Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| borrelia burgdorferi-specific monoclonal antibodies derived from mice primed with lyme disease spirochete-infected ixodes scapularis ticks. | we have generated a panel of igg monoclonal antibodies (mabs) directed against borrelia burgdorferi strain b31 antigens, using a method whereby mice were primed with organisms naturally inoculated by ixodes scapularis nymphal ticks. western blot analysis showed that these mabs recognized several b. burgdorferi b31 antigens, including the complement inhibitor factor h-binding proteins erpa/i/n and erpc. two other mabs were specific for the reva protein, and have enabled characterization of that p ... | 2002 | 12165143 |
| detection of attenuated, noninfectious spirochetes in borrelia burgdorferi-infected mice after antibiotic treatment. | xenodiagnosis by ticks was used to determine whether spirochetes persist in mice after 1 month of antibiotic therapy for vectorborne borrelia burgdorferi infection. immunofluorescence and polymerase chain reaction (pcr) were used to show that spirochetes could be found in ixodes scapularis ticks feeding on 4 of 10 antibiotic-treated mice up to 3 months after therapy. these spirochetes could not be transmitted to naive mice, and some lacked genes on plasmids correlating with infectivity. by 6 mon ... | 2002 | 12404158 |
| backbone dynamics and thermodynamics of borrelia outer surface protein a. | nuclear spin relaxation experiments performed at 298k, 308k and 318k are used to characterize the intramolecular dynamics and thermodynamics of outer surface protein a (ospa), a key protein in the life-cycle of borrelia burgdorferi, the causative agent of lyme disease. it has recently been demonstrated that ospa specifically binds to the gut of the intermediate tick host (ixodes scapularis), and that this interaction is mediated, at least in part, by residues in the c-terminal domain of ospa tha ... | 2002 | 12470954 |
| expression of spot in borrelia burgdorferi during serum starvation. | borrelia burgdorferi, the causative agent of lyme disease, is transmitted by the tick ixodes scapularis. a 2.9-kb fragment containing a putative spot gene was isolated from b. burgdorferi genomic dna by pcr amplification and cloned into a pbad24 vector. the cloned gene complemented escherichia coli mutant strain cf1693, which contains deletions of both the rela and spot genes. the spot gene in e. coli encodes a bifunctional enzyme capable of synthesizing and degrading (p)ppgpp, which mediates th ... | 2003 | 12511489 |
| geographical and seasonal correlation of multiple sclerosis to sporadic schizophrenia. | background: clusters by season and locality reveal a striking epidemiological overlap between sporadic schizophrenia and multiple sclerosis (ms). as the birth excesses of those individuals who later in life develop schizophrenia mirror the seasonal distribution of ixodid ticks, a meta analysis has been performed between all neuropsychiatric birth excesses including ms and the epidemiology of spirochaetal infectious diseases. results: the prevalence of ms and schizophrenic birth excesses entirely ... | 2002 | 12537588 |
| lyme disease spirochete, borrelia burgdorferi endemic at epicenter in rondeau provincial park, ontario. | the lyme disease spirochete, borrelia burgdorferi johnson, schmidt, hyde, steigerwalt, and brenner was discovered in blacklegged ticks, ixodes scapularis say at rondeau provincial park, ontario, canada during this 2-yr study, spirochetes were found in b. burgdorferi-positive i. scapularis larvae attached to b. burgdorferi-infected white-footed mice, peromyscus leucopus rafinesque. isolates of b. burgdorferi were cultured from blacklegged tick adults, and confirmed positive with polymerase chain ... | 2003 | 12597659 |
| a relapsing fever group spirochete transmitted by ixodes scapularis ticks. | a species of borrelia spirochetes previously unknown from north america has been found to be transmitted by ixodes scapularis ticks. infected ticks are positive for borrelia spp. by dfa test but negative for borrelia burgdorferi by polymerase chain reaction (pcr) using species-specific primers for 16s rdna, outer surface protein a, outer surface protein c, and flagellin genes. a 1,347-bp portion of 16s rdna was amplified from a pool of infected nymphs, sequenced, and compared with the homologous ... | 2001 | 12653133 |
| an analysis of spirochete load, strain, and pathology in a model of tick-transmitted lyme borreliosis. | four laboratory-grown, low-passage isolates of borrelia burgdorferi sensu stricto, b31, jd-1, 910255, and n40, were incorporated into ixodes scapularis ticks to examine the pathogenesis of these isolates in mice after tick transmission. all isolates induced multifocal, lymphoid nodular cystitis, subacute, multifocal, necrotizing myocarditis, and a localized periostitis and arthritis of the femorotibial joint 6-18 weeks after tick infestation. in terms of the number of mice that demonstrated path ... | 2001 | 12653134 |
| effects of acorn production and mouse abundance on abundance and borrelia burgdorferi infection prevalence of nymphal ixodes scapularis ticks. | risk of exposure to lyme disease is a function of the local abundance of nymphal ixodes ticks that are infected with the etiological agent, the spirochete borrelia burgdorferi. we monitored abundance of white-footed mice (the principal b. burgdorferi reservoir in the eastern and central united states) and acorns (a critical food resource for mice), and ixodes scapularis ticks, as well as ambient temperature (cumulative growing degree days) and growing season precipitation, in a forested landscap ... | 2001 | 12653136 |
| ospa immunization decreases transmission of borrelia burgdorferi spirochetes from infected peromyscus leucopus mice to larval ixodes scapularis ticks. | recombinant outer surface protein a (ospa) vaccination of wild animal reservoirs has potential application for reducing borrelia burgdorferi transmission in nature and subsequent risk of human infection. as a major reservoir host, the white-footed mouse (peromyscus leucopus) is a candidate for a vaccination program designed to reduce infection prevalence in vector ticks. in this study we characterized the effect of various levels of immunization with recombinant ospa-glutathione transferase fusi ... | 2001 | 12653137 |
| spatiotemporal variation in a lyme disease host and vector: black-legged ticks on white-footed mice. | we monitored population density of white-footed mice (peromyscus leucopus), burdens of immature black-legged ticks (ixodes scapularis) on mice, and infection prevalence of host-seeking ticks on six forest plots in southeastern new york state from 1995 through 1999. despite densities of mice that fluctuated two orders of magnitude, average larval and nymphal tick burdens per mouse remained remarkably constant. spatial variability in mouse density and tick burdens was modest. the total number of l ... | 2001 | 12653143 |
| interference between the agents of lyme disease and human granulocytic ehrlichiosis in a natural reservoir host. | agents of lyme disease (borrelia burgdorferi) and human granulocytic ehrlichiosis (ehrlichia phagocytophila) are perpetuated in a natural cycle involving the black-legged tick (ixodes scapularis) and its vertebrate hosts. using i. scapularis nymphs as the mode of infectious challenge, we studied how infection with one pathogen in white-footed mice (peromyscus leucopus) affects their ability to acquire the other agent and subsequently to infect larvae, which these agents would do in nature. two g ... | 2001 | 12653144 |
