Plaque Research Today is a free monthly online journal that collates and summarizes the latest research about Plaque, including details on dentistry, brushing, oral hygiene, mouthwash.

Horizontal transmission of mutans streptococci in children.

Doméjean S, Zhan L, DenBesten PK, Stamper J, Boyce WT, Featherstone JD

Faculté d'Odontologie, EA3847, CHU, Clermont-Ferrand, France.

It has not been established whether transmission of mutans streptococci occurs between unrelated children older than 4 years of age. The aim of the study was to investigate the possible transmission of mutans streptococci genotypes from child to child in kindergarten. We studied 96 children (ages 5-6 yrs) in three San Francisco Bay Area public schools. Mutans streptococci colonies from each child were isolated from selective culture on Mitis Salivarius Sucrose Bacitracin agar. We used arbitrary primed polymerase chain reactions to determine the mutans streptococci genotypes. Two children (not siblings) in each of the three schools (6%) shared an identical amplitype of S. mutans, unique to each pair. The 19 S. sobrinus amplitypes were found in 12 children, and all were unique to each child. The presence of matching genotypes of S. mutans demonstrates horizontal transmission of this species between unrelated children aged 5-6 years.

Published 16 December 2009 in J Dent Res, 89(1): 51-5.
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Articles on Plaque published 16 December 2009:

Oral biofilms: emerging concepts in microbial ecology.   J Dent Res, 89(1): 8-18.

Oral biofilms develop under a range of different conditions and different environments. This review will discuss emerging concepts in microbial ecology and how they relate to oral biofilm development and the treatment of oral diseases. Clues to how oral biofilms develop may lie in other complex systems, such as interactions between host and gut microbiota, and even in factors that affect biofilm development on leaf surfaces. Most of the conditions under which oral biofilms develop are tightly ... [Abstract] [Full-text]

Articles on Plaque published 15 October 2009:

Bacterial interactions in dental biofilm development.   J Dent Res, 88(11): 982-90.

Recent analyses with ribosomal RNA-based technologies have revealed the diversity of bacterial populations within dental biofilms, and have highlighted their important contributions to oral health and disease. Dental biofilms are exceedingly complex and multispecies ecosystems, where oral bacteria interact cooperatively or competitively with other members. Bacterial interactions that influence dental biofilm communities include various different mechanisms. During the early stage of biofilm ... [Abstract] [Full-text]

Articles on Plaque published 13 October 2009:

Codistribution of amyloid beta plaques and spongiform degeneration in familial Creutzfeldt-Jakob disease with the E200K-129M haplotype.   Arch Neurol, 66(10): 1240-6.

BACKGROUND: Dominantly inherited Creutzfeldt-Jakob disease (CJD) represents 5% to 15% of all CJD cases. The E200K mutation in the prion protein (PrP) gene (PRNP) is the most frequent cause of familial CJD. Coexistent amyloid beta (Abeta) plaques have been reported in some transmissible spongiform encephalopathies but to date have not been reported in familial CJD with the E200K mutation. OBJECTIVE: To characterize a family with CJD in which Abeta plaques codistribute with spongiform ... [Abstract] [Full-text]

Articles on Plaque published 8 October 2009:

A reporter of local dendritic translocation shows plaque- related loss of neural system function in APP-transgenic mice.   J Neurosci, 29(40): 12636-40.

Although neuronal communication is thought to be summated within local dendritic segments, no technique is currently available to monitor activity in vivo at this level of resolution. To overcome this challenge, we developed an optical reporter of neuronal activity using the coding sequence of Venus, flanked by short stretches of the 5'- and 3'-untranslated regions from calcium/calmodulin-dependent kinase IIalpha (CAMKIIalpha). This reporter takes advantage of the fact that CAMKIIalpha mRNA is ... [Abstract] [Full-text]

Articles on Plaque published 28 September 2009:

Impact of hydrodynamics on oral biofilm strength.   J Dent Res, 88(10): 922-6.

Mechanical removal of oral biofilms is ubiquitously accepted as the best way to prevent caries and periodontal diseases. Removal effectiveness strongly depends on biofilm strength. To investigate the influence of hydrodynamics on oral biofilm strength, we grew single- and multi-species biofilms of Streptococcus oralis J22, Actinomyces naeslundii TV14-J1, and full dental plaque at shear rates ranging from 0.1 to 50 1/sec and measured their compressive strength. Subsequently, biofilm architecture ... [Abstract] [Full-text]

Articles on Plaque published 15 September 2009:

Accumulation of reelin-positive plaques is accompanied by a decline in basal forebrain projection neurons during normal aging.   Eur J Neurosci, 30(6): 1064-76.

Besides its critical role during neurodevelopment, the extracellular glycoprotein reelin is also a pivotal regulator of adult synaptic function and plasticity, and altered reelin-mediated signalling has been suggested to contribute to neuronal dysfunction associated with Alzheimer's disease. We have recently discovered, in aged rodents and non-human primates, a pronounced decline in reelin-positive interneurons and concomitant accumulation of reelin in extracellular amyloid-like deposits, both ... [Abstract] [Full-text]

Articles on Plaque published 11 September 2009:

Transglutaminases and transglutaminase-catalyzed cross-links colocalize with the pathological lesions in Alzheimer's disease brain.   Brain Pathol, 19(4): 612-22.

Alzheimer's disease (AD) is characterized by pathological lesions, in particular senile plaques (SPs), cerebral amyloid angiopathy (CAA) and neurofibrillary tangles (NFTs), predominantly consisting of self-aggregated proteins amyloid beta (Abeta) and tau, respectively. Transglutaminases (TGs) are inducible enzymes, capable of modifying conformational and/or structural properties of proteins by inducing molecular covalent cross-links. Both Abeta and tau are substrates for TG cross-linking ... [Abstract] [Full-text]

Articles on Plaque published 9 September 2009:

Conversion of amyloid positive and negative MCI to AD over 3 years: an 11C-PIB PET study.   Neurology, 73(10): 754-60.

BACKGROUND: Patients with amnestic mild cognitive impairment (MCI) represent an important clinical group as they are at increased risk of developing Alzheimer disease (AD). (11)C-PIB PET is an in vivo marker of brain amyloid load. OBJECTIVE: To assess the rates of conversion of MCI to AD during a 3-year follow-up period and to compare levels of amyloid deposition between MCI converters and nonconverters. METHODS: Thirty-one subjects with MCI with baseline (11)C-PIB PET, MRI, and ... [Abstract] [Full-text]

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