association of different genetic types of francisella-like organisms with the rocky mountain wood tick (dermacentor andersoni) and the american dog tick (dermacentor variabilis) from localities near their northern distributional limits.dermacentor andersoni and dermacentor variabilis from allopatric and sympatric populations near their northern distributional limits were examined for the presence of francisella species using molecular techniques that targeted 373 bp of the 16s ribosomal rna gene. although there was no evidence for the presence of francisella tularensis in any tick, francisella-like endosymbionts (fles) were common in d. andersoni and d. variabilis adults and immatures. a significantly greater proportion of fem ...201122179251
Dermacentor andersoni transmission of Francisella tularensis subsp. novicida reflects bacterial colonization, dissemination, and replication coordinated with tick feeding.Ticks serve as biological vectors for a wide variety of bacterial pathogens which must be able to efficiently colonize specific tick tissues prior to transmission. The bacterial determinants of tick colonization are largely unknown, a knowledge gap attributed in large part to the paucity of tools to genetically manipulate these pathogens. In this study, we demonstrated that Francisella tularensis subsp. novicida, for which a complete two-allele transposon mutant library has been constructed, ini ...201121930762
characterization of an endosymbiont infecting wood ticks, dermacentor andersoni, as a member of the genus francisella.a microorganism (dermacantor andersoni symbiont [das]) infecting rocky mountain wood ticks (d. andersoni) collected in the bitterroot mountains of western montana was characterized as an endosymbiont belonging to the genus francisella. previously described as wolbachia like, the organism's dna was amplified from both naturally infected tick ovarial tissues and vero cell cultures by pcr assay with primer sets derived from eubacterial 16s ribosomal dna (rdna) and francisella membrane protein genes ...19979327558
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
tularaemia transmitted by ticks (dermacentor andersoni) in saskatchewan.common wood ticks (dermacentor andersoni) collected from saskatchewan landing provincial park, saskatchewan in the spring of 1982 transmitted a lethal tularaemia infection to four of six rabbits. francisella tularensis organisms were isolated from tissues taken from the dead rabbits and identified from subcultures using an indirect immunofluorescent antibody assay. one human associated with the animals developed symptoms of tularaemia and, after successful therapy, had a significant increase in ...19836667429
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