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Spirochaete
A spirochaete () or spirochete is a member of the phylum Spirochaetota (also called Spirochaetes ), which contains distinctive diderm (double-membrane) Gram-negative bacteria, most of which have long, helically coiled (corkscrew-shaped or spiraled, hence the name) cells. Spirochaetes are chemoheterotrophic in nature, with lengths between 3 and 500 μm and diameters around 0.09 to at least 3 μm. Spirochaetes are distinguished from other bacterial phyla by the location of their flagella, called endoflagella, or periplasmic flagella, which are sometimes called ''axial filaments''. Endoflagella are anchored at each end (pole) of the bacterium within the periplasmic space (between the inner and outer membranes) where they project backwards to extend the length of the cell. These cause a twisting motion which allows the spirochaete to move. When reproducing, a spirochaete will undergo asexual transverse binary fission. Most spirochaetes are free-living and anaerobic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Treponema Pallidum
''Treponema pallidum'', formerly known as ''Spirochaeta pallida'', is a Microaerophile, microaerophilic, Gram-negative bacteria, gram-negative, spirochaete bacterium with subspecies that cause the diseases syphilis, bejel (also known as endemic syphilis), and yaws. It is known to be transmitted only among humans and baboons. ''T. pallidum'' can enter the host through mucosal membranes or open lesions in the skin and is primarily spread through sexual contact. It is a helically coiled microorganism usually 6–15 μm long and 0.1–0.2 μm wide. ''T. pallidum'''s lack of both a Citric acid cycle, tricarboxylic acid cycle and processes for oxidative phosphorylation results in minimal metabolic activity. As a Chemoorganoheterotrophic, chemoorganoheterotroph, ''Treponema pallidum'' is an obligate parasite that acquires its glucose carbon source from its host. Glucose can be used not only as a primary carbon source but also in glycolytic mechanisms to generate ATP needed to power the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periplasmic Space
The periplasm is a concentrated gel-like matrix in the space between the inner cytoplasmic membrane and the bacterial outer membrane called the ''periplasmic space'' in Gram-negative (more accurately "diderm") bacteria. Using cryo-electron microscopy it has been found that a much smaller periplasmic space is also present in Gram-positive bacteria (more accurately "monoderm"), between cell wall and the plasma membrane. The periplasm may constitute up to 40% of the total cell volume of gram-negative bacteria, but is a much smaller percentage in gram-positive bacteria. Terminology Although bacteria are conventionally divided into two main groups—Gram-positive and Gram-negative, based upon their Gram-stain retention property—this classification system is ambiguous as it can refer to three distinct aspects (staining result, cell-envelope organization, taxonomic group), which do not necessarily coalesce for some bacterial species. In most situations such as in this article, Gram-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borrelia Afzelii
''Borrelia afzelii'' is a species of ''Borrelia'' endemic to parts of Eurasia where it is one of the causative agents of Lyme disease. It is transmitted by hard-bodied ticks of the Ixodes genus (''Ixodes ricinus'' in Europe, and '' Ixodes persulcatus'' in temperate regions of Asia), infecting various wild mammals in nature. Among 30 ''Borrelia'' known species, it is one of four which are likely to infect humans. Dermatological manifestations are more common in Lyme disease caused by ''B. afzelii''. It is named after Swedish dermatologist Arvid Afzelius. See also * Lyme disease Lyme disease, also known as Lyme borreliosis, is a tick-borne disease caused by species of ''Borrelia'' bacteria, Disease vector, transmitted by blood-feeding ticks in the genus ''Ixodes''. It is the most common disease spread by ticks in th ... References Further reading * External links Type strain of ''Borrelia afzelii'' at Bac''Dive'' - the Bacterial Diversity Metadatabase Lyme di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borrelia Garinii
''Borrelia garinii'' is a species of spirochete bacterium in the genus ''Borrelia''. It is endemic to parts of Eurasia where it is one of the causative organisms of human Lyme disease. It is transmitted by hard-bodied ticks of the Ixodes genus (''Ixodes ricinus'' in Europe, and '' Ixodes persulcatus'' in temperate regions of Asia), infecting various wild woodland mammals. Neurological complications are more frequent in human Lyme disease Lyme disease, also known as Lyme borreliosis, is a tick-borne disease caused by species of ''Borrelia'' bacteria, Disease vector, transmitted by blood-feeding ticks in the genus ''Ixodes''. It is the most common disease spread by ticks in th ... caused by this Borrelia species. References Further reading * External links NCBI Taxonomy Browser - Borrelia [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borrelia Bissettii
''Borrelia bissettiae'' (formerly B. bissettii, before renaming in 2019) is a spirochete bacterium. The type strain is strain DN127. It is pathogenic In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term ... and causes Lyme borreliosis in the Americas and Eurasia. See also * Lyme disease microbiology References Further reading * * External links NCBI Taxonomy Browser - Borrelia*Type strain of ''Borrelia bissettii'' at Bac''Dive'' - the Bacterial Diversity Metadatabase bissettii Bacteria described in 1998 {{Spirochaetae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borrelia Mayonii
''Borrelia mayonii'' is a Gram-negative, host-associated spirochete that is capable of causing Lyme disease. This organism can infect various vertebrate hosts such as humans via the bite of a black legged tick. Phylogenetic information ''Borrelia mayonii'' was identified as a ''sensu lato'' (broad sense), genospecies (Bbsl) of the known microbe, '' Borrelia burgdorferi''. A genospecies is a cluster of organisms with similar core genes that usually does not undergo genetic recombination with diverged organisms. Two isolates, gene strains, of ''B. mayonii'', named MN14-1420 and MN14-1539, were sequenced, process of arranging a chain of genetic information to match up to a specific organism's genetic code, and compared to the genome or genetic material of ''Borrelia burgdorferi''. With a nucleotide similarity of 93.83% in the linear chromosome compared to other known genospecies, ''B. mayonii'' can be considered a new genospecies (Bbsl). Discovery ''Borrelia mayonii'' i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borrelia Burgdorferi
