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salp15 binding to dc-sign inhibits cytokine expression by impairing both nucleosome remodeling and mrna stabilization.ixodes ticks are major vectors for human pathogens, such as borrelia burgdorferi, the causative agent of lyme disease. tick saliva contains immunosuppressive molecules that facilitate tick feeding and b. burgdorferi infection. we here demonstrate, to our knowledge for the first time, that the ixodes scapularis salivary protein salp15 inhibits adaptive immune responses by suppressing human dendritic cell (dc) functions. salp15 inhibits both toll-like receptor- and b. burgdorferi-induced productio ...200818282094
persistence of borrelia burgdorferi following antibiotic treatment in mice.the effectiveness of antibiotic treatment was examined in a mouse model of lyme borreliosis. mice were treated with ceftriaxone or saline solution for 1 month, commencing during the early (3 weeks) or chronic (4 months) stages of infection with borrelia burgdorferi. tissues from mice were tested for infection by culture, pcr, xenodiagnosis, and transplantation of allografts at 1 and 3 months after completion of treatment. in addition, tissues were examined for the presence of spirochetes by immu ...200818316520
infection and co-infection rates of anaplasma phagocytophilum variants, babesia spp., borrelia burgdorferi, and the rickettsial endosymbiont in ixodes scapularis (acari: ixodidae) from sites in indiana, maine, pennsylvania, and wisconsin.in total, 394 questing adult blacklegged ticks, ixodes scapularis say (acari: ixodidae), collected at four sites were analyzed by polymerase chain reaction (pcr) for five microbial species: anaplasma phagocytophilum, babesia microti, babesia odocoilei, borrelia burgdorferi, and the rickettsial i. scapularis endosymbiont. identities of genetic variants of a. phagocytophilum were determined by sequencing a portion of the 16s dna. in 55% of infected ticks (193/351), a single agent was detected. in ...200818402145
the tick salivary protein salp15 inhibits the killing of serum-sensitive borrelia burgdorferi sensu lato isolates.borrelia burgdorferi, the agent of lyme disease, is transmitted by ticks. during transmission from the tick to the host, spirochetes are delivered with tick saliva, which contains the salivary protein salp15. salp15 has been shown to protect spirochetes against b. burgdorferi-specific antibodies. we now show that salp15 from both ixodes ricinus and ixodes scapularis protects serum-sensitive isolates of borrelia burgdorferi sensu lato against complement-mediated killing. i. ricinus salp15 showed ...200818426890
diagnosis and treatment of lyme disease.lyme disease is the most common tick-borne disease in the united states. this review details the risk factors, clinical presentation, treatment, and prophylaxis for the disease. information was obtained from a search of the pubmed and medline databases (keyword: lyme disease) for articles published from august 31, 1997, through september 1, 2007. approximately 20,000 cases of lyme disease are reported annually. residents of the coastal northeast, northwest california, and the great lakes region ...200818452688
assessment of decorin-binding protein a to the infectivity of borrelia burgdorferi in the murine models of needle and tick infection.decorin-binding proteins (dbps) a and b of borrelia burgdorferi, the agent of lyme disease, are surface-exposed lipoproteins that presumably bind to the extracellular matrix proteoglycan, decorin. b. burgdorferi infects various tissues including the bladder, heart, joints, skin and the central nervous system, and the ability of b. burgdorferi to bind decorin has been hypothesized to be important for this disseminatory pathogenic strategy.200818507835
borrelia burgdorferi sensu stricto is clonal in patients with early lyme borreliosis.lyme borreliosis, the most commonly reported vector-borne disease in north america, is caused by the spirochete borrelia burgdorferi. given the extensive genetic polymorphism of b. burgdorferi, elucidation of the population genetic structure of the bacterium in clinical samples may be relevant for understanding disease pathogenesis and may have applicability for the development of diagnostic tests and vaccine preparations. in this investigation, the genetic polymorphism of the 16s-23s rrna (rrs- ...200818539816
comparison of the spirochete borrelia burgdorferi s. l. isolated from the tick ixodes scapularis in southeastern and northeastern united states.thirty-five strains of the lyme disease spirochete borrelia burgdorferi sensu lato (b. burgdorferi s. l.) were isolated from the blacklegged tick vector ixodes scapularis in south carolina, georgia, florida, and rhode island. they were characterized by pcr-restriction fragment length polymorphism (rflp) analysis of rrf (5s)-rrl (23s) intergenic spacer amplicons. pcr-rflp analysis indicated that the strains represented at least 3 genospecies (including a possible novel genospecies) and 4 differen ...200818576863
projected effects of climate change on tick phenology and fitness of pathogens transmitted by the north american tick ixodes scapularis.ixodes scapularis is the principal tick vector of the lyme borreliosis agent borrelia burgdorferi and other tick-borne zoonoses in northeastern north america. the degree of seasonal synchrony of nymphal and larval ticks may be important in influencing the basic reproductive number of the pathogens transmitted by i. scapularis. because the seasonal phenology of tick vectors is partly controlled by ambient temperature, climate and climate change could shape the population biology of tick-borne pat ...200818634803
