1.
Mite
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Mites, along with ticks, are small arthropods belonging to the subclass Acari and the class Arachnida. The scientific discipline devoted to the study of ticks and mites is called acarology, in soil ecosystems, mites are favored by high organic matter content and by moist conditions, wherein they actively engage in the fragmentation and mixing of organic matter. Mites are among the most diverse and successful of all the invertebrate groups and they have exploited an incredible array of habitats, and because of their small size, go largely unnoticed. Many live freely in the soil or water, but there are also a number of species that live as parasites on plants, animals. It is estimated that 48,200 species of mites have been described, mites occupy a wide range of ecological niches. For example, Oribatida mites are important decomposers and occur in many habitats and they eat a wide variety of material including living and dead plant and fungal material, lichens and carrion, some are even predatory, though no species of Oribatida mite are parasites. Many mites which have well studied are parasitic on plants. One family of mites Pyroglyphidae, or nest mites, live primarily in the nests of birds and these mites are largely parasitic and consume blood, skin and keratin. Dust mites, which feed mostly on dead skin and hair shed from humans instead of consuming them from the organism directly, insects may also be infested by parasitic mites. Examples are Varroa destructor, which attaches to the body of the bee, and Acarapis woodi. There are hundreds of species of associated with other bee species. They attach to the bees in a variety of ways, for example, Trigona corvina workers have been found with mites attached to the outer face of their hind tibiae. Some are thought to be parasites, while others are beneficial symbionts, mites also parasitize some ant species, such as Eciton burchellii. Some of the plant pests include the spider mites, thread-footed mites. Among the species that attack animals are members of the sarcoptic mange mites, demodex mites are parasites that live in or near the hair follicles of mammals, including humans. Acari are mites, except for the three families of ticks, mites also hold the record speed, for its length, Paratarsotomus macropalpis is the fastest animal on Earth. The majority of species are harmless to humans, but a few species of mites can colonize humans directly, act as vectors for disease transmission. Mites which colonize human skin are the cause of several types of skin rashes, such as grain itch, grocers itch
2.
Flea
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Fleas are small flightless insects that form the order Siphonaptera. As external parasites of mammals and birds, they live by consuming the blood of their hosts, adults are up to about 3 mm long and usually brown. Bodies flattened sideways enable them to move through their hosts fur or feathers and they lack wings, and have mouthparts adapted for piercing skin and sucking blood and hind legs adapted for jumping. The latter enable them to leap a distance of some 50 times their body length, larvae are worm-like with no limbs, they have chewing mouthparts and feed on organic debris. Over 2,500 species of fleas have been described worldwide, the Siphonaptera are most closely related to the snow scorpionflies, placing them within the endopterygote insect order Mecoptera. Fleas arose in the early Cretaceous, most likely as ectoparasites of mammals and marsupials, each species of flea is more or less a specialist on its host animal species, many species never breed on any other host, though some are less selective. The oriental rat flea, Xenopsylla cheopis, is a vector of Yersinia pestis, the disease was spread by rodents such as the black rat, which were bitten by fleas that then infected humans. Major outbreaks included the Plague of Justinian and the Black Death, both of which killed a sizeable fraction of the worlds population. Fleas appear in human culture in such forms as flea circuses, poems like John Donnes erotic The Flea, works of music such as by Modest Mussorgsky. Flea legs end in strong claws that are designed to grasp a host, unlike other insects, fleas do not possess compound eyes but instead only have simple eyespots with a single biconvex lens, some species lack eyes altogether. Their bodies are compressed, permitting easy movement through the hairs or feathers on the hosts body. The flea body is covered with hard plates called sclerites and these sclerites are covered with many hairs and short spines directed backward, which also assist its movements on the host. The tough body is able to withstand great pressure, likely an adaptation to survive attempts to eliminate them by scratching, fleas lay tiny, white, oval eggs. The larvae are small and pale, have bristles covering their bodies, lack eyes. The larvae feed on organic matter, especially the feces of mature fleas, adults feed only on fresh blood. Immediately before the jump, muscles contract and deform the resilin pad, to prevent premature release of energy or motions of the leg, the flea employs a catch mechanism. Early in the jump, the tendon of the primary jumping muscle passes slightly behind the coxa-trochanter joint, generating a torque which holds the joint closed with the leg close to the body. To trigger jumping, another muscle pulls the tendon forward until it passes the joint axis, generating the opposite torque to extend the leg, the actual take off has been shown by high-speed video to be from the tibiae and tarsi rather than from the trochantera
3.
