Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table, a reactive nonmetal, an oxidizing agent that forms oxides with most elements as well as with other compounds. By mass, oxygen is the third-most abundant element in the universe, after helium. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O2. Diatomic oxygen gas constitutes 20.8% of the Earth's atmosphere. As compounds including oxides, the element makes up half of the Earth's crust. Dioxygen is used in cellular respiration and many major classes of organic molecules in living organisms contain oxygen, such as proteins, nucleic acids and fats, as do the major constituent inorganic compounds of animal shells and bone. Most of the mass of living organisms is oxygen as a component of water, the major constituent of lifeforms. Oxygen is continuously replenished in Earth's atmosphere by photosynthesis, which uses the energy of sunlight to produce oxygen from water and carbon dioxide.
Oxygen is too chemically reactive to remain a free element in air without being continuously replenished by the photosynthetic action of living organisms. Another form of oxygen, ozone absorbs ultraviolet UVB radiation and the high-altitude ozone layer helps protect the biosphere from ultraviolet radiation. However, ozone present at the surface is a byproduct of thus a pollutant. Oxygen was isolated by Michael Sendivogius before 1604, but it is believed that the element was discovered independently by Carl Wilhelm Scheele, in Uppsala, in 1773 or earlier, Joseph Priestley in Wiltshire, in 1774. Priority is given for Priestley because his work was published first. Priestley, called oxygen "dephlogisticated air", did not recognize it as a chemical element; the name oxygen was coined in 1777 by Antoine Lavoisier, who first recognized oxygen as a chemical element and characterized the role it plays in combustion. Common uses of oxygen include production of steel and textiles, brazing and cutting of steels and other metals, rocket propellant, oxygen therapy, life support systems in aircraft, submarines and diving.
One of the first known experiments on the relationship between combustion and air was conducted by the 2nd century BCE Greek writer on mechanics, Philo of Byzantium. In his work Pneumatica, Philo observed that inverting a vessel over a burning candle and surrounding the vessel's neck with water resulted in some water rising into the neck. Philo incorrectly surmised that parts of the air in the vessel were converted into the classical element fire and thus were able to escape through pores in the glass. Many centuries Leonardo da Vinci built on Philo's work by observing that a portion of air is consumed during combustion and respiration. In the late 17th century, Robert Boyle proved. English chemist John Mayow refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus. In one experiment, he found that placing either a mouse or a lit candle in a closed container over water caused the water to rise and replace one-fourteenth of the air's volume before extinguishing the subjects.
From this he surmised that nitroaereus is consumed in both combustion. Mayow observed that antimony increased in weight when heated, inferred that the nitroaereus must have combined with it, he thought that the lungs separate nitroaereus from air and pass it into the blood and that animal heat and muscle movement result from the reaction of nitroaereus with certain substances in the body. Accounts of these and other experiments and ideas were published in 1668 in his work Tractatus duo in the tract "De respiratione". Robert Hooke, Ole Borch, Mikhail Lomonosov, Pierre Bayen all produced oxygen in experiments in the 17th and the 18th century but none of them recognized it as a chemical element; this may have been in part due to the prevalence of the philosophy of combustion and corrosion called the phlogiston theory, the favored explanation of those processes. Established in 1667 by the German alchemist J. J. Becher, modified by the chemist Georg Ernst Stahl by 1731, phlogiston theory stated that all combustible materials were made of two parts.
One part, called phlogiston, was given off when the substance containing it was burned, while the dephlogisticated part was thought to be its true form, or calx. Combustible materials that leave little residue, such as wood or coal, were thought to be made of phlogiston. Air did not play a role in phlogiston theory, nor were any initial quantitative experiments conducted to test the idea. Polish alchemist and physician Michael Sendivogius in his work De Lapide Philosophorum Tractatus duodecim e naturae fonte et manuali experientia depromti described a substance contained in air, referring to it as'cibus vitae', this substance is identical with oxygen. Sendivogius, during his experiments performed between 1598 and 1604, properly recognized that the substance is equivalent to the gaseous byproduct released by the thermal decomposition of potassium nitrate. In Bugaj’s view, the isolation of oxygen and the proper association of the substance to that part of air, required for life, lends sufficient weight to the discovery of oxygen by Sendivogius.
