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Oral Microbiota
Oral microbiology is the study of the microorganisms (microbiota) of the oral cavity and their interactions between oral microorganisms or with the host. The environment present in the human mouth is suited to the growth of characteristic microorganisms found there. It provides a source of water and nutrients, as well as a moderate temperature. Resident microbes of the mouth adhere to the teeth and gums to resist mechanical flushing from the mouth to stomach where acid-sensitive microbes are destroyed by hydrochloric acid. Anaerobic bacteria in the oral cavity include: ''Actinomyces'', '' Arachnia'' ('' Propionibacterium propionicus''), ''Bacteroides'', ''Bifidobacterium'', ''Eubacterium'', ''Fusobacterium'', ''Lactobacillus'', '' Leptotrichia'', ''Peptococcus'', ''Peptostreptococcus'', ''Propionibacterium'', ''Selenomonas'', ''Treponema'', and ''Veillonella''. Genera of fungi that are frequently found in the mouth include '' Candida'', ''Cladosporium'', ''Aspergillus'', ''Fusar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oral Thrush Aphthae Candida Albicans
The word oral may refer to: Relating to the mouth * Relating to the mouth, the first portion of the alimentary canal that primarily receives food and liquid **Oral administration of medicines ** Oral examination (also known as an oral exam or oral test), a practice in many schools and disciplines in which an examiner poses questions to the student in spoken form ** Oral hygiene, practices involved in cleaning the mouth and preventing disease **Oral medication **Oral rehydration therapy, a simple treatment for dehydration associated with diarrhea **Oral sex, sexual activity involving the stimulation of genitalia by use of the mouth, tongue, teeth or throat. **Oral stage, a human development phase in Freudian developmental psychology **Oral tradition, cultural material and tradition transmitted orally from one generation to another **Oralism, the education of deaf students through oral language by using lip reading, and mimicking of mouth shapes and breathing patterns **Speech commu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Veillonella
''Veillonella'' are Gram-negative bacteria (Gram stain pink) anaerobic cocci, unlike most Bacillota, which are Gram-positive bacteria. This bacterium is well known for its lactate fermenting abilities. It is a normal bacterium in the intestines and oral mucosa of mammals. In humans they have been implicated in cases of osteomyelitis and endocarditis, for example with the species ''Veillonella parvula''. ''Veillonella dispar'' is the most nitrate-reducing bacterium in the oral cavity, which is beneficially anti-bacterial. When ''Veillonella'' is responsible for clinical infections in humans, it should be kept in mind that more than 70% of the strains are resistant to penicillin. Fermentation Lactate is fermented to propionate and acetate by the methylmalonyl-CoA pathway. Little ATP is produced in this fermentation. High substrate affinity is suggested to be the reason. 3 Lactate → acetate + 2 propionate + + A study of Veillonella in endurance athletes found that a rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth
A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness that originate from the embryonic germ layer, the ectoderm. The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The teeth of mammals have deep roots, and this pattern is also found in some fish, and in crocodilians. In most teleost fish, however, the teeth are attached to the outer surface of the bone, while in lizards they are attached to the inner surface of the jaw by one side. In cartilaginous fish, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adhesion
Adhesion is the tendency of dissimilar particles or surfaces to cling to one another ( cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another). The forces that cause adhesion and cohesion can be divided into several types. The intermolecular forces responsible for the function of various kinds of stickers and sticky tape fall into the categories of chemical adhesion, dispersive adhesion, and diffusive adhesion. In addition to the cumulative magnitudes of these intermolecular forces, there are also certain emergent mechanical effects. Surface energy Surface energy is conventionally defined as the work that is required to build an area of a particular surface. Another way to view the surface energy is to relate it to the work required to cleave a bulk sample, creating two surfaces. If the new surfaces are identical, the surface energy γ of each surface is equal to half the work of cleavage, W: γ = (1/2)W11. If the surfac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biofilm
A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPSs). The cells within the biofilm produce the EPS components, which are typically a polymeric conglomeration of extracellular polysaccharides, proteins, lipids and DNA. Because they have three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes". Biofilms may form on living or non-living surfaces and can be prevalent in natural, industrial, and hospital settings. They may constitute a microbiome or be a portion of it. The microbial cells growing in a biofilm are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single cells that may float or swim in a liquid medium. Biofilms can form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationsh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptococcus
