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Trypticase soy agaror tryptone soya agar (TSA) and Trypticasesoy broth or tryptone soya broth (TSB) with agar are growth media for the culturing of bacteria. They are general-purpose, nonselective media providing enough nutrients to allow for a wide variety of microorganisms to grow. They are used for a wide range of applications, including culture storage, enumeration of cells (counting), isolation of pure cultures, or simply general culture.
TSA contains enzymatic digests of casein and soybean meal, which provide amino acids and other nitrogenous substances, making it a nutritious medium for a variety of organisms. Glucose is the energy source. Sodium chloride maintains the osmotic equilibrium, while dipotassium phosphate acts as buffer to maintain pH. Agar extracted from any number of organisms is used as a gelling agent.
The medium may be supplemented with blood to facilitate the growth of more fastidious bacteria or antimicrobial agents to permit the selection of various microbial groups from pure microbiota. As with any media, minor changes may be made to suit specific circumstances. TSA is frequently the base medium of other agar plate types. For example, blood agar plates (BAP) are made by enriching TSA plates with defibrinated sheep blood, and chocolate agar is made through additional cooking of BAP. Nutrient agar is also similar to TSA.
One liter of the agar contains:
An agar plate is a Petri dish that contains a growth medium solidified with agar, used to culture microorganisms. Sometimes selective compounds are added to influence growth, such as antibiotics.
A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture medium under controlled laboratory conditions. Microbial cultures are foundational and basic diagnostic methods used as a research tool in molecular biology.
Bacteriological water analysis is a method of analysing water to estimate the numbers of bacteria present and, if needed, to find out what sort of bacteria they are. It represents one aspect of water quality. It is a microbiological analytical procedure which uses samples of water and from these samples determines the concentration of bacteria. It is then possible to draw inferences about the suitability of the water for use from these concentrations. This process is used, for example, to routinely confirm that water is safe for human consumption or that bathing and recreational waters are safe to use.
A blood culture is a medical laboratory test used to detect bacteria or fungi in a person's blood. Under normal conditions, the blood does not contain microorganisms: their presence can indicate a bloodstream infection such as bacteremia or fungemia, which in severe cases may result in sepsis. By culturing the blood, microbes can be identified and tested for resistance to antimicrobial drugs, which allows clinicians to provide an effective treatment.
A growth medium or culture medium is a solid, liquid, or semi-solid designed to support the growth of a population of microorganisms or cells via the process of cell proliferation or small plants like the moss Physcomitrella patens. Different types of media are used for growing different types of cells.
MacConkey agar is a selective and differential culture medium for bacteria. It is designed to selectively isolate Gram-negative and enteric bacteria and differentiate them based on lactose fermentation. Lactose fermenters turn red or pink on McConkey agar, and nonfermenters do not change color. The media inhibits growth of Gram-positive organisms with crystal violet and bile salts, allowing for the selection and isolation of gram-negative bacteria. The media detects lactose fermentation by enteric bacteria with the pH indicator neutral red.
Lysogeny broth (LB) is a nutritionally rich medium primarily used for the growth of bacteria. Its creator, Giuseppe Bertani, intended LB to stand for lysogeny broth, but LB has also come to colloquially mean Luria broth, Lennox broth, life broth or Luria–Bertani medium. The formula of the LB medium was published in 1951 in the first paper of Bertani on lysogeny. In this article he described the modified single-burst experiment and the isolation of the phages P1, P2, and P3. He had developed the LB medium to optimize Shigella growth and plaque formation.
Tryptone is the assortment of peptides formed by the digestion of casein by the protease trypsin.
In microbiology, streaking is a technique used to isolate a pure strain from a single species of microorganism, often bacteria. Samples can then be taken from the resulting colonies and a microbiological culture can be grown on a new plate so that the organism can be identified, studied, or tested.
Mannitol salt agar or MSA is a commonly used selective and differential growth medium in microbiology. It encourages the growth of a group of certain bacteria while inhibiting the growth of others. This medium is important in medical laboratories as one method of distinguishing pathogenic microbes in a short period of time. It contains a high concentration of salt (NaCl) which is inhibitory to most bacteria - making MSA selective against most Gram-negative and selective for some Gram-positive bacteria that tolerate high salt concentrations. It is also a differential medium for mannitol-fermenting staphylococci, containing carbohydrate mannitol and the indicator phenol red, a pH indicator for detecting acid produced by mannitol-fermenting staphylococci. Staphylococcus aureus produces yellow colonies with yellow zones, whereas other coagulase-negative staphylococci produce small pink or red colonies with no colour change to the medium. If an organism can ferment mannitol, an acidic byproduct is formed that causes the phenol red in the agar to turn yellow. It is used for the selective isolation of presumptive pathogenic (pp) Staphylococcus species.
