Current knowledge among Japanese experienced general dentists regarding prevention of infective endocarditis.

Infective endocarditis (IE), a life-threatening condition predominantly occurring in patients with underlying heart disease, is mainly caused by bacteremia induced by invasive dental treatment. However, the amount of related information shared between cardiologists and dentists appears to be inadequate. In the present study, a survey regarding prevention of IE, composed of 13 major questions, 2 of which also allowed free comments, was sent to approximately 3000 dentists belonging to a prefectural dental association in Japan.

A Potential New Risk Factor for Stroke: Streptococcus Mutans With Collagen-Binding Protein.

Background: Among human oral bacteria, particular kinds of Streptococcus mutans (SM) known as dental caries pathogens contain a collagen-binding protein, Cnm, and show platelet aggregation inhibition and matrix metalloproteinase-9 activation. We have previously reported that these strains may be a risk factor for intracerebral hemorrhage. As a major sample-providing hospital, we report the clinical details, including intracranial aneurysms and ischemic stroke.

Variation of expression defects in cell surface 190-kDa protein antigen of Streptococcus mutans.

Streptococcus mutans, which consists of four serotypes, c, e, f, and k, possesses a 190-kDa cell surface protein antigen (PA) for initial tooth adhesion. We used Western blot analysis to determine PA expression in 750 S. mutans isolates from 150 subjects and found a significantly higher prevalence of the isolates with PA expression defects in serotypes f and k compared to serotypes c and e.

Contribution of the interaction of Streptococcus mutans serotype k strains with fibrinogen to the pathogenicity of infective endocarditis.

Streptococcus mutans, a pathogen responsible for dental caries, is occasionally isolated from the blood of patients with bacteremia and infective endocarditis (IE). Our previous study demonstrated that serotype k-specific bacterial DNA is frequently detected in S. mutans-positive heart valve specimens extirpated from IE patients.

Identification and functional analysis of an ammonium transporter in Streptococcus mutans.

Streptococcus mutans, a Gram-positive bacterium, is considered to be a major etiologic agent of human dental caries and reported to form biofilms known as dental plaque on tooth surfaces. This organism is also known to possess a large number of transport proteins in the cell membrane for export and import of molecules. Nitrogen is an essential nutrient for Gram-positive bacteria, though alternative sources such as ammonium can also be utilized.

Role of ABC transporter proteins in stress responses of Streptococcus mutans.

Streptococcus mutans possesses a number of ATP-binding cassette (ABC) transporters, which function as multiple sugar metabolism transporters and are promising targets for antimicrobial strategies. In the present study, we performed functional analyses of SMu0836 and SMu0837 products, which are possible ABC transporters. Isogenic mutant strains Δ0836 and Δ0837 were generated by insertional inactivation of SMu0836, and SMu0837, respectively, of strain MT8148 and found to be more sensitive to antibiotics as compared to MT8148.

[Accuracy estimation of non-invasive X-ray output analyzer].

This study estimated the accuracy of an X-ray analyzer by comparing it with an ionization chamber and a tube voltage current meter, and investigated whether it was usable as a substitute for a reference meter for output measurements for quality control purposes. The X-ray output analyzer used was a Piranha (RTI Electronics), a non-invasive instrument. The two subjects of measurements were as follows: the tube voltage, exposure, and half-value layer used in ordinary X-ray radiographic system equipment, and the exposure and half-value layer in X-ray equipment for mammographic systems.

Distribution of amoxicillin-resistant oral streptococci in dental plaque specimens obtained from Japanese children and adolescents at risk for infective endocarditis.

Background: Infective endocarditis (IE) is known to be a life-threatening disease and prevention of its onset is important. Oral amoxicillin (AMPC) is generally prescribed to patients at risk for IE prior to undergoing risky procedures, such as invasive dental treatments. We previously found that approximately 5% of systemically healthy Japanese subjects harbor strains highly resistant to AMPC.

Multilocus sequence typing of Streptococcus mutans strains with the cbm gene encoding a novel collagen-binding protein.

Objective: Streptococcus mutans, an oral pathogen associated with infective endocarditis (IE), possesses two genes encoding collagen-binding proteins, namely cnm and cbm. In this study, we used multilocus sequence typing (MLST) of S. mutans with the cbm gene.

Successful application of atelocollagen for treatment of perforated teeth.

Objective: Cervical or furcal root perforation is a serious clinical problem and one of its treatment modalities is perforation repair with composite resin. However, many cases still progress in inevitable extraction. When primary teeth are affected, early tooth loss can cause problems related to the eruption space for the permanent successors.

Distribution and molecular characterization of Porphyromonas gulae carrying a new fimA genotype.

Porphyromonas gulae is a gram-negative black-pigmented anaerobe which is known to be a pathogen for periodontitis in dogs. Approximately 41kDa filamentous appendages on the cell surface (FimA) encoded by the fimA gene are regarded as important factors associated with periodontitis. The fimA genotype was classified into two major types and strains in type B were shown to be more virulent than those in type A.

Complete genome sequence of the serotype k Streptococcus mutans strain LJ23.

Streptococcus mutans is the major pathogen of dental caries and occasionally causes infective endocarditis. Here we report the complete genome sequence of serotype k S. mutans strain LJ23, which was recently isolated from the oral cavity of a Japanese patient.

Infection of specific strains of Streptococcus mutans, oral bacteria, confers a risk of ulcerative colitis.

