rickettsia peacockii sp. nov., a new species infecting wood ticks, dermacentor andersoni, in western montana.rickettsia peacockii, a new species of spotted fever group rickettsiae, was identified from rocky mountain wood ticks (dermacentor andersoni) collected in the sapphire mountain range on the eastern side of bitterroot valley, montana. dna from r. peacockii skalkahot (t = type strain) in naturally infected tick tissue was amplified by a pcr assay with primer sets derived from eubacterial 16s ribosomal dna (rdna), rickettsial citrate synthase, and 190-kda surface antigen (rompa) genes. partial 16s ...19979103635
isolation of a spotted fever group rickettsia, rickettsia peacockii, in a rocky mountain wood tick, dermacentor andersoni, cell embryonic cell line (dae100) of the rocky mountain wood tick, dermacentor andersoni, was observed by microscopy to be chronically infected with a rickettsialike organism. the organism was identified as a spotted fever group (sfg) rickettsia by pcr amplification and sequencing of portions of the 16s rrna, citrate synthase, rickettsia genus-specific 17-kda antigen, and sfg-specific 190-kda outer membrane protein a (rompa) genes. sequence analysis of a partial rompa gene pcr fragment and indirec ...200111157215
sequence and expression analysis of the ompa gene of rickettsia peacockii, an endosymbiont of the rocky mountain wood tick, dermacentor andersoni.the transmission dynamics of rocky mountain spotted fever in montana appears to be regulated by rickettsia peacockii, a tick symbiotic rickettsia that interferes with transmission of virulent rickettsia rickettsii. to elucidate the molecular relationships between the two rickettsiae and glean information on how to possibly exploit this interference phenomenon, we studied a major rickettsial outer membrane protein gene, ompa, presumed to be involved in infection and pathogenesis of spotted fever ...200415528527
susceptibility of rickettsia monacensis and rickettsia peacockii to cecropin a, ceratotoxin a, and lysozyme.ticks host obligate intracellular bacteria that range from benign symbiotes to virulent human pathogens. the effects on those bacteria of antimicrobial peptides (amps) involved in arthropod innate immunity to microbial infections are largely unknown. we evaluated effects of amps and a c-type lysozyme on host cell-free suspensions of the tick symbiotes rickettsia monacensis and rickettsia peacockii with stain-based infectivity and viability assays. cecropin a at a concentration of 8 mum: had a le ...200516132458
a novel and naturally occurring transposon, isrpe1 in the rickettsia peacockii genome disrupting the ricka gene involved in actin-based motility.while examining the molecular basis for the lack of actin-based motility for the non-pathogenic spotted fever group (sfg) r. peacockii, we identified a novel insertion sequence (is) element, isrpe1, disrupting the coding sequence of ricka, demonstrated to induce actin-tail polymerization for the sfg rickettsiae. this rickettsial is element appears to be active in that complete terminal inverted repeat and recombinase/transposase open reading frame sequences are present and the transposase is tra ...200516164550
factors influencing in vitro infectivity and growth of rickettsia peacockii (rickettsiales: rickettsiaceae), an endosymbiont of the rocky mountain wood tick, dermacentor andersoni (acari, ixodidae).rickettsia peacockii, a spotted fever group rickettsia, is a transovarially transmitted endosymbiont of rocky mountain wood ticks, dermacentor andersoni. this rickettsia, formerly known as the east side agent and restricted to female ticks, was detected in a chronically infected embryonic cell line, dae100, from d. andersoni. we examined infectivity, ability to induce cytopathic effect (cpe) and host cell specificity of r. peacockii using cultured arthropod and mammalian cells. aposymbiotic dae1 ...200516288906
rickettsia peacockii, an endosymbiont of dermacentor andersoni, does not elicit or inhibit humoral immune responses from immunocompetent d. andersoni or ixodes scapularis cell lines.ixodes scapularis and dermacentor andersoni cell lines were stimulated with heat-killed escherichia coli and micrococcus luteus to investigate whether infection by rickettsia peacockii, an endosymbiont of d. andersoni, modifies humoral immune responses. radial diffusion assays, western blotting, flow cytometry, and quantitative reverse-transcription pcr were used to determine if expression of bacteriolytic peptides, including lysozyme and defensin, was upregulated by bacterial stimulation or inf ...200717428539