rapid introduction of lyme disease spirochete, borrelia burgdorferi sensu stricto, in ixodes scapularis (acari: ixodidae) established at turkey point provincial park, ontario, canada.borrelia burgdorferi sensu stricto (s.s.) was isolated from questing adult ixodes scapularis say ticks collected from turkey point provincial park (tppp), ontario, canada during 2005-2006. dna from ten (67%) of 15 pools of ticks was confirmed positive for b. burgdorferi s.s. using polymerase chain reaction (pcr) by targeting the rrf (5s)-rrl (23s) intergenic spacer region and ospa genes. this significant infection rate indicates an accelerated development of b. burgdorferi s.s. in tppp, because ...200818697308
transmission dynamics of borrelia burgdorferi s.s. during the key third day of feeding by nymphal ixodes scapularis (acari: ixodidae).nymphal ixodes scapularis say are the principal vectors of lyme disease spirochetes (borrelia burgdorferi sensu stricto) in the eastern united states. physicians frequently face the decision of whether or not to administer prophylactic antibiotics to human tick bite victims in lyme disease endemic regions, based on the overall probability that such bites will result in infection with b. burgdorferi s.s. we evaluated the transmission dynamics of b. burgdorferi s.s. during the key third day of nym ...200818714875
preferential protection of borrelia burgdorferi sensu stricto by a salp15 homologue in ixodes ricinus saliva.ixodes ticks are the main vectors for borrelia burgdorferi sensu lato. in the united states, b. burgdorferi is the sole causative agent of lyme borreliosis and is transmitted by ixodes scapularis. in europe, 3 borrelia species-b. burgdorferi, b. garinii, and b. afzelii-are prevalent, which are transmitted by ixodes ricinus. the i. scapularis salivary protein salp15 has been shown to bind to b. burgdorferi outer surface protein (osp) c, protecting the spirochete from antibody-mediated killing.200818752445
spatial dynamics of lyme disease: a review.lyme disease (ld), the most frequently reported vector-borne disease in the united states, requires that humans, infected vector ticks, and infected hosts all occur in close spatial proximity. understanding the spatial dynamics of ld requires an understanding of the spatial determinants of each of these organisms. we review the literature on spatial patterns and environmental correlates of human cases of ld and the vector ticks, ixodes scapularis in the northeastern and midwestern united states ...200818787920
production of outer surface protein a by borrelia burgdorferi during transmission from infected mammals to feeding ticks is insufficient to trigger ospa seroconversion.the lyme disease spirochete, borrelia burgdorferi, produces two outer surface lipoproteins, ospa and ospb, that are essential for colonization of tick vectors. both proteins are highly expressed during transmission from infected mammals to feeding ticks and during colonization of tick midguts, but are repressed when bacteria are transmitted from ticks to mammals. humans and other infected mammals generally do not produce antibodies against either protein, although some lyme disease patients do s ...200818793197
surveillance for lyme disease--united states, 1992-2006.lyme disease is a multisystem disease that occurs in north america, europe, and asia. in the united states, the etiologic agent is borrelia burgdorferi sensu stricto, a spirochete transmitted to humans by infected ixodes scapularis and i. pacificus ticks. the majority of patients with lyme disease develop a characteristic rash, erythema migrans (em), accompanied by symptoms of fever, malaise, fatigue, headache, myalgia, or arthralgia. other manifestations of infection can include arthritis, card ...200818830214
bacterin that induces anti-ospa and anti-ospc borreliacidal antibodies provides a high level of protection against canine lyme disease.groups of 15 laboratory-bred beagles were vaccinated and boosted with either a placebo or adjuvanted bivalent bacterin comprised of a traditional borrelia burgdorferi strain and a unique ospa- and ospb-negative b. burgdorferi strain that expressed high levels of ospc and then challenged with b. burgdorferi-infected ixodes scapularis ticks. the vaccinated dogs produced high titers of anti-ospa and anti-ospc borreliacidal antibodies, including borreliacidal antibodies specific for an epitope withi ...200919052162
use of tick surveys and serosurveys to evaluate pet dogs as a sentinel species for emerging lyme disease.to evaluate dogs as a sentinel species for emergence of lyme disease in a region undergoing invasion by ixodes scapularis.200919119948
positive selection in tick saliva proteins of the salp15 family.when taking their blood meal on the mammalian host, ticks transfer a multitude of different proteins from their saliva into the host. some of these proteins are hijacked by pathogens for their own purposes. borrelia burgdorferi, the lyme disease agent, is critically dependent on the presence of the tick protein salp15 when infecting the host. similarly, anaplasma phagocytophilum, which causes anaplasmosis, needs salp16, a homologue of salp15, to get transferred from the host into the tick. here ...200919159966
