title: Experimental infective endocarditis induced by human supragingival dental plaque in rats.
abstract: Human dental plaque is thought to contribute to disease, not only in the oral cavity but also at other body sites. To investigate the pathogenicity of dental plaque in tissues remote from the mouth, we examined the ability of human supragingival dental plaque to induce infective endocarditis (IE) in rats. In total, 15 out of 27 catheterized rats survived after intravenous injections with human supragingival dental plaque suspensions containing 3 x 10(6) colony-forming units (CFU) of bacterial cells. In surviving rats, infected vegetations were formed in all except one rat. The microbial composition of the infected vegetations was different from that of the respective dental plaque inocula, with Streptococcus oralis comprising the majority of the isolates. In rats affected with endocarditis, the aortic sinus was filled with fibrinous vegetation containing bacteria. Inflammatory cells infiltrated the aortic valve, the aorta adjacent to the valve, and the cardiac muscles. The inoculation of catheterized rats with a cell suspension of S. oralis isolate (5 x 10(6) CFU) was not lethal but capable of inducing endocarditis in all animals. The results suggest that if dental plaque were introduced into the bloodstream, it could serve as a potent source of bacteria causing IE in humans.
authors.affiliation: Department of Preventive Dentistry, Kagoshima University Graduate School of Medical and Dental Sciences, Sakuragaoka, Kagoshima, Japan. emi@denta.hal.kagoshima-u.ac.jp
authors.forename: Emi
authors.initials: E
authors.lastname: Nagata
authors.forename: Hidehito
authors.initials: H
authors.lastname: Okayama
authors.forename: Hiro-O
authors.initials: HO
authors.lastname: Ito
authors.forename: Ichiro
authors.initials: I
authors.lastname: Semba
authors.forename: Masakazu
authors.initials: M
authors.lastname: Inoue
authors.forename: Takahiko
authors.initials: T
authors.lastname: Oho
mesh_terms: D000328:Adult; D000818:Animals; D001021:Aortic Valve / Q000382:microbiology* / Q000473:pathology; D016470:Bacteremia / Q000150:complications* / Q000382:microbiology; D018441:Biofilms; D003773:Dental Plaque / Q000150:complications* / Q000382:microbiology; D004195:Disease Models, Animal; D004696:Endocarditis / Q000382:microbiology* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012850:Sinus of Valsalva / Q000382:microbiology / Q000473:pathology; D019533:Streptococcus oralis / Q000302:isolation & purification / Q000472:pathogenicity*