Rickettsia

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Rickettsia

 [rĭ-ket´se-ah]
a genus of bacteria of the tribe Rickettsiae, made up of small, gram-negative, rod-shaped to coccoid, often pleomorphic microorganisms, which multiply only in host cells. Organisms occur in the cytoplasm of tissue cells or free in the gut lumen of lice, fleas, ticks, and mites and are transmitted by their bites. R. cono´rii is the etiologic agent of boutonneuse fever and is transmitted by the bite of ixodid ticks. R. prowaze´kii is the agent of scrub typhus and Brill-Zinsser disease; it is transmitted between humans by the human body louse and from flying squirrels to humans by fleas and lice. R. ty´phi is the cause of murine typhus, which is transmitted to humans chiefly by rat fleas. Rickettsial diseases are not common in communities with good sanitary standards, since prevention depends on controlling the rodent and insect populations. Major epidemics have occurred, especially in times of war when standards of sanitation drop.

rickettsia

 [rĭ-ket´se-ah] (pl. rickett´siae)
An individual organism of the family Rickettsiaceae.

Rickettsia

(ri-ket'sē-ă),
A genus of bacteria (order Rickettsiales) containing small (that is, nonfilterable), often pleomorphic, coccoid to rod-shaped, gram-negative organisms that usually occur intracytoplasmically in lice, fleas, ticks, and mites but do not grow in cell-free media; pathogenic species infect humans and other animals, causing epidemic, murine, or endemic typhus, Rocky Mountain spotted fever, tsutsugamushi disease, rickettsialpox, and other diseases; type species is Rickettsia prowazekii.
[Howard T. Ricketts]

rickettsia

(rĭ-kĕt′sē-ə)
n. pl. rickett·siae (-sē-ē′)
Any of various bacteria of the genus Rickettsia, carried as parasites by many ticks, fleas, and lice, that cause diseases such as typhus and Rocky Mountain spotted fever in humans.

rick·ett′si·al adj.

Rick·ett·si·a

(ri-ket'sē-ă)
A genus of bacteria containing small (nonfilterable), often pleomorphic, coccoid to rod-shaped, gram-negative organisms that usually occur intracytoplasmically in lice, fleas, ticks, and mites; pathogenic species are parasitic in humans and other animals, causing epidemic typhus, murine or endemic typhus, Rocky Mountain spotted fever, tsutsugamushi disease, rickettsialpox, and other diseases; type species is Rickettsia prowazekii.

Rickettsia

A micro-organism intermediate in size between the largest viruses and the smallest bacteria. Rickettsiae are spread by ticks and small insects, and cause TYPHUS, Q FEVER, and ROCKY MOUNTAIN SPOTTED fever. The eponymous discoverer of the genus died of typhus while investigating the cause. (Howard Taylor Ricketts, 1871–1910, American pathologist).

Rickettsia

a GENUS of bacteria within the phylum PURPLE BACTERIA. Rickettsias are INTRACELLULAR PATHOGENS of animals, including humans. They are smaller than some of the largest VIRUSES, and like viruses can only reproduce within a host CELL. They are rod-shaped, about 1–2 μ m in length and are generally transmitted to man by INSECTS and TICKS. For example, Rocky Mountain spotted fever is caused by Rickettsia rickettsii which is transmitted by ticks.

Rickettsia

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

Rick·ett·si·a

(ri-ket'sē-ă)
Genus of bacteria that usually occur intracytoplasmically in lice, fleas, ticks, and mites; pathogenic species infect humans and other animals, causing epidemic, murine, or endemic typhus, Rocky Mountain spotted fever other diseases.
References in periodicals archive ?
Since the assay is nonspecific, the positive serologic reaction could represent an infection with another SFGR pathogen (eg, R parkeri, R akari) or a rickettsia of unknown pathogenicity (eg, R amblyommii, R montanensis).
Se obtuvieron 4 muestras positivas para Rickettsia sp., en donde el 4% (4/100) de las muestras correspondieron a garrapatas hembras (Cuadro 3).
tsutsugamushi averaged 91.8% sequence similarity to other members of Rickettsia, and the O.
Assessment of real-time PCR assay for detection of Rickettsia spp.
Rickettsia typhi as well as Rickettsia prowazekii, belongs to Tifus Group in the Rickettsiaceae Family from Rickettsialis Order and is the causative organism of murine or endemic typhus (2).