| investigations on the mode and dynamics of transmission and infectivity of borrelia burgdorferi sensu stricto and borrelia afzelii in ixodes ricinus ticks. | borrelia burgdorferi sensu lato (sl), the agent of lyme disease, is transmitted to the host during the blood meal of ixodes ticks. in most unfed ticks, spirochetes are present in the midgut and migrate during blood feeding to the salivary glands, from which they are transmitted to the host via saliva. in the present study, the efficiency of ixodes ricinus ticks to transmit b. afzelii and b. burgdorferi sensu stricto (ss) and their infectivity for mice were examined in relation to the duration of ... | 2002 | 12656125 |
| molecular characterization of anaplasma phagocytophilum and borrelia burgdorferi in ixodes scapularis ticks from pennsylvania. | ixodes scapularis ticks were collected in 2000 and 2001 from two areas in pennsylvania and tested for the presence of anaplasma phagocytophilum and borrelia burgdorferi by pcr and dna sequencing. of the ticks collected from northwestern and southeastern pennsylvania, 162 of 263 (61.6%) and 25 of 191 (13.1%), respectively, were found to be positive for b. burgdorferi. dna sequencing showed >99% identity with b. burgdorferi strains b31 and jd1. pcr testing for a. phagocytophilum revealed that 5 of ... | 2003 | 12682147 |
| epidemiology and impact of coinfections acquired from ixodes ticks. | ixodes scapularis and other ticks in the ixodes ricinus complex may transmit multiple pathogens, but research on coinfections has been limited. coinfections occur with varying frequency in ticks, but single infections are more common than dual infections. the proportion of i. scapularis or i. ricinus ticks coinfected with both borrelia burgdorferi sensu lato and anaplasma phagocytophila is generally low, ranging from < 1% to 6% in six geographic areas. a higher prevalence of tick coinfection (26 ... | 2002 | 12804168 |
| characterization of anaplasma phagocytophila and borrelia burgdorferi genotypes in ixodes scapularis ticks from pennsylvania. | 2003 | 12860614 | |
| experimental infection of dogs with borrelia burgdorferi sensu stricto using ixodes scapularis ticks artificially infected by capillary feeding. | specific pathogen-free dogs were experimentally infected with borrelia burgdorferi sensu stricto using nymphal or adult female ixodes scapularis ticks artificially infected with spirochetes by capillary feeding. the ticks were capillary fed b. burgdorferi isolate 610, previously isolated from a dog with lyme disease and grown in bsk medium. this isolate induced clinical signs in the dogs similar to those for dogs infested with ticks naturally infected with b. burgdorferi. adult ticks were more e ... | 2004 | 12884036 |
| real-time pcr for simultaneous detection and quantification of borrelia burgdorferi in field-collected ixodes scapularis ticks from the northeastern united states. | the density of spirochetes in field-collected or experimentally infected ticks is estimated mainly by assays based on microscopy. in this study, a real-time quantitative pcr (qpcr) protocol targeting the borrelia burgdorferi-specific reca gene was adapted for use with a lightcycler for rapid detection and quantification of the lyme disease spirochete, b. burgdorferi, in field-collected ixodes scapularis ticks. the sensitivity of qpcr for detection of b. burgdorferi dna in infected ticks was comp ... | 2003 | 12902243 |
| evaluation of venezuelan equine encephalitis (vee) replicon-based outer surface protein a (ospa) vaccines in a tick challenge mouse model of lyme disease. | venezuelan equine encephalitis (vee) virus replicon particles (vrps) encoding borrelia burgdorferi outer surface protein a (ospa) were evaluated for their ability to induce an immune response and provide protection from tick-borne spirochetes. vrps expressing ospa that accumulated intracellularly (vrp ospa) or that was secreted from host cells (vrp tpa-ospa) were tested. both vrp ospa and vrp tpa-ospa expressed ospa in immunized mice. mice vaccinated with vrps expressing secreted ospa produced s ... | 2003 | 12922122 |
| evaluation of permethrin and imidacloprid for prevention of borrelia burgdorferi transmission from blacklegged ticks (ixodes scapularis) to borrelia burgdorferi-free dogs. | 2003 | 12928869 | |
| experimental infection of ixodes scapularis larvae (acari: ixodidae) by immersion in low passage cultures of borrelia burgdorferi. | we describe a procedure for the introduction of borrelia burgdorferi, the spirochetal agent of lyme disease, into larvae of the tick vector ixodes scapularis. internalized spirochetes were observed in larvae examined after 15 or 45 min immersion at 32 degrees c in liquid culture suspensions of low passage b. burgdorferi strain b31. larval ticks immersed in low passage strain b31 were able to feed to repletion on white-footed mice. midguts of larvae contained many spirochetes 1 wk postengorgement ... | 2003 | 12943118 |
| an enzootic transmission cycle of lyme borreliosis spirochetes in the southeastern united states. | lyme borreliosis, or lyme disease (ld), is a tick-borne zoonotic infection of biomedical significance, caused by borrelia burgdorferi sensu lato (s.l.) spirochetes and transmitted by ixodes species ticks. it usually circulates among wildlife vertebrate reservoirs and vector ticks but may infect humans, causing multisystem problems. in far western and northern north america, the host reservoirs, tick vectors, and genospecies of borrelia are well known but not so in the southern u.s., where there ... | 2003 | 14500917 |
| dynamic changes in borrelia burgdorferi populations in ixodes scapularis (acari: ixodidae) during transmission: studies at the mrna level. | many b. burgdorferi genes are regulated at the level of transcription during b. burgdorferi passage from ticks to mammals. particular spirochete outer surface proteins of interest are ospa, ospc, and vlse. the messenger rna (mrna) levels produced by these three genes were determined by a quantitative reverse transcription pcr (q-rt-pcr) procedure for spirochete populations in nymphal i. scapularis midguts and salivary glands at specific intervals during the feeding process. the mrna values were ... | 2003 | 14511582 |
| the effects of bird feeders on lyme disease prevalence and density of ixodes scapularis (acari: ixodidae) in a residential area of dutchess county, new york. | the effects of bird feeders on local densities of ixodes scapularis ticks and prevalence of lyme disease were examined in residential areas of dutchess county, ny. ticks were collected, counted, and analyzed for borrelia burgdorferi spirochetes in 2001-2002 on residential properties with and without bird feeders. tick densities and infection prevalence were not significantly different on properties with and without bird feeders. furthermore, analysis of a questionnaire, administered to 580 local ... | 2003 | 14680124 |
| prevalence of borrelia burgdorferi (spirochaetales: spirochaetaceae) in ixodes scapularis (acari: ixodidae) adults in new jersey, 2000-2001. | using polymerase chain reaction, we analyzed 529 ixodes scapularis say adults collected from 16 of new jersey's 21 counties for the presence of borrelia burgdorferi, the etiological agent of lyme disease. overall, 261 (49.3%) were positive. b. burgdorferi was detected in ticks obtained from each county and from 53 of the 58 (93.1%) municipalities surveyed. the observed statewide prevalence in new jersey is similar to those reported from other northeastern and mid-atlantic states. | 2003 | 14680126 |