prevalence of rickettsia species in canadian populations of dermacentor andersoni and d. variabilis.we determined the prevalence of rickettsiae in dermacentor adults at 15 localities in canada. rickettsia rickettsii was not detected in any tick, whereas rickettsia peacockii was present in 76% of dermacentor andersoni adults and rickettsia montanensis in 8% of dermacentor variabilis adults. this host specificity was maintained in localities where both tick species occurred in sympatry.200919151178
genome sequence of the endosymbiont rickettsia peacockii and comparison with virulent rickettsia rickettsii: identification of virulence factors.rickettsia peacockii, also known as the east side agent, is a non-pathogenic obligate intracellular bacterium found as an endosymbiont in dermacentor andersoni ticks in the western usa and canada. its presence in ticks is correlated with reduced prevalence of rickettsia rickettsii, the agent of rocky mountain spotted fever. it has been proposed that a virulent sfg rickettsia underwent changes to become the east side agent. we determined the genome sequence of r. peacockii and provide a compariso ...200920027221
phagocytosis of the lyme disease spirochete, borrelia burgdorferi, by cells from the ticks, ixodes scapularis and dermacentor andersoni, infected with an endosymbiont, rickettsia peacockii.tick cell lines were used to model the effects of endosymbiont infection on phagocytic immune responses. the lines tested for their ability to phagocytose the lyme disease spirochete, borrelia burgdorferi (spirochaetales: spirochaetaceae), were ise6 and ide12 from the black-legged tick, ixodes scapularis say (acari: ixodidae) and dae15 from the rocky mountain wood tick, dermacentor andersoni stiles. rickettsia peacockii (rickettsiales: rickettsiaceae), an endosymbiont of d. andersoni, was used a ...200720331397
identification of intestinal bacterial flora in rhipicephalus microplus ticks by conventional methods and pcr-dgge this study, we have analyzed the intestinal microbial flora associated with rhipicephalus microplus ticks using both culture-dependent and independent methods based on pcr and denaturing gradient gel electrophoresis (pcr-dgge). the r. microplus ticks were collected from cattle and goats in jiangxi, hunan and guizhou provinces of china. three distinct strains of bacteria were isolated using culture-dependent methods: staphylococcus simulans, bacillus subtilis and bacillus flexus strain. ninete ...201525784070
prevalence of rickettsia species in dermacentor variabilis ticks from ontario, canada.relatively little is known about the prevalence of rickettsial species in dermacentor ticks in eastern canada. in this study, dermacentor ticks from the province of ontario, canada, were tested for the presence of spotted fever group rickettsial (sfgr) species, coxiella burnetii and francisella tularensis. rickettsia rickettsii was not detected in any ticks tested, but r. montanensis was detected at a prevalence of 2.2% in d. variabilis (17/778). two other sfgr species, r. parkeri and candidatus ...201627318438
'candidatus rickettsia nicoyana': a novel rickettsia species isolated from ornithodoros knoxjonesi in costa rica.rickettsiae are intracellular bacteria commonly associated with hematophagous arthropods. most of them have been described in hard ticks, but some have been found in soft ticks. here we report the detection and isolation of a new rickettsia from ornithodoros knoxjonesi larvae collected from balantiopteryx plicata (emballonuridae) in nicoya, costa rica. two ticks were processed to detect rickettsia spp. genes glta, ompa, ompb, and htra by pcr. part of the macerate was also inoculated into vero e6 ...201728268195
pcr denaturing gradient gel electrophoresis as a useful method to identify of intestinal bacteria flora in haemaphysalis flava ticks.ticks are blood-sucking ectoparasites of great medical and veterinary significance that can transmit bacteria, protozoa, fungi and viruses, causing a variety of human and animal diseases worldwide. in the present study, the intestinal bacterial flora associated with haemaphysalis flava ticks in different developmental stages were analyzed using polymerase chain reaction (pcr) and denaturing gradient gel electrophoresis (dgge). eleven distinct dgge bands were found using pcr-dgge method. sequence ...201728426403
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