"},"subdivision_ranks":{"wt":"Species"},"subdivision":{"wt":"''[[Escherichia albertii|E. albertii]]''
\n''[[Escherichia coli|E. coli]]''
\n''[[Escherichia fergusonii|E. fergusonii]]''
\n''[[Escherichia hermannii|E. hermannii]]''
\n''[[Escherichia ruysiae|E. ruysiae]]''{{cite journal|last1=Parte|first1=A.C.|title=Escherichia|journal=[[LPSN]]|url=https://lpsn.dsmz.de/genus/escherichia}}
\n''[[Escherichia marmotae|E. marmotae]]''{{cite journal|last1=Parte|first1=A.C.|title=Escherichia|journal=[[LPSN]]|url=https://lpsn.dsmz.de/genus/escherichia}}"},"type_species":{"wt":"Escherichia coli"},"type_species_authority":{"wt":"(Escherich, 1886)"}},"i":0}}]}" id="mwBA">
Escherichia | |
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SEM micrograph of cluster of Escherichia coli bacteria. Each individual bacterium is oblong. | |
Scientific classification ![]() | |
Domain: | Bacteria |
Phylum: | Pseudomonadota |
Class: | Gammaproteobacteria |
Order: | Enterobacterales |
Family: | Enterobacteriaceae |
Genus: | Escherichia Castellani & Chalmers 1919 [1] |
Type species | |
Escherichia coli (Escherich, 1886) | |
Species | |
E. albertii Contents |
Escherichia ( /ˌɛʃəˈrɪkiə/ ESH-ə-RIK-ee-ə) is a genus of Gram-negative, non-spore-forming, facultatively anaerobic, rod-shaped bacteria from the family Enterobacteriaceae. [3] In those species which are inhabitants of the gastrointestinal tracts of warm-blooded animals, Escherichia species provide a portion of the microbially derived vitamin K for their host. A number of the species of Escherichia are pathogenic. [4] The genus is named after Theodor Escherich, the discoverer of Escherichia coli . Escherichia are facultative aerobes, with both aerobic and anaerobic growth, and an optimum temperature of 37 °C. [3] Escherichia are usually motile by flagella, produce gas from fermentable carbohydrates, and do not decarboxylate lysine or hydrolyze arginine. [5] Species include E. albertii , E. fergusonii , E. hermannii , E. ruysiae , E. marmotae and most notably, the model organism and clinically relevant E. coli . Formerly, Shimwellia blattae [6] and Pseudescherichia vulneris were also classified in this genus.
While many Escherichia are commensal members of the gut microbiota, certain strains of some species, most notably the pathogenic serotypes of E. coli , are human pathogens, [7] and are the most common cause of urinary tract infections, [8] significant sources of gastrointestinal disease, ranging from simple diarrhea to dysentery-like conditions, [3] as well as a wide range of other pathogenic states [9] classifiable in general as colonic escherichiosis. While E. coli is responsible for the vast majority of Escherichia-related pathogenesis, other members of the genus have also been implicated in human disease. [10] [11] Escherichia are associated with the imbalance of microbiota of the lower reproductive tract of women. These species are associated with inflammation. [12]
Escherichia coli ( ESH-ə-RIK-ee-ə KOH-ly) 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 harmless, but some serotypes such as EPEC, and ETEC are pathogenic and can cause serious food poisoning in their hosts, and are occasionally responsible for food contamination incidents that prompt product recalls. Most strains are part of the normal microbiota of the gut and are harmless or even beneficial to humans (although these strains tend to be less studied than the pathogenic ones). For example, some strains of E. coli benefit their hosts by producing vitamin K2 or by preventing the colonization of the intestine by 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 massively in fresh fecal matter under aerobic conditions for three days, but its numbers decline slowly afterwards.
Enterococcus is a large genus of lactic acid bacteria of the phylum Bacillota. Enterococci are gram-positive cocci that often occur in pairs (diplococci) or short chains, and are difficult to distinguish from streptococci on physical characteristics alone. Two species are common commensal organisms in the intestines of humans: E. faecalis (90–95%) and E. faecium (5–10%). Rare clusters of infections occur with other species, including E. casseliflavus, E. gallinarum, and E. raffinosus.