dermatologic changes induced by repeated ixodes scapularis bites and implications for prevention of tick-borne infection.previous studies in rodents and people have demonstrated that repeated tick exposure is associated with reduced borrelia burgdorferi transmission but the mechanism of prevention remains unclear. we examined the acute histopathologic reactions to initial and repeated ixodes scapularis bites in balb/c mice and in people. skin biopsies of balb/c mice infested for the first time by i. scapularis nymphs revealed vascular dilatation and an accumulation of inflammatory cells adjacent to the bite site b ...200919196014
detection of borrelia burgdorferi and borrelia lonestari in birds in tennessee.lyme disease in the united states is caused by the bacterial spirochete borrelia burgdorferi s.s. (johnson, schmid, hyde, steigerwalt, and brenner), which is transmitted by tick vectors ixodes scapularis (say) and i. pacificus (cooley and kohls). borrelia lonestari, transmitted by the tick amblyomma americanum l., may be associated with a related syndrome, southern tick-associated rash illness (stari). borrelia lonestari sequences, reported primarily in the southeastern states, have also been de ...200919198527
climate and tick seasonality are predictors of borrelia burgdorferi genotype distribution.the blacklegged tick, ixodes scapularis, is of significant public health importance as a vector of borrelia burgdorferi, the agent of lyme borreliosis. the timing of seasonal activity of each immature i. scapularis life stage relative to the next is critical for the maintenance of b. burgdorferi because larvae must feed after an infected nymph to efficiently acquire the infection from reservoir hosts. recent studies have shown that some strains of b. burgdorferi do not persist in the primary res ...200919251900
a borreliacidal factor in amblyomma americanum saliva is associated with phospholipase a2 activity.previous work in our laboratory described the in vitro killing of borrelia burgdorferi when co-cultured with saliva from adult amblyomma americanum. borreliacidal activity was not evident using ixodes scapularis saliva. mixing trypsin with saliva eliminated the borreliacidal activity of a. americanum saliva, while incorporating a trypsin inhibitor restored all borreliacidal activity, indicating this factor was of protein or peptide origin. one-dimensional page indicated at least 7 major protein ...200919271281
the use of harvested white-tailed deer (odocoileus virginianus) and geographic information system (gis) methods to characterize distribution and locate spatial clusters of borrelia burgdorferi and its vector ixodes scapularis in indiana.ixodes scapularis (say) is the vector for borrelia burgdorferi (bb) the causative agent of lyme disease (ld). the increased number and presence of ticks in the environment pose a significant health risk to people and many domestic animals including dogs, cats, and horses. this study characterized the distribution and expansion of i. scapularis and bb and identified areas of increased risk of ld transmission in indiana using geographical information systems (gis) and spatial analysis. a cross-sec ...200919272000
langerhans cell deficiency impairs ixodes scapularis suppression of th1 responses in mice.ixodes scapularis ticks transmit a number of human pathogens, including the lyme disease spirochete borrelia burgdorferi. i. scapularis suppresses host immunity in the skin to promote feeding and systemically skew t-helper (th)-cell differentiation toward th2 cells in secondary lymphoid organs. although components of tick saliva are known to influence th-cell polarization, the mechanism whereby tick feeding in the skin modulates regional and systemic th-cell responses is unknown. in this study, ...200919273564
inhibition of neutrophil function by two tick salivary proteins.the saliva of hematophagous arthropods contains potent anti-inflammatory and antihemostatic activities that promote acquisition of the blood meal and enhance infection with pathogens. we have shown that polymorphonuclear leukocytes (pmn) treated with the saliva of the tick ixodes scapularis have reduced expression of beta(2) integrins, impaired pmn adherence, and reduced killing of borrelia burgdorferi, the causative agent of lyme disease. here we describe two ixodes proteins that are induced up ...200919332533
a borreliacidal factor in amblyomma americanum saliva is associated with phospholipase a(2) activity.previous work in our laboratory described the in vitro killing of borrelia burgdorferi when co-cultured with saliva from adult amblyomma americanum. borreliacidal activity was not evident using ixodes scapularis saliva. mixing trypsin with saliva eliminated the borreliacidal activity of a. americanum saliva, while incorporating a trypsin inhibitor restored all borreliacidal activity, indicating this factor was of protein or peptide origin. one dimensional page indicated at least 7 major protein ...200919545533