An extremophile is an organism that thrives in physically or geochemically extreme conditions that are detrimental to most life on Earth. In contrast, organisms that live in more moderate environments may be termed mesophiles or neutrophiles. In the 1980s and 1990s, biologists found that microbial life has great flexibility for surviving in extreme environments—niches that are acidic or extraordinarily hot, for example—that would be inhospitable to complex organisms; some scientists concluded that life may have begun on Earth in hydrothermal vents far under the ocean's surface. According to astrophysicist Steinn Sigurdsson, "There are viable bacterial spores that have been found that are 40 million years old on Earth—and we know they're hardened to radiation." Some bacteria were found living in the cold and dark in a lake buried a half-mile deep under the ice in Antarctica, in the Marianas Trench, the deepest place in Earth's oceans. Some microorganisms have been found thriving inside rocks up to 1,900 feet below the sea floor under 8,500 feet of ocean off the coast of the northwestern United States.
According to one of the researchers, "You can find microbes everywhere—they're adaptable to conditions, survive wherever they are." A key to extremophile adaptation is their amino acid composition, affecting their protein folding ability under particular conditions. There are many classes of extremophiles; these classifications are not exclusive. Many extremophiles are classified as polyextremophiles. For example, organisms living inside hot rocks deep under Earth's surface are thermophilic and barophilic such as Thermococcus barophilus. A polyextremophile living at the summit of a mountain in the Atacama Desert might be a radioresistant xerophile, a psychrophile, an oligotroph. Polyextremophiles are well known for their ability to tolerate both low pH levels. Acidophile An organism with optimal growth at pH levels of 3 or belowAlkaliphile An organism with optimal growth at pH levels of 9 or aboveAnaerobe An organism that does not require oxygen for growth such as Spinoloricus cinzia. Two sub-types exist: facultative obligate anaerobe.
A facultative anaerobe can tolerate aerobic conditions. Cryptoendolith An organism that lives in microscopic spaces within rocks, such as pores between aggregate grains; these may be called endolith, a term that includes organisms populating fissures and faults filled with groundwater in the deep subsurface. Halophile An organism requiring at least 0.2M concentrations of salt for growth. Hyperthermophile An organism that can thrive at temperatures above 80 °C, such as those found in hydrothermal systemsHypolith An organism that lives underneath rocks in cold deserts. Lithoautotroph An organism whose sole source of carbon is carbon dioxide and exergonic inorganic oxidation such as Nitrosomonas europaea. Metallotolerant Capable of tolerating high levels of dissolved heavy metals in solution, such as copper, cadmium and zinc. Examples include Ferroplasma sp. Cupriavidus metallidurans and GFAJ-1. Oligotroph An organism capable of growth in nutritionally limited environments. Osmophile An organism capable of growth in environments with a high sugar concentration.
Piezophile Also referred to as barophile, is an organism that lives optimally at high pressures such as those deep in the ocean or underground. Piezophilic organisms live under conditions of extreme pressure. High pressures can cause proteins to fold into themselves. Piezophiles have less large bulky amino acids that would take up space and prevent the other amino acids from coming close enough to create the reinforced area around the core of proteins. Polyextremophile A polyextremophile is an organism that qualifies as an extremophile under more than one category. Psychrophile/Cryophile An organism capable of survival, growth or reproduction at temperatures of −15 °C or lower for extended periods. Psychrophilic organisms live in environments at temperature below –15 °C. Low temperatures cause the kinetic energy and motion within proteins to slow, which prevents them from functioning properly. Cryophiles' proteins have adapted their amino acid composition to live in cold conditions and mitigate this threat.
