| seasonal and geographical distribution of adult ixodes scapularis say (acari: ixodidae) in louisiana. | the distribution and seasonality of adult black-legged ticks (ixodes scapularis say) in louisiana was measured. the presence of adult ticks was determined by flagging at 106 sites throughout louisiana. it was concluded that ixodes scapularis is widely distributed throughout louisiana. ticks were also collected twice per month at one site over a 15-month period by flagging and use of co2 traps to establish the relative seasonal abundance pattern of free-living adult ticks. host-seeking, black-leg ... | 2005 | 16599148 |
| an antivector vaccine protects against a lethal vector-borne pathogen. | vaccines that target blood-feeding disease vectors, such as mosquitoes and ticks, have the potential to protect against the many diseases caused by vector-borne pathogens. we tested the ability of an anti-tick vaccine derived from a tick cement protein (64trp) of rhipicephalus appendiculatus to protect mice against tick-borne encephalitis virus (tbev) transmitted by infected ixodes ricinus ticks. the vaccine has a "dual action" in immunized animals: when infested with ticks, the inflammatory and ... | 2006 | 16604154 |
| 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 |
| evaluating satellite sensor-derived indices for lyme disease risk prediction. | the wetness and greenness indices created using landsat thematic mapper (tm) data from june 1995 and 1997 and july 2002 were tested for their ability to predict the location of sites with different levels of nymphal blacklegged tick, ixodes scapularis say, abundance in rhode island. in 1995, there were statistically significant differences in the mean of greenness and wetness indices between sites classified as low and moderate tick abundance areas (p = 0.005 and p = 0.041, respectively). in 199 ... | 2006 | 16619620 |
| investigation of ground level and remote-sensed data for habitat classification and prediction of survival of ixodes scapularis in habitats of southeastern canada. | in southeastern canada, most populations of ixodes scapularis say, the lyme disease vector, occur in carolinian forests. climate change projections suggest a northward range expansion of i. scapularis this century, but it is unclear whether more northerly habitats are suitable for i. scapularis survival. in this study, we assessed the suitability of woodlands of the lower great lakes/st. lawrence plain region for i. scapularis by comparing tick egg survival in four different woodlands. woodlands ... | 2006 | 16619627 |
| detection of anaplasma phagocytophilum and babesia odocoilei dna in ixodes scapularis (acari: ixodidae) collected in indiana. | the blacklegged tick, ixodes scapularis say, first reported in indiana in 1987, has now been detected in more than half of indiana's counties. the first case of human granulocytic ehrlichiosis (human anaplasmosis) in indiana was reported in 2002. we now report the detection of anaplasma phagocytophilum and babesia odocoilei (emerson and wright 1968) in i. scapularis ticks collected in northern indiana. using polymerase chain reaction analysis, 41 of 193 adult ticks (21.2%) collected from deer we ... | 2006 | 16619631 |
| 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 |
| possibilities for relapsing fever reemergence. | relapsing fever borrelia infections have attracted little attention in recent years; however, where endemic, these infections still result in considerable illness and death. despite the marked antimicrobial drug susceptibility of these organisms, therapy is often delayed through lack of clinical suspicion. with increasing travel, infections may be imported, through exotic relapsing fever infection or through resurgence of infected disease vectors. although louseborne relapsing fever is now geogr ... | 2006 | 16704771 |
| epidemic spread of lyme borreliosis, northeastern united states. | we examined the degree of host specialization of different strains of borrelia burgdorferi, the tickborne pathogen that causes lyme borreliosis in the northeastern united states. we first assessed the genetic population structures of b. burgdorferi in ticks obtained from different mammalian host species and in questing ticks sampled in a woodland ecosystem in connecticut. by comparing the patterns found in our study with data from another cross-sectional study, we demonstrate that b. burgdorferi ... | 2006 | 16704808 |
| babesia microti primarily invades mature erythrocytes in mice. | babesia microti is a tick-borne red blood cell parasite that causes babesiosis in people. its most common vertebrate reservoir is the white-footed mouse. to determine whether b. microti invades reticulocytes, as does the canine pathogen b. gibsoni, we infected the susceptible inbred mouse strains c.b-17.scid and dba/2 with a clinical isolate of b. microti. staining of fixed permeabilized red blood cells with 4',6'-diamidino-2-phenylindole or yoyo-1, a sensitive nucleic acid stain, revealed paras ... | 2006 | 16714547 |
| borrelia burgdorferi lacking bbk32, a fibronectin-binding protein, retains full pathogenicity. | bbk32, a fibronectin-binding protein of borrelia burgdorferi, is one of many surface lipoproteins that are differentially expressed by the lyme disease spirochete at various stages of its life cycle. the level of bbk32 expression in b. burgdorferi is highest during infection of the mammalian host and lowest in flat ticks. this temporal expression profile, along with its fibronectin-binding activity, strongly suggests that bbk32 may play an important role in lyme pathogenesis in the host. to test ... | 2006 | 16714558 |
