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characterization of an immunoreactive protein from the agent of human granulocytic ehrlichiosis.a gene that is homologous to the ehrlichia chaffeensis groel operon was recovered and characterized by broad-range pcr amplification of whole blood from patients with human granulocytic ehrlichiosis (hge) and from infected hl60 cell cultures. sequence analysis of an 820-bp dna fragment recovered directly from human blood showed 76.5 and 76.3% identity with cognate sequences from e. chaffeensis and cowdria ruminantium, respectively. analysis of a 1.6-kb dna fragment derived from an hge agent-infe ...19979114402
inhibition of efficient polymerase chain reaction amplification of borrelia burgdorferi dna in blood-fed ticks.polymerase chain reaction (pcr) analysis is a widely used method for detection of borrelia burgdorferi dna in biological specimens, including ticks. studies have demonstrated that substances present in mammalian blood can inhibit pcr amplification. this would limit the utility of pcr for determination of b. burgdorferi infection in engorged ticks that have taken a blood meal from a human or other animal host. to systematically assess the potential for such inhibition, nymphal ixodes scapularis, ...19979129540
human disease in europe caused by a granulocytic ehrlichia species.human granulocytic ehrlichiosis (hge) was recently described in north america. it is caused by an ehrlichia species closely related to ehrlichia phagocytophila and ehrlichia equi, recognized to infect mostly ruminants and horses, respectively. the vector in north america is the tick ixodes scapularis, which is also the vector of the lyme disease agent, borrelia burgdorferi. previous serologic studies in patients with a diagnosis of lyme borreliosis indicate that hge may exist in europe. we repor ...19979163481
transmission of the agent of human granulocytic ehrlichiosis by host-seeking ixodus scapularis (acari:ixodidae) in southern new york state.ixodes scapularis say nymphs collected from a natural focus of human granulocytic ehrlichiosis (hge) in westchester county, new york, transmitted the hge agent to uninfected mice in the laboratory. infection was demonstrated in 3 of 8 mice by polymerase chain reaction analysis of whole blood and microscopic examination of blood smears for morulae. two of these mice were also positive by xenodiagnosis. positive xenodiagnostic larvae maintained infection through molting and transferred infection t ...19979220669
ability of the lyme disease spirochete borrelia burgdorferi to infect rodents and three species of human-biting ticks (blacklegged tick, american dog tick, lone star tick) (acari:ixodidae).the infectivity of a diverse collection of borrelia burgdorferi strains from north america for mice was determined as a prelude to vector competence experiments with the 3 primary human-biting tick species in the eastern united states (ixodes scapularis say, dermacentor variabilis (say), amblyomma americanum (l.)]. of the 34 b. burgdorferi strains inoculated into mice, 29 were infectious; the exceptions were 5 isolates from texas. vector competence experiments were conducted with 2 strains from ...19979220680
simulation of blacklegged tick (acari:ixodidae) population dynamics and transmission of borrelia burgdorferi.a model (lymesim) was developed for computer simulation of blacklegged tick, ixodes scapularis say, population dynamics and transmission of the lyme disease agent. borrelia burgdorferi johnson. schmid, hyde, steigerwalt & brenner, lymesim simulates the effects of ambient temperature, saturation deficit, precipitation, habitat type, and host type and density on tick populations. epidemiological parameters including host infectivity, tick infectivity, transovarial transmission, and transstadial tr ...19979220682
effects of ixodes scapularis and borrelia burgdorferi on modulation of the host immune response: induction of a th2 cytokine response in lyme disease-susceptible (c3h/hej) mice but not in disease-resistant (balb/c) mice.previous studies have demonstrated that both ixodes scapularis saliva and borrelia burgdorferi antigens modulated lymphokines and monokines in vitro. the studies presented here were designed to delineate the role of i. scapularis and b. burgdorferi in modulation of the host immune response in vivo. infestation of c3h/hej mice with infected i. scapularis resulted in an up regulation of il-4 as early as 8 days after tick infestation, while the levels of t helper cell type 1 (th1) cytokines, interl ...19979234760
deer ticks (ixodes scapularis) and the agents of lyme disease and human granulocytic ehrlichiosis in a new york city park.rodent trapping and drag sampling in van cortlandt park, new york city, yielded all stages of ixodes scapularis, the deer tick vector of lyme disease and human granulocytic ehrlichiosis (hge). polymerase chain reaction analyses of the ticks showed borrelia burgdorferi and the ehrlichia sp. that causes hge.19979284380
antibodies to ehrlichia equi in dogs from the northeastern united states.to determine whether dogs living in tickinfested areas of the northeastern united states had been exposed to ehrlichia equi, an etiologic agent of granulocytic ehrlichiosis.19979364226
feeding density influences acquisition of borrelia burgdorferi in larval ixodes scapularis (acari: ixodidae).the intensity of borrelia burgdorferi transmission in nature is dependent upon the efficiency of acquisition of spirochetes by larval ixodes scapularis say (= i. dammini spielman, clifford, piesman & corwin). white-footed mice infected with b. burgdorferi were infested weekly for 5 consecutive weeks with 25 or 250 larval i. scapularis. prevalence of infection in nymphs derived from larvae fed at high density (25.0-38.9%) was consistently higher than in nymphs derived from larvae fed at low densi ...19979379464
detection of borrelia burgdorferi ospa in ixodes scapularis larvae by an antigen-capture enzyme-linked immunosorbent assay.the borrelia burgdorferi outer surface protein a (ospa) was quantified by an antigen-capture elisa. the test detected 0.156 ng ospa/b, using purified rabbit igg as a detection system. dose-response relationship was described by a three-parameter equation and second degree polynomials. the estimated amount of ospa in host-attached ixodes scapularis larvae was positively correlated with the tick's engorgement status, whereas the presence of blood in ospa-negative larvae reduced test absorbance. th ...19979385607
duration of borrelia burgdorferi infectivity in white-footed mice for the tick vector ixodes scapularis under laboratory and field conditions in ontario.the duration of borrelia burgdorferi infectivity in white-footed mice (peromyscus leucopus) experimentally inoculated or infested with infected ixodes scapularis nymphs was evaluated. infectivity was assessed by infesting these mice with unfed i. scapularis larvae at 7, 21, 35 and 49 days post-inoculation (dpi) or post-infestation (pi). at 7 dpi, b. burgdorferi was transmitted from 18 of 24 syringe-inoculated mice and all three tick-infected mice to i. scapularis larvae which fed upon them. howe ...19979391960
