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Shigella
''Shigella'' is a genus of bacteria that is Gram negative, facultatively anaerobic, non–spore-forming, nonmotile, rod shaped, and is genetically nested within ''Escherichia''. The genus is named after Kiyoshi Shiga, who discovered it in 1897. ''Shigella'' causes disease in primates, but not in other mammals; it is the causative agent of human shigellosis. It is only naturally found in humans and gorillas. During infection, it typically causes dysentery. ''Shigella'' is a leading cause of bacterial diarrhea worldwide, with 80–165 million annual cases (estimated) and 74,000 to 600,000 deaths. It is one of the top four pathogens that cause moderate-to-severe diarrhea in African and South Asian children. Classification ''Shigella'' species are classified by three serogroups and one serotype: * Serogroup ''A'': '' S. dysenteriae'' (15 serotypes) * Serogroup ''B'': '' S. flexneri'' (9 serotypes) * Serogroup ''C'': '' S. boydii'' (19 serotypes) * Serogroup ''D'': '' S. so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shigellosis
Shigellosis, known historically as dysentery, is an infection of the intestines caused by ''Shigella'' bacteria. Symptoms generally start one to two days after exposure and include diarrhea, fever, abdominal pain, and feeling the need to pass stools even when the bowels are empty. The diarrhea may be bloody. Symptoms typically last five to seven days and it may take several months before bowel habits return entirely to normal. Complications can include reactive arthritis, sepsis, seizures, and hemolytic uremic syndrome. Shigellosis is caused by four specific types of ''Shigella''. These are typically spread by exposure to infected feces. This can occur via contaminated food, water, or hands or sexual contact. Contamination may be spread by flies or when changing diapers (nappies). Diagnosis is by stool culture. The risk of infection can be reduced by properly washing the hands. There is no vaccine. Shigellosis usually resolves without specific treatment. Rest, and suffic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shigella Flexneri
''Shigella flexneri'' is a species of Gram-negative bacteria in the genus ''Shigella'' that can cause diarrhea in humans. Several different serogroups of ''Shigella'' are described; ''S. flexneri'' belongs to group ''B''. ''S. flexneri'' infections which can usually be treated with antibiotics, although some strains have become resistant. Less severe cases are not usually treated because they become more resistant in the future. Shigella are closely related to ''Escherichia coli'', but can be differentiated from ''E.coli'' based on pathogenicity, physiology (failure to ferment lactose or decarboxylate lysine) and serology. Discovery The species was named after the American physician Simon Flexner; the genus Shigella is named after Japanese physician Kiyoshi Shiga, who researched the cause of dysentery. Shiga entered the Tokyo Imperial University School of Medicine in 1892, during which he attended a lecture by Dr. Shibasaburo Kitasato. Shiga was impressed by Dr. Kitasato's int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shigella Sonnei
''Shigella sonnei'' is a species of '' Shigella''. Together with '' Shigella flexneri'', it is responsible for 90% of shigellosis cases. ''Shigella sonnei'' is named for the Danish bacteriologist Carl Olaf Sonne. It is a Gram-negative, rod-shaped, nonmotile, non-spore-forming bacterium. Pathophysiology This species polymerizes host cell actin. Evolution This species is clonal and has spread worldwide. Analysis of 132 strains has shown that they originated from a common ancestor in Europe around 1500 AD. Causes "Group D" '' Shigella'' bacteria cause shigellosis. Those infected with the bacteria release it into their stool, thus causing possibility of spread through food or water, or from direct contact to a person orally. Having poorly sanitized living conditions or contaminated food or water contributes to contracting the disease. People at risk Infants and toddlers, the elderly, and people living with chronic health conditions are all susceptible to the most severe sympt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shigella Boydii
''Shigella boydii'' is a Gram-negative bacterium of the genus ''Shigella''. Like other members of the genus, ''S. boydii'' is a nonmotile, nonsporeforming, rod-shaped bacterium which can cause dysentery in humans through fecal-oral contamination. ''Shigella boydii'' is the most genetically divergent species of the genus ''Shigella''. There are 19 known serotypes of ''Shigella boydii''. ''S. boydii'' is restricted to the Indian subcontinent. The species is named after the British bacteriologist John Boyd. Sequenced genomes *''Shigella boydii'' strain BS512 (serotype 18; group 1) has one chromosome and five plasmids. References External links''Shigella boydii'' Genome Project Page— by Entrez The Entrez () Global Query Cross-Database Search System is a federated search engine, or web portal that allows users to search many discrete health sciences databases at the National Center for Biotechnology Information (NCBI) website. The NCB ... *Type strain of ''Shigella bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kiyoshi Shiga