| differential expression and sequence conservation of the anaplasma marginale msp2 gene superfamily outer membrane proteins. | bacterial pathogens in the genera anaplasma and ehrlichia encode a protein superfamily, pfam01617, which includes the predominant outer membrane proteins (omps) of each species, major surface protein 2 (msp2) and msp3 of anaplasma marginale and anaplasma ovis, anaplasma phagocytophilum msp2 (p44), ehrlichia chaffeensis p28-omp, ehrlichia canis p30, and ehrlichia ruminantium map1, and has been shown to be involved in both antigenic variation within the mammalian host and differential expression b ... | 2006 | 16714578 |
| borrelia burgdorferi ospc protein required exclusively in a crucial early stage of mammalian infection. | this study demonstrates a strict temporal requirement for a virulence determinant of the lyme disease spirochete borrelia burgdorferi during a unique point in its natural infection cycle, which alternates between ticks and small mammals. ospc is a major surface protein produced by b. burgdorferi when infected ticks feed but whose synthesis decreases after transmission to a mammalian host. we have previously shown that spirochetes lacking ospc are competent to replicate in and migrate to the sali ... | 2006 | 16714588 |
| 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 |
| an ixodes scapularis protein required for survival of anaplasma phagocytophilum in tick salivary glands. | anaplasma phagocytophilum is the agent of human anaplasmosis, the second most common tick-borne illness in the united states. this pathogen, which is closely related to obligate intracellular organisms in the genera rickettsia, ehrlichia, and anaplasma, persists in ticks and mammalian hosts; however, the mechanisms for survival in the arthropod are not known. we now show that a. phagocytophilum induces expression of the ixodes scapularis salp16 gene in the arthropod salivary glands during vector ... | 2006 | 16717118 |
| sacred cows and sympathetic squirrels: the importance of biological diversity to human health. | | 2006 | 16729846 |
| bioinformatics and multiepitope dna immunization to design rational snake antivenom. | snake venom is a potentially lethal and complex mixture of hundreds of functionally diverse proteins that are difficult to purify and hence difficult to characterize. these difficulties have inhibited the development of toxin-targeted therapy, and conventional antivenom is still generated from the sera of horses or sheep immunized with whole venom. although life-saving, antivenoms contain an immunoglobulin pool of unknown antigen specificity and known redundancy, which necessitates the delivery ... | 2006 | 16737347 |
| anaplasma phagocytophilum in central and western wisconsin: a molecular survey. | anaplasma phagocytophilum is an obligate intracellular bacterium that is transmitted to humans through the bite of ixodes spp. ticks, and causes a febrile disease known as human granulocytic anaplasmosis. the presence of a. phagocytophilum in wisconsin white-tailed deer blood and in deer ticks was assessed using pcr and dna sequencing. sampling sites in the western part of the state (buffalo county) and central region (waushara, waupaca, and green lake counties) were used. in buffalo county, 5.6 ... | 2006 | 16738890 |
| 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 |
| antiinflammatory and immunosuppressive activity of sialostatin l, a salivary cystatin from the tick ixodes scapularis. | here we report the ability of the tick ixodes scapularis, the main vector of lyme disease in the united states, to actively and specifically affect the host proteolytic activity in the sites of infestation through the release of a cystatin constituent of its saliva. the cystatin presence in the saliva was verified both biochemically and immunologically. we named the protein sialostatin l because of its inhibitory action against cathepsin l. we also show that the proteases it targets, although li ... | 2006 | 16772304 |
| use of refrigeration as a practical means to preserve viability of in vitro-cultured ide8 tick cells. | in vitro cultivation of the ide8 cell line, derived from embryonic ixodes scapularis ticks, constitutes an important system for the study of tick-borne pathogens, as these cells support growth of rickettsial species which are not normally transmitted by this tick. however, since cryopreservation of ide8 cells is not always successful, there is a need to develop alternative ways to preserve these cells. in the present study, a suspension of ide8 cells in culture medium was kept under refrigeratio ... | 2006 | 16779573 |
| transcriptional regulation of the borrelia burgdorferi antigenically variable vlse surface protein. | the lyme disease agent borrelia burgdorferi can persistently infect humans and other animals despite host active immune responses. this is facilitated, in part, by the vls locus, a complex system consisting of the vlse expression site and an adjacent set of 11 to 15 silent vls cassettes. segments of nonexpressed cassettes recombine with the vlse region during infection of mammalian hosts, resulting in combinatorial antigenic variation of the vlse outer surface protein. we now demonstrate that sy ... | 2006 | 16788197 |