community-based prevention of lyme disease and other tick-borne diseases through topical application of acaricide to white-tailed deer: background and rationale.this series of articles describes the first large-scale experiment designed to explore the efficacy of reducing the risk of tick-borne disease in highly endemic communities of the northeastern and mid-atlantic united states through deployment of a self-application device that treats white-tailed deer with acaricide to prevent feeding by adult ixodes scapularis ticks and all stages of amblyomma americanum ticks where both species occur. the results of the multicenter study are reported in the acc ...200919650729
topical treatment of white-tailed deer with an acaricide for the control of ixodes scapularis (acari: ixodidae) in a connecticut lyme borreliosis hyperendemic community.the 4-poster device for the topical treatment of white-tailed deer, odocoileus virginianus (zimmermann), against ticks using the acaricide amitraz, was evaluated in a lyme borreliosis endemic community in connecticut. as part of a 5-year project from 1997 to 2002, 21-24 of the 4-posters were distributed at residential sites in old lyme, ct, in a core treatment area of approximately 5.2 km(2) in fall 1997. the 4-posters were active october to mid-december and march into may, corresponding to the ...200919650731
effects of tick control by acaricide self-treatment of white-tailed deer on host-seeking tick infection prevalence and entomologic risk for ixodes scapularis-borne pathogens.we evaluated the effects of tick control by acaricide self-treatment of white-tailed deer on the infection prevalence and entomologic risk for three ixodes scapularis-borne bacteria in host-seeking ticks. ticks were collected from vegetation in areas treated with the "4-poster" device and from control areas over a 6-year period in five geographically diverse study locations in the northeastern united states and tested for infection with two known agents of human disease, borrelia burgdorferi and ...200919650738
managing japanese barberry (ranunculales: berberidaceae) infestations reduces blacklegged tick (acari: ixodidae) abundance and infection prevalence with borrelia burgdorferi (spirochaetales: spirochaetaceae).in many connecticut forests with an overabundance of white-tailed deer (odocoileus virginianus zimmermann), japanese barberry (berberis thunbergii dc) has become the dominant understory shrub, which may provide a habitat favorable to blacklegged tick (ixodes scapularis say) and white-footed mouse (peromyscus leucopus rafinesque) survival. to determine mouse and larval tick abundances at three replicate sites over 2 yr, mice were trapped in unmanipulated dense barberry infestations, areas where b ...200919689875
phylogeography of borrelia burgdorferi in the eastern united states reflects multiple independent lyme disease emergence events.since its first description in coastal connecticut in 1976, both the incidence of lyme disease and the geographic extent of endemic areas in the us have increased dramatically. the rapid expansion of lyme disease into its current distribution in the eastern half of the us has been due to the range expansion of the tick vector, ixodes scapularis, upon which the causative agent, borrelia burgdorferi is dependent for transmission to humans. in this study, we examined the phylogeographic population ...200919706476
assessment of polymicrobial infections in ticks in new york state.ixodes scapularis ticks are clinically important hematophagous vectors. a single tick bite can lead to a polymicrobial infection. we determined the prevalence of polymicrobial infection with borrelia burgdorferi, anaplasma phagocytophilum, babesia microti, borrelia miyamotoi, and powassan virus in 286 adult ticks from the two counties in new york state where lyme disease is endemic, utilizing a masstag multiplex polymerase chain reaction assay. seventy-one percent of the ticks harbored at least ...201019725770
efficacy of a nonadjuvanted, outer surface protein a, recombinant vaccine in dogs after challenge by ticks naturally infected with borrelia burgdorferi.in a blinded, controlled study, thirty purpose-bred, borrelia burgdorferi negative, mixed-breed dogs 10 to 12 weeks of age were randomly divided into three groups of ten animals each for the purpose of evaluating a recombinant nonadjuvanted b. burgdorferi ospa vaccine (recombitek lyme [merial limited]) for efficacy and safety. two groups received two doses of two different lots ofa nonadjuvanted, ospa, recombinant vaccine; the third group served as nonvaccinated controls. all dogs were challenge ...200019757556
passage through ixodes scapularis ticks enhances the virulence of a weakly pathogenic isolate of borrelia burgdorferi.lyme disease is the most common tick-borne illness in the united states. in this paper we explore the contribution of ixodes scapularis ticks to the pathogenicity of borrelia burgdorferi in mice. previously we demonstrated that an isolate of b. burgdorferi sensu stricto (designated n40), passaged 75 times in vitro (n40-75), was infectious but was no longer able to cause arthritis and carditis in c3h mice. we now show that n40-75 spirochetes can readily colonize i. scapularis and multiply during ...201019822652