| geographic information systems and spatial analysis of adult ixodes scapularis (acari: ixodidae) in the middle atlantic region of the u.s.a. | in the middle atlantic region of the u.s.a., the vector of lyme disease, human granulocytic ehrlichiosis, babesiosis, and other human and veterinary pathogens is the black-legged tick, ixodes scapularis say. in 1997 and 1998, 663 adult i. scapularis ticks were collected from 320 transects spanning 66,400 km2 in five states of the middle atlantic region. tick abundance patterns were clustered, with relatively high numbers along the coastal plain of the chesapeake bay, decreasing to the west and s ... | 2003 | 14680128 |
| ospc facilitates borrelia burgdorferi invasion of ixodes scapularis salivary glands. | outer surface protein c (ospc) is a differentially expressed major surface lipoprotein of borrelia burgdorferi. ospc is swiftly upregulated when spirochetes leave the ixodes scapularis tick gut, migrate to the salivary gland, and exit the arthropod vector. here we show that ospc strongly binds to the tick salivary gland, suggesting a role for ospc in spirochete adherence to this tissue. in vivo studies using a murine model of lyme borreliosis showed that while ospc f(ab)(2) fragments did not inf ... | 2004 | 14722614 |
| disruption of ixodes scapularis anticoagulation by using rna interference. | ixodes scapularis ticks transmit many pathogens, including borrelia burgdorferi, anaplasma phagocytophilum, and babesia microti. vaccines directed against arthropod proteins injected into the host during tick engorgement could prevent numerous infectious diseases. salp14, a salivary anticoagulant, poses a key target for such intervention. salp14 is the prototypic member of a family of potential i. scapularis anticoagulants, expressed and secreted in tick saliva during tick feeding. rna interfere ... | 2004 | 14745044 |
| ixodes scapularis ticks (acari: ixodidae) from louisiana are competent to transmit borrelia burgdorferi, the agent of lyme borreliosis. | the principal vector of borrelia burgdorferi, the lyme borreliosis spirochete, in the northeast and midwestern regions of the united states is the blacklegged tick ixodes scapularis. because of a favorable environment, i. scapularis is also plentiful in the south; however, a correlation with lyme borreliosis cases does not exist in this region of the united states. concern existed that something intrinsic to ticks found in louisiana could mitigate their ability to transmit b. burgdorferi. theref ... | 2003 | 14765677 |
| ospb antibody prevents borrelia burgdorferi colonization of ixodes scapularis. | borrelia burgdorferi outer surface protein ospb is expressed by spirochetes in the ixodes scapularis gut. ospb is transcribed from a bicistronic operon with ospa, a known spirochete adhesion gene in the tick gut. here we examine whether ospb also has a specific function in ticks. ospb specifically binds to a protein or protein complex within the tick gut. we also assessed whether selected nonborreliacidal ospb antibodies or f(ab)(2) fragments interfere with b. burgdorferi-tick attachment in vivo ... | 2004 | 14977984 |
| lyme disease spirochete, borrelia burgdorferi, endemic in epicenter at turkey point, ontario. | the lyme disease spirochete, borrelia burgdorferi johnson, schmidt, hyde, steigerwalt, and brenner, was discovered in blacklegged ticks, ixodes scapularis say at turkey point, ontario, canada. we report the first isolation of b. burgdorferi from a vertebrate animal collected on mainland ontario. during this 2-yr study, spirochetes were isolated from the white-footed mouse, peromyscus leucopus rafinesque, and attached i. scapularis larvae. similarly, isolates of b. burgdorferi were cultured from ... | 2004 | 15061282 |
| borrelia burgdorferi infection in a natural population of peromyscus leucopus mice: a longitudinal study in an area where lyme borreliosis is highly endemic. | blood samples from peromyscus leucopus mice captured at an enzootic site in connecticut were examined for antibodies to and dna of borrelia burgdorferi, to characterize the dynamics of infection in this reservoir population. from trappings conducted over the course of 2 transmission seasons, 598 (75%) of 801 serum samples from 514 mice were found to be positive by enzyme immunoassay. seropositivity correlated with date of capture and mouse age, was similar among locations within the site, increa ... | 2004 | 15073690 |
| prevalence of borrelia burgdorferi, bartonella spp., babesia microti, and anaplasma phagocytophila in ixodes scapularis ticks collected in northern new jersey. | pcr analysis of ixodes scapularis ticks collected in new jersey identified infections with borrelia burgdorferi (33.6%), babesia microti (8.4%), anaplasma phagocytophila (1.9%), and bartonella spp. (34.5%). the i. scapularis tick is a potential pathogen vector that can cause coinfection and contribute to the variety of clinical responses noted in some tick-borne disease patients. | 2004 | 15184475 |
| sequence typing reveals extensive strain diversity of the lyme borreliosis agents borrelia burgdorferi in north america and borrelia afzelii in europe. | the genetic polymorphism of borrelia burgdorferi and borrelia afzelii, two species that cause lyme borreliosis, was estimated by sequence typing of four loci: the rrs-rrla intergenic spacer (igs) and the outer-membrane-protein gene p66 on the chromosome, and the outer-membrane-protein genes ospa and ospc on plasmids. the major sources of dna for pcr amplification and sequencing were samples of the b. burgdorferi tick vector ixodes scapularis, collected at a field site in an endemic region of the ... | 2004 | 15184561 |
| anaplasma phagocytophilum, babesia microti, and borrelia burgdorferi in ixodes scapularis, southern coastal maine. | ixodes scapularis (deer ticks) from maine were tested for multiple infections by polymerase chain reaction and immunofluorescence. in 1995, 29.5%, 9.5%, and 1.9% of deer ticks were infected with borrelia burgdorferi, anaplasma phagocytophilum, and babesia microti, respectively. in 1996 and 1997, the number of a. phagocytophilum-infected ticks markedly declined. in 1995 through 1996, 4 (1.3%) of 301 were co-infected. | 2004 | 15200875 |
| direct detection of borrelia burgdorferi in ixodes scapularis (acari: ixodidae) nymphs by hybridization to ribosomal rna. | a method for direct detection of borrelia burgdorferi johnson, schmid, hyde, steigerwalt & brenner has been developed. cells are lysed to facilitate release of ribosomal rna. lysates are filtered onto nylon membranes that are hybridized with probes specific for sequences in b. burgdorferi 23s rrna. the technique is rapid and does not require any enzymatic amplification steps. with the use of a cocktail containing five different probes, approximately 1,000 organisms could be detected. the assay w ... | 2000 | 15218912 |
| passive tick surveillance, dog seropositivity, and incidence of human lyme disease. | data on nymphal ixodes scapularis ticks submitted by the public to the university of rhode island tick research laboratory for testing from 1991 to 2000 were compared with human case data from the rhode island department of health to determine the efficacy of passive tick surveillance at assessing human risk of lyme disease. numbers of ticks submitted were highly correlated with human cases by county (r = 0.998, n = 5 counties) and by town (r = 0.916, n = 37 towns), as were the numbers of positi ... | 2004 | 15228814 |