They have a high amount of glycine amino acids, the small size of which allows for more flexibility within the protein once it is folded. Psychrophiles have a low concentration of charged amino acids, hydrophobic amino acids, proline residues; the low amount of charged amino acids reduces the amount of interactions between them, while the reduced amount of hydrophobic amino acids allows the non-polar core of the protein to be smaller. Psychrophilic proteins have a small amount of proline amino acids because they cause a rigid structure; these adaptations allow psychrophilic proteins to be more flexible so they do not freeze under cold conditions. Radioresistant Organisms resistant to high levels of ionizing radiation, most ultraviolet radiation; this category
The lung microbiota, is the pulmonary microbial community consisting of a complex variety of microorganisms found in the lower respiratory tract on the mucous layer and the epithelial surfaces. These microorganisms include bacteria, fungi and bacteriophages; the bacterial part of the microbiota has been more studied. It consists of a core of nine genera: Prevotella, Pseudomonas, Fusobacterium, Veillonella and Streptococcus, they are aerobes as well as anaerobes and aerotolerant bacteria. The microbial communities are variable in particular individuals and compose of about 140 distinct families; the bronchial tree for instance contains a mean of 2000 bacterial genomes per cm2 surface. The harmful or harmful bacteria are detected in respiratory specimens; the most significant are Moraxella catarrhalis, Haemophilus influenzae, Streptococcus pneumoniae. They are known to cause respiratory disorders under particular conditions namely if the human immune system is impaired; the mechanism by which they persist in the lower airways in healthy individuals is unknown.
Fungal genera that are found in the lung microbiota include Candida, Neosartorya and Aspergillus, among others. The airway epithelium together with alveolar macrophages and dendritic cells play a major role in the initial recognition of bacterial products getting into the lower airways with the air. Since some of these products are potent proinflammatory stimuli it is important for the immune system to distinguish between pathogens and non-pathogenic commensals; this prevents the development of constant inflammation and forms tolerance against harmless microbiota. This process becomes much more intriguing when taking into account that commensals share their surface molecules with pathogens. Epithelial cells are equipped with sensitive recognition tools - toll like receptors, nucleotide-binding oligomerization domain -like receptors and retinoic acid-inducible gene -I-like receptors which recognize a broad variety of microbial structural components. After recognition of pathogenic bacteria proinflammatory pathways are activated and cellular components of the adaptive and innate immunity are recruited to the infection site.
One key regulator in this process is the NF-κB which translocates from the cytoplasm into the nucleus and activates pro-inflammatory genes in epithelial cells and macrophages. The DNA-binding protein complex recognizes a discrete nucleotide sequence in the upstream region of a variety of response genes; the activation of NF-κB by a number of stimuli: bacterial cell walls or inflammatory cytokines results in its translocation to the nucleus. In contrast, harmless bacteria do not cause the translocation of NF-κB into the nucleus thus preventing the inflammation although they can express the same microbe-associated molecular patterns. One possible mechanism explaining this effect was suggested by Neish showing that non-pathogenic S. typhimurium PhoPc and S. pullorum are able to prohibit the ubiquitination of NF-κB inhibitor molecule nuclear factor of NF-κB light polypeptide gene enhancer in B-cells inhibitor alpha. Another explanation of commensal tolerance of the epithelium refers to the post-translational modification of a protein by the covalent attachment of one or more ubiquitin monomers.
The inhibition of ubiquitination leads to reduction of inflammation, because only polyubiquitinated (IκB-κ is targeted for degradation by the 26 S proteasome, allowing NF-κB translocation to the nucleus and activation the transcription of effector genes. Probiotic bacteria such as Lactobacilli are able to modulate the activity of the Ub-proteasome system via inducing reactive oxygen species production in epithelial cells. In mammalian cells, ROS have been shown to serve as critical second messengers in multiple signal transduction pathways in response to proinflammatory cytokines. Bacterially induced ROS causes oxidative inactivation of the catalytic cysteine residue of Ub 12 resulting in incomplete but transient loss of cullin-1 neddylation and consequent effects on NF-κB and β-catenin signaling. Another commensal species, B. thetaiotaomicron, attenuates pro-inflammatory cytokine expression by promoting nuclear export of NF-κB subunit RelA, through a peroxisome proliferator activated receptor γ -dependent pathway.