distribution of antibodies reactive to borrelia lonestari and borrelia burgdorferi in white-tailed deer (odocoileus virginianus) populations in the eastern united states.southern tick-associated rash illness is a lyme-like syndrome that occurs in the southern states. borrelia lonestari, which has been suggested as a possible causative agent of southern tick-associated rash illness, naturally infects white-tailed deer (wtd; odocoileus virginianus) and is transmitted by the lone star tick (amblyomma americanum). to better understand the prevalence and distribution of borrelia exposure among wtd, we tested wtd from 21 eastern states for antibodies reactive to b. lo ...200919874183
antibodies against a tick protein, salp15, protect mice from the lyme disease agent.traditionally, vaccines directly target a pathogen or microbial toxin. lyme disease, caused by borrelia burgdorferi, is a tick-borne illness for which a human vaccine is not currently available. b. burgdorferi binds a tick salivary protein, salp15, during transmission from the vector, and this interaction facilitates infection of mice. we now show that salp15 antiserum significantly protected mice from b. burgdorferi infection. salp15 antiserum also markedly enhanced the protective capacity of a ...200919917502
molecular identification of salp15, a key salivary gland protein in the transmission of lyme disease spirochetes, from ixodes persulcatus and ixodes pacificus (acari: ixodidae).salp15 is a multifunctional protein, vital to the tick in its need to obtain vertebrate host blood without stimulating a host inflammatory and immune response. the salpl5 protein from both ixodes scapularis say and ixodes ricinus (l.), the principal vectors of the lyme disease spirochete in eastern north america and europe, respectively, have been well characterized and found to bind the murine cd4 receptor, dc-sign, and the ospc protein of borrelia burgdorferi. in the current study, we characte ...200919960697
niche partitioning of borrelia burgdorferi and borrelia miyamotoi in the same tick vector and mammalian reservoir species.the lyme borreliosis agent borrelia burgdorferi and the relapsing fever group species borrelia miyamotoi co-occur in the united states. we used species-specific, quantitative polymerase chain reaction to study both species in the blood and skin of peromyscus leucopus mice and host-seeking ixodes scapularis nymphs at a connecticut site. bacteremias with b. burgdorferi or b. miyamotoi were most prevalent during periods of greatest activity for nymphs or larvae, respectively. whereas b. burgdorferi ...200919996447
extraction of total nucleic acids from ticks for the detection of bacterial and viral pathogens.ticks harbor numerous bacterial, protozoal, and viral pathogens that can cause serious infections in humans and domestic animals. active surveillance of the tick vector can provide insight into the frequency and distribution of important pathogens in the environment. nucleic-acid based detection of tick-borne bacterial, protozoan, and viral pathogens requires the extraction of both dna and rna (total nucleic acids) from ticks. traditional methods for nucleic acid extraction are limited to extrac ...201020180313
two novel salp15-like immunosuppressant genes from salivary glands of ixodes persulcatus schulze tick.salp15, a 15-kda tick salivary gland protein, is known for several suppressive activities against host immunity and critical functions for the transmission of lyme borrelia in ixodes scapularis and ixodes ricinus, the major vectors found in north america and western europe. salp15 inhibits the activation of cluster of differentiation (cd)4(+)t-cells through the repression of t-cell receptor (tcr)-triggered calcium fluxes and interleukin (il)-2 production. furthermore, salp15 adheres to the spiro ...201020201978
invasion of the lyme disease vector ixodes scapularis: implications for borrelia burgdorferi endemicity.lyme disease risk is increasing in the united states due in part to the spread of blacklegged ticks ixodes scapularis, the principal vector of the spirochetal pathogen borrelia burgdorferi. a 5-year study was undertaken to investigate hypothesized coinvasion of i. scapularis and b. burgdorferi in lower michigan. we tracked the spatial and temporal dynamics of the tick and spirochete using mammal, bird, and vegetation drag sampling at eight field sites along coastal and inland transects originati ...201020229127
one-year duration of immunity induced by vaccination with a canine lyme disease bacterin.laboratory-reared beagles were vaccinated with a placebo or a bacterin comprised of borrelia burgdorferi s-1-10 and ospa-negative/ospb-negative b. burgdorferi 50772 and challenged after 1 year with b. burgdorferi-infected ixodes scapularis ticks. for the placebo recipients, spirochetes were recovered from 9 (60%) skin biopsy specimens collected after 1 month, and the organisms persisted in the skin thereafter. ten (67%) dogs also developed joint infection (3 dogs), lameness or synovitis (7 dogs) ...201020237200
phagocytosis of the lyme disease spirochete, borrelia burgdorferi, by cells from the ticks, ixodes scapularis and dermacentor andersoni, infected with an endosymbiont, rickettsia peacockii.tick cell lines were used to model the effects of endosymbiont infection on phagocytic immune responses. the lines tested for their ability to phagocytose the lyme disease spirochete, borrelia burgdorferi (spirochaetales: spirochaetaceae), were ise6 and ide12 from the black-legged tick, ixodes scapularis say (acari: ixodidae) and dae15 from the rocky mountain wood tick, dermacentor andersoni stiles. rickettsia peacockii (rickettsiales: rickettsiaceae), an endosymbiont of d. andersoni, was used a ...200720331397
