococci in the community poses a public health concern. In this study, we investigated the prevalence of Staphylococcus species colonizing the oral cavity and hand (skin) of healthy university students and their phenotypic and genetic characteristics in northern Japan. Among a total of 332 subjects, 6 and 110 methicillin-resistant and susceptible Staphylococcus aureus (MRSA and MSSA, respectively) isolates were recovered from 105 subjects. MRSA isolates were genotyped as CC5, CC8, CC45, and CC59 with SCCmec-IIa or IV, among which an isolate of ST6562 (single-locus variant of ST8) harbored SCCmec-IVa, PVL genes and ACME-I, which are the same traits as the USA300 clone. ST1223 S. argenteus was isolated from the oral cavity and hand of a single student. Coagulase-negative Staphylococcus (CoNS) was recovered from 154 subjects (172 isolates), and classified into 17 species, with S. capitis being the most common (38%), followed by S. warneri (24%) and S. epidermidis (15%), including nine mecA-positive isolates. S. capitis was differentiated into seven clusters/subclusters, and genetic factors associated with the NRCS-A clone (nsr, tarJ, ebh) were detected in 10–21% of isolates. The colonization of the USA300-like MRSA variant and S. capitis with the traits of the NRCS-A clone in healthy individuals was noteworthy.

The aim of this study was to determine the variation in mineral ions (Ca and P) concentrations in 2-day dental plaque taken from different areas of the deciduous and the permanent dentition that may be related to the caries status of tooth surfaces obtained from children and young adults. We also compared those minerals between the deciduous and the permanent dentition. Plaque samples were collected from eight dentition sites, including the upper-anterior-buccal (UAB) and-lingual (UAL), lower-anterior-buccal (LAB) and-lingual (LAL), upper-posterior-buccal (UPB) and-lingual (UPL), lower-posterior-buccal (LPB) and-lingual (LPL) regions. Significant differences among these eight different sites were determined from Ca and P ions concentrations, as well as the Ca/P ratio, calculated by ANOVA. Plaque associated with the LAL region closest to the main salivary ducts and that is less prone to caries, had significantly higher levels of Ca, P ions concentrations, a higher Ca/P ratio than any other dentition areas in both children and young adult subjects. Statistical differences were seen in minerals between children and young adults. Ca ion concentrations in dental plaque from young adults were significantly higher than those of children at the LAL site. Statistical analysis of the relationships between Ca and P ions showed that there were strong associations between Ca and P ions, especially in the UPB, LAL and LPL regions where there is a high exposure to saliva. We conclude that there is a site-specificity of plaque mineral content in both children and young adults, which may reflect the differences in exposure to saliva, resulting in differences in the local cariostatic challenge. tooth surface such as saliva or dental plaque fluid. Importantly, the DS of plaque fluid is directly related to not only pH but also Ca and P ions concentrations which are common ion constituents of enamel hydroxyapatite 1). The release of these ions into the plaque-fluid phase, following bacterial acid production, can reduce the driving force for demineralization by increasing DS of plaque fluid with respect to enamel mineral. Increasing the concentrations of mineral ions in dental plaque should therefore reduce its own caries-forming potential. Our previous study showed that 4-day plaque samples from young adults, associated with the lower anterior lingual site, which

Background: Single-blind, nine case comparative studies were conducted to evaluate salivary fluoride concentrations following toothbrushing using experimental toothpastes containing Surface Pre-Reacted Glass-ionomer (S-PRG) fillers. Preliminary tests were conducted in order to determine the volume of usage as well as the concentrations (wt%) of S-PRG filler. Based on the results given these experiments, we compared the salivary fluoride concentrations following toothbrushing with 0.5 g of 4 different types of toothpastes: 5 wt % S-PRG filler, 1400 ppm F AmF (amine fluoride), 1500 ppm F NaF (sodium fluoride), and MFP (monofluorophosphate) containing toothpaste. Methods: Of the 12 participants, 7 participated in the preliminary study and 8 participated in the main study. All participants brushed their teeth using the scrubbing method for 2 minutes. At first 1.0 and 0.5 g of 20 wt % S-PRG filler toothpastes were used to compare, then followed by 0.5 g of 0 (control), 1, and 5 wt % S-PRG toothpastes, respectively. ThepParticipants spat out once and rinsed with 15 mL of distilled water for 5 seconds. Saliva was collected for 3 minutes each at different time intervals of 0 (baseline), 5, 10, 15, 30, 60, 120, and 180 minutes (min) after the rinsing. Fluoride concentrations were determined using a fluoride-electrode, and the area under the curve (AUC: ppm‧min) of each toothpaste was calculated as the salivary fluoride retention. The main study was then conducted to evaluate the salivary fluoride concentrations as well as the AUC value using 0.5 g of 5 wt % S-PRG filler toothpaste, followed by NaF, MFP, and AmF toothpaste. Results: Since there were no statistical differences between using 1.0 g and 0.5 g of 20 wt % S-PRG toothpastes in salivary fluoride concentrations as well as the AUC value throughout the 180 min measurement, the volume was set as 0.5 g for the following studies. Concentrations of 5 and 20 wt % S-PRG toothpastes retained 0.09 ppm F or more in saliva even after 180 min. No statistical differences were seen in the salivary fluoride concentrations at any time intervals as well as the AUC value between 5 and 20 wt % S-PRG toothpastes. Based on these results, the concentration of 5 wt % S-PRG toothpaste was used for the main comparative study. MFP toothpaste resulted in by far the lowest salivary fluoride concentrations (0.06 ppm F at 180 min) and the AUC value (24.6 ppm‧min), whereas 5 wt % S-PRG toothpaste (0.15 ppm F at 180 min, 92.3 ppm‧min) displayed retention on par with AmF toothpaste which appeared to result in higher values (0.17 ppm F at 180 min, 103 ppm‧min), compared to NaF toothpaste (0.12 ppm F at 180 min, 49.3 ppm‧min). Conclusions: The salivary fluoride concentrations following toothbrushing with 0.5 g of 5 wt % S-PRG filler containing toothpaste showed retention similar to the best performing 1400 ppm F AmF toothpaste even 180 min after toothbrushing.

No abstract

SummaryAn association between dermatomyositis-polymyositis and malignancy has been reported. However, controversy exists regarding a direct causal relationship between the two diseases. We describe a patient who had the concurrent onset and paralled clinical course of dermatomyositis and malignancy, and discuss the possible mechanisms for the association of the two disorders .