was a Japanese physician and bacteriologist. He had a well-rounded education and career that led to many scientific discoveries. In 1897, Shiga was credited with the discovery and identification of the ''Shigella'' ''dysenteriae'' microorganism which causes dysentery, and the Shiga toxin which is produced by the bacteria. He conducted research on other diseases such as tuberculosis and trypanosomiasis, and made many advancements in bacteriology and immunology. Personal life Shiga was born in Sendai, Miyagi Prefecture. His original surname was Satō, but he changed it to his mother's maiden name, Shiga, after being brought up by his maternal family. Shiga was raised during Japan's Industrial age and restoration. The changing times put financial troubles on his family. In 1900, Kiyoshi Shiga married Ichiko Shiga and in the following years had eight children. He faced many family hardships. Shiga lost his wife in 1944 to stomach cancer, his eldest son to turbulent seas during a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shigella Dysenteriae
''Shigella dysenteriae'' is a species of the rod-shaped bacterial genus ''Shigella''. ''Shigella'' species can cause shigellosis ( bacillary dysentery). Shigellae are Gram-negative, non-spore-forming, facultatively anaerobic, nonmotile bacteria. ''S. dysenteriae'' has the ability to invade and replicate in various species of epithelial cells and enterocytes. Signs and symptoms The most commonly observed signs associated with ''Shigella'' dysentery include colitis, malnutrition, rectal prolapse, tenesmus, reactive arthritis, and central nervous system problems. Further, ''S. dysenteriae'' is associated with the development of hemolytic-uremic syndrome, which includes anemia, thrombocytopenia, and kidney failure. If infected with ''S. dysenteriae'', an individual will experience a severe case of shigellosis. Mortality is higher with ''S. dysenteriae'' type 1. Most cases of shigellosis are in developing countries. Shigellosis outbreaks in Asia, Latin America and Africa have had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escherichia Coli
''Escherichia coli'' ( )Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Escherichia'' that is commonly found in the lower intestine of warm-blooded organisms. Most ''E. coli'' strains are part of the normal microbiota of the gut, where they constitute about 0.1%, along with other facultative anaerobes. These bacteria are mostly harmless or even beneficial to humans. For example, some strains of ''E. coli'' benefit their hosts by producing vitamin K2 or by preventing the colonization of the intestine by harmful pathogenic bacteria. These mutually beneficial relationships between ''E. coli'' and humans are a type of mutualistic biological relationship—where both the humans and the ''E. coli'' are benefitting each other. ''E. coli'' is expelled into the environment within fecal matter. The bacterium grows massi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysentery
Dysentery ( , ), historically known as the bloody flux, is a type of gastroenteritis that results in bloody diarrhea. Other symptoms may include fever, abdominal pain, and a feeling of incomplete defecation. Complications may include dehydration. The cause of dysentery is usually the bacteria from genus '' Shigella'', in which case it is known as shigellosis, or the amoeba '' Entamoeba histolytica''; then it is called amoebiasis. Other causes may include certain chemicals, other bacteria, other protozoa, or parasitic worms. It may spread between people. Risk factors include contamination of food and water with feces due to poor sanitation. The underlying mechanism involves inflammation of the intestine, especially of the colon. Efforts to prevent dysentery include hand washing and food safety measures while traveling in countries of high risk. While the condition generally resolves on its own within a week, drinking sufficient fluids such as oral rehydration solutio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verotoxin
Shiga toxins are a family of related toxins with two major groups, Stx1 and Stx2, expressed by genes considered to be part of the genome of lambdoid prophages. The toxins are named after Kiyoshi Shiga, who first described the bacterial origin of dysentery caused by '' Shigella dysenteriae''. Shiga-like toxin (SLT) is a historical term for similar or identical toxins produced by ''Escherichia coli''. The most common sources for Shiga toxin are the bacteria ''S. dysenteriae'' and some serotypes of ''Escherichia coli'' (shigatoxigenic or STEC), which include serotypes O157:H7, and O104:H4. Nomenclature Microbiologists use many terms to describe Shiga toxin and differentiate more than one unique form. Many of these terms are used interchangeably. # Shiga toxin type 1 and type 2 (Stx-1 and 2) are the Shiga toxins produced by some'' E. coli'' strains. Stx-1 is identical to Stx of ''Shigella'' spp. or differs by only one amino acid. Stx-2 shares 55% amino acid homology w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Diarrhea
Diarrhea (American English), also spelled diarrhoea or diarrhœa (British English), is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin with loss of the normal stretchiness of the skin and irritable behaviour. This can progress to decreased urination, loss of skin color, a fast heart rate, and a decrease in responsiveness as it becomes more severe. Loose but non-watery stools in babies who are exclusively breastfed, however, are normal. What is diarrhea? How is it caused, treated and prevented? (see also script)The most common cause is an infection of the intestines due to a virus, bacterium, or parasite—a condition also known as gastroenteritis. These infections are often acquired from food or water that has been contaminated by feces, or directly from another person who is infected. The three types of diarrhea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