uncoordinated phylogeography of borrelia burgdorferi and its tick vector, ixodes scapularis.vector-borne microbes necessarily co-occur with their hosts and vectors, but the degree to which they share common evolutionary or biogeographic histories remains unexplored. we examine the congruity of the evolutionary and biogeographic histories of the bacterium and vector of the lyme disease system, the most prevalent vector-borne disease in north america. in the eastern and midwestern us, ixodes scapularis ticks are the primary vectors of borrelia burgdorferi, the bacterium that causes lyme ...201020394659
active and passive surveillance and phylogenetic analysis of borrelia burgdorferi elucidate the process of lyme disease risk emergence in canada.northward expansion of the tick ixodes scapularis is driving lyme disease (ld) emergence in canada. information on mechanisms involved is needed to enhance surveillance and identify where ld risk is emerging.201020421192
analysis of a borrelia burgdorferi phosphodiesterase demonstrates a role for cyclic-di-guanosine monophosphate in motility and virulence.the genome of borrelia burgdorferi encodes a set of genes putatively involved in cyclic-dimeric guanosine monophosphate (cyclic-di-gmp) metabolism. although bb0419 was shown to be a diguanylate cyclase, the extent to which bb0419 or any of the putative cyclic-di-gmp metabolizing genes impact b. burgdorferi motility and pathogenesis has not yet been reported. here we identify and characterize a phosphodiesterase (bb0363). bb0363 specifically hydrolyzed cyclic-di-gmp with a k(m) of 0.054 microm, c ...201020444101
bacterial pathogens in ixodid ticks from a piedmont county in north carolina: prevalence of rickettsial organisms.in north carolina, reported human cases of tick-borne illness, specifically rocky mountain spotted fever, have escalated over the past decade. to determine the relative abundance of vectors and to estimate the risk of acquiring a tick-borne illness in peri-residential landscapes, ticks were collected in chatham county, a typical piedmont county and, samples of the ticks were tested for infection with selected bacterial pathogens using real-time quantitative polymerase chain reaction assays. tick ...201020455778
forest and surface water as predictors of borrelia burgdorferi and its vector ixodes scapularis (acari: ixodidae) in indiana.the objective of this study was to assess whether the distribution of borrelia burgdorferi, the causative agent of lyme disease, and its vector tick ixodes scapularis say (acari: ixodidae) across indiana is influenced by large-scale landscape features, specifically the proportion of forest within the surrounding landscape and the distance to water features such as lakes and major streams. hunter-killed deer were checked for ticks in designated check-stations in the opening firearm hunting season ...201020496594
genotypic variation and mixtures of lyme borrelia in ixodes ticks from north america and europe.lyme disease, caused by various species of borrelia, is transmitted by ixodes ticks in north america and europe. studies have shown the genotype of borrelia burgdorferi sensu stricto (s.s.) or the species of b. burgdorferi sensu lato (s.l.) affects the ability of the bacteria to cause local or disseminated infection in humans.201020498837
the crystal structures of two salivary cystatins from the tick ixodes scapularis and the effect of these inhibitors on the establishment of borrelia burgdorferi infection in a murine model.we have previously demonstrated that two salivary cysteine protease inhibitors from the borrelia burgdorferi (lyme disease) vector ixodes scapularis- namely sialostatins l and l2 - play an important role in tick biology, as demonstrated by the fact that silencing of both sialostatins in tandem results in severe feeding defects. here we show that sialostatin l2 - but not sialostatin l - facilitates the growth of b. burgdorferi in murine skin. to examine the structural basis underlying these diffe ...201020545851
borrelia burgdorferi has minimal impact on the lyme disease reservoir host peromyscus leucopus.the epidemiology of vector-borne zoonotic diseases is determined by encounter rates between vectors and hosts. alterations to the behavior of reservoir hosts caused by the infectious agent have the potential to dramatically alter disease transmission and human risk. we examined the effect of borrelia burgdorferi, the etiological agent of lyme disease, on one of its most important reservoir hosts, the white-footed mouse, peromyscus leucopus. we mimic natural infections in mice using the vector (b ...201120569016
detection of lyme disease spirochete, borrelia burgdorferi sensu lato, including three novel genotypes in ticks (acari: ixodidae) collected from songbirds (passeriformes) across canada.lyme disease is reported across canada, but pinpointing the source of infection has been problematic. in this three-year, bird-tick-pathogen study (2004-2006), 366 ticks representing 12 species were collected from 151 songbirds (31 passerine species/subspecies) at 16 locations canada-wide. of the 167 ticks/pools tested, 19 (11.4%) were infected with borrelia burgdorferi sensu lato (s.l.). sequencing of the rrf-rrl intergenic spacer gene revealed four borrelia genotypes: b. burgdorferi sensu stri ...201020618658