Fusobacterium is a genus of obligate anaerobic, Gram-negative, non-sporeforming bacteria belonging to Gracilicutes. Individual cells are slender, rod-shaped bacilli with pointed ends. Fusobacterium was discovered in 1900 by Courmont and Cade and is common in the flora of humans.
Proteus is a genus of Gram-negative bacteria. It is a rod shaped, aerobic and motile bacteria, which is able to migrate across surfaces due its “swarming” characteristic in temperatures between 20 and 37 °C. Their size generally ranges from 0.4–0.8 μm in diameter and 1.0–3.0 μm in length. They tend to have an ammonia smell. Proteus bacilli are widely distributed in nature as saprophytes, being found in decomposing animal matter, sewage, manure soil, the mammalian intestine, and human and animal feces. They are opportunistic pathogens, commonly responsible for urinary and septic infections, often nosocomial.
Coliform bacteria are defined as either motile or non-motile Gram-negative non-spore forming Bacilli that possess β-galactosidase to produce acids and gases under their optimal growth temperature of 35-37°C. They can be aerobes or facultative aerobes, and are a commonly used indicator of low sanitary quality of foods, milk, and water. Coliforms can be found in the aquatic environment, in soil and on vegetation; they are universally present in large numbers in the feces of warm-blooded animals as they are known to inhabit the gastrointestinal system. While coliform bacteria are not normally causes of serious illness, they are easy to culture, and their presence is used to infer that other pathogenic organisms of fecal origin may be present in a sample, or that said sample is not safe to consume. Such pathogens include disease-causing bacteria, viruses, or protozoa and many multicellular parasites.
Enterobacter is a genus of common Gram-negative, facultatively anaerobic, rod-shaped, non-spore-forming bacteria of the family Enterobacteriaceae. It is the type genus of the order Enterobacterales. Several strains of these bacteria are pathogenic and cause opportunistic infections in immunocompromised hosts and in those who are on mechanical ventilation. The urinary and respiratory tracts are the most common sites of infection. The genus Enterobacter is a member of the coliform group of bacteria. It does not belong to the fecal coliforms group of bacteria, unlike Escherichia coli, because it is incapable of growth at 44.5 °C in the presence of bile salts. Some of them show quorum sensing properties.
Peptostreptococcus is a genus of anaerobic, Gram-positive, non-spore forming bacteria. The cells are small, spherical, and can occur in short chains, in pairs or individually. They typically move using cilia. Peptostreptococcus are slow-growing bacteria with increasing resistance to antimicrobial drugs. Peptostreptococcus is a normal inhabitant of the healthy lower reproductive tract of women.
Bacteroides is a genus of Gram-negative, obligate anaerobic bacteria. Bacteroides species are non endospore-forming bacilli, and may be either motile or nonmotile, depending on the species. The DNA base composition is 40–48% GC. Unusual in bacterial organisms, Bacteroides membranes contain sphingolipids. They also contain meso-diaminopimelic acid in their peptidoglycan layer.
Mecillinam (INN) or amdinocillin (USAN) is an extended-spectrum penicillin antibiotic of the amidinopenicillin class that binds specifically to penicillin binding protein 2 (PBP2), and is only considered to be active against Gram-negative bacteria. It is used primarily in the treatment of urinary tract infections, and has also been used to treat typhoid and paratyphoid fever. Because mecillinam has very low oral bioavailability, an orally active prodrug was developed: pivmecillinam.
Porphyromonas is a Gram-negative, non-spore-forming, obligately anaerobic and non-motile genus from the family Porphyromonadaceae. There were 16 different Porphyromonas species documented as of 2015, which reside in both animal and human reservoirs. It was discovered more recently that Porphyromonas also exist in the environment, albeit to a lesser extent. This genus is notably implicated in the modulation of oral cavity, respiratory tract, and gastrointestinal tract disease states. It is suggested that Porphyromonas either operate as benign bacteria pertinent to host immunity or are potential pathobionts that opportunistically provoke diseased states when homeostasis is disrupted. Despite its characterization not being fully elucidated due to sparse research, various studies report the prevalence of this genus at 58.7% in healthy states compared with 41.3% in diseased states.
