J Med Microbiol Email Content Delivery
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Google Scholar
Right arrow Articles by Nemoto, H.
Right arrow Articles by Ooshima, T.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nemoto, H.
Right arrow Articles by Ooshima, T.
Agricola
Right arrow Articles by Nemoto, H.
Right arrow Articles by Ooshima, T.
J Med Microbiol 57 (2008), 891-895; DOI: 10.1099/jmm.0.47836-0
© 2008 Society for General Microbiology
ISSN 1473-5644

Molecular characterization of Streptococcus mutans strains isolated from the heart valve of an infective endocarditis patient

Hirotoshi Nemoto, Kazuhiko Nakano, Ryota Nomura and Takashi Ooshima

Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan

Correspondence
Kazuhiko Nakano
nakano{at}dent.osaka-u.ac.jp

Received 22 December 2007
Accepted 7 February 2008

Streptococcus mutans, known to be an aetiological agent of dental caries, is occasionally isolated from patients with infective endocarditis (IE). S. mutans strains with a defect in all three types of glucosyltransferase (GTF) obtained from an infected heart valve extirpated from an IE patient have been reported previously. In this study, molecular analyses of strains detected in heart valve (strain V1) and dental plaque (strain P1) samples taken from the same patient were performed. Complete nucleotide alignments of the gtfB, gtfC and gtfD regions in strains V1 and P1, as well as in the reference strain MT8148, were determined, which revealed the existence of alignments with a high similarity to erythromycin- and spectinomycin-resistance genes in the middle of the gtfB–gtfC and gtfD genes, respectively, of V1. Strain V1 also showed a higher MIC for these two antibiotics compared with strain P1. Next, primers to detect the specific sequences of the antibiotic-resistance genes in strain V1 were constructed and PCR amplification was performed with template DNA from dental plaque and infected valve tissue samples taken from the patient. Attenuated expression of GTFs in V1 caused a significantly lower susceptibility to phagocytosis by human polymorphonuclear leukocytes compared with the reference strain. These results suggest that the blood isolate V1 found in the oral cavity invaded and survived in the bloodstream for a long duration and that this was related to its virulence in IE in our patient.

Abbreviations: GTF, glucosyltransferase; IE, infective endocarditis.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
INT J SYST EVOL MICROBIOL J MED MICROBIOL MICROBIOLOGY J GEN VIROL ALL SGM JOURNALS
Copyright © 2008 Society for General Microbiology.