Rickettsia rickettsii
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Rickettsia rickettsii is a gram-negative, intracellular, coccobacillus bacterium that is around 0.8 to 2.0 micrometers long. R. rickettsi is the agent of Rocky Mountain spotted fever. R. rickettsii is one of the most pathogenic Rickettsia strains known to humans and affects a large majority of the Western Hemisphere, Rocky Mountain spotted fever first emerged in the Idaho Valley in 1896. At that time, not much information was known about the disease, the first clinical description of Rocky Mountain Spotted Fever was reported in 1899 by Edward E. Maxey. Howard Ricketts, a professor of pathology at the University of Chicago in 1902, was the first to identify. At this time, the trademark rash now began to emerge in the western Montana area. His research entailed interviewing victims of the disease and collecting and studying infected animals and he was also known to inject himself with pathogens to measure their effects. Unfortunately, his research was cut short after his death from an insect bite. S. Burt Wolbach is credited for the first detailed description of the agent that causes R. rickettsii in 1919. He clearly recognized it as a bacterium which was seen most frequently in endothelial cells. The most common hosts for the R. rickettsii bacteria are ticks, ticks that carry R. rickettsia fall into the family of Ixodidae ticks, also known as hard bodied ticks. Ticks are vectors, reservoirs and amplifiers of this disease, there are currently three known tick specifics that commonly carry R. rickettsii. American dog tick Rocky Mountain Wood Tick Brown dog tick, ticks can contract R. rickettsii by many means. Once a tick becomes infected with this pathogen, they are infected for life, in addition, an infected male tick can transmit the organism to an uninfected female during mating. Once infected, the tick can transmit the infection to her offspring. Due to its confinement in the midgut and small intestine, Rickettsia rickettsii can be transmitted to mammals, transmission to mammals can occur in multiple ways. One way of contraction is through the contact of infected host feces to an uninfected host, if infected host feces comes into contact with an open skin wound, it is possible for the disease to be transmitted. Additionally, an uninfected host can become infected with R. rickettsii when eating food that contains the feces of the infected vector, another way of contraction is by the bite of an infected tick
4.
Anaplasma phagocytophilum
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Anaplasma phagocytophilum is a gram-negative bacterium that is unusual in its tropism to neutrophils. It causes anaplasmosis in sheep and cattle, also known as fever and pasture fever. Anaplasma phagocytophilum is a Gram-negative, obligate bacterium of neutrophils and it causes human granulocytic anaplasmosis, which is a tick-borne rickettsial disease. Because this bacterium invades neutrophils, it has a unique adaptation, anaplasma phagocytophilum is a small, obligate, intracellular bacterium with a Gram-negative cell wall. It is 0. 2–1.0 μm and lacks a lipopolysaccharide biosynthetic machinery, the bacterium first resides in an early endosome, where it acquires nutrients for binary fission and grows into small groups called morulae. This bacterium prefers to grow within myeloid or granulocytic cells, anaplasma phagocytophilum causes human granulocytic anaplasmosis. This disease was first identified in 1990, although this pathogen was known to cause veterinary disease since 1932, since 1990, incidence of this disease has increased, and it is now recognized in Europe. This disease was first identified due to a Wisconsin patient who died with a severe illness two weeks after a tick bite. During the last stage of the infection, a group of bacteria were seen within the neutrophils in the blood. Other symptoms include fever, headache, absence of skin rash, leucopenia, thrombocytopenia, the disease is multisystemic, but the most severe changes are anaemia and leukopenia. This organism causes lameness which can be confused with symptoms of Lyme disease and it is a vector borne zoonotic disease whose morula can be visualized within neutrophils from the peripheral blood and synovial fluid. It can cause lethargy, ataxia, loss of appetite, anaplasma phagocytophilum binds to fucosylated and sialylated scaffold proteins on neutrophil and granulocyte surfaces. A type IV secretion apparatus is known to help in the transfer of molecules between the bacterium and the host, the most studied ligand is PSGL-1. The bacterium adheres to PSGL-1 through 44-kDa major surface protein-2, after the bacterium enters the cell, the endosome stops maturation and does not accumulate markers of late endosomes or phagolysosomes. Because of this, the vacuole does not become acidified or fused to lysosomes, a. phagocytophilum then divides until cell lysis or when the bacteria leave to infect other cells. This bacterium has the ability to affect neutrophils by altering the function of the host cell and it can survive the first encounter with the host cell by detoxifying superoxide produced by neutrophil phagocyte oxidase assembly. It also disrupts normal neutrophil function, such as cell adhesion, transmigration, motility, degranulation, respiratory burst. It causes an increase in the secretion of IL-8, a chemoattractant that increases the phagocytosis of neutrophils, the purpose of this is to increase bacterial dissemination into the neutrophil
5.
