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Related to rickettsiae: bacteria, viruses, Chlamydiæ, chlamydiae, Spirochetes


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.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


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
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(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.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
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
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.


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.
English-Spanish Medical Dictionary © Farlex 2012
References in periodicals archive ?
Hard-body ticks are the primary vector of spotted fever group (SFG) rickettsiae; recently, several emerging and reemerging SFG rickettsiae were found to infect humans (1).
The rickettsiae belong to a group of Gram-negative, arthropod-borne, obligate intracellular bacteria that cause a wide spectrum of disease, varying from mild and self-resolving to fatal infections.
On each slide, serum samples that had previously been determined to be either unreactive or reactive to SFG rickettsiae were used as negative and positive controls, respectively (LABRUNA et al., 2007; COELHO et al., 2016).
In marine bivalves, Rickettsiae have not been observed in the gametes, ruling out vertical transmission (Gulka et al.
Rickettsiae and related ehrlichial organisms are obligate intracellular bacteria carried by mites, fleas, ticks, and lice and are the agents of numerous tick-borne diseases found in Virginia, such as Rocky Mountain spotted fever (Rickettsia rickettsii), Tidewater spotted fever (Rickettsia parkeri), Human monotropic ehrlichiosis (Ehrlichia chaffeensis), and Ewingii ehrlichiosis (Ehrlichia ewingii).
"We just want to encourage you to have a low threshold for considering rickettsiae when the symptoms are consistent and the exposure history for tick bites or tick exposures are consistent," said Naomi Drexler, MPH, an epidemiologist with CDC's Rickettsial Zoonoses Branch during a May 24 CDC Clinician Outreach and Communication Activity call.
prowazekii may kill its host cells prematurely--before large numbers of rickettsiae accumulate.
Other spotted fever group rickettsiae also have been linked to febrile rash illnesses.
2004a Characterization of spotted fever group rickettsiae in flea and tick specimens from Northern Peru.
The first proposed method of identification based on molecular biology was the PCR / RFLP method of the gene that encodes citrate synthase, which allowed differentiation of nine species of rickettsiae of SFG.