| a novel real-time pcr assay for the speciation of medically important ticks. | the identification of ticks using morphological characters is a well-established practice, however specimens that are small or damaged are often difficult to speciate. a novel, rapid real-time pcr assay, which targets the second internal transcribed spacer (its2) region in the nuclear ribosomal dna gene, was developed for identification of four tick species of utmost medical importance in the united states: ixodes scapularis, i. pacificus, dermacentor variabilis, and amblyomma americanum. comput ... | 2006 | 16796512 |
| evaluation of white-tailed deer (odocoileus virginianus) as natural sentinels for anaplasma phagocytophilum. | anaplasma phagocytophilum, the causative agent of human granulocytotropic anaplasmosis, can infect white-tailed deer (wtd; odocoileus virginianus), and this species is a crucial host for adult ixodes scapularis, the primary vector of a. phagocytophilum. the goal of this study was to determine the geographic distribution of a. phagocytophilum among wtd across a 19 state region and to evaluate the utility of wtd as natural sentinels. serologic testing using the indirect fluorescent antibody (ifa) ... | 2006 | 16796517 |
| bmcystatin, a cysteine proteinase inhibitor characterized from the tick boophilus microplus. | the bovine tick rhipicephalus (boophilus) microplus is a blood-sucking animal, which is responsible for babesia spp and anaplasma marginale transmission for cattle. from a b. microplus fat body cdna library, 465 selected clones were sequenced randomly and resulted in 60 contigs. an open reading frame (orf) contains 98 amino acids named bmcystatin, due to 70% amino acid identity to a classical type 1 cystatin from ixodes scapularis tick (genbank accession no. ). the bmcystatin amino acid sequence ... | 2006 | 16806070 |
| antithrombotic properties of ixolaris, a potent inhibitor of the extrinsic pathway of the coagulation cascade. | ixolaris is a two-kunitz tick salivary gland protein identified in ixodes scapularis that presents extensive sequence homology to tfpi. it binds to fxa or fx as scaffolds and inhibits tissue factor/fviia complex (extrinsic xnase). differently from tfpi, ixolaris does not bind to the active site cleft of fxa. instead, complex formation is mediated by the fxa heparin-binding exosite, which may also results in decreased fxa activity into the prothrombinase complex. in this report, we show that reco ... | 2006 | 16807644 |
| reduction of tick infections with anaplasma marginale and a. phagocytophilum by targeting the tick protective antigen subolesin. | subolesin was recently shown by both gene silencing and immunization with the recombinant protein to protect against tick infestations, and to cause reduced tick survival and degeneration of gut and salivary gland tissues. in this research, we extended these studies by testing whether targeting subolesin by rnai or vaccination interfered with the ability of ticks to become infected with two tick-borne pathogens, anaplasma marginale which causes bovine anaplasmosis and anaplasma phagocytophilum, ... | 2006 | 16816958 |
| reinfestation sources for chagas disease vector, triatoma infestans, argentina. | reinfestation by triatoma infestans after insecticide spraying has caused elimination efforts in the dry chaco region to fail repeatedly. the sources and spatial extent that need to be considered to understand the reinfestation pattern and to plan a comprehensive control program were studied in 2 adjacent rural communities in northwestern argentina from 1993 to 1997. the effects of external, residual, and primary sources on the reinfestation pattern were evaluated by using geographic information ... | 2006 | 16836826 |
| 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 |
| rickettsia felis from cat fleas: isolation and culture in a tick-derived cell line. | rickettsia felis, the etiologic agent of spotted fever, is maintained in cat fleas by vertical transmission and resembles other tick-borne spotted fever group rickettsiae. in the present study, we utilized an ixodes scapularis-derived tick cell line, ise6, to achieve isolation and propagation of r. felis. a cytopathic effect of increased vacuolization was commonly observed in r. felis-infected cells, while lysis of host cells was not evident despite large numbers of rickettsiae. electron microsc ... | 2006 | 16885313 |
| 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 |
| estimation of european wild boar relative abundance and aggregation: a novel method in epidemiological risk assessment. | wild boars are important disease reservoirs. it is well known that abundance estimates are needed in wildlife epidemiology, but the expense and effort required to obtain them is prohibitive. we evaluated a simple method based on the frequency of faecal droppings found on transects (fbii), and developed a spatial aggregation index, based on the runs test statistic. estimates were compared with hunting data, and with porcine circovirus and aujeszky's disease virus seroprevalences and mycobacterium ... | 2007 | 16893488 |
| the lyme vaccine: a cautionary tale. | people living in endemic areas acquire lyme disease from the bite of an infected tick. this infection, when diagnosed and treated early in its course, usually responds well to antibiotic therapy. a minority of patients develops more serious disease, particularly after a delay in diagnosis or therapy, and sometimes chronic neurological, cardiac, or rheumatological manifestations. in 1998, the fda approved a new recombinant lyme vaccine, lymerix, which reduced new infections in vaccinated adults b ... | 2007 | 16893489 |