Clostridium cadaveris is an enteric, gas-forming, motile, strictly anaerobic gram-positive bacterium of the genus Clostridium. First described by Klein in 1899, it was noted to be the most prominent bacteria during human decomposition; historically it was described as "putrefying flora".
Escherichia coli is a gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms (endotherms). Most E. coli strains are harmless, but pathogenic varieties cause serious food poisoning, septic shock, meningitis, or urinary tract infections in humans. Unlike normal flora E. coli, the pathogenic varieties produce toxins and other virulence factors that enable them to reside in parts of the body normally not inhabited by E. coli, and to damage host cells. These pathogenic traits are encoded by virulence genes carried only by the pathogens.
Pseudescherichia vulneris is a Gram-negative bacterial species. P. vulneris is a fermentative, oxidase-negative, motile rod, which holds characteristics of the family Enterobacteraceae. This bacterium can colonize in the respiratory tract, genital tract, stool, and urinary tract. However, P. vulneris is most often associated with wounds and has been known to colonize open wounds of both humans and animals. This association gave the bacterium its species name, vulneris, which is Latin for wound. It has also been infrequently reported in cases of meningitis. It was identified as Escherichia vulneris in 1982 with a 2017 genomic analysis of its original genus resulting in the creation of its new genus Pseudescherichia.
Enterococcus malodoratus is a species of the genus Enterococcus and a gram positive bacteria capable of opportunistic pathogenic response. These microbes have a thick polypeptide layer. Enterococcus can be found in the gastrointestinal tracts of humans and other mammals. In a study on the enterococcal flora of swine, E. malodoratus was found in the intestines and feces. It was not identified within the tonsils of swine, nor within cats, calves, dogs, horse, or poultry. The name "malodoratus" translates to "ill smelling".
Dialister pneumosintes is a nonfermentative, anaerobic, gram-negative rod that grows with small, circular, transparent, shiny, smooth colonies on blood agar. D. pneumosintes has been recovered from deep periodontal pockets, but little is known about the relationship between the organism and destructive periodontal disease.
Kocuria is a genus of gram-positive bacteria. Kocuria is named after Miloslav Kocur, a Czech microbiologist. It has been found in the milk of water deer and reindeer. Cells are coccoid, resembling Staphylococcus and Micrococcus, and can group in pairs, chains, tetrads, cubical arrangements of eight, or irregular clusters. They have rigid cell walls and are either aerobic or facultative anaerobic. Kocuria can usually survive in mesophilic temperatures.
Escherichia hermannii is a Gram-negative, rod-shaped species of bacterium. Strains of this species were originally isolated from human wounds, sputum, and stool. The species is named for American microbiologists George J. Hermann and Lloyd G. Herman.
Shimwellia is a genus of Gram-negative bacteria of the family Enterobacteriaceae. The two species of Shimwellia are Shimwellia blattae and Shimwellia pseudoproteus.
Nonpathogenic organisms are those that do not cause disease, harm or death to another organism. The term is usually used to describe bacteria. It describes a property of a bacterium – its inability to cause disease. Most bacteria are nonpathogenic. It can describe the presence of non-disease causing bacteria that normally reside on the surface of vertebrates and invertebrates as commensals. Some nonpathogenic microorganisms are commensals on and inside the body of animals and are called microbiota. Some of these same nonpathogenic microorganisms have the potential to cause disease, or being pathogenic, if they enter the body, multiply and cause symptoms of infection. Immunocompromised individuals are especially vulnerable to bacteria that are typically nonpathogenic; because of a compromised immune system, disease occurs when these bacteria gain access to the body's interior. Genes have been identified that predispose disease and infection with nonpathogenic bacteria by a small number of persons. Nonpathogenic Escherichia coli strains normally found in the gastrointestinal tract have the ability to stimulate the immune response in humans, though further studies are needed to determine clinical applications.
Shimwellia blattae is a species of bacterium, one of two in the genus Shimwellia. It is an aerobic enteric bacterium first isolated from the hindgut of cockroaches. Although it is related to human pathogens, including Escherichia coli, S. blattae is not pathogenic to humans. It is notable for its ability to synthesize vitamin B12 de novo.
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