PPAR-γ target transcriptionally active Rel A and induce early nuclear clearance limiting the duration of NF-κB action. The balance between pathogens and commensals is important in the maintenance of homeostasis in the respiratory tract; the airways are continually exposed to a multitude of microorganisms, some of which are able to persist and colonize respiratory tract. This is possible due to the presence of nutrients and optimal growth temperature. There are several host-derived nutrient sources for microbial residents: secretions from airway epithelial cells, secretions from submucosal glands and transudate from plasma. Moreover, the pool of available nutrients is increased by the activities of some members of the microbiota. Macromolecular components of respiratory secretions are converted to nutrients. Thus, the metabolic activity of present bacteria allow for the colonization of new species; the commensal bacteria defend our airways against the pathogens. There are several possible mechanisms.
Commensals are the native competitors of pathogenic bacteria, because they tend to occupy the same ecological niche inside the human body. Secondly, they are able to produce an
Water is a transparent, tasteless and nearly colorless chemical substance, the main constituent of Earth's streams and oceans, the fluids of most living organisms. It is vital for all known forms of life though it provides no calories or organic nutrients, its chemical formula is H2O, meaning that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. Water is the name of the liquid state of H2O at standard ambient pressure, it forms precipitation in the form of rain and aerosols in the form of fog. Clouds are formed from suspended droplets of its solid state; when finely divided, crystalline ice may precipitate in the form of snow. The gaseous state of water is water vapor. Water moves continually through the water cycle of evaporation, condensation and runoff reaching the sea. Water covers 71% of the Earth's surface in seas and oceans. Small portions of water occur as groundwater, in the glaciers and the ice caps of Antarctica and Greenland, in the air as vapor and precipitation.
Water plays an important role in the world economy. 70% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a major source of food for many parts of the world. Much of long-distance trade of commodities and manufactured products is transported by boats through seas, rivers and canals. Large quantities of water and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a wide variety of chemical substances. Water is central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, sport fishing, diving; the word water comes from Old English wæter, from Proto-Germanic *watar, from Proto-Indo-European *wod-or, suffixed form of root *wed-. Cognate, through the Indo-European root, with Greek ύδωρ, Russian вода́, Irish uisce, Albanian ujë; the identification of water as a substance Water is a polar inorganic compound, at room temperature a tasteless and odorless liquid, nearly colorless with a hint of blue.
This simplest hydrogen chalcogenide is by far the most studied chemical compound and is described as the "universal solvent" for its ability to dissolve many substances. This allows it to be the "solvent of life", it is the only common substance to exist as a solid and gas in normal terrestrial conditions. Water is a liquid at the pressures that are most adequate for life. At a standard pressure of 1 atm, water is a liquid between 0 and 100 °C. Increasing the pressure lowers the melting point, about −5 °C at 600 atm and −22 °C at 2100 atm; this effect is relevant, for example, to ice skating, to the buried lakes of Antarctica, to the movement of glaciers. Increasing the pressure has a more dramatic effect on the boiling point, about 374 °C at 220 atm; this effect is important in, among other things, deep-sea hydrothermal vents and geysers, pressure cooking, steam engine design. At the top of Mount Everest, where the atmospheric pressure is about 0.34 atm, water boils at 68 °C. At low pressures, water cannot exist in the liquid state and passes directly from solid to gas by sublimation—a phenomenon exploited in the freeze drying of food.