| unique macrophage and tick cell-specific protein expression from the p28/p30-outer membrane protein multigene locus in ehrlichia chaffeensis and ehrlichia canis. | ehrlichia chaffeensis and ehrlichia canis are tick-transmitted rickettsial pathogens that cause human and canine monocytic ehrlichiosis respectively. we tested the hypothesis that these pathogens express unique proteins in response to their growth in vertebrate and tick host cells and that this differential expression is similar in closely related ehrlichia species. evaluation of nine e. chaffeensis isolates and one e. canis isolate demonstrated that protein expression was host cell-dependent. t ... | 2006 | 16922866 |
| comparative genome hybridization reveals substantial variation among clinical isolates of borrelia burgdorferi sensu stricto with different pathogenic properties. | clinical and murine studies suggest that there is a differential pathogenicity of different genotypes of borrelia burgdorferi, the spirochetal agent of lyme disease. comparative genome hybridization was used to explore the relationship between different genotypes. the chromosomes of all studied isolates were highly conserved (>93%) with respect to both sequence and gene order. plasmid sequences were substantially more diverse. plasmids lp54, cp26, and cp32 were present in all tested isolates, an ... | 2006 | 16923879 |
| constitutive expression of outer surface protein c diminishes the ability of borrelia burgdorferi to evade specific humoral immunity. | the lyme disease spirochete borrelia burgdorferi reduces the expression of outer surface protein c (ospc) in response to the development of an anti-ospc humoral response, leading to the hypothesis that the ability to repress ospc expression is critical for the pathogen to proceed to chronic infection. b. burgdorferi was genetically modified to constitutively express ospc by introducing an extra ospc copy fused with the borrelial flagellar gene (flab) promoter. such a genetic modification did not ... | 2006 | 16926410 |
| host heterogeneity dominates west nile virus transmission. | heterogeneity in host populations and communities can have large effects on the transmission and control of a pathogen. in extreme cases, a few individuals give rise to the majority of secondary infections, which have been termed super spreading events. here, we show that transmission of west nile virus (wnv) is dominated by extreme heterogeneity in the host community, resulting in highly inflated reproductive ratios. a single relatively uncommon avian species, american robin (turdus migratorius ... | 2006 | 16928635 |
| confirmation of tick bite by detection of antibody to ixodes calreticulin salivary protein. | ticks introduce a variety of pharmacologically active molecules into their host during attachment and feeding in order to obtain a blood meal. people who are repeatedly exposed to ticks may develop an immune response to tick salivary proteins. despite this response, people usually are unaware of having been bitten, especially if they are not repeatedly exposed to ticks. in order to develop a laboratory marker of tick exposure that would be useful in understanding the epidemiology of tick-borne i ... | 2006 | 16928887 |
| structure of conkunitzin-s1, a neurotoxin and kunitz-fold disulfide variant from cone snail. | cone snails (conus) are predatory marine mollusks that immobilize prey with venom containing 50-200 neurotoxic polypeptides. most of these polypeptides are small disulfide-rich conotoxins that can be classified into families according to their respective ion-channel targets and patterns of cysteine-cysteine disulfides. conkunitzin-s1, a potassium-channel pore-blocking toxin isolated from c. striatus venom, is a member of a newly defined conotoxin family with sequence homology to kunitz-fold prot ... | 2006 | 16929098 |
| rna interference of the salivary gland nitrophorin 2 in the triatomine bug rhodnius prolixus (hemiptera: reduviidae) by dsrna ingestion or injection. | mass sequencing of cdna libraries from salivary glands of triatomines has resulted in the identification of many novel genes of unknown function. the aim of the present work was to develop a functional rna interference (rnai) technique for rhodnius prolixus, which could be widely used for functional genomics studies in triatomine bugs. to this end, we investigated whether double-stranded rna (dsrna) can inhibit gene expression of r. prolixus salivary nitrophorin 2 (np2) and what impact this migh ... | 2006 | 16935217 |
| salivary gland extracts of culicoides sonorensis inhibit murine lymphocyte proliferation and no production by macrophages. | culicoides biting midges serve as vectors of pathogens affecting humans and domestic animals. culicoides sonorensis is a vector of several arboviruses in north american that cause substantial economic losses to the us livestock industry. previous studies showed that c. sonorensis saliva, like the saliva of many hematophagous arthropods, contains numerous pharmacological agents that affect hemostasis and early events in the inflammatory response, which may enhance the infectivity of culicoides-bo ... | 2006 | 16968936 |
| plasmodium falciparum-infected erythrocytes induce tissue factor expression in endothelial cells and support the assembly of multimolecular coagulation complexes. | plasmodium falciparum malaria infects 300-500 million people every year, causing 1-2 million deaths annually. evidence of a coagulation disorder, activation of endothelial cells (ec) and increase in inflammatory cytokines are often present in malaria. | 2007 | 17002660 |