| multiplex real-time pcr for detection of anaplasma phagocytophilum and borrelia burgdorferi. | a multiplex real-time pcr assay was developed for the simultaneous detection of anaplasma phagocytophilum and borrelia burgdorferi. the assay was tested on various anaplasma, borrelia, erhlichia, and rickettsia species, as well as on bartonella henselae and escherichia coli, and the assay was found to be highly specific for a. phagocytophilum and the borrelia species tested (b. burgdorferi, b. parkeri, b. andersonii, and b. bissettii). the analytical sensitivity of the assay is comparable to tha ... | 2004 | 15243077 |
| the luxs gene is not required for borrelia burgdorferi tick colonization, transmission to a mammalian host, or induction of disease. | luxs mutants of borrelia burgdorferi strain 297 naturally colonized their arthropod (ixodes scapularis) vector, were maintained in ticks throughout the molting process (larvae to nymphs), were tick transmitted to uninfected mice, and elicited histopathology in mice indistinguishable from that induced by wild-type b. burgdorferi. | 2004 | 15271949 |
| abundance of ixodes scapularis (acari: ixodidae) after the complete removal of deer from an isolated offshore island, endemic for lyme disease. | monhegan is an isolated 237-ha island lying 16 km off the coast of maine. introduced to the island in 1955, white-tailed deer, odocoileus virginianus zimmerman, reached a density of approximately 37/km2 by the mid-1990s. black-legged ticks, ixodes scapularis say, first noticed in the late 1980s, flourished thereafter. norway rats (rattus norvegicus berkenhout) on monhegan are highly infected with borrelia burgdorferi johnson, schmidt, hyde, steigerwalt, and brenner, the agent of lyme disease. by ... | 2004 | 15311475 |
| a technique for longitudinally sampling individual adult ixodes scapularis (acari: ixodidae). | the first technique for repeatedly sampling individual ixodes scapularis adult ticks was developed and validated. gut samples from the same individual ticks were removed and analyzed at weekly intervals. multiple analyses were conducted on each gut sample (e.g., total protein concentration, presence of viable b. burgdorferi spirochetes, and concentration of outer surface protein a [ospa]). female i. scapularis survived for up to 25 d after gut sampling. seventy-five percent of females oviposited ... | 2004 | 15311478 |
| short report: duration of tick attachment required for transmission of powassan virus by deer ticks. | infected deer ticks (ixodes scapularis) were allowed to attach to naive mice for variable lengths of time to determine the duration of tick attachment required for powassan (pow) virus transmission to occur. viral load in engorged larvae detaching from viremic mice and in resulting nymphs was also monitored. ninety percent of larval ticks acquired pow virus from mice that had been intraperitoneally inoculated with 10(5) plaque-forming units (pfu). engorged larvae contained approximately 10 pfu. ... | 2004 | 15381804 |
| interaction and transmission of two borrelia burgdorferi sensu stricto strains in a tick-rodent maintenance system. | in the northeastern united states, the lyme disease agent, borrelia burgdorferi sensu stricto, is maintained by enzoonotic transmission, cycling between white-footed mice (peromyscus leucopus) and black-legged ticks (ixodes scapularis). b. burgdorferi sensu stricto is genetically variable and has been divided into three major genotypes based on 16s-23s ribosomal dna spacer (rst) analysis. to better understand how genetic differences in b. burgdorferi sensu stricto may influence transmission dyna ... | 2004 | 15528545 |
| borrelia species in host-seeking ticks and small mammals in northern florida. | the aim of this study was to improve understanding of several factors related to the ecology and environmental risk of borrelia infection in northern florida. small mammals and host-seeking adult ticks were collected at several sites, and specimens were tested for the presence of borrelia species, primarily by pcr amplification. tissues from some vertebrates and ticks were initially cultured in bsk-h medium to isolate spirochetes, but none were recovered. however, comparison of partial flagellin ... | 2004 | 15528699 |
| trospa, an ixodes scapularis receptor for borrelia burgdorferi. | the lyme disease agent borrelia burgdorferi naturally persists in a cycle that primarily involves ticks and mammals. we have now identified a tick receptor (trospa) that is required for spirochetal colonization of ixodes scapularis. b. burgdorferi outer surface protein a, which is abundantly expressed on spirochetes within the arthropod and essential for pathogen adherence to the vector, specifically bound to trospa. trospa mrna levels in ticks increased following spirochete infestation and decr ... | 2004 | 15537536 |
| control of immature ixodes scapularis (acari: ixodidae) on rodent reservoirs of borrelia burgdorferi in a residential community of southeastern connecticut. | a 3-yr community-based study was conducted on residential properties on mason's island, mystic, ct, to determine the efficacy of a rodent-targeted acaricide (fipronil) to control immature ixodes scapularis (say) on peromyscus leucopus. results indicated that modified commercial bait boxes were effective as an acaricide delivery method for reducing nymphal and larval tick infestations on white-footed mice by 68 and 84%, respectively. passive application of fipronil significantly reduced the infec ... | 2004 | 15605643 |
| an ecological approach to preventing human infection: vaccinating wild mouse reservoirs intervenes in the lyme disease cycle. | many pathogens, such as the agents of west nile encephalitis and plague, are maintained in nature by animal reservoirs and transmitted to humans by arthropod vectors. efforts to reduce disease incidence usually rely on vector control or immunization of humans. lyme disease, for which no human vaccine is currently available, is a commonly reported vector-borne disease in north america and europe. in a recently developed, ecological approach to disease prevention, we intervened in the natural cycl ... | 2004 | 15608069 |
| hypersensitivity to ticks and lyme disease risk. | although residents of lyme disease-endemic regions describe frequent exposure to ticks, lyme disease develops in relatively few. to determine whether people who experience cutaneous hypersensitivity against tick bite have fewer episodes of lyme disease than those who do not, we examined several factors that might restrict the incidence of lyme disease among residents of block island, rhode island. of 1,498 study participants, 27% (95% confidence interval [ci] 23%-31%) reported > or = 1 tick bite ... | 2005 | 15705320 |
| borrelia burgdorferi sigma54 is required for mammalian infection and vector transmission but not for tick colonization. | previous studies have shown that a sigma54-sigma(s) cascade regulates the expression of a few key lipoproteins in borrelia burgdorferi, the agent of lyme disease. here, we demonstrate that these sigma factors, both together and independently, regulate a much more extensive number of genes and cellular processes. microarray analyses of sigma54 and sigma(s) mutant strains identified 305 genes regulated by sigma54 and 145 regulated by sigma(s), whereas the sigma54-sigma(s) regulatory cascade appear ... | 2005 | 15743918 |