''Cryptococcus'' is a genus of fungi in the family Cryptococcaceae that includes both yeasts and filamentous species. The filamentous, sexual forms or teleomorphs were formerly classified in the genus ''Filobasidiella'', while ''Cryptococcus'' was reserved for the yeasts. Most yeast species formerly referred to ''Cryptococcus'' have now been placed in different genera. The name ''Cryptococcus'' comes from the Greek for "hidden sphere" (literally "hidden berry"). Some ''Cryptococcus'' species cause a disease called cryptococcosis. Taxonomy The genus was described by French mycologist Jean Paul Vuillemin in 1901, when he failed to find ascospores characteristic of the genus ''Saccharomyces'' in the yeast previously known as ''Saccharomyces neoformans''. Over 300 additional names were subsequently added to the genus, almost all of which were later removed following molecular research based on cladistic analysis of DNA sequences. As a result, some ten species are currently recogniz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penicillium
''Penicillium'' () is a genus of ascomycetous fungi that is part of the mycobiome of many species and is of major importance in the natural environment, in food spoilage, and in food and drug production. Some members of the genus produce penicillin, a molecule that is used as an antibiotic, which kills or stops the growth of certain kinds of bacteria. Other species are used in cheesemaking. According to the ''Dictionary of the Fungi'' (10th edition, 2008), the widespread genus contains over 300 species. Taxonomy The genus was first described in the scientific literature by Johann Heinrich Friedrich Link in his 1809 work ''Observationes in ordines plantarum naturales''; he wrote, "''Penicillium. Thallus e floccis caespitosis septatis simplicibus aut ramosis fertilibus erectis apice penicillatis''", where ''penicillatis'' means "having tufts of fine hair". Link included three species—'' P. candidum'', '' P. expansum'', and '' P. glaucum''—all of which produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternaria
''Alternaria'' is a genus of Deuteromycetes fungi. All species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma. They are present in the human mycobiome and readily cause opportunistic infections in immunocompromised people such as AIDS patients. There are 299 species in the genus; they are ubiquitous in the environment and are a natural part of fungal flora almost everywhere. They are normal agents of decay and decomposition. The spores are airborne and found in the soil and water, as well as indoors and on objects. The club-shaped spores are single or form long chains. They can grow thick colonies which are usually green, black, or gray. At least 20% of agricultural spoilage is caused by ''Alternaria'' species, with the most severe losses reaching 80% of yield. Many human health disorders can be caused by these fungi, which grow on skin and mucous me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glomus (fungus)
''Glomus'' is a genus of arbuscular mycorrhizal (AM) fungi, and all species form symbiotic relationships (mycorrhizae) with plant roots. ''Glomus'' is the largest genus of AM fungi, with ''ca.'' 85 species described, but is currently defined as non-monophyletic. Classification ''Glomus'' is one of the genera in the family Glomeraceae, in the division Glomeromycota. Some members of the genus were originally described as ''Sclerocystis'' species, but this genus has been entirely transferred to ''Glomus''. However, further taxonomic changes are likely as the phylogeny of AM fungi becomes better understood. ''Glomus'' is likely related to the fossil fungus '' Glomites'', discovered in the Rhynie chert deposits from the Early Devonian (400 million years ago). Ecology As with other AM fungi, all ''Glomus'' species are thought to be obligate symbionts, dependent on their mycorrhizal association with plant roots to complete their life cycle. They cannot be cultured in the laboratory i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusarium
''Fusarium'' is a large genus of filamentous fungi, part of a group often referred to as hyphomycetes, widely distributed in soil and associated with plants. Most species are harmless saprobes, and are relatively abundant members of the soil microbial community. Some species produce mycotoxins in cereal crops that can affect human and animal health if they enter the food chain. The main toxins produced by these ''Fusarium'' species are fumonisins and trichothecenes. Despite most species apparently being harmless (some existing on the skin as commensal members of the skin flora), some ''Fusarium'' species and subspecific groups are among the most important fungal pathogens of plants and animals. The name of ''Fusarium'' comes from Latin ''fusus'', meaning a spindle. Taxonomy The taxonomy of the genus is complex. A number of different schemes have been used, and up to 1,000 species have been identified at times, with approaches varying between wide and narrow concepts of speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspergillus
'''' () is a genus consisting of several hundred mold species found in various climates worldwide. ''Aspergillus'' was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli. Viewing the fungi under a microscope, Micheli was reminded of the shape of an ''aspergillum'' (holy water sprinkler), from Latin ''spargere'' (to sprinkle), and named the genus accordingly. Aspergillum is an asexual spore-forming structure common to all ''Aspergillus'' species; around one-third of species are also known to have a sexual stage. While some species of ''Aspergillus'' are known to cause fungal infections, others are of commercial importance. Taxonomy Species ''Aspergillus'' consists of 837 species of fungi. Growth and distribution ''Aspergillus'' is defined as a group of conidial fungi—that is, fungi in an asexual state. Some of them, however, are known to have a teleomorph (sexual state) in the Ascomycota. With DNA evidence, all members of the genus '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