| county-level surveillance of white-tailed deer infestation by ixodes scapularis and dermacentor albipictus (acari: ixodidae) along the illinois river. | from 1998 to 2003, 4,935 hunter-killed deer in northern and central illinois were examined for ticks; 4,066 blacklegged ticks, ixodes scapularis say, and 6,530 winter ticks, dermacentor albipictus (packard) (acari: ixodidae), were collected. i. scapularis was the predominant tick species in the northern portion of the study area, with a decreasing north-to-south prevalence gradient. in contrast, d. albipictus was more common in the south with a decreasing south-to-north prevalence gradient. comp ... | 2006 | 17017213 |
| sarcoptes scabiei (acari: sarcoptidae) mite extract modulates expression of cytokines and adhesion molecules by human dermal microvascular endothelial cells. | the inflammatory and immune responses seen with the worldwide disease scabies, caused by the mite sarcoptes scabiei (de geer) (acari: sarcoptidae), are complex. clinical symptoms are delayed for weeks in patients when they are infested with scabies for the first time. this study was undertaken to elucidate the role of the human dermal microvascular endothelial cell (hmvec-d) in modulating the inflammatory and immune responses in the skin to s. scabiei. extracts of s. scabiei were incubated with ... | 2006 | 17017228 |
| 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 |
| repellent activity of fractioned compounds from chamaecyparis nootkatensis essential oil against nymphal ixodes scapularis (acari: ixodidae). | preliminary repellent activity of 14 natural products isolated from essential oil components extracted from the heartwood of alaska yellow cedar, chamaecyparis nootkatensis (d. don) spach., were evaluated against nymphal ixodes scapularis say in a laboratory bioassay and compared with technical grade n,n-diethyl-3-methylbenzamide (deet). four hours after treatment, nootkatone and valencene-13-ol had repellent concentration (rc)50 values of 0.0458 and 0.0712% (wt:vol), respectively; two additiona ... | 2006 | 17017233 |
| babesia spp. identified by pcr in ticks collected from domestic and wild ruminants in southern switzerland. | concurrent infections with vector-borne pathogens affected a cattle herd in switzerland, and one of the pathogens was identified as babesia bigemina, which had never been observed in this country before. therefore, a survey of the occurrence of ruminant babesia spp. and their tick vectors in switzerland was conducted. a total of 2,017 ticks were collected from sheep, goats, cattle, and wild ruminants (deer, roe deer, and chamois) in southern parts of switzerland and identified morphologically. t ... | 2006 | 17021198 |
| longitudinal analysis of tick densities and borrelia, anaplasma, and ehrlichia infections of ixodes ricinus ticks in different habitat areas in the netherlands. | from 2000 to 2004, ticks were collected by dragging a blanket in four habitat areas in the netherlands: dunes, heather, forest, and a city park. tick densities were calculated, and infection with borrelia burgdorferi and anaplasma and ehrlichia species was investigated by reverse line blot analysis. the lowest tick density was observed in the heather area (1 to 8/100 m2). in the oak forest and city park, the tick densities ranged from 26 to 45/100 m2. the highest tick density was found in the du ... | 2006 | 17028227 |
| 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 |
| evaluation of an imidacloprid (8.8% w/w)--permethrin (44.0% w/w) topical spot-on and a fipronil (9.8% w/w)--(s)-methoprene (8.8% w/w) topical spot-on to repel, prevent attachment, and kill adult ixodes scapularis and amblyomma americanum ticks on dogs. | this study evaluated the effectiveness of two topical spot-on formulations -- imidacloprid(8.8% w/w)-permethrin (44.0% w/w) and fipronil (9.8% w/w)-(s)-methoprene (8.8% w/w)--to repel, prevent the attachment of, and kill adult ixodes scapularis and amblyomma americanum on dogs. twelve purpose-bred beagles were distributed into three groups of four dogs each; one group served as untreated controls, and each of the other two groups received one of the test products. dogs were exposed to 25 adult t ... | 2006 | 17039440 |
| coinfections acquired from ixodes ticks. | the pathogens that cause lyme disease (ld), human anaplasmosis, and babesiosis can coexist in ixodes ticks and cause human coinfections. although the risk of human coinfection differs by geographic location, the true prevalence of coinfecting pathogens among ixodes ticks remains largely unknown for the majority of geographic locations. the prevalence of dually infected ixodes ticks appears highest among ticks from regions of north america and europe where ld is endemic, with reported prevalences ... | 2006 | 17041141 |
| p38 mitogen-activated protein kinase controls nf-kappab transcriptional activation and tumor necrosis factor alpha production through rela phosphorylation mediated by mitogen- and stress-activated protein kinase 1 in response to borrelia burgdorferi antigens. | the interaction of borrelia burgdorferi, the causative agent of lyme borreliosis, with phagocytic cells induces the activation of nf-kappab and the expression of proinflammatory cytokines including tumor necrosis factor alpha (tnf-alpha). b. burgdorferi-induced tnf-alpha production is also dependent on the activation of p38 mitogen-activated protein (map) kinase. the specific contribution of these signaling pathways to the response of phagocytic cells to the spirochete and the molecular mechanis ... | 2007 | 17074860 |
