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Oral Colonization (oral + colonization)

Distribution by Scientific Domains
Medical Sciences87%

Selected Abstracts

Oral colonization by Lactobacillus reuteri ATCC 55730 after exposure to probiotics

INTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 5 2009
ESBER ÇAGLAR
Objective., The aim of this study was to investigate whether Lactobacillus reuteri ATCC 55730 can be detected in the oral cavity after discontinuation of administration of a product prepared with this bacterium. Materials and Methods., The study consisted of three 2-week periods: clearance period, intervention period, and post-treatment period. Twenty-five volunteers consumed a chewable tablet of L. reuteri ATCC 55730 (108 cfu/tablet) during a 14-day trial period. Saliva samples were collected and cultured onto MRS agar after a clearance period of 2 weeks and then daily after a 2-week intervention period for as long as L. reuteri was found. Lactobacillus reuteri colonies were analysed in saliva samples. The analysis was performed using selective media for L. reuteri followed by confirmation using the specific detection of reuterin produced by L. reuteri. Results., The number of L. reuteri carriers decreased gradually, and after 1 week only 8% of the subjects harboured the bacterium. After 5 weeks, L. reuteri was not detected in any of the subjects. Conclusion., Consuming L. reuteri for 2 weeks does not seem to be sufficient for permanent colonization of L. reuteri in the oral cavity. [source]

Probiotics and oral health effects in children

INTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 1 2008
SVANTE TWETMAN
Background., Probiotics are living micro-organisms added to food which beneficially affect the host by improving its intestinal microbial balance. Objective., This paper aims to present a general background on probiotics and its health effects in children, and to examine the evidence for oral colonization and the possible impact on oral health in children and young adults. Methods., For delivery and general health effects, recent systematic reviews, meta-analyses, and other relevant papers were used. Concerning oral installation and oral effects, a broad search for publications in English was conducted through February 2007 in PubMed. Studies describing an installation or intervention trial in humans with a controlled design and an oral endpoint measure were considered. Fourteen papers with dental focus were identified, of which two were narrative reviews. Results., Only one study of dental interest was conducted in children. Four papers dealt with oral installation of probiotic bacteria, and although detectable levels were found in saliva shortly after intake, the studies failed to demonstrate a long-term installation. Seven papers evaluated the effect of lactobacilli- or bifidobacteria-derived probiotics on the salivary levels of caries-associated bacteria in placebo-controlled designs. All but one reported a hampering effect on mutans streptococci and/or yeast. The single study carried out in early childhood reported a significant caries reduction in 3- to 4-year-old children after 7 months of daily consumption of probiotic milk. Conclusion., Bacteriotheraphy in the form of probiotic bacteria with an inhibitory effect on oral pathogens is a promising concept, especially in childhood, but this may not necessarily lead to improved oral health. Further placebo controlled trials that assess carefully selected and defined probiotic strains using standardized outcomes are needed before any clinical recommendations can be made. [source]

The changing faces of Streptococcus antigen I/II polypeptide family adhesins

MOLECULAR MICROBIOLOGY, Issue 2 2010
L. Jeannine Brady
Summary Streptococcus mutans antigen I/II (AgI/II) protein was one of the first cell wall-anchored adhesins identified in Gram-positive bacteria. It mediates attachment of S. mutans to tooth surfaces and has been a focus for immunization studies against dental caries. The AgI/II family polypeptides recognize salivary glycoproteins, and are also involved in biofilm formation, platelet aggregation, tissue invasion and immune modulation. The genes encoding AgI/II family polypeptides are found among Streptococcus species indigenous to the human mouth, as well as in Streptococcus pyogenes, S. agalactiae and S. suis. Evidence of functionalities for different regions of the AgI/II proteins has emerged. A sequence motif within the C-terminal portion of Streptococcus gordonii SspB (AgI/II) is bound by Porphyromonas gingivalis, thus promoting oral colonization by this anaerobic pathogen. The significance of other epitopes is now clearer following resolution of regional crystal structures. A new picture emerges of the central V (variable) region, predicted to contain a carbohydrate-binding trench, being projected from the cell surface by a stalk formed by an unusual association between an N-terminal ,-helix and a C-terminal polyproline helix. This presentation mode might be important in determining functional conformations of other Gram-positive surface proteins that have adhesin domains flanked by ,-helical and proline-rich regions. [source]