acquisition of lyme disease spirochetes by cofeeding ixodes scapularis ticks.ixodes scapularis ticks acquired spirochetes while cofeeding with borrelia burgdorferi-infected nymphs (donors) on uninfected naive gerbils. overall, 19% (67 of 345) of the recipient nymphs randomly exposed to gerbils with donor nymphs acquired spirochetes by fluorescent antibody (fa) tests, 18% (62 of 345) by the polymerase chain reaction. in a second experiment, donor nymphs were placed on the left ears, recipient nymphs were placed on the left and right ears, and xenodiagnostic larvae were pl ...19979392600
ticks, lyme disease spirochetes, trypanosomes, and antibody to encephalitis viruses in wild birds from coastal georgia and south carolina.ticks and blood samples were collected from wild birds mist-netted on st. catherine's island, georgia, and at the wedge plantation in coastal south carolina in 1994 and 1995. immature stages of 5 species of ixodid ticks were recovered from 10 of 148 (7%) birds belonging to 6 species in georgia, whereas 6 ixodid species were recovered from 45 of 259 (17%) birds representing 10 avian species in south carolina. borrelia burgdorferi sensu lato was isolated from 27 of 120 (23%) screened ticks (ixodes ...19979406799
the outer surface protein a (ospa) vaccine against lyme disease: efficacy in the rhesus monkey.the efficacy of an outer surface protein a (ospa) vaccine in three different formulations was investigated in the rhesus monkey. the challenge infection was administered using ixodes scapularis ticks that were infected with the b31 strain of borrelia burgdorferi. protection was assessed against both infection and disease, by a variety of procedures. some of the animals were radically immune suppressed, as an attempt to reveal any putative low level infection in the vaccinated animals. the signif ...19979413097
simulation of management strategies for the blacklegged tick (acari: ixodidae) and the lyme disease spirochete, borrelia burgdorferi.a computer model (lymesim) was developed to simulate the effects of management technologies on populations of the blacklegged tick, ixodes scapularis say, and the lyme disease spirochete borrelia burgdorferi johnson, schmid, hyde, steigerwalt & brenner in eastern north america. technologies considered in this study were area-wide acaricide, acaricide self-treatment of white-footed mice and white-tailed deer, vegetation reduction, and white-tailed deer density reduction. computer simulations were ...19979439122
prevalence of tick-borne pathogens in ixodes scapularis in a rural new jersey county.to assess the potential risk for other tick-borne diseases, we collected 100 adult ixodes scapularis in hunterdon county, a rapidly developing rural county in lyme disease endemic western new jersey. we tested the ticks by polymerase chain reaction for borrelia burgdorferi, babesia microti, and the rickettsial agent of human granulocytic ehrlichiosis (hge). fifty-five ticks were infected with at least one of the three pathogens: 43 with b. burgdorferi, five with b. microti, and 17 with the hge a ...19989452402
a population genetic study of borrelia burgdorferi sensu stricto from eastern long island, new york, suggested frequency-dependent selection, gene flow and host adaptation.eastern long island, new york, is one of the major foci of lyme disease in the united states. as in almost all other parts of north america, lyme disease in this region is caused by a single genomic species of spirochete, borrelia burgdorferi sensu stricto. for three consecutive years, natural populations of lyme borrelia in this region were sampled and studied for gene flow among different locations, changes in population structure over time, and selective forces. the genetic diversity of borre ...19979474903
coinfection with babesia microti and borrelia burgdorferi in a western wisconsin resident.a 68-year-old woman, who had not traveled outside of western wisconsin, was hospitalized after 4 weeks of chills, fevers, myalgias, neuralgias in her right arm, and pain in the right upper quadrant of her abdomen. physical examination revealed hepatosplenomegaly, and laboratory studies showed anemia, thrombocytopenia, increased aspartate transaminase level, and microscopic hematuria. wright's stain of a blood smear revealed intraerythrocytic organisms consistent with babesia species. a polymeras ...19989559037
temporal correlations between tick abundance and prevalence of ticks infected with borrelia burgdorferi and increasing incidence of lyme disease.the abundance of host-seeking ixodes scapularis nymphs, the principal vector for the lyme disease agent, borrelia burgdorferi, in old lyme, lyme, and east haddam, connecticut, was compared with the incidence of reported human lyme disease in the 12-town area around the connecticut river and the state of connecticut for the period 1989 to 1996. ticks were sampled from lawns and woodlands by dragging flannel over the vegetation and examined for the presence of b. burgdorferi by indirect fluorescen ...19989574684
serologic survey for antibodies to borrelia burgdorferi in white-tailed deer in ontario.serum samples collected from 623 white-tailed deer (odocoileus virginianus) in southern ontario (canada) from 1985 to 1989 were tested for antibodies to borrelia burgdorferi using an indirect fluorescent antibody (ifa) staining method. samples from 150 of the deer were also tested using an enzyme-linked immunosorbent assay (elisa). at ifa titers of 1:64 and 1:128 deer with antibodies to b. burgdorferi appeared to be widespread throughout southern ontario, with an apparent prevalence ranging from ...19989577798
prevention of borrelia burgdorferi transmission in guinea pigs by tick immunity.we examined the effect of repeated infestation of guinea pigs with ixodes scapularis on the capacity of ticks to transmit borrelia burgdorferi infection. repeated challenges with nymphs or larvae lead to a reduction in duration of nymphal tick attachment and weight of recovered ticks consistent with the development of tick immunity. only one of 18 i. scapularis-immune guinea pigs challenged with b. burgdorferi-infected nymphal ticks became infected, whereas 10 of 18 naive guinea pigs similarly c ...19989660463
vector competence of ixodes scapularis and ixodes ricinus (acari: ixodidae) for three genospecies of borrelia burgdorferi.the vector competence of 2 tick species, ixodes ricinus (l.) and ixodes scapularis say, was determined and compared for 3 genospecies of borrelia burgdorferi. the 3 genospecies of b. burgdorferi used in the following experiments were borrelia burgdorferi sensu stricto (b-31 and b-31.d1 clone), borrelia afzelii (strain pgau. c3), and borrelia garinii (strain vs286 and vsbp). spirochetes from all 5 strains were inoculated intradermally into outbred mice; larval ticks of both species were subsequen ...19989701928
distribution of ixodes pacificus and ixodes scapularis re concurrent babesiosis and lyme disease. 19989704540
isolation of aerobic microbes from ixodes scapularis (acari: ixodidae), the vector of lyme disease in the eastern united states.the spirochete borrelia burgdorferi johnson, schmid, hyde, steigerwalt & benner is transmitted by ixodes scapularis say, a vector of lyme disease. as a 1st step into investigating the possibility of biocontrol of the tick, we identified the microbiota associated with the ticks. we collected, identified, and determined the sex of ticks from foliage and deer. seventy-three initial bacterial isolates were recovered from 43 ticks (27 adults and 16 nymphs). the bacteria isolated from nymphs were qual ...19989725033