Although oral bacteria-associated systemic diseases have been reported, association between Streptococcus mutans, pathogen of dental caries, and ulcerative colitis (UC) has not been reported. We investigated the effect of various S. mutans strains on dextran sodium sulfate (DSS)-induced mouse colitis.

Trps1 is necessary for normal temporomandibular joint development.

Mutation of the human TRPS1 gene leads to trichorhinophalangeal syndrome (TRPS), which is characterized by an abnormal development of various organs including the craniofacial skeleton. Trps1 has recently been shown to be expressed in the jaw joints of zebrafish; however, whether Trps1 is expressed in the mammalian temporomandibular joint (TMJ), or whether it is necessary for TMJ development is unknown. We have analyzed (1) the expression pattern of Trps1 during TMJ development in mice and (2) TMJ development in Trps1 knockout animals.

Diversity of fimbrillin among Porphyromonas gulae clinical isolates from Japanese dogs.

Porphyromonas gulae, a gram-negative black-pigmented anaerobe, is a pathogen for periodontitis in dogs. An approximately 41-kDa fimbrial subunit protein (FimA) encoded by fimA is regarded as associated with periodontitis. In the present study, the fimA genes of 17 P.

Amoxicillin-resistant oral streptococci identified in dental plaque specimens from healthy Japanese adults.

Background: Infective endocarditis (IE) is known to be a life-threatening disease and invasive dental procedures are considered to be important factors. Oral amoxicillin (AMPC) is widely used for prophylaxis in patients with heart disorders who are at risk for IE. However, there is only limited information regarding the inhibition of oral bacteria by AMPC.

Involvement of a periodontal pathogen, Porphyromonas gingivalis on the pathogenesis of non-alcoholic fatty liver disease.

Background: Non-alcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome that is closely associated with multiple factors such as obesity, hyperlipidemia and type 2 diabetes mellitus. However, other risk factors for the development of NAFLD are unclear. With the association between periodontal disease and the development of systemic diseases receiving increasing attention recently, we conducted this study to investigate the relationship between NAFLD and infection with Porphyromonas gingivalis (P.

α-Enolase of Streptococcus pneumoniae induces formation of neutrophil extracellular traps.

Streptococcus pneumoniae is the most common causative agent of community-acquired pneumonia throughout the world, with high morbidity and mortality rates. A major feature of pneumococcal pneumonia is abundant neutrophil infiltration. In this study, we identified S.

Krüppel-like factor 4 regulates membranous and endochondral ossification.

Krüppel-like factor 4 (KLF4/GKLF/EZF) is a zinc finger type of transcription factor highly expressed in the skin, intestine, testis, lung and bone. The role played by Klf4 has been studied extensively in normal epithelial development and maintenance; however, its role in bone cells is unknown. Previous reports showed that Klf4 is expressed in the developing flat bones but its expression diminishes postnatally.

Streptococcus sanguinis induces foam cell formation and cell death of macrophages in association with production of reactive oxygen species.

Streptococcus sanguinis, a normal inhabitant of the human oral cavity, is a common streptococcal species implicated in infective endocarditis. Herein, we investigated the effects of infection with S. sanguinis on foam cell formation and cell death of macrophages.

The collagen-binding protein of Streptococcus mutans is involved in haemorrhagic stroke.

Although several risk factors for stroke have been identified, one-third remain unexplained. Here we show that infection with Streptococcus mutans expressing collagen-binding protein (CBP) is a potential risk factor for haemorrhagic stroke. Infection with serotype k S.

Establishment of Streptococcus mutans in infants induces decrease in the proportion of salivary α-haemolytic bacteria.

Objective: For paediatric dentists, an indicator to assess caries risk of infants is very important. Conventionally, the number and/or proportions of Streptococcus mutans have been employed as risk indicator; however, because such figures reflect the existing situation, they are not suitable for assessing caries risk of infants that have not yet been infected with S. mutans.

Molecular detection of human periodontal pathogens in oral swab specimens from dogs in Japan.

Periodontal diseases are known to be major diseases in humans, and are also common in dogs. The purpose of the present study was to analyze the distribution of periodontitis-related bacterial species using oral swab specimens collected from 26 pet dogs. The distribution of an animal gingival organism Porphyromonas gulae, in addition to 10 human periodontitis-related bacterial species, including Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Capnocytophaga ochracea, Capnocytophaga sputigena, Prevotella intermedia, Prevotella nigrescens, Aggregatibacter actinomycetemcomitans, Campylobacter rectus, and Eikenella corrodens, were evaluated by polymerase chain reaction with species-specific sets of primers.

Distribution of oral streptococci highly resistant to amoxicillin in dental plaque specimens from Japanese children and adolescents.

Oral streptococci are major pathogens of infective endocarditis. Prophylactic antibiotics are commonly given to subjects with certain kinds of heart disorders when invasive dental treatments are performed, with amoxicillin (AMPC) being widely used for this purpose. However, there is little information regarding AMPC-resistant oral streptococci.

Multilocus sequence typing analysis of Streptococcus mutans strains with the cnm gene encoding collagen-binding adhesin.

Streptococcus mutans is one of the oral pathogens associated with infective endocarditis (IE). With respect to bacterial binding ability to the extracellular matrix, the Cnm protein, a cell surface collagen-binding adhesin of S. mutans, is known as one of the possible virulence factors with regard to IE.