Proteobacteria
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The Proteobacteria are a major phylum of Gram-negative bacteria. The name of the phylum has never been published as no type genus has been proposed. They include a variety of pathogens, such as Escherichia, Salmonella, Vibrio, Helicobacter, Yersinia. Others are free-living, and include many of the responsible for nitrogen fixation. Carl Woese established this grouping in 1987, calling it informally the purple bacteria, the Alphaproteobacteria grow at very low levels of nutrients and have unusual morphology such as stalks and buds. They include agriculturally important bacteria capable of inducing nitrogen fixation in symbiosis with plants, the type order is the Caulobacterales, comprising stalk-forming bacteria such as Caulobacter. The Betaproteobacteria are highly diverse and contain chemolithoautotrophs, photoautotrophs. The type order is the Burkholderiales, comprising a range of metabolic diversity. The Gammaproteobacteria are the largest class in terms of species with validly published names, the type order is the Pseudomonadales, which include the genera Pseudomonas and the nitrogen-fixing Azotobacter. The Deltaproteobacteria include bacteria that are predators on other bacteria and are important contributors to the side of the sulfur cycle. The type order is the Myxococcales, which includes organisms with self-organising abilities such as Myxococcus spp, the Epsilonproteobacteria are often slender, Gram-negative rods that are helical or curved. The type order is the Campylobacterales, which includes important food pathogens such as Campylobacter spp, the type order is the Oligoflexales, which contains the genus Oligoflexus. The Acidithiobacillia contain only sulfur-oxidising autotrophs, the type order is the Acidithiobacillales, which includes economically important organisms used in the mining industry such as Acidithiobacillus spp. All Proteobacteria are Gram-negative, though some may stain Gram-positive or Gram-variable in practice, many move about using flagella, but some are nonmotile or rely on bacterial gliding. The last include the Myxobacteriales, an order of bacteria that can aggregate to form fruiting bodies. Also, a variety in the types of metabolism exists. Most members are facultatively or obligately anaerobic, Chemolithoautotrophic, and heterotrophic, a variety of genera, which are not closely related to each other, convert energy from light through photosynthesis. Proteobacteria are associated with the imbalance of microbiota of the reproductive tract of women
6.
Orientia tsutsugamushi
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Orientia tsutsugamushi is the causative organism of scrub typhus, and the natural vector and reservoir is probably trombiculid mites. The organism is an intracellular pathogen, which needs to infect eukaryotic cells in order to multiply. The envelope is similar to that of Gram negative bacteria, but it is not easily stained with Gram stain, genetic methods have revealed even greater complexity than had been previously described. Infection with one serotype does not confer immunity to other serotypes, repeated infection in the same individual is therefore possible, and this complicates vaccine design. The bacterium was initially categorised in the genus Rickettsia, but is now classed in a genus, Orientia. It is 0.5 µm wide and 1.2 to 3.0 µm long, the organism is highly virulent and should only be handled in a laboratory with biosafety level 3 facilities. O. tsutsugamushi is sensitive in vitro to doxycycline, rifampicin and azithromycin and it is innately resistant to all β-lactam antibiotics because it lacks a classical peptidoglycan cell wall. Aminoglycosides are also ineffective in human infection because the organism is intracellular, there are currently no licensed scrub typhus vaccines available. It is now known there is enormous antigenic variation in Orientia tsutsugamushi strains. Any scrub typhus vaccine should give protection to all the strains present locally, a vaccine developed for one locality may not be protective in another locality, because of antigenic variation. This complexity continues to hamper efforts to produce a viable vaccine
7.
Alphaproteobacteria
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Alphaproteobacteria is a class of bacteria in the phylum Proteobacteria. Its members are diverse and possess few commonalities, but nevertheless share a common ancestor. Like all Proteobacteria, its members are Gram-negative and some of its intracellular parasitic members lack peptidoglycan and are consequently gram variable. Moreover, the class includes the protomitochondrion, the bacterium that was engulfed by the ancestor and gave rise to the mitochondria. A species of technological interest is Rhizobium radiobacter, scientists use this species to transfer foreign DNA into plant genomes. There is some disagreement on the phylogeny of the orders, especially for the location of the Pelagibacterales and this issue stems form the large difference in gene content and the large difference in GC-richness between members of several order. Specifically, Pelagibacterales, Rickettsiales and Holosporales contains species with AT-rich genomes and it has been argued that it could be a case of convergent evolution that would result in an artefactual clustering. The basal group is Magnetococcidae, which is composed by a diversity of magnetotactic bacteria. The Rickettsidae is composed of the intracellular Rickettsiales and the free-living Pelagibacterales, the Caulobacteridae is composed of the Holosporales, Rhodospirillales, Sphingomonadales, Rhodobacterales, Caulobacterales, Kiloniellales, Kordiimonadales, Parvularculales and Sneathiellales. These molecular signatures provide novel means for the circumscription of these taxonomic groups, alphaproteobacteria at the US National Library of Medicine Medical Subject Headings Bacterial Phylogeny Webpage, Alpha Proteobacteria
8.
International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
. PMID 16223955.