reported distribution of ixodes scapularis and ixodes pacificus (acari: ixodidae) in the united states.lyme disease, caused by infection with borrelia burgdorferi, is the most frequently reported arthropod-borne disease in the united states. to develop a national map of the distribution of the vectors of b. burgdorferi to humans (ixodes scapularis say and ixodes pacificus cooley & kohls ticks), we sent questionnaires to acarologists, health officials, and lyme disease researchers; surveyed the 1966-1996 medline data base; and reviewed 1907-1995 national tick collection data. tick collection metho ...19989775584
reservoir competence of the meadow vole (rodentia: cricetidae) for the lyme disease spirochete borrelia burgdorferi.the reservoir competence of the meadow vole, microtus pennsylvanicus ord, for the lyme disease spirochete borrelia burgdorferi johnson, schmid, hyde, steigerwalt & brenner was established on patience island, ri. meadow voles were collected from 5 locations throughout rhode island. at 4 of the field sites, m. pennsylvanicus represented only 4.0% (n = 141) of the animals captured. however, on patience island, m. pennsylvanicus was the sole small mammal collected (n = 48). of the larval ixodes scap ...19989775612
geographic distribution of ticks (acari: ixodidae) in michigan, with emphasis on ixodes scapularis and borrelia burgdorferi.a 12-yr (1985-1996) passive survey in michigan based upon tick submissions from citizens yielded 4,755 ticks of 21 species, 16 of which were probably indigenous in the state. three species of dermacentor [most common, d. variabilis say and d. albipictus (packard)]; 2 species of amblyomma [most common, a. americanum (l.)]; and 12 species of ixodes (most common, i. cookei packard and i. scapularis say), as well as haemaphysalis leporispalustris (packard), rhipicephalus sanguineus latreille, and th ...19989775623
coinfection of blacklegged ticks (acari: ixodidae) in dutchess county, new york, with the agents of lyme disease and human granulocytic ehrlichiosis.adult blacklegged ticks, ixodes scapularis say, collected from forested sites in dutchess county, ny, were tested for infection with the etiologic agents of lyme disease, borrelia burgdorferi johnson, schmid, hyde, steigerwalt & brenner, and human granulocytic ehrlichiosis (hge). rates of infection with the 2 pathogens were high and independent of one another, confirming prior findings and suggesting that a variety of hosts may be competent reservoirs of the hge agent.19989775627
estimation of the incidence of lyme disease.the incidence of lyme disease in most endemic areas is unknown but will be an important factor in determining the cost-effectiveness of lyme disease vaccines in those areas. the authors developed a deterministic model with nine components to estimate the frequency of ixodes scapularis tick bites and the resulting incidence of lyme disease in residents of endemic areas. for each component, best point estimates and plausible ranges of values were based on the published literature, unpublished data ...19989829875
geographic risk for lyme disease and human granulocytic ehrlichiosis in southern new york state.ixodes scapularis, the tick vector of lyme disease and human granulocytic ehrlichiosis (hge), is prevalent in much of southern new york state. the distribution of this species has increased, as have reported cases of both lyme disease and hge. the unreliability of case reports, however, demonstrates the need for tick and pathogen surveillance in order to accurately define areas of high risk. in this study, a total of 89,550 m2 at 34 study sites was drag sampled in 1995 and a total of 51,540 m2 a ...19989835546
disparity in the natural cycles of borrelia burgdorferi and the agent of human granulocytic ehrlichiosis.we studied the prevalence of borrelia burgdorferi and the agent of human granulocytic ehrlichiosis (hge) among questing nymphal and adult ixodes scapularis ticks of the same generation and the infectivity of wild white-footed mice for ticks feeding on them. the prevalence of b. burgdorferi infection in host-seeking ticks increased less than twofold from nymphal (31% to 33%) to adult (52% to 56%) stage, and 52% of white-footed mice were infected. prevalence of the agent of hge increased 4.5- to 1 ...199910221871
infections of granulocytic ehrlichiae and borrelia burgdorferi in white-tailed deer in connecticut.serum or whole blood samples, obtained from 141 white-tailed deer (odocoileus virginianus) in connecticut (usa) during 1980, 1991, and 1996, were analyzed to detect past or current infections of ehrlichia phagocytophila genogroup organisms and borrelia burgdorferi. when the bds or nch-1 strains of granulocytic ehrlichiae were used separately in indirect fluorescent antibody (ifa) staining methods, antibody positivity rates varied from 25 to 64% in 1991 and 1996, respectively. all 50 sera tested ...199910231753
incidence rates of lyme disease in maryland: 1993 through 1996.the incidence rate per 100,000 population by gender and age group was calculated for the 24 maryland jurisdictions using 1,392 cases reported to the lyme disease registry during 1993 to 1996. the overall incidence rate for the state was 7.0 cases per 100,000 inhabitants. males (incidence rate = 7.7) were 1.2 times more affected than females (incidence rate = 6.2) (p < 0.001). the bimodal overall age distribution shows a peak in the 10 to 19 age category (incidence rate = 8.5) and in the 50 to 59 ...199910333675
longitudinal study of infection with borrelia burgdorferi in a population of peromyscus leucopus at a lyme disease-enzootic site in maryland.the maintenance of borrelia burgdorferi in a population of peromyscus leucopus was investigated from 202 mark and recapture mice and 61 mice that were removed from a site in baltimore county, maryland. borrelia burgdorferi infection was detected by culture and polymerase chain reaction (pcr) of ear tissue, and exposure to the spirochete was quantified by serology. overall prevalence of b. burgdorferi, as determined by culture and pcr of ear tissue at first capture, was 25% in the longitudinal sa ...199910348235
borrelia burgdorferi in tick cell culture modulates expression of outer surface proteins a and c in response to temperature.the lyme disease spirochete borrelia burgdorferi sensu stricto downregulates outer surface protein a (ospa) and upregulates outer surface protein c (ospc) during tick feeding. the switching of these proteins correlates with increased spirochetal infectivity for the mammal. we examined the effect of temperature on differential expression of ospa and ospc by b. burgdorferi cocultivated with a cell line isolated from the vector tick ixodes scapularis. the effect of incubation at 31, 34, or 37 degre ...199910364575
effects of environmental ph on membrane proteins in borrelia burgdorferi.borrelia burgdorferi, the causative agent of lyme disease, alternates between the microenvironments of the tick vector, ixodes scapularis, and a mammalian host. the environmental conditions the spirochete encounters during its infectious cycle are suspected to differ greatly in many aspects, including available nutrients, temperature, and ph. here we identify alterations in the membrane protein profile, as determined by immunoblotting and two-dimensional nonequilibrium ph gradient gel electropho ...199910377088