| borreliacidal activity of saliva of the tick amblyomma americanum. | amblyomma americanum (linneaus) (acari: ixodidae), an important tick vector of human and animal disease, is not a competent vector of the bacterial agent of lyme disease, borrelia burgdorferi, although its range overlaps the geographical distribution of lyme disease within the united states. a possible mechanism that could prevent acquisition of b. burgdorferi spirochetes from infected hosts is the toxic effect of a. americanum saliva on b. burgdorferi. the data presented here indicate that afte ... | 2005 | 15752182 |
| improving the specificity of 16s rdna-based polymerase chain reaction for detecting borrelia burgdorferi sensu lato-causative agents of human lyme disease. | 16s rdna sequences of borrelia burgdorferi sensu lato were aligned with the 16s rdna sequences of borrelia hermsii, borrelia turicatae, and borrelia lonestari in order to identify primers that might be used to more specifically identify agents of human lyme disease in ticks in human skin samples. | 2005 | 15752343 |
| bpta (bbe16) is essential for the persistence of the lyme disease spirochete, borrelia burgdorferi, in its natural tick vector. | borrelia burgdorferi (bb), the agent of lyme disease, is a zoonotic spirochetal bacterium that depends on arthropod (ixodes ticks) and mammalian (rodent) hosts for its persistence in nature. the quest to identify borrelial genes responsible for bb's parasitic dependence on these two diverse hosts has been hampered by limitations in the ability to genetically manipulate virulent strains of bb. despite this constraint, we report herein the inactivation and genetic complementation of a linear plasm ... | 2005 | 15860579 |
| molecular identification and analysis of borrelia burgdorferi sensu lato in lizards in the southeastern united states. | lyme borreliosis (lb) group spirochetes, collectively known as borrelia burgdorferi sensu lato, are distributed worldwide. wild rodents are acknowledged as the most important reservoir hosts. ixodes scapularis is the primary vector of b. burgdorferi sensu lato in the eastern united states, and in the southeastern united states, the larvae and nymphs mostly parasitize certain species of lizards. the primary aim of the present study was to determine whether wild lizards in the southeastern united ... | 2005 | 15870353 |
| histopathological studies of experimental lyme disease in the dog. | experimental borrelia infection was induced in 62 specific--pathogen-free beagle dogs by exposure to ixodes scapularis ticks harbouring the spirochaete borrelia burgdorferi. clinical signs of lyme disease occurred in 39/62 dogs, the remaining 23 being subclinically infected. clinical signs consisted of one to six episodes of transitory lameness with joint swelling and pain, most commonly affecting the elbow or shoulder joints. the polymerase chain reaction and culture demonstrated that the dogs ... | 2005 | 15904927 |
| presence of borrelia burgdorferi (spirochaetales: spirochaetaceae) in southern kettle moraine state forest, wisconsin, and characterization of strain w97f51. | lyme disease, caused by borrelia burgdorferi johnson, schmidt, hyde, steigerwalt & brenner; babesiosis, caused by babesia microti franca; and human granulocytic ehrlichiosis, caused by anaplasma phagocytophilum bakken & dumler have been reported in wisconsin, mainly in the endemic areas of the northwestern part of the state. people exposed to blacklegged ticks, ixodes scapularis say, from this region can potentially contract one or all of these diseases concurrently. within the past several year ... | 2005 | 15962800 |
| differential infectivity of the lyme disease spirochete borrelia burgdorferi derived from ixodes scapularis salivary glands and midgut. | blood fed nymphal ixodes scapularis say infected with borrelia burgdorferi were dissected to obtain salivary gland and midgut extracts. extracts were inoculated into c3h/hej mice, and ear, heart, and bladder were cultured to determine comparative infectivity. aliquots of extracts were then analyzed by quantitative polymerase chain reaction to determine the number of spirochetes inoculated into mice. a comparative median infectious dose (id50) was determined for both salivary gland and midgut ext ... | 2005 | 15962807 |
| capillary feeding of specific dsrna induces silencing of the isac gene in nymphal ixodes scapularis ticks. | ixodes scapularis transmits several pathogens including borrelia burgdorferi. bioactive compounds in tick saliva support tick feeding and influence pathogen transmission to the mammalian host. these studies utilized oral delivery of dsrna to silence an anticomplement gene (isac) in i. scapularis nymphs. silencing of isac significantly reduced fed-tick weight compared to delivery of control lacz dsrna, and immunoblots specific for flab protein indicated a reduction in spirochete load in isac-sile ... | 2005 | 16033437 |
| the lyme disease agent exploits a tick protein to infect the mammalian host. | the lyme disease agent, borrelia burgdorferi, is maintained in a tick-mouse cycle. here we show that b. burgdorferi usurps a tick salivary protein, salp15 (ref. 3), to facilitate the infection of mice. the level of salp15 expression was selectively enhanced by the presence of b. burgdorferi in ixodes scapularis, first indicating that spirochaetes might use salp15 during transmission. salp15 was then shown to adhere to the spirochaete, both in vitro and in vivo, and specifically interacted with b ... | 2005 | 16049492 |
| role of borrelia burgdorferi linear plasmid 25 in infection of ixodes scapularis ticks. | the tick-borne bacterium borrelia burgdorferi has over 20 different circular and linear plasmids. some b. burgdorferi plasmids are readily lost during in vitro culture or genetic manipulation. linear plasmid 25, which is often lost in laboratory strains, is required for the infection of mice. strains missing linear plasmid 25 (lp25(-)) are able to infect mice if the bbe22 gene on lp25 is provided on a shuttle vector. in this study, we examined the role of lp25 and bbe22 in tick infections. we te ... | 2005 | 16077125 |
| lyme disease agent borrows a practical coat. | 2005 | 16079876 | |
| defining plasmids required by borrelia burgdorferi for colonization of tick vector ixodes scapularis (acari: ixodidae). | maintenance in nature of borrelia burgdorferi, the pathogenic bacterium that causes lyme disease, requires transmission through an infectious cycle that includes a tick vector and a mammalian host. the genetic requirements for persistence in these disparate environments have not been well defined. b. burgdorferi has a complex genome composed of a chromosome and >20 plasmids. previous work has demonstrated that b. burgdorferi requires two plasmids, lp25 and lp28-1, in the mammalian host. to inves ... | 2005 | 16119559 |
| tick exposure and lyme disease at a summer camp in maryland. | after investigating an outbreak of lyme disease among counselors at a summer camp in kent county, maryland in 1994, we wanted to determine the incidence of lyme disease (ld) at the camp the following summer and identify risk factors for tick exposure. any ticks that were detected on campers' skin or clothing were collected by the camp nurse and we studied them for infection with borrelia burgdorferi. in addition, we sent detailed questionnaires home with the 1,623 campers. a total of 537 campers ... | 2005 | 16161531 |
| the abcs of lyme disease spirochaetes in ticks. | 2005 | 16168758 | |