| cutting edge: cd4 is the receptor for the tick saliva immunosuppressor, salp15. | salp15 is an ixodes scapularis salivary protein that inhibits cd4+ t cell activation through the repression of tcr ligation-triggered calcium fluxes and il-2 production. we show in this study that salp15 binds specifically to the cd4 coreceptor on mammalian host t cells. salp15 specifically associates through its c-terminal residues with the outermost two extracellular domains of cd4. upon binding to cd4, salp15 inhibits the subsequent tcr ligation-induced t cell signaling at the earliest steps ... | 2006 | 17082567 |
| highly prevalent coxiella sp. bacterium in the tick vector amblyomma americanum. | laboratory-reared and field-collected amblyomma americanum ticks were hosts of a coxiella sp. and a rickettsia sp. while the coxiella sp. was detected in 50 of 50 field-collected ticks, the rickettsia sp. was absent from 32% of ticks. the coxiella sp. showed evidence of a reduced genome and may be an obligate endosymbiont. | 2007 | 17085709 |
| 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 |
| anaplasma phagocytophilum subverts tick salivary gland proteins. | anaplasma phagocytophilum is a bacterium that is transmitted by ixodes spp. ticks, in which it resides in salivary glands. ticks inoculate the pathogen into hosts together with an array of salivary molecules that reduce host anti-tick inflammation. sukumaran et al. recently showed that a. phagocytophilum uses a tick salivary protein, salp16, to enhance its uptake from the host and into the salivary gland. occupation and exploitation of tick salivary glands have implications for the maintenance a ... | 2007 | 17092773 |
| borrelia burgdorferi alters its gene expression and antigenic profile in response to co2 levels. | the etiologic agent of lyme disease, borrelia burgdorferi, must adapt to the distinct environments of its arthropod vector and mammalian host during its complex life cycle. b. burgdorferi alters gene expression and protein synthesis in response to temperature, ph, and other uncharacterized environmental factors. the hypothesis tested in this study is that dissolved gases, including co(2), serve as a signal for b. burgdorferi to alter protein production and gene expression. in this study we focus ... | 2007 | 17098904 |
| catalytic advantages provided by selenocysteine in methionine-s-sulfoxide reductases. | methionine sulfoxide reductases are key enzymes that repair oxidatively damaged proteins. two distinct stereospecific enzyme families are responsible for this function: msra (methionine-s-sulfoxide reductase) and msrb (methionine-r-sulfoxide reductase). in the present study, we identified multiple selenoprotein msra sequences in organisms from bacteria to animals. we characterized the selenocysteine (sec)-containing chlamydomonas msra and found that this protein exhibited 10-50-fold higher activ ... | 2006 | 17105189 |
| diagnosis, treatment, and prognosis of erythema migrans and lyme arthritis. | most patients with erythema migrans, the pathognomonic rash of lyme disease, do not recall a deer tick bite. the rash is classically 5 to 68 cm of annular homogenous erythema (59%), central erythema (30%), central clearing (9%), or central purpura (2%). serologic testing is not indicated for patients with erythema migrans, because initially, the result is usually negative. successful treatment of a patient with erythema migrans can be accomplished with 20 days of oral doxycycline, amoxicillin, o ... | 2006 | 17113969 |
| reservoir competency of goats for anaplasma phagocytophilum. | the susceptibility of goats to infection by anaplasma phagocytophilum (a. phagocytophilum) strains ap-variant 1 and ap-ha was assessed by infestation of goats with field-collected ixodes scapularis (i. scapularis) ticks. both strains were infectious in the goat model. these results demonstrate that goats can be used in a laboratory setting to propagate a. phagocytophilum. transmission from an infected goat to a naïve goat by i. scapularis tick feeding was used to demonstrate that goats are reser ... | 2006 | 17114757 |
| isolation of anaplasma phagocytophilum strain ap-variant 1 in a tick-derived cell line. | ten isolates of the ap-variant 1 strain of anaplasma phagocytophilum were made in the ixodes scapularis (i. scapularis)-derived cell line, ise6. two isolates were obtained from laboratory-infected goats and eight isolates were obtained from field-collected i. scapularis ticks. each isolate showed 16s rrna sequences identical to those as previously described for the ap-variant 1 strain. these are the first tissue culture isolates of the ap-variant 1 strain and will allow for further characterizat ... | 2006 | 17114772 |
| 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 |
| infection of ixodes scapularis ticks with rickettsia monacensis expressing green fluorescent protein: a model system. | ticks (acari: ixodidae) are ubiquitous hosts of rickettsiae (rickettsiaceae: rickettsia), obligate intracellular bacteria that occur as a continuum from nonpathogenic arthropod endosymbionts to virulent pathogens of both arthropod vectors and vertebrates. visualization of rickettsiae in hosts has traditionally been limited to techniques utilizing fixed tissues. we report epifluorescence microscopy observations of unfixed tick tissues infected with a spotted fever group endosymbiont, rickettsia m ... | 2007 | 17125789 |