investigation of venereal, transplacental, and contact transmission of the lyme disease spirochete, borrelia burgdorferi, in syrian hamsters.a hamster was inoculated with the si-1 strain of borrelia burgdorferi and subsequently served as a host to larval ixodes scapularis say. approximately 68% of the nymphs resulting from the fed larvae were infected. nymphs from this group were fed on uninfected hamsters, and 3 of 4 males and 6 of 6 females became infected. the infected hamsters were allowed to mate with uninfected partners to test for venereal transmission. six infected females were mated with 6 uninfected males, whereas 3 infecte ...199910386432
ixodes scapularis: effects of repeated infestations with pathogen-free nymphs on macrophage and t lymphocyte cytokine responses of balb/c and c3h/hen mice.schoeler, g. b., manweiler, s. a., and wikel, s. k. 1999. ixodes scapularis: effects of repeated infestations with pathogen-free nymphs on macrophage and t lymphocyte cytokine responses of balb/c and c3h/hen mice. experimental parasitology 92, 239-248. ixodes scapularis is the principal vector in the united states of borrelia burgdorferi, the causative agent of lyme borreliosis, the human granulocytic ehrichiosis agent, and babesia microti. infestation with i. scapularis nymphs has previously be ...199910425152
geographic survey of vector ticks (ixodes scapularis and ixodes pacificus) for infection with the lyme disease spirochete, borrelia burgdorferi.populations of adult ixodes scapularis and ixodes pacificus, the two principal vectors of lyme disease spirochetes in the united states, were collected from 17 sites in 12 states. female ticks were fed on experimental rabbits; ticks and rabbits were subsequently examined for infection with borrelia burgdorferi. fourteen rabbits were exposed to i. scapularis ticks from the northeastern states of connecticut, new york, new jersey, and maryland; all 14 rabbits became infected with b. burgdorferi. a ...199910436883
infection with agents of human granulocytic ehrlichiosis, lyme disease, and babesiosis in wild white-footed mice (peromyscus leucopus) in connecticut.white-footed mice, peromyscus leucopus, were captured in southern connecticut during 1997 and 1998 to determine the prevalence of infections caused by granulocytic ehrlichia sp., borrelia burgdorferi, and babesia microti. of the 50 mice captured and recaptured, 25 of 47 (53.2%) and 23 of 48 (47.9%) contained antibodies to the bds or nch-1 ehrlichia strains, respectively, as determined by indirect fluorescent antibody (ifa) staining methods. the majority (83.3%) of 48 mice also contained antibodi ...199910449470
vaccination against lyme disease with recombinant borrelia burgdorferi outer-surface protein a (rospa) in horses.eight 1-year-old ponies were vaccinated with recombinant ospa (ospa gene derived from b. burgdorferi b31) with adjuvant (aluminium hydroxide). four ponies were used as non-vaccinated controls with adjuvant. one hundred and twelve days after the first vaccination, the vaccinated and non-vaccinated ponies were challenged by exposure to b. burgdorferi-infected adults tick (ixodes scapularis) collected from westchester county, new york (tick infection rate >/=60%). protection from infection was eval ...199910519945
a mathematical model of the ecology of lyme disease.a mathematical model of enzootic lyme-disease transmission in a natural focus is presented. this model is based on the life history of the vector tick ixodes scapularis say and the primary reservoir host peromyscus leucopus. using this model, the threshold condition for the disease to be able to invade a nonenzootic region is determined as a function of the various possible transmission chains operating throughout the year. these expressions show that the transmission chain in which ticks acquir ...199910520492
population dynamics of a naturally occurring heterogeneous mixture of borrelia burgdorferi clones.two unique isolates of borrelia burgdorferi, differing in plasmid content and outer surface protein c expression, were cultured on sequential captures of a single free-living peromyscus leucopus mouse and were examined for differences in transmissibility. both isolates were transmissible from inoculated c.b-17 mice to larval ixodes scapularis ticks and, subsequently, from infected nymphal ticks to c3h/hej mice. plasmid and protein analyses suggested that the original isolates were a mixed popula ...199910531219
identification, characterization, and expression of three new members of the borrelia burgdorferi mlp (2.9) lipoprotein gene family.we previously reported on the existence of a family of lipoprotein genes, designated 2.9 lipoprotein genes, encoded in at least seven versions on the circular (supercoiled) cp32 and cp18 plasmids of borrelia burgdorferi 297. a distinguishing feature of the 2.9 lipoproteins were highly similar signal sequences but variable mature polypeptides that segregated into two antigenic classes. further screenings of b. burgdorferi 297 genomic libraries led to the identification of three additional 2.9 lip ...199910531261
ticks and antibodies to borrelia burgdorferi from mammals at cape hatteras, nc and assateague island, md and va.results of a survey for ixodid ticks and/or serum antibodies to borrelia burgdorferi from 14 species of small to large mammals from eastern coastal areas of the united states are presented. most samples were obtained from july 1987 through june 1989 (excluding december-march) at 3 locales: assateague is. national seashore, worcester co., md., and accomack co., va. (approximately 38 degrees 05' n 75 degrees 10' w), and cape hatteras national seashore, dare co., nc (approximately 35 degrees 30' n ...199910534951
seasonal activity and host associations of ixodes scapularis (acari: ixodidae) in southeastern missouri.based on tick collections recovered from wild vertebrates and by dragging, the seasonal occurrence of adult blacklegged ticks, ixodes scapularis say, extended from october through may in southeastern missouri. adult activity was bimodal with the higher peak occurring in november followed by a lower peak in february. the activity of immature i. scapularis had the general pattern of that found in the northeast where lyme disease is hyperendemic, with larval activity (july) peaking after that of ny ...199910593072
cytokine responses of c3h/hen mice infested with ixodes scapularis or ixodes pacificus nymphs.lyme borreliosis, caused by borrelia burgdorferi, is transmitted by ixodes scapularis in the eastern and midwestern united states and by ixodes pacificus in the far-western united states. studies have shown that infestation with i. scapularis nymphs modulates host cytokine production; however, the influence of i. pacificus infestation on host cytokines remains uninvestigated. this study demonstrated how repeated infestations with pathogen-free i. scapularis or i. pacificus nymphs affects the pro ...200010607289
