| natural history of tick-borne spotted fever in the usa. susceptibility of small mammals to virulent rickettsia rickettsii. | in the ecology of spotted fever rickettsiae, one of the as yet unsolved problems concerns the significance of small animals in the distribution of rickettsia rickettsii in nature. in the bitter root valley of western montana, a great variety of rodents, rabbits and hares are known to serve as the preferred hosts for the immature stages of the vector tick, dermacentor andersoni.the authors analyse the susceptibility of various species of small mammals to virulent r. rickettsii and evaluate their ... | 1966 | 5296999 |
| collection of dermacentor andersoni (stiles) with carbon dioxide and its application in studies of colorado tick fever virus. | | 1965 | 5841585 |
| serotypes of spotted fever group rickettsiae isolated from dermacentor andersoni (stiles) ticks in western montana. | adult dermacentor andersoni ticks were collected by flagging vegetation in 18 canyons bordering the bitterroot valley, montana, an area where nearly 400 cases of rocky mountain spotted fever (rmsf) have occurred since 1900. three hundred and nine (8.3%) of the 3,705 ticks collected contained hemocyte-associated rickettsia-like organisms of three morphologic types, coccobacillary, fine bacillary, and coarse bacillary (long forms). only the coccobacillary and fine bacillary organisms stained with ... | 1981 | 6782899 |
| dna typing of rickettsiae in naturally infected ticks using a polymerase chain reaction/restriction fragment length polymorphism system. | we used the polymerase chain reaction/restriction fragment length polymorphism (pcr/rflp) rickettsial typing system of regnery and others to rapidly identify rickettsiae in naturally infected ticks. unlike previously described methods, our pcr assays type rickettsiae directly from tick tissues without first isolating the organisms. we collected 226 adult dermacentor andersoni ticks in the bitterroot mountains of western montana and analyzed them for possible rickettsial infection by hemolymph te ... | 1994 | 7906924 |
| 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 ... | 1997 | 9103635 |
| nonpathogenic rickettsias related to the spotted fever group isolated from ticks, dermacentor variabilis and dermacentor andersoni from eastern montana. | | 1963 | 14053295 |
| tick paralysis presenting in an urban environment. | we report the case of a 17-month-old female with tick paralysis presenting to an urban los angeles emergency department. the tick was later identified as the north american wood tick, dermacentor andersoni, and was likely obtained while the family was vacationing on a dude ranch in montana. we discuss the epidemiology of tick paralysis, a differential diagnosis for health care providers, and methods of detection and removal. given the increasing popularity of outdoor activities and ease of trave ... | 2004 | 14984905 |
| 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 ... | 2004 | 15528527 |
| characterization of genetic diversity in dermacentor andersoni (acari: ixodidae) with body size and weight polymorphism. | morphological and discrete genetic differences are found between geographically isolated, allopatric, tick populations. however, we have found differences in sympatric tick populations. notable differences were found in the body size and weight of dermacentor andersoni collected from a single location in montana, usa. these ticks were separated in groups consisting of big (b) and small (s) individuals. the objectives of this study were: (a) to characterize genetic diversity in b and s d. anderso ... | 2004 | 15639135 |
| distribution, seasonality, and hosts of the rocky mountain wood tick in the united states. | anaplasma marginale theiler is a tick-borne pathogen that causes anaplasmosis in cattle. there are approximately 20 tick species worldwide that are implicated as vectors of this pathogen. in the united states, dermacentor andersoni stiles and dermacentor variabilis (say) are the principal vectors. the risk of transmission of anaplasmosis to cattle has been largely based on the distribution of d. andersoni in the united states. we developed a centralized geographic database that incorporates coll ... | 2006 | 16506443 |
| molecular typing of novel rickettsia rickettsii isolates from arizona. | seven isolates of rickettsia rickettsii were obtained from a skin biopsy, two whole-blood specimens, and from rhipicephalus sanguineus ticks from eastern arizona. molecular typing of seven isolates of r. rickettsii and dna samples from two other rh. sanguineus ticks infected with r. rickettsii was conducted by pcr and dna sequencing of rompa and 12 variable-number tandem repeat regions (vntrs). all dna specimens from arizona were identical to each other and to reference human and dermacentor and ... | 2006 | 17114781 |
| epidemiology of colorado tick fever in montana, utah, and wyoming, 1995-2003. | colorado tick fever (ctf) is a biphasic, febrile illness caused by a coltivirus and transmitted by the rocky mountain wood tick, dermacentor andersoni, in the western united states and canada. symptoms generally include acute onset of fever, headache, chills, and myalgias; illness often lasts for 3 weeks or more. laboratory-confirmed cases of ctf were identified from public health department records in montana, utah, and wyoming, and from the centers for disease control and prevention diagnostic ... | 2010 | 19725767 |