• We have systematically probed the genomic data available for Rickettsia to reveal how rickettsial genomes have given rise to the great diversity of organisms that we know today. (innovations-report.com)
  • Plasmids and rickettsial evolution: insight from Rickettsia felis. (nih.gov)
  • Altogether, we propose a new rickettsial classification scheme with the addition of a fourth lineage, transitional group (TRG) rickettsiae, that is unique from TG and SFG rickettsiae and harbors genes from possible exchanges with AG rickettsiae via conjugation. (nih.gov)
  • We offer insight into the evolution of a plastic plasmid system in rickettsiae, including the role plasmids may have played in the acquirement of virulence traits in pathogenic strains, and the likely origin of plasmids within the rickettsial tree. (nih.gov)
  • Direct rickettsial counts that included the enumeration of both viable and nonviable rickettsiae were used to obtain baseline values. (ajtmh.org)
  • Rickettsia is a genus of nonmotile , Gram-negative , nonspore-forming , highly pleomorphic bacteria that can be present as cocci (0.1 μm in diameter), rods (1-4 μm long), or thread-like (10 μm long). (wikipedia.org)
  • New Latin Rickettsia , genus name , after Howard Taylor Ricketts (1871-1910), American pathologist . (thefreedictionary.com)
  • 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. (thefreedictionary.com)
  • Several assay systems were compared for measuring the concentration of viable Rickettsia australis , including embryonated eggs, tissue cultures, and mouse inoculation. (ajtmh.org)
  • Overall, the plaque assay using buffalo green monkey kidney cells with centrifugation of the rickettsiae onto the monolayers was the most sensitive assay for detecting R. australis , while the embryonated egg assay and mouse lethality titrations were the least sensitive. (ajtmh.org)
  • As such it provides an ideal resource for research directed at developing vaccines, diagnostics and therapeutics for the diverse group of pathogens that constitute the Rickettsia. (innovations-report.com)
  • The recent discovery of another parallel between Rickettsia and viruses may become a basis for fighting HIV infection. (wikipedia.org)
  • ATP production in Rickettsia is the same as that in mitochondria. (wikipedia.org)
  • In fact, of all the microbes known, the Rickettsia is probably the closest relative (in a phylogenetic sense) to the mitochondria. (wikipedia.org)
  • Rickettsia parkeri, a tick-borne bacterium discovered in 1937, was considered nonpathogenic until 2004. (thefreedictionary.com)
  • However, phylogenies including pRF genes yielded different topologies and suggest a close relationship between pRF and ancestral group (AG) rickettsiae, including the recently completed genome of R. bellii str. (nih.gov)
  • Plant diseases have been associated with these Rickettsia-like organisms (RLOs): Beet latent rosette RLO Citrus greening bacterium possibly this citrus greening disease Clover leaf RLO Grapevine infectious necrosis RLO Grapevine Pierce's RLO Grapevine yellows RLO Witch's broom disease on Larix spp. (wikipedia.org)
  • RML369-C. This relatedness is further supported by the distribution of pRF genes across other rickettsiae, as 10 pRF genes (or inactive derivatives) also occur in AG (but not SFG) rickettsiae, with five of these genes characteristic of typical plasmids. (nih.gov)
  • Dr. Gillespie concluded: "The results obtained in this study are consistent with the recent explosion in the number of identified plasmids in Rickettsia. (innovations-report.com)
  • 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. (thefreedictionary.com)
  • Within the cytoplasm, rickettsiae begin to divide and are able to polymerize host actin filaments to drive themselves to be linked intra- and intercellularly (Gouin et al. (kenyon.edu)
  • Different forms of Rickettsia and the diseases that they cause can be found all over the world. (kenyon.edu)
  • Laboratory-confirmed diagnosis is seldom achieved during the acute stage of illness, when therapeutic decisions are crucial, although effective direct detection of rickettsiae by immunohistochemical and molecular methods is possible. (asmscience.org)
  • Cultivation of rickettsiae requires antibiotic-free cell culture and a biosafety level 3 biocontainment facility and procedures and does not provide a timely diagnosis. (asmscience.org)
  • Left) Direct immunofluorescence staining of skin biopsy specimens with anti-SFG Rickettsia antibodies facilitates rapid diagnosis. (asmscience.org)
  • Renee--I don't know what you are staining for--but in my experience with Coxiella, I would choose the Pinkerton's method for rickettsias (overnight method) over the standard Machiavello stain. (histosearch.com)
  • We believe the current work provides a robust evolutionary framework that allows for the interpretation of the genomic characteristics of the four main lineages of Rickettsia. (innovations-report.com)