isolation, cultivation, and characterization of borrelia burgdorferi from rodents and ticks in the charleston area of south carolina.twenty-eight borrelia burgdorferi isolates from the charleston, s.c., area are described. this represents the first report and characterization of the lyme disease spirochete from that state. the isolates were obtained from december 1994 through december 1995 from the tick ixodes scapularis, collected from vegetation, and from the rodents peromyscus gossypinus (cotton mouse), neotoma floridana (eastern wood rat), and sigmodon hispidus (cotton rat). all isolates were screened immunologically by i ...200010618074
temporal changes in outer surface proteins a and c of the lyme disease-associated spirochete, borrelia burgdorferi, during the chain of infection in ticks and mice.the lyme disease-associated spirochete, borrelia burgdorferi, is maintained in enzootic cycles involving ixodes ticks and small mammals. previous studies demonstrated that b. burgdorferi expresses outer surface protein a (ospa) but not ospc when residing in the midgut of unfed ticks. however, after ticks feed on blood, some spirochetes stop making ospa and express ospc. our current work examined the timing and frequency of ospa and ospc expression by b. burgdorferi in infected ixodes scapularis ...200010618120
human granulocytic ehrlichiosis agent infection in a pony vaccinated with a borrelia burgdorferi recombinant ospa vaccine and challenged by exposure to naturally infected ticks.a pony was vaccinated with recombinant ospa vaccine (rospa) and then exposed 3 months later to borrelia burgdorferi-infected ticks (ixodes scapularis) collected in westchester county, n.y. at 2 weeks after tick exposure, the pony developed a high fever (105 degrees f). buffy coat smears showed that 20% of neutrophils contained ehrlichial inclusion bodies (morulae). flunixin meglumine (1 g daily) was given for 2 days, and the body temperature returned to normal. pcr for ehrlichial dna was perform ...200010618280
acquisition of coinfection and simultaneous transmission of borrelia burgdorferi and ehrlichia phagocytophila by ixodes scapularis ticks.the agents of lyme disease (borrelia burgdorferi) and human granulocytic ehrlichiosis (ehrlichia phagocytophila) are both transmitted by the tick ixodes scapularis. in nature, ticks are often infected with both agents simultaneously. we studied whether previous infection with either borrelia or ehrlichia in ticks would affect acquisition and transmission of a second pathogen. ehrlichia-infected i. scapularis nymphs were fed upon borrelia-infected mice, and borrelia-infected i. scapularis nymphs ...200010722618
first isolation of lyme disease spirochete, borrelia burgdorferi, from blacklegged tick, ixodes scapularis, removed from a bird in nova scotia, canada. 199910726372
first isolation of lyme disease spirochete, borrelia burgdorferi from blacklegged tick, ixodes scapularis, collected at rondeau provincial park, ontario. 200010763556
tick infestations of birds in coastal georgia and alabama.mist-netted birds were examined for ticks on jekyll island, glynn co., georgia (32 bird species) in 1996-1998, and at fort morgan, baldwin co., alabama (36 species) in 1998 during fall migration. sixty-two (14.7%) of 423 birds from jekyll island and 22 (13.3%) of 165 birds from fort morgan were infested with ticks. the mean number of ticks per infested bird was 2.0 on jekyll island and 6.3 at fort morgan. ten species of birds were infested with ticks on jekyl1 island where 87% of all ticks were ...200010780541
arthropod- and host-specific borrelia burgdorferi bbk32 expression and the inhibition of spirochete transmission.antisera to bbk32 (a borrelia burgdorferi fibronectin-binding protein) and bbk50, two ags synthesized during infection, protect mice from experimental syringe-borne lyme borreliosis. therefore, b. burgdorferi bbk32 and bbk50 expression within ixodes scapularis ticks and the murine host, and the effect of bbk32 and bbk50 antisera on spirochetes throughout the vector-host life cycle were investigated. bbk32 and bbk50 mrna and protein were first detected within engorged ticks, demonstrating regulat ...200010799897
surveillance for lyme disease--united states, 1992-1998.lyme disease is caused by infection with the spirochete borrelia burgdorferi and is the most commonly reported vector-borne disease in the united states. borrelia burgdorferi is transmitted to humans by infected ixodes scapularis and i. pacificus ticks. lyme disease is typically evidenced in its early stage by a characteristic rash (erythema migrans), accompanied by nonspecific symptoms (e.g., fever, malaise, fatigue, headache, myalgia, and arthralgia). lyme disease can usually be treated succes ...200010817483
methods for estimating gene frequencies and detecting selection in bacterial populations.recent breakthroughs in molecular technology, most significantly the polymerase chain reaction (pcr) and in situ hybridization, have allowed the detection of genetic variation in bacterial communities without prior cultivation. these methods often produce data in the form of the presence or absence of alleles or genotypes, however, rather than counts of alleles. using relative allele frequencies from presence-absence data as estimates of population allele frequencies tends to underestimate the f ...200010835376
presence of spirochete causing lyme disease, borrelia burgdorferi, in the blacklegged tick, ixodes scapularis, in southern ontario. 200010862230
decorin-binding protein a (dbpa) of borrelia burgdorferi is not protective when immunized mice are challenged via tick infestation and correlates with the lack of dbpa expression by b. burgdorferi in ticks.previous studies showed that decorin-binding protein a (dbpa) of borrelia burgdorferi was a protective immunogen in the murine model of lyme borreliosis when mice were challenged (needle inoculated) intradermally with in vitro-cultivated spirochetes. in the present study, dbpa-immunized c3h/hej mice were not protected from infection when infested with ixodes scapularis nymphs harboring virulent b. burgdorferi 297. this lack of protection correlated with the failure to detect dbpa on b. burgdorfe ...200010899883
borrelia burgdorferi and the causative agent of human granulocytic ehrlichiosis in deer ticks, delaware.during the 1998 hunting season in delaware, 1,480 ticks were collected from 252 white- tailed deer; 98% were ixodes scapularis, a significant increase from the 85% reported in 1988. ticks were tested for borrelia burgdorferi and the causative agent of human granulocytic ehrlichiosis. infection rates remained stable in new castle and kent counties, but increased from <1% to 8% in sussex county.200010905979
attachment of borrelia burgdorferi within ixodes scapularis mediated by outer surface protein a.borrelia burgdorferi outer surface protein (osp) a has been used as a lyme disease vaccine that blocks transmission: ospa antibodies of immune hosts enter ticks during blood feeding and destroy spirochetes before transmission to the host can occur. b. burgdorferi produce ospa in the gut of unfed ixodes scapularis ticks, and many spirochetes repress ospa production during the feeding process. this preferential expression suggests that ospa may have an important function in the vector. here we sho ...200010953031
