The involvement of oral bacteria in the pathogenesis of cardiovascular diseases has been the focus of attention in many studies, and several periodontal pathogens have been detected in diseased cardiovascular lesions, suggesting relationships between oral microorganisms and cardiovascular diseases. However, no information is available regarding the involvement of cariogenic pathogens such as Streptococcus mutans. The presence of oral streptococcal species and periodontitis-related bacteria in 35 heart valve and 27 atheromatous plaque clinical specimens, as well as 32 dental plaque specimens from the same subjects, was analyzed using a PCR method. Furthermore, broad-range PCR with DNA sequencing analysis was employed to identify the bacterial species in those samples. Streptococcus mutans was frequently detected in the heart valve (69%) and atheromatous plaque (74%) specimens, while other bacterial species, including those related to periodontitis, were detected with much lower frequencies. The bacterial composition in cardiovascular tissues was found to be markedly distinct from that in dental plaque, with only a limited number of species, including S. mutans, in the cardiovascular regions shown to have possibly originated from the oral cavity. Semiquantitative assay results revealed that S. mutans was detected in significant quantities in the heart valve (40%) and atheromatous plaque (48%) specimens, whereas the quantities of all other tested bacterial species, including several related to periodontitis, were negligible in the cardiovascular samples. These results indicate that S. mutans is a possible causative agent of cardiovascular disease.Accumulated evidence suggests that oral bacterial pathogens are associated with several kinds of systemic diseases, such as infective endocarditis (IE), cardiovascular diseases, bacterial pneumonia, low birth weight, and diabetes mellitus (12). Those associations are speculated to be initiated by transient or prolonged bacteremia caused by oral infection: i.e., from professional dental treatments and daily oral care practices such as tooth brushing and flossing, as well as from food chewing, which possibly induces dissemination of oral bacteria into the bloodstream (21). Oral streptococcal species are major components of the oral microflora that are known to occasionally cause bacteremia and IE (13). Streptococcus mutans, a major pathogenic agent of dental caries, has also been isolated from the blood of patients with IE, strongly suggesting a close relationship of the pathogen with IE (5, 23, 24).The recent development of several molecular techniques has enabled prompt identification of targeted bacterial species in specimens with significantly improved specificity and sensitivity. PCR methods using primers constructed with a species-specific nucleotide alignment are widely used for the detection of specific species. In addition, broad-range eubacterial PCR with amplification of bacterial DNA and subsequent direct sequencing is considered to be a reliable diagnostic tool ...

Our results suggest that specific oral bacterial species, such as S. mutans and A. actinomycetemcomitans, are related to bacteremia and may be etiologic factors for the development of cardiovascular diseases.

AGEs may be factors associated with diabetic periodontitis and may be useful as biomarkers that reflect such deterioration.

No abstract

Streptococcus mutans, known to be an aetiologic agent of dental caries, also causes infective endocarditis (IE), although a comparison of isolates from the oral cavity and infected heart valve of the same patient has not been reported. In the present study, infected heart valve and dental plaque samples from a patient with IE were analysed. Broad-range PCR with DNA sequencing revealed that 50 clones from the dental plaque isolates were composed of oral streptococci and periodontopathic bacteria, whereas only Streptococcus mutans was detected in 50 clones from the heart valve. Eighteen strains of Streptococcus mutans were isolated from dental plaque and seven from the heart valve, and the biochemical properties of each were in accordance with those of Streptococcus mutans. DNA fingerprinting analysis revealed that all the oral isolates of Streptococcus mutans had similar patterns, which were different from those of the isolates from the infected heart valve. Western blotting using glucosyltransferase (GTF)-specific antiserum showed that the seven strains from the heart valve lacked the three types of intact GTF. In addition, the sucrose-dependent adhesion rates of these isolates were significantly lower than those of the oral isolates (P<0?001). Furthermore, the isolates from the heart valve were less susceptible to erythromycin and kanamycin. These results indicate that the properties of the Streptococcus mutans strains isolated from the infected valve were different from those of typical oral strains, which may be related to the effects of IE. INTRODUCTIONOral streptococci, which are major members of oral flora, frequently cause bacteraemia and infective endocarditis (IE) (Douglas et al., 1993). In 26 studies published between 1993 and 2003, 3784 cases of IE were presented, in which oral streptococci were considered to be involved in 21 %, second highest in frequency to Staphylococcus aureus (Moreillon & Que, 2004). According to a review of 848 IE cases in Japan, the most common type of micro-organism isolated from patient samples was Gram-positive streptococci (93?1 %), among which oral streptococci were frequently detected at a prevalence of 38?6 % (Nakatani et al., 2003). Streptococcus mutans, a major cause of dental caries, has occasionally been isolated from the blood of patients with IE and several case reports regarding the association of Streptococcus mutans and IE have been presented (Vose et al., 1987;Ullman et al., 1988;Gauduchon et al., 2001).The complete genome of Streptococcus mutans strain UA159 has been sequenced and was shown to be composed of approximately 2 million base pairs containing nearly 2000 open reading frames (Ajdić et al., 2002). Among them, three types of glucosyltransferase (GtfB, GtfC and GtfD) and protein antigen c (PAc) are known to be major cell surface proteins. In the case of IE, GtfB, GtfC and GtfD are known to induce the production of cytokines, such as interleukin-6 (IL-6) from monocytes (Shun et al., 2005). Several reports have discussed the association of PAc with IE, a...