Rickettsia africae is a species of Rickettsia .
It can cause African tick-bite fever.
Rickettsia is a genus of nonmotile, Gram-negative, nonspore-forming, highly pleomorphic bacteria that may occur in the forms of cocci 0.1 μm in diameter, rods 1–4 μm long, or threads of up to about 10 μm long. The term "rickettsia" has nothing to do with rickets, which is a deficiency disease resulting from lack of vitamin D; the bacterial genus Rickettsia was named after Howard Taylor Ricketts, in honour of his pioneering work on tick-borne spotted fever.
Rickettsia prowazekii is a species of gram-negative, alphaproteobacteria, obligate intracellular parasitic, aerobic Bacillus bacteria that is the etiologic agent of epidemic typhus, transmitted in the feces of lice. In North America, the main reservoir for R. prowazekii is the flying squirrel. R. prowazekii is often surrounded by a protein microcapsular layer and slime layer; the natural life cycle of the bacterium generally involves a vertebrate and an invertebrate host, usually an arthropod, typically the human body louse. A form of R. prowazekii that exists in the feces of arthropods remains stably infective for months. R. prowazekii also appears to be the closest free-living relative of mitochondria, based on genome sequencing.
The Rickettsiales, informally called rickettsias, are an order of small Alphaproteobacteria that are endosymbionts of eukaryotic cells. Some are notable pathogens, including Rickettsia, which causes a variety of diseases in humans, and Ehrlichia, which causes diseases in livestock. Another genus of well-known Rickettsiales are the Wolbachia, which infect approximately two-thirds of all arthropods and nearly all filarial nematodes. Genetic studies support the endosymbiotic theory according to which mitochondria and related organelles developed from members of this group.
Coxiella burnetii is an obligate intracellular bacterial pathogen, and is the causative agent of Q fever. The genus Coxiella is morphologically similar to Rickettsia, but with a variety of genetic and physiological differences. C. burnetii is a small Gram-negative, coccobacillary bacterium that is highly resistant to environmental stresses such as high temperature, osmotic pressure, and ultraviolet light. These characteristics are attributed to a small cell variant form of the organism that is part of a biphasic developmental cycle, including a more metabolically and replicatively active large cell variant form. It can survive standard disinfectants, and is resistant to many other environmental changes like those presented in the phagolysosome.
Genome size is the total amount of DNA contained within one copy of a single genome. It is typically measured in terms of mass in picograms or less frequently in Daltons or as the total number of nucleotide base pairs typically in megabases. One picogram equals 978 megabases. In diploid organisms, genome size is used interchangeably with the term C-value. An organism's complexity is not directly proportional to its genome size; some single cell organisms have much more DNA than humans.
The Weil–Felix test is an agglutination test for the diagnosis of rickettsial infections. It was first described in 1916. By virtue of its long history and of its simplicity, it has been one of the most widely employed tests for rickettsia on a global scale, despite being superseded in many settings by more sensitive and specific diagnostic tests.
Meningoencephalitis, also known as herpes meningoencephalitis, is a medical condition that simultaneously resembles both meningitis, which is an infection or inflammation of the meninges, and encephalitis, which is an infection or inflammation of the brain.
A rickettsiosis is a disease caused by intracellular bacteria.
Orientia tsutsugamushi is a mite-borne bacterium belonging to the family Rickettsiaceae and is responsible for a disease called scrub typhus in humans. It is a natural and an obligate intracellular parasite of mites belonging to the family Trombiculidae. With a genome of only 2.4–2.7 Mb, it has the most repeated DNA sequences among bacterial genomes sequenced so far. The disease, scrub typhus, occurs when infected mite larvae accidentally bite humans. Primarily indicated by undifferentiated febrile illnesses, the infection can be complicated and often fatal.
Rickettsia conorii is a Gram-negative, obligate intracellular bacterium of the genus Rickettsia that causes human disease called Boutonneuse fever, Mediterranean spotted fever, Israeli tick typhus, Astrakhan spotted fever, Kenya tick typhus, Indian tick typhus, or other names that designate the locality of occurrence while having distinct clinical features. It is a member of the spotted fever group and the most geographically dispersed species in the group, recognized in most of the regions bordering on the Mediterranean Sea and Black Sea, Israel, Kenya, and other parts of North, Central, and South Africa, and India. The prevailing vector is the brown dog tick, Rhipicephalus sanguineus. The bacterium was isolated by Emile Brumpt in 1932 and named after A. Conor who, in collaboration with A. Bruch, provided the first description of boutonneuse fever in Tunisia in 1910.
Rickettsia typhi is a species of infectious bacterium of the genus Rickettsia; it is the causative agent of Murine typhus.
African tick bite fever (ATBF) is a bacterial infection spread by the bite of a tick. Symptoms may include fever, headache, muscles pains, and a rash. At the site of the bite there is typically a red skin sore with a dark center. Onset usually occur 4–10 days after the bite. Complications are rare, however may include joint inflammation. Some people do not develop symptoms.
Rickettsia australis is a bacterium that causes a medical condition called Queensland tick typhus. The probable vectors are the tick species, Ixodes holocyclus and Ixodes tasmani. Small marsupials are suspected reservoirs of this bacterium.
Rickettsia felis is a species of bacterium, the pathogen that causes cat-flea typhus in humans. In cats the disease is known as flea-borne spotted fever. Rickettsia felis also is regarded as the causative organism of many cases of illnesses generally classed as fevers of unknown origin in humans in Africa.
Rickettsia honei is a species of Rickettsia.
Rickettsia sibirica is a species of Rickettsia. This bacterium is the etiologic agent of North Asian tick typhus, which is also known as Siberian tick typhus. The ticks that transmit it are primarily various species of Dermacentor and Haemaphysalis.
Rickettsia japonica is a species of Rickettsia. It can cause Japanese spotted fever.
Rickettsia peacockii is a species of gram negative Alphaproteobacteria of the spotted fever group, identified from Rocky Mountain wood ticks. Its type strain is SkalkahoT. The organism is passed transstadially and transovarially, and infections are localized in ovarial tissues.
Rickettsia heilongjiangensis is a species of gram negative Alphaproteobacteria, within the spotted fever group, being carried by ticks. It is pathogenic.
Liposcelis is a genus of insects in the order Psocoptera, the booklice and barklice. There are about 126 species. Many species are associated with human habitation and several are well known as pests of stored products. The genus is distributed nearly worldwide.
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