influence of soluble proteins from the salivary glands of ixodid ticks on the in-vitro proliferative responses of lymphocytes from balb/c and c3h/hen mice.in the u.s.a., borrelia burgdorferi, the causative agent of lyme borreliosis, is transmitted to humans by the ticks ixodes scapularis and i. pacificus. tick modulation of host immunity is an important factor in tick transmission of such pathogens. the proliferative responses of lymphocytes from balb/c and c3h/hen mice exposed to the salivary-gland soluble proteins (sgsp) of i. scapularis, i. pacificus or dermacentor andersoni were therefore compared in vitro. this produced the present report, th ...200010983564
lyme disease.lyme disease, which is caused by borrelia burgdorferi and transmitted in the united states primarily by ixodes scapularis (the deer tick), is the most common vector borne disease in the united states. its most frequent manifestation, a characteristic, expanding annular rash (erythema migrans), sometimes accompanied by myalgia, arthralgia, and malaise, occurs in nearly 90% of persons with symptomatic infection. other manifestations of lyme disease include seventh cranial nerve palsy, aseptic meni ...200010987718
identification of ixodes scapularis in newfoundland, canada. 200010992615
detection of borreliacidal antibodies in dogs after challenge with borrelia burgdorferi-infected ixodes scapularis ticks.detection of borreliacidal antibodies is an accurate serodiagnostic test for confirmation of lyme disease in humans. in this study, 13 pathogen-free beagles, 12 to 26 weeks old, were infected with borrelia burgdorferi by tick challenge. dogs were monitored for clinical signs and symptoms of lyme disease along with borreliacidal antibody production against b. burgdorferi sensu stricto isolates 297 and 50772. ten (77%) dogs developed lameness in one or more legs within 210 days after attachment of ...200011015381
serologic confirmation of ehrlichia equi and borrelia burgdorferi infections in horses from the northeastern united states.to determine whether horses living in tick-infested areas of northeastern united states with clinical signs of borreliosis or granulocytic ehrlichiosis had detectable serum antibodies to both borrelia burgdorferi and ehrlichia equi.200011019714
enhancement of ospc expression by borrelia burgdorferi in the presence of tick hemolymph.borrelia burgdorferi b31 cultured at 28 degrees c was used to assay the effects of tick hemolymph on outer surface protein c (ospc) surface expression. using immunofluorescence, ospc surface expression was shown to increase in cultures treated with hemolymph from both ixodes scapularis and dermacentor variabilis, while control samples (non-hemolymph treated) showed no increase in the levels of ospc. sodium dodecyl sulfate-polyacrylamide gel electrophoresis also showed an increase in ospc from sp ...200011094292
coinfection with borrelia burgdorferi and the agent of human granulocytic ehrlichiosis suppresses il-2 and ifn gamma production and promotes an il-4 response in c3h/hej mice.previously we demonstrated that borrelia burgdorferi transmission by ixodes scapularis suppressed il-2 and ifn gamma production and promoted il-4 production in mice. the present studies were conducted to determine whether coinfection with the human granulocytic ehrlichiosis (he) agent would promote a th2 cytokine response in mice. transmission to the spleen of the agent of human granulocytic ehrlichiosis (aohge) and b. burgdorferi occurred 4 and 7 days, respectively, after tick infestation. coin ...200011116438
effect of tick removal on transmission of borrelia burgdorferi and ehrlichia phagocytophila by ixodes scapularis nymphs.the effect of feeding duration on pathogen transmission was studied for individual ticks infected with either laboratory or field strains of the lyme disease spirochete borrelia burgdorferi and field strains of ehrlichia phagocytophila, an agent of human granulocytic ehrlichiosis. infected nymphal ixodes scapularis were allowed to feed individually on mice, and equal numbers were removed at 24-h intervals for < or =96 h. mice were assayed for infection by culture, serologic testing, and polymera ...200111181154
complement-mediated killing of borrelia burgdorferi by nonimmune sera from sika deer.various species of cervid deer are the preferred hosts for adult, black-legged ticks (ixodes scapularis and ixodes pacificus) in the united states. although frequently exposed to the agent of lyme disease (borrelia burgdorferi), these animals, for the most part, are incompetent as transmission reservoirs. we examined the borreliacidal activity of normal and b. burgdorferi-immune sera from sika deer (cervus nippon) maintained in a laboratory setting and compared it to that of similar sera from re ...200011191897
rodent ectoparasites from two locations in northwestern florida.from feb.-apr. 1999, 19 species of ectoparasitic arthropods (2 sucking lice, 4 fleas, 4 ticks, 2 mesostigmatid mites, 5 chiggers, 2 fur mites) were recovered from 106 rodents belonging to 5 species (cotton mouse, peromyscus gossypinus, n = 64; cotton rat, sigmodon hispidus, n = 23; eastern woodrat, neotoma floridana, n = 9; golden mouse, ochrotomys nuttalli, n = 9; eastern gray squirrel, sciurus carolinensis, n = 1) at tall timbers research station, leon county, florida. during the same period, ...200011217221
ixodes scapularis (acari: ixodidae): abundance and rate of infection with borrelia burgdorferi in four state parks in wisconsin.four state parks located in lyme disease endemic regions of wisconsin were surveyed for the presence of ixodes scapularis say during may and june of 1998 by drag sampling along hiking trails. nymphal abundance varied between parks, with the average number of nymphs encountered in 1 h ranging from 6.2 +/- 3.8-47.1 +/- 36.3 (mean +/- sd). questing nymphs were tested for the presence of borrelia burgdorferi by culture in bsk medium and 7-12% was found to be infected. the average risk of encounterin ...200111268688
prevalence of infection in ticks submitted to the human tick test kit program of the u.s. army center for health promotion and preventive medicine.in 1997, ticks removed from humans and received alive by the tick-borne disease laboratory of the u.s. army center for health promotion and preventive medicine (usachppm) were tested for pathogens by polymerase chain reaction (pcr). thirty-three of 222 (15%) amblyomma americanum (l.) dnas produced amplicons of the expected size of ehrlichia chaffeensis anderson, dawson & wilson and 26/222 (12%) produced amplicons indicating borrelia burgdorferi johnson, schmid, hyde, steigalt & brenner. five (2% ...200111268694
contrasts in tick innate immune responses to borrelia burgdorferi challenge: immunotolerance in ixodes scapularis versus immunocompetence in dermacentor variabilis (acari: ixodidae).the blacklegged tick, ixodes scapularis say, transmits the lyme disease spirochete borrelia burgdorferi, whereas the american dog tick, dermacentor variabilis (say), is unable to transmit the bacterium. we compared the innate immune response of these ticks against spirochetes directly inoculated into the hemocoel cavity of ticks. in i. scapularis, some borrelia were found associated with hemocytes, while numerous other spiral-shaped, intact bacteria remained free in the hemolymph. in contrast, i ...200111268698
