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Nasopharyngeal and oral immune system
Published in Phillip D. Smith, Richard S. Blumberg, Thomas T. MacDonald, Principles of Mucosal Immunology, 2020
Hiroshi Kiyono, Kohtaro Fujihashi
The oral cavity contains a complex consortium of approximately 2 × 1010 bacteria from six phyla, including Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, Spirochaetes, and Fusobacteria. The oral microbiome contributes to local mucosal homeostasis and certain metabolic functions, including deglycosylation of complex carbohydrate, sulfate reduction, and amino acid absorption. The overgrowth of a pathogenic bacteria or an alteration in the normal microbiome, termed microbial dysbiosis, may contribute to dental caries or periodontal diseases. For example, periodontal disease is associated with a significant alteration in the oral microbiome. Bacteria such as P. gingivalis, Tannerella forsythensis, and Treponema denticola are closely associated with severe periodontitis and are termed as “red-complex” bacteria, but they do not induce periodontal disease in the absence of the microbiota, reflected in observations that germ-free mice infected with P. gingivalis do not develop inflamed gingival tissues and the associated alveolar bone loss. In addition, specific pathogen-free mice do not develop gingival inflammation. These findings indicate that dysbiosis of the oral microbiome with increased numbers of red-complex bacteria likely contributes to the induction of chronic severe periodontitis. The role of the oral microbiota in systemic diseases such as gastrointestinal and head and neck cancers is under investigation. Thus, the oral cavity microbiota impacts stomatological and possibly systemic diseases.
Production, Extraction and Characterization of Alginates from Seaweeds
Published in Gokare A. Ravishankar, Ranga Rao Ambati, Handbook of Algal Technologies and Phytochemicals, 2019
Faiez Hentati, Alina V. Ursu, Guillaume Pierre, Cedric Delattre, Bogdan Trica, Slim Abdelkafi, Gholamreza Djelveh, Tanase Dobre, Philippe Michaud
The phenol-sulfuric acid assay (Dubois et al. 1956) improved by Albalasmeh et al. (2013) remains the most reliable method to obtain a response of each monosaccharide in the alginate sample. Under the action of concentrated and hot mineral acids, the hydrolyzed saccharides undergo extensive internal dehydration, followed by a cyclization resulting in the formation of furfural and hydroxymethylfurfural derivatives, reacting with phenol. Finally, the formation of a colored (yellow-red) complex makes it possible to follow the total sugar concentration by measuring the absorbance at λ485. d-glucose is generally used as standard.
Bacterial Infections of the Oral Cavity
Published in K. Balamurugan, U. Prithika, Pocket Guide to Bacterial Infections, 2019
P. S. Manoharan, Praveen Rajesh
Some common bacteria and their associations with diseases are mentioned as discussed in various studies and reports given in the literature. In 1968, Sigmund Socransky classified bacterial species into colored complexes. Bleeding-associated bacteria were named red complex. P. gingivalis, T. forsythiam, and T. denticola are the bacteria in this group, and they are also associated in deep periodontal pockets (Haffajee et al., 2006). The second is the orange complex which constitutes F. nucelatum, P. intermedia, P. nigrescens, P. micros, S. constellatus, E. nodatum, C. showae, C. gracilus, and C. rectus. P. intermedia along with P. gingivalis was found to occur in deep pockets. The third yellow complex include bacteria such as S. sanguis, S. oralis, S. mitis, S. gordonii, and S. intermedius. Capnocytophaga spp., Eikkenella corrodens, Campylobacter concisus. and Actinobacillus actinomycetemcomitans [serotype a] form the fourth green complex. Veillonella parvula and Actinomyces odontolyticus form the fifth purple complex.
Rapid specific detection of oral bacteria using Cas13-based SHERLOCK
Published in Journal of Oral Microbiology, 2023
Jett Liu, Camden Carmichael, Hatice Hasturk, Wenyuan Shi, Batbileg Bor
Oral polymicrobial dysbiosis has been well established as an etiology for numerous oral diseases, while a healthy oral microbiome has been suggested as crucial to preventing oral and systemic diseases [1–7]. In the case of periodontitis, a specific subgroup of microorganisms termed the red complex has been strongly associated with disease [1]. For caries, multiple acid-producing bacteria have been implicated in cavity formation [8,9]. Furthermore, specific bacteria such as Streptococcus mutans, Porphyromonas gingivalis, and Fusobacterium nucleatum are more intensely studied and have been highly associated with oral diseases [7,10–12]. These bacteria and others are also implicated in systemic diseases including various cancers, digestive diseases, cardiovascular diseases [3], and neurodegenerative diseases [13,14].
Newly identified pathogens in periodontitis: evidence from an association and an elimination study
Published in Journal of Oral Microbiology, 2023
Eduardo Lobão Veras, Nídia Castro dos Santos, João Gabriel S. Souza, Luciene C. Figueiredo, Belen Retamal-Valdes, Valentim A. R. Barão, Jamil Shibli, Martinna Bertolini, Marcelo Faveri, Flavia Teles, Poliana Duarte, Magda Feres
Socransky et al. [3] used the Checkerboard DNA-DNA hybridization technique to evaluate the composition of subgingival biofilm samples (n = 13,261) from 160 volunteers with periodontitis and 25 with periodontal health. The authors described three microbial complexes (green, purple, and yellow) associated with periodontal health and two groups of microorganisms (red and orange) strongly associated with clinical signs of disease. The red complex was composed of Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola while the orange complex congregated ten species from different genera, such as Fusobacterium, Prevotella, and Campylobacter. Importantly, a subsequent study demonstrated that four Actinomyces species were also closely related to periodontal health [4]. These studies have greatly contributed to increasing knowledge of the periodontal microbial ecology. Furthermore, the 40 bacterial species from these microbial complexes have been successfully used as biological markers in studies testing the effects of periodontal therapies on reestablishing a health-associated microbiome [5,6,7–11,12,13–15].
Oral microbiome in older adults with mild cognitive impairment
Published in Journal of Oral Microbiology, 2023
Dongxin Da, Qianhua Zhao, Hao Zhang, Wanqing Wu, Xiaoli Zeng, Xiaoniu Liang, Yiwei Jiang, Zhenxu Xiao, Jin Yu, Saineng Ding, Li Zheng, Ying Zhang, Xiaogang Xu, Ding Ding
Several previous studies have demonstrated the association between oral periodontal pathogens and cognitive decline. Periodontitis is a chronic inflammation caused by dental plaque in periodontal tissues, and the ‘red complex’ plays an important role in the formation of dental plaque biofilm [33]. The ‘red complex’ was periodontal pathogens including Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola [34]. However, inconsistent with previous studies, three species belonging to ‘red complex’ were not found to be significantly different in both groups. There were two reasons as the explanation. First, the structure of salivary microbiome might be different from that in peripheral blood, cerebrospinal fluid, and brain. Second, most of the above studies only focused on one or two species of bacteria. Confounding factors including the microbial interaction might not be controlled.