At high pressures, the liquid and gas states are no longer distinguishable, a state called supercritical steam. Water differs from most liquids in that it becomes less dense as it freezes; the maximum density of water in its liquid form is 1,000 kg/m3. The density of ice is 917 kg/m3. Thus, water expands 9% in volume as it freezes, which accounts for the fact that ice floats on liquid water; the details of the exact chemical nature of liquid water are not well understood. Pure water is described as tasteless and odorless, although humans have specific sensors that can feel the presence of water in their mouths, frogs are known to be able to smell it. However, water from ordinary sources has many dissolved substances, that may give it varying tastes and odors. Humans and other animals have developed senses that enable them to evaluate the potability of water by avoiding water, too salty or putrid; the apparent color of natural bodies of water is determined more by dissolved and suspended solids, or by reflection of the sky, than by water itself.
Light in the visible electromagnetic spectrum can traverse a couple meters of pure water without significant absorption, so that it looks transparent and colorless. Thus aquatic plants and other photosynthetic organisms can live in water up to hundreds of meters deep, because sunlight can reach them. Water vapour is invisible as a gas. Through a thickness of 10 meters or more, the intrinsic color of water is visibly turquoise, as its absorption spectrum has
Microbiology is the study of microorganisms, those being unicellular, multicellular, or acellular. Microbiology encompasses numerous sub-disciplines including virology, parasitology and bacteriology. Eukaryotic microorganisms possess membrane-bound cell organelles and include fungi and protists, whereas prokaryotic organisms—all of which are microorganisms—are conventionally classified as lacking membrane-bound organelles and include Bacteria and Archaea. Microbiologists traditionally relied on culture and microscopy. However, less than 1% of the microorganisms present in common environments can be cultured in isolation using current means. Microbiologists rely on molecular biology tools such as DNA sequence based identification, for example 16s rRNA gene sequence used for bacteria identification. Viruses have been variably classified as organisms, as they have been considered either as simple microorganisms or complex molecules. Prions, never considered as microorganisms, have been investigated by virologists, however, as the clinical effects traced to them were presumed due to chronic viral infections, virologists took search—discovering "infectious proteins".
The existence of microorganisms was predicted many centuries before they were first observed, for example by the Jains in India and by Marcus Terentius Varro in ancient Rome. The first recorded microscope observation was of the fruiting bodies of moulds, by Robert Hooke in 1666, but the Jesuit priest Athanasius Kircher was the first to see microbes, which he mentioned observing in milk and putrid material in 1658. Antonie van Leeuwenhoek is considered a father of microbiology as he observed and experimented with microscopic organisms in 1676, using simple microscopes of his own design. Scientific microbiology developed in the 19th century through the work of Louis Pasteur and in medical microbiology Robert Koch; the existence of microorganisms was hypothesized for many centuries before their actual discovery. The existence of unseen microbiological life was postulated by Jainism, based on Mahavira’s teachings as early as 6th century BCE. Paul Dundas notes that Mahavira asserted the existence of unseen microbiological creatures living in earth, water and fire.
Jain scriptures describe nigodas which are sub-microscopic creatures living in large clusters and having a short life, said to pervade every part of the universe in tissues of plants and flesh of animals. The Roman Marcus Terentius Varro made references to microbes when he warned against locating a homestead in the vicinity of swamps "because there are bred certain minute creatures which cannot be seen by the eyes, which float in the air and enter the body through the mouth and nose and thereby cause serious diseases."In the golden age of Islamic civilization, Iranian scientists hypothesized the existence of microorganisms, such as Avicenna in his book The Canon of Medicine, Ibn Zuhr who discovered scabies mites, Al-Razi who gave the earliest known description of smallpox in his book The Virtuous Life. In 1546, Girolamo Fracastoro proposed that epidemic diseases were caused by transferable seedlike entities that could transmit infection by direct or indirect contact, or vehicle transmission.
