Publications

ecology of rocky mountain spotted fever in western montana. i. isolation of rickettsia rickettsii from wild mammals.		1962	14041199
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
natural infection of dogs on cape cod with rickettsia rickettsii.	four isolates of rickettsiae from sick dogs on cape cod, mass., were serologically identical to isolates of rickettsia rickettsii from human patients with rocky mountain spotted fever. the antigenic analysis used the indirect fluorescent-antibody test and antisera prepared in mice to each of the isolates and to reference strains of r. rickettsii and rickettsia montana. serological responses of infected dogs were specific for r. rickettsii, although antibodies to r. montana were also detected in ...	1979	114534
spotted fever group rickettsiae in dermacentor variabilis from cape cod, massachusetts.	spotted fever group (sfg) rickettsiae were identified by indirect immunofluorescent antibody tests in 1.1% of 6,956 specimens of dermacentor variabilis collected on cape cod, massachusetts. forty-one of 45 rickettsial isolates were serotyped as rickettsia montana, one as rickettsia rickettsii, and three were unidentified. studies of canines and humans with clinical evidence of spotted fever, and of healthy dogs with antibody to sfg rickettsiae, indicated that exposure of the canine population to ...	1980	6773430
rocky mountain spotted fever in clermont county, ohio. ii. distribution of population and infected ticks in an endemic area.	the epidemiology of rocky mountain spotted fever (rmsf) in relation to the distribution of the human population and infected ticks has not been defined. a study was undertaken in clermont county, ohio, to describe the distribution of population in a highly endemic focus of rmsf and to determine the prevalence of ticks infected with rickettsiae of the spotted fever group. this area was compared to another area of similar size in the same county where the incidence of rmsf was much lower. the popu ...	1980	7352458
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
endemicity of spotted fever group rickettsiae in connecticut.	to compare rickettsial infectivity and seropositivity rates against spotted fever group (sfg) rickettsiae, ticks and wild mammals were collected from three areas where rickettsia rickettsii was thought to be enzootic in connecticut during 1978-1979, and from four additional sites (with no reported human cases) between 1976 and 1979. of the 1,001 dermacentor variabilis examined by the hemolymph test, 59 (5.9%) contained rickettsia-like organisms; direct immunofluorescence tests verified the prese ...	1981	6789690
rocky mountain spotted fever in areas of high and low prevalence: survey for canine antibodies to spotted fever rickettsiae.	antibodies to rickettsia rickettsii were detected by indirect immunofluorescence in sera from 149 of 467 dogs (32%) examined from 4 military installations located in kentucky, north carolina, pennsylvania, and virginia. the prevalence at individual installations ranged from 4.3% at fort knox, ky, to 63.4% at fort bragg, nc. most of the seropositive dogs were in the working and sporting groups of dogs. the difference in antibody prevalence between sexes was not significant. serologic responses we ...	1982	6808878
antibodies to spotted fever-group rickettsiae in dogs and prevalence of infected ticks in southern connecticut.	blood samples and ticks were obtained from dogs to assess canine exposure to spotted fever-group (sfg) rickettsiae during 1978-1980 in southern connecticut. of the 1,576 dog sera screened by microimmunofluorescence. 174 (11.0%) contained specific antibodies at titers greater than or equal to 1:64 against rickettsia montana (n = 34), r rickettsii (n = 31), r rhipicephali (n = 19), or the unclassified 369-c rickettsia (n = 90). end points greater than or equal to 1:8,192 to r rickettsii and to r r ...	1982	6803626
epidemiology of rocky mountain spotted fever in ohio, 1981: serologic evaluation of canines and rickettsial isolation from ticks associated with human case exposure sites.	a survey for the prevalence of rocky mountain spotted fever (rmsf) antibodies in dogs associated with confirmed human cases in ohio was conducted during 1981. twelve of 14 confirmed cases (85%) had a history of dog association prior to onset of rmsf. a total of 29 dogs were included in the study, with 16 dogs providing serum samples for antibody testing and the remainder providing tick samples. serum samples tested by indirect microimmunofluorescence techniques revealed 12/16 dogs (75%) to be se ...	1984	6435461
rickettsia rickettsii and rickettsia montana from ixodid ticks in connecticut.	dermacentor variabilis, infected with spotted fever group rickettsiae, parasitized 8 of 70 raccoons captured in newtown, connecticut. the spotted fever agent, rickettsia rickettsii, was isolated and identified from 4 adult d. variabilis and from 1 nymphal ixodes texanus removed from raccoons. this verifies the presence of this etiologic agent in ticks in an area where 6 people had clinical signs and symptoms of rocky mountain spotted fever (rmsf) and antibodies to r. rickettsii. these are the fi ...	1986	3946737
antibodies to spotted fever-group rickettsiae in dogs in north carolina.	a seroepidemiologic survey was conducted to determine the prevalence of antibodies reactive with 4 spotted fever-group (sfg) rickettsiae in sera of dogs from various geographic regions in north carolina. serum specimens were obtained from 600 dogs, and antibody titers were determined, using microimmunofluorescence. data analysis (setting as the criterion for a positive result, a rickettsia rickettsii titer greater than or equal to 1:64) overestimated the actual prevalence of canine exposure to t ...	1987	3118744
antibodies to ehrlichia canis, ehrlichia platys, and spotted fever group rickettsiae in louisiana dogs.	antibodies to ehrlichia canis, ehrlichia platys, and spotted fever group (sfg) rickettsiae were detected by indirect immunofluorescence in sera from 27 ill individually owned thrombocytopenic dogs (platelet concentrations less than 200,000 platelets/microliters) and 59 healthy kenneled dogs located in southern louisiana. platelet concentrations less than 100,000 platelets/microliters were detected in 63% of ill thrombocytopenic dogs and 6.8% of healthy kennel dogs. one ill thrombocytopenic dog h ...	1988	3146636
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
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
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
detection of rickettsia rickettsii and bartonella henselae in rhipicephalus sanguineus ticks from california.	sixty-two questing adult rhipicephalus sanguineus (latreille) ticks were collected by direct removal from blades of turfgrass and adjacent concrete walkways at a suburban home in riverside county, ca, and tested for the presence of rickettsia, bartonella, and ehrlichia dna. polymerase chain reaction (pcr) was used to amplify fragments of the 17-kda antigen gene and the rompa gene of the spotted fever group rickettsiae. one male tick contained r. rickettsii dna; its genotype differed from r. rick ...	2007	17294935
status of the "east side hypothesis" (transovarial interference) 25 years later.	rocky mountain spotted fever (rmsf) cases in the notorious bitterroot valley outbreak of the early 20th century were peculiarly distributed, with virtually all reported from the west side of the valley. such a distribution remained unexplained until burgdorfer and colleagues (1981) reported that endosymbiotic rickettsiae were prevalent in wood ticks on the east side of the bitterroot river valley but not on the west side. the "east side agent" was said to prevent the transovarial transmission of ...	2009	19538274
absence of rickettsia rickettsii and occurrence of other spotted fever group rickettsiae in ticks from tennessee.	rocky mountain spotted fever (rmsf) is the most common tick-borne illness in tennessee. little is known about the occurrence of r. rickettsii, the causative agent, in ticks in tennessee. to better understand the prevalence and distribution of rickettsial agents in ticks, we tested 1,265 amblyomma, dermacentor, and ixodes adult and nymphal ticks. additionally, we tested 231 amblyomma americanum larvae. ticks were collected from 49 counties from humans, wild animals, domestic canines, and flannel ...	2010	20810834