| forest fragmentation predicts local scale heterogeneity of lyme disease risk. | fragmentation of the landscape has been proposed to play an important role in defining local scale heterogeneity in lyme disease risk through influence on mammalian host density and species composition. we tested this observed relationship in a suburban region around lyme, connecticut, where we collected data on the density of the tick vector, ixodes scapularis and prevalence of the lyme bacterium, borrelia burgdorferi at 30 sites. analysis of the landscape pattern of forest patches was performe ... | 2005 | 16187106 |
| geographic distribution of ticks (acari: ixodidae) in iowa with emphasis on ixodes scapularis and their infection with borrelia burgdorferi. | in iowa, public concern regarding lyme disease has increased markedly over the last decade. in response to these concerns, a statewide surveillance program was initiated in 1990 based on ticks received by the department of entomology at iowa state university. ticks were received from health care professionals, state government agencies, and the general public. a total of 5,343 ticks from all 99 iowa counties were identified during the 12 years of this study. dermacentor variabilis was the most n ... | 2005 | 16187889 |
| oral vaccine that breaks the transmission cycle of the lyme disease spirochete can be delivered via bait. | borrelia burgdorferi causes lyme disease, a potentially debilitating human disease for which no vaccine is currently available. we developed an oral bait delivery system for an anti-b. burgdorferi vaccine based in ospa. mice were immunized orally via gavage and bait feeding. challenge was performed via ixodes scapularis field nymphs carrying multiple b. burgdorferi strains. vaccination protected 89% of the mice and the systemic immune response was skewed toward igg2a/2b production. moreover, thi ... | 2006 | 16198456 |
| seroprevalence of antibodies against borrelia burgdorferi and anaplasma phagocytophilum in cats. | to determine whether cats in the northeastern united states develop serum antibodies against antigens of borrelia burgdorferi and anaplasma phagocytophilum and whether coinfection with the 2 organisms occurs. | 2005 | 16334946 |
| an annotated catalog of salivary gland transcripts from ixodes scapularis ticks. | over 8000 expressed sequence tags from six different salivary gland cdna libraries from the tick ixodes scapularis were analyzed. these libraries derive from feeding nymphs infected or not with the lyme disease agent, borrelia burgdorferi, from unfed adults, and from adults feeding on a rabbit for 6-12 h, 18-24 h, and 3-4 days. comparisons of the several libraries led to identification of several significantly differentially expressed transcripts. additionally, over 500 new predicted protein seq ... | 2006 | 16431279 |
| three multiplex assays for detection of borrelia burgdorferi sensu lato and borrelia miyamotoi sensu lato in field-collected ixodes nymphs in north america. | two hundred fifty new jersey field-collected ixodes scapularis say ticks and 17 colorado ixodes spinipalpis hadwen & nuttall ticks were tested using three separate multiplex real-time polymerase chain reaction (pcr) assays. one assay targets the rrs-rrla igs region of borrelia spp. to detect borrelia burgdorferi sensu lato (s.l.) and borrelia miyamotoi s.l. the second assay targets the ospa region of b. burgdorferi s.l. to detect b. burgdorferi sensu stricto (s.s.), borrelia bissettii, and borre ... | 2005 | 16465748 |
| kinetics of borrelia burgdorferi infection in larvae of refractory and competent tick vectors. | the acquisition of borrelia burgdorferi by the larvae of competent and refractory ixodid ticks was assessed by quantitative polymerase chain reaction (pcr). larvae were fed on infected mice, and the spirochete loads were determined during feeding and up to 93 d postfeeding. amblyomma americanum (l.) was refractory to b. burgdorferi infection, with almost no detection of spirochete dna during or postfeeding. in contrast, ixodes scapularis say supported high loads of spirochetes (10(3)-10(4) per l ... | 2006 | 16506448 |
| strategies for reducing the risk of lyme borreliosis in north america. | the incidence of lyme borreliosis continues to increase in the united states. in 1991, when lyme borreliosis first became a nationally reportable disease to the centers for disease control and prevention (cdc), a total of 9470 cases were reported; in contrast, by 2002 a total of 23,763 cases were reported, >2.5x the total in 1991. area-wide acaricides can be highly effective in killing nymphal ixodes scapularis, with >95% of nymphs killed in studies using cyfluthrin, deltamethrin, or carbaryl. t ... | 2006 | 16524769 |
| myd88 deficiency enhances acquisition and transmission of borrelia burgdorferi by ixodes scapularis ticks. | borrelia burgdorferi strains exhibit various degrees of infectivity and pathogenicity in mammals, which may be due to their relative ability to evade initial host immunity. innate immune cells recognize b. burgdorferi by toll-like receptors (tlrs) that use the intracellular molecule myd88 to mediate effector functions. to determine whether impaired tlr signaling enhances ixodes scapularis acquisition of b. burgdorferi, we fed nymphs on wild-type (wt) and myd88-/- mice previously infected with tw ... | 2006 | 16552045 |
| a reverse transcriptase-polymerase chain reaction assay of borrelia burgdorferi 16s rrna for highly sensitive quantification of pathogen load in a vector. | we developed a real-time quantitative detection assay for the pathogen borrelia burgdorferi, a lyme borreliosis (lb) agent, using reverse transcription-polymerase chain reaction (rt-pcr) with primers and probe for a borrelia genus-specific region of 16s ribosomal rna. the standard curve of the assay was linear by semi-log plot over more than five orders of magnitude, and the detection limit of the assay was one thousandth of a single cell of b. burgdorferi. the minimum target level for detection ... | 2006 | 16584333 |
| a modest model explains the distribution and abundance of borrelia burgdorferi strains. | the distribution and abundance of borrelia burgdorferi, including human lyme disease strains, is a function of its interactions with vertebrate species. we present a mathematical model describing important ecologic interactions affecting the distribution and abundance of b. burgdorferi strains, marked by the allele at the outer surface protein c locus, in ixodes scapularis ticks, the principal vector. the frequency of each strain in ticks can be explained by the vertebrate species composition, t ... | 2006 | 16606995 |
| spatiotemporal patterns of host-seeking ixodes scapularis nymphs (acari: ixodidae) in the united states. | the risk of lyme disease for humans in the eastern united states is dependent on the density of host-seeking ixodes scapularis say nymphal stage ticks infected with borrelia burgdorferi. although many local and regional studies have estimated lyme disease risk using these parameters, this is the first large-scale study using a standardized methodology. density of host-seeking i. scapularis nymphs was measured by drag sampling of closed canopy deciduous forest habitats in 95 locations spaced amon ... | 2006 | 16619595 |
| molecular analysis of microbial communities identified in different developmental stages of ixodes scapularis ticks from westchester and dutchess counties, new york. | ixodes scapularis ticks play an important role in the transmission of a wide variety of pathogens between various mammalian species, including humans. pathogens transmitted by ticks include borrelia, anaplasma and babesia. although ticks may harbour both pathogenic and non-pathogenic microflora, little is known about how the diversity of the microflora within ticks may influence the transmission of pathogens. to begin addressing this question, we examined the composition of bacterial communities ... | 2006 | 16623735 |