recent discovery of widespread ixodes affinis (acari: ixodidae) distribution in north carolina with implications for lyme disease studies.ixodes affinis, which is similar morphologically to ixodes scapularis, is widely distributed in north carolina. collections have documented this species in 32 of 41 coastal plain counties, but no piedmont or mountain counties. this coastal plain distribution is similar to its distribution in georgia and south carolina, where it is considered an enzootic vector of borrelia burgdorferi sensu stricto. an updated list of hosts for i. affinis in the u.s.a. is included, increasing the number to 15 mam ...201020618664
seasonal prevalence of serum antibodies to whole cell and recombinant antigens of borrelia burgdorferi and anaplasma phagocytophilum in white-tailed deer in connecticut.whole-blood samples were obtained from 214 white-tailed deer (odocoileus virginianus) representing 44 sites in connecticut (usa) during 1992, 1993, 1996, 1999, and 2000 through 2006. sera were analyzed for total antibodies to whole-cell or recombinant antigens of borrelia burgdorferi sensu stricto and anaplasma phagocytophilum, the respective causative agents of lyme borreliosis and human granulocytic anaplasmosis. deer sera contained antibodies to both bacteria during different seasons and thro ...201020688684
genotypic diversity of borrelia burgdorferi strains detected in ixodes scapularis larvae collected from north american songbirds.we genotyped borrelia burgdorferi strains detected in larvae of ixodes scapularis removed from songbirds and compared them with those found in host-seeking i. scapularis nymphs sampled throughout the eastern united states. birds are capable of transmitting most known genotypes, albeit at different frequencies than expected based on genotypes found among host-seeking nymphs.201020971869
tick histamine release factor is critical for ixodes scapularis engorgement and transmission of the lyme disease agent.ticks are distributed worldwide and affect human and animal health by transmitting diverse infectious agents. effective vaccines against most tick-borne pathogens are not currently available. in this study, we characterized a tick histamine release factor (thrf) from ixodes scapularis and addressed the vaccine potential of this antigen in the context of tick engorgement and b. burgdorferi transmission. results from western blotting and quantitative reverse transcription-pcr showed that thrf is s ...201021124826
antialarmin effect of tick saliva during the transmission of lyme disease.tick saliva has potent immunomodulatory properties. in arthropod-borne diseases, this effect is largely used by microorganisms to increase their pathogenicity and to evade host immune responses. we show that in lyme borreliosis, tick salivary gland extract and a tick saliva protein, salp15, inhibit in vitro keratinocyte inflammation induced by borrelia burgdorferi sensu stricto or by the major outer surface lipoprotein of borrelia, ospc. chemokines (interleukin-8 [il-8] and monocyte chemoattract ...201021134970
bb0844, an rpos-regulated protein, is dispensable for borrelia burgdorferi infectivity and maintenance in the mouse-tick infectious cycle.the genome of borrelia burgdorferi, the causative agent of lyme disease, is comprised of a large linear chromosome and numerous smaller linear and circular plasmids. b. burgdorferi exhibits substantial genomic variation, and previous studies revealed genotype-specific variation at the right chromosomal telomere. a correlation has also been established between genotype and invasiveness. the correlation between chromosome length and genotype and between genotype and invasiveness suggested that a g ...201021173312
diverse borrelia burgdorferi strains in a bird-tick cryptic cycle.the blacklegged tick ixodes scapularis is the primary vector of the most prevalent vector-borne zoonosis in north america, lyme disease (ld). enzootic maintenance of the pathogen borrelia burgdorferi by i. scapularis and small mammals is well documented, whereas its "cryptic" maintenance by other specialist ticks and wildlife hosts remains largely unexplored because these ticks rarely bite humans. we quantified b. burgdorferi infection in a cryptic bird-rabbit-tick cycle. furthermore, we explore ...201121257811
biodiversity and lyme disease: dilution or amplification?reduced lyme disease risk by the 'dilution effect' is often cited as an example of biodiversity providing 'ecosystem services' to public health. using a mechanistic model we investigated how transmission of the lyme disease agent, borrelia burgdorferi, by ixodes scapularis ticks amongst highly efficient reservoir mice is affected by varying the abundance of a less efficient reservoir host. simulations indicated either amplification or dilution may occur, with the outcome depending precisely on m ...200921352766
investigation of genotypes of borrelia burgdorferi in ixodes scapularis ticks collected during surveillance in canada.the genetic diversity of borrelia burgdorferi sensu stricto, the agent of lyme disease in north america, has consequences for the performance of serological diagnostic tests and disease severity. to investigate b. burgdorferi diversity in canada, where lyme disease is emerging, bacterial dna in 309 infected adult ixodes scapularis ticks collected in surveillance was characterized by multilocus sequence typing (mlst) and analysis of outer surface protein c gene (ospc) alleles. six ticks carried b ...201121421790
