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Serotype
A serotype or serovar is a distinct variation within a species of bacteria or virus or among immune cells of different individuals. These microorganisms, viruses, or Cell (biology), cells are classified together based on their shared reactivity between their surface antigens and a particular antiserum, allowing the classification of organisms to a Infraspecific name, level below the species. A group of serovars with common antigens is called a serogroup or sometimes ''serocomplex''. Serotyping often plays an essential role in determining species and subspecies. The ''Salmonella'' genus of bacteria, for example, has been determined to have over 2600 serotypes. ''Vibrio cholerae'', the species of bacteria that causes cholera, has over 200 serotypes, based on cell antigens. Only two of them have been observed to produce the potent enterotoxin that results in cholera: O1 and O139. Serotypes were discovered in hemolytic streptococci by the American microbiologist Rebecca Lancefield i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmonella
''Salmonella'' is a genus of bacillus (shape), rod-shaped, (bacillus) Gram-negative bacteria of the family Enterobacteriaceae. The two known species of ''Salmonella'' are ''Salmonella enterica'' and ''Salmonella bongori''. ''S. enterica'' is the type species and is further divided into six subspecies that include over 2,650 serotypes. ''Salmonella'' was named after Daniel Elmer Salmon (1850–1914), an American veterinary surgeon. ''Salmonella'' species are non-Endospore, spore-forming, predominantly motility, motile enterobacteriaceae, enterobacteria with cell diameters between about 0.7 and 1.5 micrometre, μm, lengths from 2 to 5 μm, and peritrichous flagella (all around the cell body, allowing them to move). They are chemotrophs, obtaining their energy from Redox, oxidation and reduction reactions, using organic sources. They are also facultative aerobic organism, facultative anaerobes, capable of generating adenosine triphosphate with oxygen ("aerobically") ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serotypes – Antibody Versus Antigen
A serotype or serovar is a distinct variation within a species of bacteria or virus or among immune cells of different individuals. These microorganisms, viruses, or cells are classified together based on their shared reactivity between their surface antigens and a particular antiserum, allowing the classification of organisms to a level below the species. A group of serovars with common antigens is called a serogroup or sometimes ''serocomplex''. Serotyping often plays an essential role in determining species and subspecies. The ''Salmonella'' genus of bacteria, for example, has been determined to have over 2600 serotypes. ''Vibrio cholerae'', the species of bacteria that causes cholera, has over 200 serotypes, based on cell antigens. Only two of them have been observed to produce the potent enterotoxin that results in cholera: O1 and O139. Serotypes were discovered in hemolytic streptococci by the American microbiologist Rebecca Lancefield in 1933. Procedure ''Serotyping' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quellung Reaction
The quellung reaction, also called the Neufeld reaction, is a biochemical reaction in which antibodies bind to the bacterial capsule of ''Streptococcus pneumoniae'', ''Klebsiella pneumoniae'', ''Neisseria meningitidis'', ''Bacillus anthracis'', ''Haemophilus influenzae'', ''Escherichia coli'', and ''Salmonella''. The antibody reaction allows these species to be visualized under a microscope. If the reaction is positive, the capsule becomes opaque and appears to enlarge. Quellung is the German word for "swelling" and describes the microscopic appearance of pneumococcal or other bacterial capsules after their polysaccharide antigen has combined with a specific antibody. The antibody usually comes from serum taken from an immunized laboratory animal. As a result of this combination, and precipitation of the large, complex molecule formed, the capsule appears to swell, because of increased surface tension, and its outlines become demarcated. The pneumococcal quellung reaction was fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Leukocyte Antigen
The human leukocyte antigen (HLA) system is a complex of genes on chromosome 6 in humans that encode cell-surface proteins responsible for regulation of the immune system. The HLA system is also known as the human version of the major histocompatibility complex (MHC) found in many animals. Mutations in HLA genes may be linked to autoimmune diseases such as type I diabetes, and celiac disease. The HLA gene complex resides on a 3 Mbp stretch within chromosome 6, p-arm at 21.3. HLA genes are highly polymorphic, which means that they have many different alleles, allowing them to fine-tune the adaptive immune system. The proteins encoded by certain genes are also known as '' antigens'', as a result of their historic discovery as factors in organ transplants. HLAs corresponding to MHC class I ( A, B, and C), all of which are the HLA Class1 group, present peptides from inside the cell. For example, if the cell is infected by a virus, the HLA system brings fragments of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HLA-A24
HLA-A24 (A24) is a human leukocyte antigen ''serotype'' within HLA-A serotype group. The serotype is determined by the antibody recognition of α24 subset of HLA-A α-chains. For A24, the alpha, "A", chain are encoded by the HLA-A allele group and the β-chain are encoded by B2M locus. This group currently is dominated by A*24:02. A24 and A are almost synonymous in meaning. A24 is a split antigen of the broad antigen HLA-A9 and it is a sister serotype of HLA-A23. A*24:02 has one of the highest "A" frequencies identified for a number of peoples, including Papua New Guineans, Indigenous Taiwanese (Eastern Tribals), Yupik and Greenland leuts It is common over much of Southeastern Asia. In Eurasia it is least common in Ireland, and A24 is relatively uncommon in Africa except North Africa and Kenya. Serotype There are over 90 known A*24 alleles, 69 code for different isoforms and 7 are nulls. A*24:03 can also be detected as A2403 serotype. Associated disease A24 has a secon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HLA-A9
