Rickettsia (redirected from Rickettsia canadensis)

Rickettsia /Rick·ett·sia/ (rĭ-ket´se-ah) a genus of the tribe Rickettsieae, transmitted by lice, fleas, ticks, and mites to humans and other animals, causing various diseases.

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Rickettsia a´kari  the etiologic agent of rickettsialpox, transmitted by the mite Allodermanyssus sanguineus from the reservoir of infection in house mice.

Rickettsia austra´lis  the etiologic agent of North Queensland tick typhus, possibly transmitted by Ixodes ticks.

Rickettsia cono´rii  the etiologic agent of boutonneuse fever (Marseilles fever, Mediterranean fever) and possibly of Indian tick typhus, Kenya typhus, and South American tick-bite fever; transmitted by Rhipicephalus and Haemaphysalis ticks.

Rickettsia prowaze´kii  the etiologic agent of epidemic typhus and the latent infection Brill's disease, which are transmitted between humans via Pediculus humanus.

Rickettsia rickett´sii  the etiologic agent of Rocky Mountain spotted fever, transmitted by Dermacentor, Rhipicephalus, Haemaphysalis, Amblyomma, and Ixodes ticks.

Rickettsia tsutsugamu´shi  the etiologic agent of scrub typhus, transmitted by larval mites of the genus Trombicula, including T. akamushi and T. deliensis, from rodent reservoirs of infection.

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rickettsia /rick·ett·sia/ (rĭ-ket´se-ah) pl. rickett´siae   an individual organism of the Rickettsiaceae.rickett´sial

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Rick·ett·si·a (r-kts-)

n.

A genus of gram-negative bacteria that are carried as parasites by many ticks, fleas, and lice and cause diseases such as typhus, scrub typhus, and Rocky Mountain spotted fever.

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Rickettsia

A rod-shaped infectious microorganism that can reproduce only inside a living cell. Scrub typhus is a rickettsial disease.

Mentioned in: Scrub Typhus

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Rickettsia

[riket′sē·ə] pl. rickettsiae

Etymology: Howard T. Ricketts, American pathologist, 1871-1910

a genus of microorganisms that combines aspects of both bacteria and viruses. They can be observed with a light microscope, divide by fission, and may be controlled with antibiotics. They also exist as viruslike intracellular parasites, living in the intestinal tracts of insects such as lice. Thus a human infested with lice is also likely to be infected with a form of typhus transmitted by Rickettsia prowazeki. Rickettsial diseases have been responsible for many of history's worst epidemics. The various species are distinguished on the basis of similarities in the diseases they cause. The spotted fever group includes diseases such as Rocky Mountain spotted fever and rickettsialpox; the typhus group includes epidemic typhus and murine typhus; and a miscellaneous group includes Q fever and trench fever. Rickettsial diseases are uncommon in parts of the world where insect and rodent populations are well controlled. rickettsial, adj.

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rickets (rik´ts),

n a condition caused by deficiency of vitamin D or calcium in infants and children, with disturbance in the mineralization of osseous and dental tissues. Marked by bending and bowing of bones, nodular enlargements at the ends of bones, myalgia, delay in closure of fontanels, and other problems. See also osteomalacia.

rickets, adult,

n See osteomalacia.

rickets, refractory,

n See rickets, resistant.

rickets, renal,

n a disturbance marked by excessive excretion of phosphorus and calcium resulting from a lowered renal threshold of excretion of these mineral elements. See also osteodystrophy, renal.

rickets, resistant,

n (late rickets, refractory rickets), rickets that responds only to extremely large amounts of vitamin D.

Rickettsia

n a genus of microorganisms that combine aspects of both bacteria and viruses. Examples of rickettsial diseases are Rocky Mountain spotted fever and typhus.

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Rickettsia

a genus of small, rod-shaped, round to pleomorphic microorganisms in the order Rickettsiales. They are true bacteria, gram-negative, and cultivable only in living tissues. Transmitted by lice and ticks, they cause disease in humans and domestic animals but are also found in the cytoplasm of tissue cells of lice, fleas, ticks and mites, which may act as reservoirs and vectors. See also ehrlichia and coxiella.

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Rickettsia akari

causes rickettsial pox in humans, mice and rats.

Rickettsia australis

causes queensland tick typhus in humans, small marsupials, rats.

Rickettsia canadensis

causes new typhus in humans and rabbits.

Rickettsia conjunctivae

see Chlamydophila pecorum.

Rickettsia conorii

causes boutonneuse fever in humans and dogs and small feral mammals.

Rickettsia ovina

see Ehrlichia ovina.

Rickettsia phagocytophila

see Anaplasmaphagocytophila.

Rickettsia prowazeki

causes epidemic typhus in humans and possibly cattle, sheep and goats.

Rickettsia rickettsii

causes spotted fever in humans and many feral animals, especially rodents and in dogs and birds. See also rocky mountain spotted fever.

Rickettsia ruminantium

see Ehrlichiaruminantium.

Rickettsia rupricaprae

see Mycoplasmaconjunctivae.

Rickettsia sibirica

causes Siberian tick typhus in humans and many feral mammals, especially rodents.

Rickettsia tsutsugamushi

see Orientia tsutsugamushi.

Rickettsia typhi

causes murine typhus in humans and the brown rat.

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rickettsia

pl. rickettsiae; an organism in the order Rickettsiales.