| climate, deer, rodents, and acorns as determinants of variation in lyme-disease risk. | risk of human exposure to vector-borne zoonotic pathogens is a function of the abundance and infection prevalence of vectors. we assessed the determinants of lyme-disease risk (density and borrelia burgdorferi-infection prevalence of nymphal ixodes scapularis ticks) over 13 y on several field plots within eastern deciduous forests in the epicenter of us lyme disease (dutchess county, new york). we used a model comparison approach to simultaneously test the importance of ambient growing-season te ... | 2006 | 16669698 |
| infectivity of the highly transformable bbe02- lp56- mutant of borrelia burgdorferi, the lyme disease spirochete, via ticks. | infectious borrelia burgdorferi strains that have increased transformability with the shuttle vector pbsv2 were recently constructed by inactivating the gene encoding bbe02, a putative restriction-modification gene product expressed by the linear plasmid lp25 (kawabata et al., infect. immun. 72:7147-7154, 2004). the absence of the linear plasmid lp56, which carries another putative restriction-modification gene, further enhanced transformation rates. the infectivity of these mutants was assessed ... | 2006 | 16714602 |
| ixodes scapularis ticks collected by passive surveillance in canada: analysis of geographic distribution and infection with lyme borreliosis agent borrelia burgdorferi. | passive surveillance for the occurrence of the tick ixodes scapularis say (1821) and their infection with the lyme borreliosis spirochaetes borrelia burgdorferi s.l. has taken place in canada since early 1990. ticks have been submitted from members of the public, veterinarians, and medical practitioners to provincial, federal, and university laboratories for identification, and the data have been collated and b. burgdorferi detected at the national microbiology laboratory. the locations of colle ... | 2006 | 16739422 |
| borrelia burgdorferi in ixodes scapularis ticks, chicago area. | 2006 | 16752480 | |
| genetic diversity of borrelia burgdorferi sensu stricto in peromyscus leucopus, the primary reservoir of lyme disease in a region of endemicity in southern maryland. | in the north central and northeastern united states, borrelia burgdorferi sensu stricto, the etiologic agent of lyme disease (ld), is maintained in an enzootic cycle between the vector, ixodes scapularis, and the primary reservoir host, peromyscus leucopus. genetic diversity of the pathogen based on sequencing of two plasmid-located genes, those for outer surface protein a (ospa) and outer surface protein c (ospc), has been examined in both tick and human specimens at local, regional, and worldw ... | 2006 | 16885284 |
| distribution and characterization of borrelia burgdorferi isolates from ixodes scapularis and presence in mammalian hosts in ontario, canada. | the blacklegged tick, ixodes scapularis say (acari: ixodidae), has a wide geographical distribution in ontario, canada, with a detected range extending at least as far north as the 50th parallel. our data of 591 adult i. scapularis submissions collected from domestic animals (canines, felines, and equines) and humans during a 10-yr period (1993-2002) discloses a monthly questing activity in ontario that peaks in may and october. the lyme disease spirochete borrelia burgdorferi johnson, schmidt, ... | 2006 | 16892637 |
| prevalence of borrelia burgdorferi in small mammals in new york state. | intensive small mammal trapping was conducted in 12 counties in new york state during 1998-2000 to investigate the prevalence and site specificity of the lyme disease spirochete, borrelia burgdorferi in, and presence of the blacklegged tick, ixodes scapularis say on, the wild mice peromyscus leucopus rafinesque and peromyscus maniculatus wagner and other small mammal species. previously captured mice (1992-1997) from throughout new york state also were recruited into the study, providing a total ... | 2006 | 17017230 |
| vector seasonality, host infection dynamics and fitness of pathogens transmitted by the tick ixodes scapularis. | fitness of tick-borne pathogens may be determined by the degree to which their infection dynamics in vertebrate hosts permits transmission cycles if infective and uninfected tick stages are active at different times of the year. to investigate this hypothesis we developed a simulation model that integrates the transmission pattern imposed by seasonally asynchronous nymphal and larval ixodes scapularis ticks in northeastern north america, with a model of infection in white-footed mice (peromyscus ... | 2007 | 17032476 |
| disruption of the salivary protein 14 in ixodes scapularis nymphs and impact on pathogen acquisition. | we previously examined the physiological role of the anticoagulant salivary protein 14 (salp14) in adult ixodes scapularis and showed that salp14 played a role in tick feeding and engorgement. we now analyze whether the disruption of the salp14 family expression by rna interference affects tick weight in naïve nymph i. scapularis. salp14 expression after dsrna injection was significantly reduced, as shown by mrna and protein analysis. however, nymph engorgement weight was not altered in salp9pac ... | 2006 | 17038693 |
| migratory songbirds disperse ticks across canada, and first isolation of the lyme disease spirochete, borrelia burgdorferi, from the avian tick, ixodes auritulus. | during a 3-yr comprehensive study, 196 ixodid ticks (9 species) were collected from 89 passerine birds (32 species) from 25 localities across canada to determine the distribution of avian-associated tick species and endogenous lyme disease spirochetes, borrelia burgdorferi johnson, schmid, hyde, steigerwalt, and brenner. we report the following first records of tick parasitism on avian hosts: the rabbit-associated tick, ixodes dentatus marx, from manitoba and ontario; the mouse tick, ixodes muri ... | 2005 | 17089744 |
| comparison of direct fluorescent antibody staining and real-time polymerase chain reaction for the detection of borrelia burgdorferi in ixodes scapularis ticks. | borrelia burgdorferi, the agent responsible for causing lyme disease in humans and animals, is transmitted via the bite of infected ixodes spp. ticks. ticks removed from humans and animals are routinely tested by diagnostic laboratories to determine if they are infected with these bacteria. the objective of this study was to compare the efficacy of 2 commonly used methods, direct fluorescent antibody staining and real-time polymerase chain reaction (pcr), for the detection of b. burgdorferi in i ... | 2006 | 17121087 |
| mammal diversity and infection prevalence in the maintenance of enzootic borrelia burgdorferi along the western coastal plains of maryland. | the primary vector of borrelia burgdorferi in north america, ixodes scapularis, feeds on various mammalian, avian, and reptilian hosts. several small mammal hosts; peromyscus leucopus, tamias striatus, microtus pennsylvanicus, and blarina spp. can serve as reservoirs in an enzootic cycle of lyme disease. the primary reservoir in the northeast united states is the white-footed mouse, p. leucopus. the infection prevalence of this reservoir as well as the roles of potential secondary reservoirs has ... | 2006 | 17187577 |
