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Related to Rickettsia rickettsii: Borrelia burgdorferi, Rickettsia akari, Rickettsia prowazekii


n. pl. rick·ett·si·ae (-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.

[New Latin Rickettsia, genus name, after Howard Taylor Ricketts (1871-1910), American pathologist.]

rick·ett′si·al adj.


n, pl -siae (-sɪˌiː) or -sias
(Microbiology) any of a group of parasitic bacteria that live in the tissues of ticks, mites, and other arthropods, and cause disease when transmitted to man and other animals
[C20: named after Howard T. Ricketts (1871–1910), US pathologist]
rickˈettsial adj


(rɪˈkɛt si ə)

n., pl. -si•as, -si•ae (-siˌi)
any of various rod-shaped infectious microorganisms of the heterogeneous group Rickettsieae, formerly classified with the bacteria but markedly smaller and reproducing only inside a living cell: parasitic in fleas, ticks, mites, or lice and transmitted by bite.
[< New Latin (1916), after Howard T. Ricketts (1871–1910), U.S. pathologist; see -ia]
rick•ett′si•al, adj.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.rickettsia - any of a group of very small rod-shaped bacteria that live in biting arthropods (as ticks and mites) and cause disease in vertebrate hosts; they cause typhus and other febrile diseases in human beings
eubacteria, eubacterium, true bacteria - a large group of bacteria having rigid cell walls; motile types have flagella
family Rickettsiaceae, Rickettsiaceae - microorganism resembling bacteria inhabiting arthropod tissues but capable of causing disease in vertebrates


n. ricketsia, rickettsia, uno de los organismos gram-negativos que se reproducen solamente en células huéspedes de pulgas, piojos, garrapatas y ratones, y que se transmiten a humanos a través de las mordidas de éstos.
References in periodicals archive ?
RMSF is a severe tickborne disease caused by the bacterium Rickettsia rickettsii.
To the Editor: Rickettsia rickettsii is the etiologic agent of Rocky Mountain spotted fever (RMSF), a highly lethal tick-borne rickettsioses restricted to the Western Hemisphere (1,2).
muris-like Spotted Fever Rickettsia rickettsii, Dermacentor Rickettsiosis R.
Rickettsia rickettsii IgG IFA Kit, sufficient for 4000 determinations,
On d 8 of hospitalization, positive results (indirect immunofluoresence assay, State Health Laboratory, Jacksonville) were obtained for Rickettsia rickettsii, the pathogen causing Rocky Mountain spotted fever (RMSF).
Rickettsia rickettsii, which causes Rocky Mountain spotted fever, produces chills, fever, severe headache, myalgia, mental confusion, and rash.
Rocky Mountain spotted fever is caused by the Rickettsia rickettsii bacteria, which are typically spread through tick bites.
However, laboratory analysis soon confirmed that some of the ticks carried Rickettsia rickettsii, the bacterium that causes Rocky Mountain spotted fever.
Infrequency of Rickettsia rickettsii in Dermacentor variabilis removed from humans, with comments on the role of other human-biting ticks associated with spotted fever group rickettsiae in the United States.
Lyme Disease), Rickettsia rickettsii (Rocky Mountain spotted fever), Bartonella spp.
Among 13 siblings of the cases, 2 had high titers of antibodies to Rickettsia rickettsii, the causative agent of RMSF.