HLA-A9 (A9) is a broad antigen HLA- A serotype that recognized the HLA-A23 and HLA-A24 HLA-A24 (A24) is a human leukocyte antigen ''serotype'' within HLA-A serotype group. The serotype is determined by the antibody recognition of α24 subset of HLA-A α-chains. For A24, the alpha, "A", chain are encoded by the HLA-A allele group a ... serotypes. A*2402 appears to have evolved from A*23 alleles by a process of gene conversion. The A23 is more common in Africa and regions proximal to Africa. A24 is at very high frequencies in Austronesia and certain indigenous peoples of the Arctic, North America, South America and West Pacific Rim. While it is common over most of Eurasia, it is found at low abundance in NW Europe. A24 appears to have been carried by the first colonizers of South Eastern Asia. References {{DEFAULTSORT:Hla-A9 9 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HLA-A23
HLA-A23 (A23) is a human leukocyte antigen ''serotype'' within HLA-A serotype group. The serotype is determined by the antibody recognition of α23 subset of HLA-A α-chains. For A23, the alpha, "A", chain are encoded by the HLA-A allele group and the β-chain are encoded by B2M locus. This group currently is dominated by A*2301. A23 and A are almost synonymous in meaning. A23 is a split antigen of the broad antigen HLA-A9 and it is a sister serotype of HLA-A24. A23 is common in Africa and regions of the Middle East, Mediterranean, and India than Europe, East Asia or the Americas. Serotype Allele Haplotypes A23-B7 is found in N.Afr. and S.Afr non-caucasians. A23-B44 is found in Albania, Zimbabwe, Morocco, Spain and Danes. A23-B58 is found in the !kung and Zaire. Associated diseases A*23:Cw*07 is associated with higher viral load in HIV The human immunodeficiency viruses (HIV) are two species of '' Lentivirus'' (a subgroup of retrovirus) that infect humans. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vibrio Cholerae
''Vibrio cholerae'' is a species of Gram-negative bacteria, Gram-negative, Facultative anaerobic organism, facultative anaerobe and Vibrio, comma-shaped bacteria. The bacteria naturally live in Brackish water, brackish or saltwater where they attach themselves easily to the chitin-containing shells of crabs, shrimp, and other shellfish. Some strains of ''V. cholerae'' are pathogenic to humans and cause a deadly disease called cholera, which can be derived from the consumption of undercooked or raw marine life species or drinking contaminated water. ''V. cholerae'' was first described by Félix-Archimède Pouchet in 1849 as some kind of protozoa. Filippo Pacini correctly identified it as a bacterium and from him, the scientific name is adopted. The bacterium as the cause of cholera was discovered by Robert Koch in 1884. Sambhu Nath De isolated the cholera toxin and demonstrated the toxin as the cause of cholera in 1959. The bacterium has a flagellum (a tail like structure) at one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholera
Cholera () is an infection of the small intestine by some Strain (biology), strains of the Bacteria, bacterium ''Vibrio cholerae''. Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea lasting a few days. Vomiting and muscle cramps may also occur. Diarrhea can be so severe that it leads within hours to severe dehydration and electrolyte imbalance. This can in turn result in Enophthalmia, sunken eyes, cold or cyanotic skin, decreased skin elasticity, wrinkling of the hands and feet, and, in severe cases, death. Symptoms start two hours to five days after exposure. Cholera is caused by a number of Serotype, types of ''Vibrio cholerae'', with some types producing more severe disease than others. It is spread mostly by Waterborne diseases, unsafe water and Foodborne illness, unsafe food that has been contaminated with human feces containing the bacteria. Undercooked shellfish is a common source. Humans are the only known host fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococci
''Streptococcus'' is a genus of gram-positive spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occurs along a single axis, thus when growing they tend to form pairs or chains, which may appear bent or twisted. This differs from staphylococci, which divide along multiple axes, thereby generating irregular, grape-like clusters of cells. Most streptococci are oxidase-negative and catalase-negative, and many are facultative anaerobes (capable of growth both aerobically and anaerobically). The term was coined in 1877 by Viennese surgeon Albert Theodor Billroth (1829–1894), by combining the prefix "strepto-" (from ), together with the suffix "-coccus" (from Modern , from .) In 1984, many bacteria formerly grouped in the genus ''Streptococcus'' were separated out into the genera '' Enterococcus'' and '' Lactococcus''. Currently, over 50 species are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus Pneumoniae
''Streptococcus pneumoniae'', or pneumococcus, is a Gram-positive, spherical bacteria, hemolysis (microbiology), alpha-hemolytic member of the genus ''Streptococcus''. ''S. pneumoniae'' cells are usually found in pairs (diplococci) and do not form Bacterial morphological plasticity, spores and are non motile. As a significant human pathogenic bacterium ''S. pneumoniae'' was recognized as a major cause of pneumonia in the late 19th century, and is the subject of many humoral immunity studies. ''Streptococcus pneumoniae'' resides asymptomatically in healthy carriers typically colonizing the respiratory tract, sinuses, and nasopharynx, nasal cavity. However, in susceptible individuals with immunocompromised, weaker immune systems, such as the elderly and young children, the bacterium may become pathogenic and spread to other locations to cause disease. It spreads by direct person-to-person contact via respiratory droplets and by auto inoculation in persons carrying the bacteria in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latex Fixation Test
A latex fixation test, also called a latex agglutination assay or test (LA assay or test), is an assay used clinically in the identification and typing of many important microorganisms. These tests use the patient's antigen-antibody immune response. This response occurs when the body detects a pathogen and forms an antibody specific to an identified antigen (a protein configuration) present on the surface of the pathogen. Agglutination tests, specific to a variety of pathogens, can be designed and manufactured for clinicians by coating microbeads of latex with pathogen-specific antigens or antibodies. In performing a test, laboratory clinicians will mix a patient's cerebrospinal fluid, serum or urine with the coated latex particles in serial dilutions with normal saline (important to avoid the prozone effect) and observe for agglutination (clumping). Agglutination of the beads in any of the dilutions is considered a positive result, confirming either that the patient's body has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