In 1676, Antonie van Leeuwenhoek, who lived most of his life in Delft, observed bacteria and other microorganisms using a single-lens microscope of his own design. He is considered a father of microbiology as he pioneered the use of simple single-lensed microscopes of his own design. While Van Leeuwenhoek is cited as the first to observe microbes, Robert Hooke made his first recorded microscopic observation, of the fruiting bodies of moulds, in 1665, it has, been suggested that a Jesuit priest called Athanasius Kircher was the first to observe microorganisms. Kircher was among the first to design magic lanterns for projection purposes, so he must have been well acquainted with the properties of lenses, he wrote "Concerning the wonderful structure of things in nature, investigated by Microscope" in 1646, stating "who would believe that vinegar and milk abound with an innumerable multitude of worms." He noted that putrid material is full of innumerable creeping animalcules. He published his Scrutinium Pestis in 1658, stating that the disease was caused by microbes, though what he saw was most red or white blood cells rather than the plague agent itself.
The field of bacteriology was founded in the 19th century by Ferdinand Cohn, a botanist whose studies on algae and photosynthetic bacteria led him to describe several bacteria including Bacillus and Beggiatoa. Cohn was the first to formulate a scheme for the taxonomic classification of bacteria, to discover endospores. Louis Pasteur and Robert Koch were contemporaries of Cohn, are considered to be the father of microbiology and medical microbiology, respectively. Pasteur is most famous for his series of experiments designed to disprove the widely held theory of spontaneous generation, thereby solidifying microbiology's identity as a biological science. One of his students, Adrien Certes, is considered the founder of marine microbiology. Pasteur designed methods for food preservation and vaccines against several diseases such as anthrax, fowl cholera and rabies. Koch is best known for his contributions to the germ theory of disease, proving that specific diseases were caused by specific pathogenic microorganisms.
He developed a series of criteria. Koch was one of the first scientists to focus on the i
The term skin flora refers to the microorganisms which reside on the skin human skin. Many of them are bacteria of which there are around 1000 species upon human skin from nineteen phyla. Most are found in the upper parts of hair follicles. Skin flora is non-pathogenic, either commensal or mutualistic; the benefits bacteria can offer include preventing transient pathogenic organisms from colonizing the skin surface, either by competing for nutrients, secreting chemicals against them, or stimulating the skin's immune system. However, resident microbes can cause skin diseases and enter the blood system, creating life-threatening diseases in immunosuppressed people. A major non-human skin flora is Batrachochytrium dendrobatidis, a chytrid and non-hyphal zoosporic fungus that causes chytridiomycosis, an infectious disease thought to be responsible for the decline in amphibian populations; the estimate of the number of species present on skin bacteria has been radically changed by the use of 16S ribosomal RNA to identify bacterial species present on skin samples direct from their genetic material.
Such identification had depended upon microbiological culture upon which many varieties of bacteria did not grow and so were hidden to science. Staphylococcus epidermidis and Staphylococcus aureus were thought from cultural based research to be dominant; however 16S ribosomal RNA research finds that while common, these species make up only 5% of skin bacteria. However, skin variety provides a diverse habitat for bacteria. Most come from four phyla: Actinobacteria, Firmicutes and Bacteroidetes. There are three main ecological areas: sebaceous and dry. Propionibacteria and Staphylococci species were the main species in sebaceous areas. In moist places on the body Corynebacteria together with Staphylococci dominate. In dry areas, there is a mixture of species but b-Proteobacteria and Flavobacteriales are dominant. Ecologically, sebaceous areas had greater species richness than dry one; the areas with least similarity between people in species were the spaces between fingers, the spaces between toes and umbilical cord stump.
Most were beside the nostril, on the back. A study of the area between toes in 100 young adults found 14 different genera of fungi; these include yeasts such as Candida albicans, Rhodotorula rubra and Trichosporon cutaneum, dermatophytes such as Microsporum gypseum, Trichophyton rubrum and nondermatophyte fungi such as Rhizopus stolonifer, Trichosporon cutaneum, Scopulariopsis brevicaulis, Alternaria alternata, Aspergillus flavus and Penicillium species. A study by the National Human Genome Research Institute in Bethesda, researched the DNA of human skin fungi at 14 different locations on the body; these were the ear canal, between the eyebrows, the back of the head, behind the ear, the heel, between the toes, back, nostrils, chest and the crook of the elbow. The study showed a large fungal diversity across the body, the richest habitat being the heel, which hosts about 80 species of fungi. By way of contrast, there are 40 between the toes. Other rich areas are the palm and inside the elbow, with from 18 to 32 species.