''Borrelia burgdorferi'' is a bacterial species of the spirochete class in the genus '' Borrelia'', and is one of the causative agents of Lyme disease in humans. Along with a few similar genospecies, some of which also cause Lyme disease, it makes up the species complex of ''Borrelia burgdorferi'' sensu lato. The complex currently comprises 20 accepted and 3 proposed genospecies. ''B. burgdorferi'' sensu stricto exists in North America and Eurasia and until 2016 was the only known cause of Lyme disease in North America. ''B. burgdorferi'' are often mistakenly described as Gram negative because of their two external membranes, but they lack lipopolysaccharide and possess many surface lipoproteins, unlike true Gram-negative bacteria. Microbiology ''Borrelia burgdorferi'' is named after the researcher Willy Burgdorfer, who first isolated the bacterium in 1982. ''Borrelia burgdorferi'' is a microaerophile, requiring small amounts of oxygen in order to undergo glycolysis and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptospirosis
Leptospirosis is a blood infection caused by the bacterium ''Leptospira'' that can infect humans, dogs, rodents and many other wild and domesticated animals. Signs and symptoms can range from none to mild (headaches, Myalgia, muscle pains, and fevers) to severe (pulmonary hemorrhage, bleeding in the lungs or meningitis). Weil's disease ( ), the acute, severe form of leptospirosis, causes the infected individual to become jaundiced (skin and eyes become yellow), develop kidney failure, and bleed. Bleeding from the lungs associated with leptospirosis is known as severe pulmonary haemorrhage syndrome. More than ten genetic types of ''Leptospira'' cause disease in humans. Both wild and domestic animals can spread the disease, most commonly rodents. The bacteria are spread to humans through animal urine or manure, feces, or water or soil contaminated with animal urine and feces, coming into contact with the eyes, mouth, nose or breaks in the skin. In developing countries, the dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptospira
''Leptospira'' () is a genus of spirochaete bacteria, including a small number of pathogenic and saprophytic species. ''Leptospira'' was first observed in 1907 in kidney tissue slices of a leptospirosis victim who was described as having died of " yellow fever". Taxonomy ''Leptospira'', together with the genera ''Leptonema'' and ''Turneria'', is a member of the family Leptospiraceae. The genus ''Leptospira'' is divided into 20 species based on DNA hybridization studies. Pathogenic ''Leptospira'' :''Leptospira alstonii'' Smythe et al. 2013 ''Leptospira alstoni''" Haake et al. 1993:''Leptospira interrogans'' (Stimson 1907) Wenyon 1926 emend. Faine and Stallman 1982 ["''Spirochaeta interrogans''" Stimson 1907; "''Spirochaeta nodosa''" Hubener & Reiter 1916; "''Spirochaeta icterohaemorrhagiae''" Inada et al. 1916; "''Spirochaeta icterogenes''" Uhlenhuth & Fromme 1916; "''Leptospira icteroides''" Noguchi 1919] :''Leptospira kirschneri'' Ramadass et al. 1992 :''Leptospira noguchi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genome Size
Genome size is the total amount of DNA contained within one copy of a single complete genome. It is typically measured in terms of mass in picograms (trillionths or 10−12 of a gram, abbreviated pg) or less frequently in daltons, or as the total number of nucleotide base pairs, usually in megabases (millions of base pairs, abbreviated Mb or Mbp). One picogram is equal to 978 megabases. In diploid organisms, genome size is often used interchangeably with the term C-value. An organism's complexity is not directly proportional to its genome size; total DNA content is widely variable between biological taxa. Some single-celled organisms have much more DNA than humans, for reasons that remain unclear (see Junk DNA and C-value). Variation in genome size and gene content Since the 1950s, with the emergence of various molecular techniques, the genome sizes of thousands of eukaryotes have been analyzed, and these data are available in online databases for animals, plants, and fung ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GC Content
In molecular biology and genetics, GC-content (or guanine-cytosine content) is the percentage of nitrogenous bases in a DNA or RNA molecule that are either guanine (G) or cytosine (C). This measure indicates the proportion of G and C bases out of an implied four total bases, also including adenine and thymine in DNA and adenine and uracil in RNA. GC-content may be given for a certain fragment of DNA or RNA or for an entire genome. When it refers to a fragment, it may denote the GC-content of an individual gene or section of a gene (domain), a group of genes or gene clusters, a non-coding region, or a synthetic oligonucleotide such as a primer. Structure Qualitatively, guanine (G) and cytosine (C) undergo a specific hydrogen bonding with each other, whereas adenine (A) bonds specifically with thymine (T) in DNA and with uracil (U) in RNA. Quantitatively, each GC base pair is held together by three hydrogen bonds, while AT and AU base pairs are held together by two hydrogen bon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecological Niche
In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of Resource (biology), resources and competitors (for example, by growing when resources are abundant, and when predators, parasites and pathogens are scarce) and how it in turn alters those same factors (for example, limiting access to resources by other organisms, acting as a food source for predators and a consumer of prey). "The type and number of variables comprising the dimensions of an environmental niche vary from one species to another [and] the relative importance of particular environmental variables for a species may vary according to the geographic and biotic contexts". See also Chapter 2: Concepts of niches, pp. 7 ''ff'' A Grinnellian niche is determined by the habitat in which a species lives and its accompanying Behavioral ecology, behavioral adaptations. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