infection of ixodes scapularis (acari: ixodidae) with borrelia burgdorferi using a new artificial feeding technique.to study interactions between ixodes scapularis (say) and borrelia burgdorferi, an artificial feeding system was refined to allow controlled manipulation of single variables. the feeding system uses a mouse skin mounted on a water-jacketed glass membrane feeder. i. scapularis were infected using either bsk-h-cultured b. burgdorferi spirochetes or a b. burgdorferi-infected mouse skin as the source of spirochetes. sixty-six percent of nymphs successfully fed to repletion using the artificial feedi ...200111296818
assessing the association between the geographic distribution of deer ticks and seropositivity rates to various tick-transmitted disease organisms in dogs.to determine whether the geographic distribution of deer ticks (ixodes scapularis) was associated with the distribution of dogs seropositive for various tick-transmitted disease organisms (ie, borrelia burgdorferi, rickettsia rickettsii, the human granulocytic ehrlichiosis [hge] agent, ehrlichia canis, and bartonella vinsonii subsp berkhoffii).200111318358
purification and characterization of borrelia burgdorferi from feeding nymphal ticks (ixodes scapularis).here we describe a protocol for purifying borrelia burgdorferi from feeding ticks by velocity centrifugation and percoll density gradient centrifugation. the purified spirochetes were motile and 10- to 20-fold purer than the bacteria in crude tick homogenates. the purified bacteria were present in sufficient quantity for protein and gene expression studies. in comparison to culture-grown bacteria, tick-borne spirochetes had several proteins that were upregulated and a few that were downregulated ...200111349010
inhibition of borrelia burgdorferi-tick interactions in vivo by outer surface protein a antibody.borrelia burgdorferi outer surface protein (osp) a is preferentially expressed by spirochetes in the ixodes scapularis gut and facilitates pathogen-vector adherence in vitro. here we examined b. burgdorferi-tick interactions in vivo by using abs directed against ospa from each of the three major b. burgdorferi sensu lato genospecies: b. burgdorferi sensu stricto, borrelia afzelii, and borrelia garinii. abs directed against b. burgdorferi sensu stricto (isolate n40) destroy the spirochete and can ...200111390491
genetic heterogeneity of borrelia burgdorferi sensu lato in the southern united states based on restriction fragment length polymorphism and sequence analysis.fifty-six strains of borrelia burgdorferi sensu lato, isolated from ticks and vertebrate animals in missouri, south carolina, georgia, florida, and texas, were identified and characterized by pcr-restriction fragment length polymorphism (rflp) analysis of rrf (5s)-rrl (23s) intergenic spacer amplicons. a total of 241 to 258 bp of intergenic spacers between tandemly duplicated rrf (5s) and rrl (23s) was amplified by pcr. msei and drai restriction fragment polymorphisms were used to analyze these ...200111427560
prevention of lyme disease: a review of the evidence.the healthy people 2010 public health goals targeted a 44% decrease in the incidence of lyme disease, the most commonly reported tick-borne illness in the united states. to review lyme disease prevention, clinical trials, epidemiological and experimental studies, and predictive models were evaluated. geographic distribution of ixodid vectors and local landscape predict lyme disease risk. density of infected ticks correlates with incidence and prevalence of lyme disease, but risk quantitation is ...200111444404
prophylaxis with single-dose doxycycline for the prevention of lyme disease after an ixodes scapularis tick bite.it is unclear whether antimicrobial treatment after an ixodes scapularis tick bite will prevent lyme disease.200111450675
efficacy of an amitraz-impregnated collar in preventing transmission of borrelia burgdorferi by adult ixodes scapularis to dogs.to determine whether an amitraz-impregnated collar could prevent transmission of borrelia burgdorferi by ixodes scapularis to dogs.200111469572
birds disperse ixodid (acari: ixodidae) and borrelia burgdorferi-infected ticks in canada.a total of 152 ixodid ticks (acari: ixodidae) consisting of nine species was collected from 82 passerine birds (33 species) in 14 locations in canada from 1996 to 2000. the lyme disease spirochete borrelia burgdorferi johnson, schmidt, hyde, steigerwaldt & brenner was cultured from the nymph of a blacklegged tick, ixodes scapularis say, that had been removed from a common yellowthroat, geothlypis trichas l., from bon portage island, nova scotia. as a result of bird movement, a nymphal i. scapula ...200111476328
natural antibody affects survival of the spirochete borrelia burgdorferi within feeding ticks.natural antibodies are those immunoglobulin molecules found in mammalian serum that arise in the absence of exposure to environmental pathogens and may comprise an early host defense against invading pathogens. the spirochete borrelia burgdorferi first encounters natural antibodies when its arthropod vector, ixodes scapularis, begins feeding on a mammalian host. natural antibodies may therefore have an impact on pathogens within blood-sucking vectors, prior to pathogen transmission to the mammal ...200111553590
protection against tick-transmitted lyme disease in dogs vaccinated with a multiantigenic vaccine.in an effort to develop a safe and effective vaccine for the prevention of lyme borreliosis that addresses concerns raised over currently available vaccines, dogs were vaccinated twice with a multiantigenic preparation of borrelia burgdorferi, strain n40, on days 0 and 20 of the experiment. about 70 and 154 days after the first immunization, dogs were challenged by exposing them to field-collected ixodes scapularis ticks harboring b. burgdorferi. vaccinated dogs were completely protected from in ...200111567763
analysis of borrelia burgdorferi gene expression during life cycle phases of the tick vector ixodes scapularis.borrelia burgdorferi exists in nature via an enzootic cycle whereby the organism must adapt to the diverse environmental conditions provided inside the arthropod transmission vector and the mammalian reservoir hosts. b. burgdorferi genes shown to be regulated by temperature, ph and/or cell density during the organism's growth in culture medium were assayed for expression during various stages of the tick feeding cycle by reverse transcription-polymerase chain reaction (rt-pcr). ospa, ospc, flab, ...200111580974
analysis of borrelia burgdorferi vlse gene expression and recombination in the tick vector.expression and recombination of the antigenic variation vlse gene of the lyme disease spirochete borrelia burgdorferi were analyzed in the tick vector. to assess vlse expression, ixodes scapularis nymphs infected with the b. burgdorferi strain b31 were fed on mice for 48 or 96 h or to repletion and then crushed and acetone fixed either immediately thereafter (ticks collected at the two earlier time points) or 4 days after repletion. unfed nymphs also were examined. at all of the time points inve ...200111598084
canine surveillance system for lyme borreliosis in wisconsin and northern illinois: geographic distribution and risk factor analysis.a seroprevalence survey for borrelia burgdorferi was conducted among the healthy canine pet population in selected counties of wisconsin and northern illinois to determine the distribution of lyme disease and associated risk factors. information obtained for each dog included place of residence, lyme disease vaccination status, history of travel and tick exposure, signalment, and medical history. serum samples were screened by enzyme-linked immunosorbent assay and confirmed by an immunoblot proc ...200111716112