The head and the trunk hosted between 10 each. The umbilicus, or navel, is an area of the body, exposed to UV light, soaps, or bodily secretions and because it is an undisturbed community of bacteria it is an excellent part of the skin microbiome to study; the navel, or umbilicus is a moist microbiome of the body, that contains a large amount of bacteria bacteria that favors moist conditions such as Corynebacterium and Staphylococcus. The Belly Button Biodiversity Project began at North Carolina State University in early 2011 with two initial groups of 35 and 25 volunteers. Volunteers were given sterile cotton swabs and were asked to insert the cotton swabs into their navels, to turn the cotton swab around three times and return the cotton swab to the researchers in a vial that contained a 0.5 ml 10% phosphate saline buffer. Researchers at North Carolina State University, led by Jiri Hulcr grew the samples in a culture until the bacterial colonies were large enough to be photographed and these pictures were posted on the Belly Button Biodiversity Project's website.
These samples were analyzed using 16S rDNA libraries so that strains that did not grow well in cultures could be identified. The researchers at North Carolina State University discovered that while it was difficult to predict every strain of bacteria in the microbiome of the navel that they could predict which strains would be prevalent and which strains of bacteria would be quite rare in the microbiome, it was found that the navel microbiomes only contained a few prevalent types of bacteria and many different types of rare bacteria. Other types of rare organisms were discovered inside the navels of the volunteers including three types of Archaea and two of the three types of Archaea were found in one volunteer who claimed not to have bathed or showered for many years. Staphylococcus and Corynebacterium wer
The uterine microbiome is the commensal, bacteria, yeasts/fungi present in a healthy uterus, amniotic fluid and endometrium and the specific environment which they inhabit. It has been only confirmed that the uterus and its tissues are not sterile. Due to improved 16S rRNA gene sequencing techniques, detection of bacteria that are present in low numbers is possible. Using this procedure that allows the detection of bacteria that cannot be cultured outside the body, studies of microbiota present in the uterus are expected to increase. Bacteria and one genus of yeasts are a normal part of the uterus before and during pregnancy; the uterus has been found to possess its own characteristic microbiome that differs from the vaginal microbiome. Despite its close spatial connection with the vagina, the microbiome of the uterus more resembles the commensal bacteria found in the oral cavity. In addition, the immune system is able to differentiate between those bacteria found in the uterus and those that are pathogenic.
Hormonal changes have an effect on the microbiota of the uterus. The organisms listed below have been identified as commensals in the healthy uterus; some have the potential for growing to the point of causing disease: Other taxa can be present, without causing disease or an immune response. Their presence is associated with negative birth outcomes. Prophylactic antibiotics have been injected into the uterus to treat infertility; this has been done before the transfer of embryos with the intent to improve implantation rates. No association exists between antibiotic treatment. Infertility treatments progress to the point where a microbiological analysis of the uterine microbiota is performed. Preterm birth is associated with certain species of bacteria that are not part of the healthy uterine microbiome; the immune response becomes more pronounced. Investigations into reproductive-associated microbiomes began around 1885 by Theodor Escherich, he wrote. There was a general consensus at the time and recently that the uterus was sterile and this was referred to as the sterile womb paradigm.
Other investigations used sterile diapers for meconium collection. No bacteria were able to be cultured from the samples. Other studies showed that bacteria were detected and were directly proportional to the time between birth and the passage of meconium. Investigations into the role of the uterine microbiome in the development of the infant microbiome are ongoing. Human microbiome Human microbiome project Human virome List of antimicrobial peptides in the female reproductive tract List of bacterial vaginosis microbiota Placental microbiome Vaginal epithelium Vaginal microbiota in pregnancy