occurrence of soil- and tick-borne fungi and related virulence tests for pathogenicity to ixodes scapularis (acari: ixodidae).ixodes scapularis say, the blacklegged tick, vectors borrelia burgdorferi johnson et al. 1984, the bacterium that causes lyme disease, the most important vector-borne disease in the united states. efforts to reduce i. scapularis populations are shifting toward the development of biological control methods. currently, only a few entomopathogenic fungal species are considered virulent to ticks. we hypothesized that these species may not represent the most abundant local taxa that would be pathogen ...201121485371
regional variation in immature ixodes scapularis parasitism on north american songbirds: implications for transmission of the lyme pathogen, borrelia burgdorferi.borrelia burgdorferi, the etiological agent of lyme disease, is transmitted among hosts by the black-legged tick, ixodes scapularis, a species that regularly parasitizes various vertebrate hosts, including birds, in its immature stages. lyme disease risk in the united states is highest in the northeast and in the upper midwest where i. scapularis ticks are most abundant. because birds might be important to the range expansion of i. scapularis and b. burgdorferi, we explored spatial variation in ...201121485384
the hybrid histidine kinase hk1 is part of a two-component system that is essential for survival of borrelia burgdorferi in feeding ixodes scapularis ticks.two-component systems (tcs) are a principal mechanism by which bacteria adapt to their surroundings. borrelia burgdorferi encodes only two tcs. one is comprised of a histidine kinase, hk2, and the response regulator, rrp2. while the contribution of hk2 remains unclear, rrp2 is part of a regulatory pathway involving the spirochete's alternate sigma factors, rpon and rpos. genes within the rrp2/rpon/rpos regulon function to promote tick transmission and early infection. the other tcs consists of a ...201121606185
strain diversity of borrelia burgdorferi in ticks dispersed in north america by migratory birds.the role of migratory birds in the dispersal of ixodes scapularis ticks in the northeastern u.s. is well established and is presumed to be a major factor in the expansion of the geographic risk for lyme disease. population genetic studies of b. burgdorferi sensu stricto, the agent of lyme disease in this region, consistently reveal the local presence of as many as 15 distinct strain types as designated by major groups of the ospc surface lipoprotein. recent evidence suggests such strain diversit ...201121635638
analysis of the hd-gyp domain cyclic dimeric gmp phosphodiesterase reveals a role in motility and the enzootic life cycle of borrelia burgdorferi.hd-gyp domain cyclic dimeric gmp (c-di-gmp) phosphodiesterases are implicated in motility and virulence in bacteria. borrelia burgdorferi possesses a single set of c-di-gmp-metabolizing enzymes, including a putative hd-gyp domain protein, bb0374. recently, we characterized the eal domain phosphodiesterase pdea. a mutation in pdea resulted in cells that were defective in motility and virulence. here we demonstrate that bb0374/pdeb specifically hydrolyzed c-di-gmp with a k(m) of 2.9 nm, confirming ...201121670168
the ability of a topical novel combination of fipronil, amitraz and (s)-methoprene to protect dogs from borrelia burgdorferi and anaplasma phagocytophilum infections transmitted by ixodes scapularis.healthy, purpose-bred laboratory beagle dogs that had not been exposed to ticks and were seronegative for borrelia burgdorferi and anaplasma phagocytophilum were randomly assigned to four groups of eight dogs each. control group 1 was not treated. groups 2, 3 and 4 were treated with a single topical application of a new formulation of fipronil, amitraz and (s)-methoprene (certifectâ„¢, merial limited, ga, usa) at 28, 21 or 14 days prior to tick infestation, respectively. each dog was infested with ...201121777736
ixodes scapularis and borrelia burgdorferi among diverse habitats within a natural area in east-central illinois.abstract the distributions of the tick vector, ixodes scapularis, and of the etiologic agent of lyme disease, borrelia burgdorferi (bb), have continued expanding in illinois over the past 20 years, but the extent of their spread is not well known. the role of multiple habitats in the establishment and maintenance of i. scapularis and bb at local scales is not well understood, and the use of integrated approaches to evaluate local scale dynamics is rare. we evaluated habitat diversity and tempora ...201121688974
Molting success of Ixodes scapularis varies among individual blood meal hosts and species.The blacklegged tick (Ixodes scapularis) is an important vector of emerging human pathogens. It has three blood-feeding stages, as follows: larva, nymph, and adult. Owing to inefficient transovarial transmission, at least for the Lyme disease agent (Borrelia burgdorferi), larval ticks rarely hatch infected, but they can acquire infection during their larval blood meal. Nymphal ticks are primarily responsible for transmitting pathogens to hosts, including humans. The transition from uninfected ho ...201121845946
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