Etest is a way of determining antimicrobial sensitivity by placing a strip impregnated with antimicrobials onto an agar plate. A strain of bacterium or fungus will not grow near a concentration of antibiotic or antifungal if it is sensitive. For some microbial and antimicrobial combinations, the results can be used to determine a minimum inhibitory concentration (MIC). Etest is a proprietary system manufactured by bioMérieux. It is a laboratory test used in healthcare settings to help guide physicians by indicating what concentration of antimicrobial could successfully be used to treat patients' infections.
Super Optimal Broth is a nutrient-rich bacterial growth medium used for microbiological culture, generally of Escherichia coli. This nutrient-rich microbial broth contains peptides, amino acids, water soluble vitamins and glucose in a low-salt formulations. It was developed by Douglas Hanahan in 1983 and is an adjusted version of the commonly used LB medium. Growth of E. coli in SOB or SOC medium results in higher transformation efficiencies of plasmids. SOC medium can also be used to regenerate Klebsiella oxytoca strains for the improved transformation efficiency.
Brain heart infusion (BHI) is a growth medium for growing microorganisms. It is a nutrient-rich medium, and can therefore be used to culture a variety of fastidious organisms. In particular, it has been used to culture streptococci, pneumococci and meningococci, which can be otherwise challenging to grow. BHI is made by combining an infusion from boiled bovine or porcine heart and brain with a variety of other nutrients. BHI broth is often used in food safety, water safety, and antibiotic sensitivity tests.
Cystine tryptic agar (CTA), also known as cystine trypticase agar, is a growth medium used for the identification of microorganisms.
Middlebrook 7H9 broth is a liquid growth medium specially used for culture of Mycobacterium species, notably Mycobacterium tuberculosis.
Tryptic soy broth or Trypticase soy broth is used in microbiology laboratories as a culture broth to grow aerobic bacteria. It is a complex, general purpose medium that is routinely used to grow certain pathogenic bacteria, which tend to have high nutritional requirements. Its agar counterpart is tryptic soy agar (TSA). One of the components of Tryptic soy broth is Phytone, which is an enzymatic digest of soybean meal.
Bioburden is normally defined as the number of bacteria living on a surface that has not been sterilized.
Acaricomes phytoseiuli is a bacterium which is thought to be a pathogen of the mite Phytoseiulus persimilis. A. phytoseiuli causes a set of symptoms in the mite, known as nonresponding syndrome or NR syndrome. Dramatic changes in longevity, fecundity, and behavior are characteristic with this disease. The bacteria accumulate in the lumen of the mite's digestive tract and cause extreme degeneration of its epithelium. Infection with A. phytoseiuli greatly reduces the mite's attraction to herbivore-induced plant volatiles, and the mite is more prone to leave patches with ample prey. The disease is transmitted horizontally by means of feces and debris. The strain that was isolated was “CSC”. Differences between strain CSC compared to its closest phylogenetic neighbors are as follows: CSC uses glucose-1-phosphate and L-glutamic acid, and its colonies are more yellow in appearance as compared to its phylogenetic neighbors which are more cream/white in color.
In microbiology, the term isolation refers to the separation of a strain from a natural, mixed population of living microbes, as present in the environment, for example in water or soil flora, or from living beings with skin flora, oral flora or gut flora, in order to identify the microbe(s) of interest. Historically, the laboratory techniques of isolation first developed in the field of bacteriology and parasitology, before those in virology during the 20th century.
Diagnostic microbiology is the study of microbial identification. Since the discovery of the germ theory of disease, scientists have been finding ways to harvest specific organisms. Using methods such as differential media or genome sequencing, physicians and scientists can observe novel functions in organisms for more effective and accurate diagnosis of organisms. Methods used in diagnostic microbiology are often used to take advantage of a particular difference in organisms and attain information about what species it can be identified as, which is often through a reference of previous studies. New studies provide information that others can reference so that scientists can attain a basic understanding of the organism they are examining.