| assessing peridomestic entomological factors as predictors for lyme disease. | the roles of entomologic risk factors, including density of nymphal blacklegged ticks (ixodes scapularis), prevalence of nymphal infection with the etiologic agent (borrelia burgdorferi), and density of infected nymphs, in determining the risk of human lyme disease were assessed at residences in the endemic community of south kingstown, ri. nymphs were sampled between may and july from the wooded edge around 51 and 47 residential properties in 2002 and 2003, respectively. nymphs were collected f ... | 2006 | 17249354 |
| outer surface protein b is critical for borrelia burgdorferi adherence and survival within ixodes ticks. | survival of borrelia burgdorferi in ticks and mammals is facilitated, at least in part, by the selective expression of lipoproteins. outer surface protein (osp) a participates in spirochete adherence to the tick gut. as ospb is expressed on a bicistronic operon with ospa, we have now investigated the role of ospb by generating an ospb-deficient b. burgdorferi and examining its phenotype throughout the spirochete life cycle. similar to wild-type isolates, the ospb-deficient b. burgdorferi were ab ... | 2007 | 17352535 |
| immunity against ixodes scapularis salivary proteins expressed within 24 hours of attachment thwarts tick feeding and impairs borrelia transmission. | in north america, the black-legged tick, ixodes scapularis, an obligate haematophagus arthropod, is a vector of several human pathogens including borrelia burgdorferi, the lyme disease agent. in this report, we show that the tick salivary gland transcriptome and proteome is dynamic and changes during the process of engorgement. we demonstrate, using a guinea pig model of i. scapularis feeding and b. burgdorferi transmission, that immunity directed against salivary proteins expressed in the first ... | 2007 | 17505544 |
| role of outer surface protein d in the borrelia burgdorferi life cycle. | borrelia burgdorferi preferentially induces selected genes in mice or ticks, and studies suggest that ospd is down-regulated in response to host-specific signals. we now directly show that ospd expression is generally elevated within ixodes scapularis compared with mice. we then assessed the importance of ospd throughout the spirochete life cycle by generating ospd-deficient b. burgdorferi and examining the mutant in the murine model of tick-transmitted lyme borreliosis. the lack of ospd did not ... | 2007 | 17620358 |
| biochemical and functional characterization of salp20, an ixodes scapularis tick salivary protein that inhibits the complement pathway. | ixodes ticks are vectors of several pathogens including borrelia burgdorferi. tick saliva contains numerous molecules that facilitate blood feeding without host immune recognition and rejection. we have expressed, purified, and characterized ixodes scapularis salivary protein 20 (salp20), a potential inhibitor of the alternative complement pathway that shares homology with the isac protein family. when analysed by sds-page and size exclusion chromatography, salp20 was approximately 48 kda, more ... | 2007 | 17651236 |
| gene organization of a novel defensin of ixodes ricinus: first annotation of an intron/exon structure in a hard tick defensin gene and first evidence of the occurrence of two isoforms of one member of the arthropod defensin family. | antimicrobial peptides (defensins) are effectors of the immune system. herein, we describe a novel ixodes ricinus defensin gene(s), analyse its structure and compare it with other known antimicrobial peptides from different tick species. for the first time, an intron/exon structure is discovered in a hard-tick defensin gene. the intron/exon genomic organization of the gene is similar to the organization in ornithodoros moubata, but not to that of the intronless defensins of dermacentor variabili ... | 2007 | 17651239 |
| tick-host-pathogen interactions in lyme borreliosis. | borrelia burgdorferi, the spirochetal agent of lyme borreliosis, is predominantly transmitted by ixodes ticks. spirochetes have developed many strategies to adapt to the different environments that are present in the arthropod vector and the vertebrate host. this review focuses on b. burgdorferi genes that are preferentially expressed in the tick and the vertebrate host, and describes how selected gene products facilitate spirochete survival throughout the enzootic life cycle. interestingly, b. ... | 2007 | 17656156 |
| feeding by the tick, ixodes scapularis, causes cd4(+) t cells responding to cognate antigen to develop the capacity to express il-4. | effects of tick feeding on an early antigen-specific t cell response were studied by monitoring a clonotypic population of adoptively transferred t cell receptor (tcr) transgenic cd4 cells responding to a tick-associated antigen. when recipient mice were infested with pathogen-free ixodes scapularis nymphs several days prior to t cell transfer and intradermal injection of soluble cognate antigen at the feeding site, the clonotypic cd4 cells gained the ability to express the th2 effector cytokine ... | 2007 | 17883452 |
| identification of salp15 homologues in ixodes ricinus ticks. | the 15-kda ixodes scapularis salivary gland protein salp15 protects borrelia burgdorferi sensu stricto from antibody-mediated killing and facilitates infection of the mammalian host. in addition, salp 15 has been shown to inhibit t-cell activation. we determined whether ixodes ricinus, the major vector for lyme borreliosis in western europe, also express salp15-related genes. we show that engorged i. ricinus express salp15 and we have identified three salp15 homologues within these ticks by reve ... | 2007 | 17896872 |
| a tick antioxidant facilitates the lyme disease agent's successful migration from the mammalian host to the arthropod vector. | the tick ixodes scapularis is an efficient vector for microbes, including the lyme disease agent borrelia burgdorferi. ticks engorging on vertebrates induce recruitment of inflammatory cells to the bite site. for efficient transmission to the vector, pathogens have to traffic through this complex feeding site while avoiding the deleterious effects of immune cells. we show that a tick protein, salp25d, plays a critical role-in the mammalian host-for acquisition of borrelia burgdorferi by the vect ... | 2007 | 18005713 |
| role of migratory birds in introduction and range expansion of ixodes scapularis ticks and of borrelia burgdorferi and anaplasma phagocytophilum in canada. | during the spring in 2005 and 2006, 39,095 northward-migrating land birds were captured at 12 bird observatories in eastern canada to investigate the role of migratory birds in northward range expansion of lyme borreliosis, human granulocytic anaplasmosis, and their tick vector, ixodes scapularis. the prevalence of birds carrying i. scapularis ticks (mostly nymphs) was 0.35% (95% confidence interval [ci] = 0.30 to 0.42), but a nested study by experienced observers suggested a more realistic infe ... | 2008 | 18245258 |
| co-circulating microorganisms in questing ixodes scapularis nymphs in maryland. | ixodes scapularis can be infected with borrelia burgdorferi, anaplasma phagocytophilum, bartonella spp., babesia microti, and rickettsia spp., including spotted-fever group rickettsia. as all of these microorganisms have been reported in maryland, the potential for these ticks to have concurrent infections exists in this region. to assess the frequency of these complex infections, 348 i. scapularis nymphs collected in 2003 were screened for these microorganisms by pcr with positives being confir ... | 2007 | 18260514 |