host associations of ticks parasitizing rodents at borrelia burgdorferi enzootic sites in south carolina.a total of 237 rodents was collected in 4 regions of south carolina from july 1994 through december 1995. eight species were collected, including cotton mouse, hispid cotton rat, eastern woodrat, marsh rice rat, white-footed mouse, eastern harvest mouse, golden mouse, and black rat. of the 1,514 ticks recovered from these hosts, ixodes minor neumann, including larvae, nymphs, and adults, was the most abundant species, representing 54% of the total. only immature stages of other tick species were ...200111780825
the efficacy of co-feeding as a means of maintaining borrelia burgdorferi: a north american model system.although research on co-feeding as a means of maintaining tick-borne pathogens has focused chiefly on viruses, recent interest has been directed toward the importance of this phenomenon in maintaining the lyme disease spirochete, borrelia burgdorferi. in the current study, an experimental model was developed to determine under what conditions immature co-feeding ticks exchange b. burgdorferi using the principal north american vector (ixodes scapularis) and reservoir (peromyscus leucopus) species ...200111813659
vector interactions and molecular adaptations of lyme disease and relapsing fever spirochetes associated with transmission by ticks.pathogenic spirochetes in the genus borrelia are transmitted primarily by two families of ticks. the lyme disease spirochete, borrelia burgdorferi, is transmitted by the slow-feeding ixodid tick ixodes scapularis, whereas the relapsing fever spirochete, b. hermsii, is transmitted by ornithodoros hermsi, a fast-feeding argasid tick. lyme disease spirochetes are generally restricted to the midgut in unfed i. scapularis. when nymphal ticks feed, the bacteria pass through the hemocoel to the salivar ...200211897061
geographic uniformity of the lyme disease spirochete (borrelia burgdorferi) and its shared history with tick vector (ixodes scapularis) in the northeastern united states.over 80% of reported cases of lyme disease in the united states occur in coastal regions of northeastern and mid-atlantic states. the genetic structure of the lyme disease spirochete (borrelia burgdorferi) and its main tick vector (ixodes scapularis) was studied concurrently and comparatively by sampling natural populations of i. scapularis ticks along the east coast from 1996 to 1998. borrelia is genetically highly diverse at the outer surface protein ospc. since borrelia is highly clonal, the ...200211901105
glass capillary tube feeding: a method for infecting nymphal ixodes scapularis (acari: ixodidae) with the lyme disease spirochete borrelia burgdorferi.we evaluated an artificial capillary feeding method to infect nymphal ixodes scapularis (say) ticks with borrelia burgdoeferi, the causative agent of lyme disease. thirty to 70% of the nymphs were infected after feeding for 2.5 h from glass capillary tubes filled with a solution of spirochetes. capillary infection was stable and persisted in the nymphs for at least 10 d after feeding. capillary feeding also maintained natural vector competence patterns because i. scapularis ticks acquired infect ...200211931028
the prevalence of borrelia burgdorfieri (spirochaetales: spirochaetaceae) and the agent of human granulocytic ehrlichiosis (rickettsiaceae: ehrlichieae) in ixodes scapularis (acari:ixodidae) collected during 1998 and 1999 from minnesota.we tested 103 adult ixodes scapularis say from 12 counties in minnesota for the presence of borrelia burgdorferi and the causative agent of human granulocytic ehrlichiosis (hge), using polymerase chain reaction (pcr). a total of 17 ticks (16.5%) was positive for b. burgdoiferi using nested pcr for the flagellin gene. or both pcr for the ospa gene and nested pcr for the flagellin gene. a total of four ticks (3.8%) was positive for the agent of hge using nested pcr for 16s rdna. counties in minnes ...200211931260
examination of the borrelia burgdorferi transcriptome in ixodes scapularis during feeding.borrelia burgdorferi gene expression within the guts of engorging ixodes scapularis ticks was examined by use of differential immunoscreening and differential expression with a customized amplified library. fourteen chromosomal genes involved in energy metabolism, substrate transport, and signal transduction and 10 (4 chromosomal and 6 plasmid) genes encoding putative lipoproteins and periplasmic proteins were preferentially expressed in engorging ticks. these data demonstrate a new approach to ...200212003955
reassessment of a midwestern lyme disease focus for borrelia burgdorferi and the human granulocytic ehrlichiosis agent.previous studies from the late 1980s defined the risk of human lyme disease by determining the prevalence of borrelia burgdorferi infection in ixodes scapularis ticks and peromyscus sp. mice captured from areas around la crosse, wis. high percentages of b. burgdorferi-infected i. scapularis ticks and p. leucopus mice were common in areas located north of interstate 90 but were not detected in areas south of this major east-west thoroughfare. in this study, we reevaluated the extent of b. burgdor ...200212037066
protection against lyme disease spirochete transmission provided by prompt removal of nymphal ixodes scapularis (acari: ixodidae).public health recommendations for lyme disease prevention generally include daily tick checks and prompt removal of attached ticks as a means of decreasing the risk of acquiring lyme disease in highly endemic regions. in the current study, we determined whether crushing nymphal ticks during removal with forceps increased the risk of b. burgdorferi transmission, what degree of protection from transmission of b. burgdorferi was provided by removal of nymphal ixodes scapularis say at specific inter ...200212061448
borrelia burgdorferi population kinetics and selected gene expression at the host-vector interface.by using real-time quantitative pcr, the population dynamics and gene transcription of borrelia burgdorferi were examined in ticks and skin of mice during acquisition of the infection from mice by ticks and during transmission of the infection from ticks to mice. population dynamics were determined by using a flab dna target. a quantitative analysis of flab, ospa, ospc, dbpa, and arp transcription was also performed. the results revealed that both uninfected larval and nymphal ixodes scapularis ...200212065476
genetic diversity of the outer surface protein c gene of southern borrelia isolates and its possible epidemiological, clinical, and pathogenetic implications.the ospc genes of 20 southern borrelia strains were sequenced. the strains consisted of b. burgdorferi sensu stricto, b. andersonii, b. bissettii, one undescribed genospecies, mi-8, and one probably new borrelia species, txw-1. a high degree of similarity exists between b. burgdorferi sensu stricto and b. bissettii and between b. bissettii and b. andersonii. lateral transfers of the ospc gene probably occurred between b. burgdorferi sensu stricto and b. bissettii and between b. bissettii and b. ...200212089279
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