| deer browse resistant exotic-invasive understory: an indicator of elevated human risk of exposure to ixodes scapularis (acari: ixodidae) in southern coastal maine woodlands. | we evaluated the relationships between forest understory structure and the abundance of questing adult and nymphal blacklegged ticks, ixodes scapularis say (acari: ixodidae), in three maine towns endemic for lyme disease, 2001-2003. in fragmented new england woodlands, over-abundant white-tailed deer, odocoileus virginianus zimmerman, overbrowse palatable species, allowing browse-resistant exotic-invasive species to replace native forest understory structures. we predicted there would be more ti ... | 2006 | 17162946 |
| relative abundance and prevalence of selected borrelia infections in ixodes scapularis and amblyomma americanum (acari: ixodidae) from publicly owned lands in monmouth county, new jersey. | to evaluate their potential importance in the transmission of ixodid tick-borne borrelioses in monmouth county, nj, we collected host-seeking ixodes scapularis say and amblyomma americanum (l.) (acari: ixodidae) adults and nymphs to determine relative encounter frequencies and the infection prevalence of selected borrelia spp. in their respective tick vectors. we also reviewed records of all ticks submitted for identification by the public in monmouth county during 2001-2005. relative abundance ... | 2006 | 17162963 |
| 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 |
| gene silencing of the tick protective antigens, bm86, bm91 and subolesin, in the one-host tick boophilus microplus by rna interference. | the use of rna interference (rnai) to assess gene function has been demonstrated in several three-host tick species but adaptation of rnai to the one-host tick, boophilus microplus, has not been reported. we evaluated the application of rnai in b. microplus and the effect of gene silencing on three tick-protective antigens: bm86, bm91 and subolesin. gene-specific double-stranded (dsrna) was injected into two tick stages, freshly molted unfed and engorged females, and specific gene silencing was ... | 2007 | 17196597 |
| the low seroprevalence of tick-transmitted agents of disease in dogs from southern ontario and quebec. | infectious diseases caused by pathogens transmitted by ticks and other insect vectors are an important cause of morbidity and mortality in both dogs and humans throughout north america. the purpose of this study was to determine the seroprevalence of selected vector-transmitted pathogens in southern ontario and quebec. samples submitted to the vector borne disease diagnostic laboratory (vbddl) at the north carolina state university college of veterinary medicine were evaluated for antibodies to ... | 2006 | 17217089 |
| adaptation of a luciferase gene reporter and lac expression system to borrelia burgdorferi. | the development of new genetic systems for studying the complex regulatory events that occur within borrelia burgdorferi is an important goal of contemporary lyme disease research. although recent advancements have been made in the genetic manipulation of b. burgdorferi, there still remains a paucity of basic molecular systems for assessing differential gene expression in this pathogen. herein, we describe the adaptation of two powerful genetic tools for use in b. burgdorferi. the first is a pho ... | 2007 | 17220265 |
| regulators of expression of the oligopeptide permease a proteins of borrelia burgdorferi. | borrelia burgdorferi undergoes an infectious cycle that requires adaptation to different hosts and marked differences in environment. b. burgdorferi copes with its different environments by regulating the expression of proteins required for survival in specific settings. the b. burgdorferi oligopeptide permease (opp) is one of only a few transporters encoded by the b. burgdorferi genome. opp proteins in other bacteria serve multiple environmental adaptation functions. b. burgdorferi appears to b ... | 2007 | 17237172 |
| construction and analysis of variants of a polyvalent lyme disease vaccine: approaches for improving the immune response to chimeric vaccinogens. | there is currently no lyme disease vaccine commercially available for use in humans. outer surface protein c (ospc) of the borrelia has been widely investigated as a potential vaccinogen. at least 38 ospc types have been defined. while the antibody response to ospc is protective, the range of protection is narrow due to the localization of protective epitopes within ospc type-specific domains. to develop a broadly protective vaccine, we previously constructed a tetravalent chimeric vaccinogen co ... | 2007 | 17239505 |
| 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 |
| response of nymphal ixodes scapularis, the primary tick vector of lyme disease spirochetes in north america, to barriers derived from wood products or related home and garden items. | forest products were tested to see if they functioned as a barrier to nymphal ixodes scapularis. these products could potentially be used to define a border between high density and low density tick zones on residential properties in lyme disease endemic regions of north america. common home and garden items were also tested. three wood products effectively acted as barriers to nymphal i. scapularis: alaska yellow cedar sawdust, alaska yellow cedar woodchips, and cellulose. these three products ... | 2006 | 17249361 |
| new records of immature ixodes scapularis from mississippi. | | 2006 | 17249363 |