Oral biofilms, periodontitis, and pulmonary infections

ORAL DISEASES, Issue 6 2007
S Paju
Bacteria from the oral biofilms may be aspirated into the respiratory tract to influence the initiation and progression of systemic infectious conditions such as pneumonia. Oral bacteria, poor oral hygiene, and periodontitis seem to influence the incidence of pulmonary infections, especially nosocomial pneumonia episodes in high-risk subjects. Improved oral hygiene has been shown to reduce the occurrence of nosocomial pneumonia, both in mechanically-ventilated hospital patients and non-ventilated nursing home residents. It appears that oral colonization by potential respiratory pathogens, possibly fostered by periodontitis, and possibly by bacteria specific to the oral cavity or to periodontal diseases contribute to pulmonary infections. Thus, oral hygiene will assume an even more important role in the care of high-risk subjects , patients in the hospital intensive care and the elderly. The present paper critically reviews the recent literature on the effect of oral biofilms and periodontitis on pneumonia. [source]

Factors influencing oral colonization of mutans streptococci in young children

AUSTRALIAN DENTAL JOURNAL, Issue 2 2007
V. Law
Abstract This paper aims to critically review current knowledge about the key factors involved in oral colonization of the cariogenic group of bacteria, mutans streptococci (MS) in young children. MS, consisting mainly of the species Streptococcus mutans and Streptococcus sobrinus, are commonly cultured from the mouths of infants, with prevalence of infection ranging from around 30 per cent in 3 month old predentate children to over 80 per cent in 24 month old children with primary teeth. MS is usually transmitted to children through their mothers, and the risk of transmission increases with high maternal salivary levels of MS and frequent inoculation. Factors that affect the colonization of MS may be divided into bacterial virulence, host-related and environmental factors. Complex interaction among these factors determine the success and timing of MS colonization in the child. As clinical studies have shown that caries risk is correlated with age at which initial MS colonization occurred, strategies for the prevention of dental caries should include timely control of colonization of the cariogenic bacteria in the mouths of young children. [source]

Clinical and microbiological assessment of patients with a long-term diagnosis of human immunodeficiency virus infection and Candida oral colonization

CLINICAL MICROBIOLOGY AND INFECTION, Issue 4 2009
A. C. D. Delgado
Abstract The objective of this study was to evaluate Candida oral colonization in human immunodeficiency virus (HIV)-infected patients undergoing long-term highly active antiretroviral therapy (ARV). The cross-sectional study included 331 HIV patients, diagnosed from 1983 to 2003. Oral swabs were performed, and Candida species were determined using ID 32C. Isolates were tested for antifungal susceptibility. Clinical and laboratory data were collected to identify the association with Candida colonization. In total, 161 Candida isolates were detected among 147 of the 331 patients (44%), independently of the time when HIV infection was diagnosed. Candida albicans strains represented 137 (85%) of the isolates, and were susceptible to all of the tested antifungal drugs. Among the non- C. albicans strains, six isolates were dose-dependently susceptible to fluconazole, nine to itraconazole, and seven to ketoconazole. The isolation of Candida was significantly higher in patients with virological failure (83/147; p 0.0002) and CD4+ T-lymphocyte counts <200 cells/mm3 (30/83; p 0.0003). Recovery of Candida in the oral cavity was independent of protease inhibitor (PI) usage (p 0.60). Colonized patients typically underwent salvage therapy (p 0.003), and had more episodes of opportunistic fungal infections (p 0.046) and malignancies (p 0.004). Oral Candida colonization in patients under ARV therapy was associated with the immunosupressed status of HIV-infected patients, i.e. low number of CD4+ T-cells per cubic millimetre, failure of ARV therapy (salvage therapy), and higher number of opportunistic infections and malignancies. Despite the fact that PIs have in vitro antifungal activity, the use of this class of antiretroviral agent did not influence the presence of Candida in the oral cavity of AIDS patients. [source]