| wild turkey (meleagris gallopavo) as a host of ixodid ticks, lice, and lyme disease spirochetes (borrelia burgdorferi sensu lato) in california state parks. | rio grande wild turkeys (meleagris gallopavo intermedia) were evaluated as potential hosts of ixodid ticks, lice, and lyme disease spirochetes (borrelia burgdorferi sensu lato [s.l.]) in three state parks in sonoma county, california, usa, during 2003 and 2004. in total, 113 birds were collected, 50 (44.2%) of which were found to be infested by 361 ixodid ticks representing three species: the western black-legged tick (ixodes pacificus, n=248), the rabbit tick (haemaphysalis leporispalustris, n= ... | 2006 | 17255442 |
| new tick defensin isoform and antimicrobial gene expression in response to rickettsia montanensis challenge. | recent studies aimed at elucidating the rickettsia-tick interaction have discovered that the spotted fever group rickettsia rickettsia montanensis, a relative of r. rickettsii, the etiologic agent of rocky mountain spotted fever, induces differential gene expression patterns in the ovaries of the hard tick dermacentor variabilis. here we describe a new defensin isoform, defensin-2, and the expression patterns of genes for three antimicrobials, defensin-1 (vsna1), defensin-2, and lysozyme, in the ... | 2007 | 17261604 |
| ixodes ticks belonging to the ixodes ricinus complex encode a family of anticomplement proteins. | the alternative pathway of complement is an important innate defence against pathogens including ticks. this component of the immune system has selected for pathogens that have evolved countermeasures. recently, a salivary protein able to inhibit the alternative pathway was cloned from the american tick ixodes scapularis (valenzuela et al., 2000; j. biol. chem. 275, 18717-18723). here, we isolated two different sequences, similar to isac, from the transcriptome of i. ricinus salivary glands. exp ... | 2007 | 17298559 |
| uninfected mosquito bites confer protection against infection with malaria parasites. | despite decades of research and multiple initiatives, malaria continues to be one of the world's most debilitating infectious diseases. new insights for malaria control and vaccine development will be essential to thwart the staggering worldwide impact of this disease (a. bjorkman and a. bhattarai, acta trop. 94:163-169, 2005); ultimately successful vaccine strategies will undoubtedly be multifactorial, incorporating multiple antigens and targeting diverse aspects of the malaria parasites' biolo ... | 2007 | 17339356 |
| t-cell signaling pathways inhibited by the tick saliva immunosuppressor, salp15. | the ixodes scapularis salivary protein salp15 inhibits the activation of t cells through its interaction with the coreceptor cd4. salp15 prevents the activation of lck upon tcr engagement and the formation of lipid rafts. we have now analyzed the signaling pathways that are inhibited by the tick salivary protein in cd4(+) t cells. salp15 affects tyrosine phosphorylation of several early signal components downstream of lck, including lat and vav1, which results in improper actin polymerization. t ... | 2007 | 17343683 |
| 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 |
| wildlife, exotic pets, and emerging zoonoses. | most emerging infectious diseases are zoonotic; wildlife constitutes a large and often unknown reservoir. wildlife can also be a source for reemergence of previously controlled zoonoses. although the discovery of such zoonoses is often related to better diagnostic tools, the leading causes of their emergence are human behavior and modifications to natural habitats (expansion of human populations and their encroachment on wildlife habitat), changes in agricultural practices, and globalization of ... | 2007 | 17370509 |
| transovarial silencing of the subolesin gene in three-host ixodid tick species after injection of replete females with subolesin dsrna. | rna interference (rnai) has become the most powerful experimental tool for the study of gene function in ticks. subolesin, initially called 4d8, was found to be protective against tick infestations when used as a vaccine and was shown to be highly conserved among ixodid tick species at the nucleotide and protein levels. rnai caused systemic silencing of subolesin and demonstrated that this protein is involved in regulation of tick feeding, reproduction, and development. recently, these results w ... | 2007 | 17372765 |
| molecular characterization of bacterial endosymbionts of acanthamoeba isolates from infected corneas of korean patients. | the endosymbionts of 4 strains of acanthamoeba (ka/e9, ka/e21, ka/e22, and ka/e23) isolated from the infected corneas of korean patients were characterized via orcein stain, transmission electron microscopic examination, and 16s rdna sequence analysis. double membrane-bound, rod-shaped endosymbionts were distributed randomly throughout both the trophozoites and cysts of each of acanthamoeba isolates. the endosymbionts of ka/e9, ka/e22, and ka/e23 were surrounded by electron-translucent areas. no ... | 2007 | 17374972 |
| repellency of two terpenoid compounds isolated from callicarpa americana (lamiaceae) against ixodes scapularis and amblyomma americanum ticks. | callicarpenal (13, 14, 15, 16-tetranor-3-cleroden-12-al) and intermedeol [(4s,5s,7r,10s)-eudesm-11-en-4-ol], isolated from american beautyberry, callicarpa americana (lamiaceae), were evaluated in laboratory bioassays for repellent activity against host-seeking nymphs of the blacklegged tick, ixodes scapularis, and lone star tick, amblyomma americanum. a strip of organdy cloth treated with test solution was doubly wrapped (treatment on outer layer) around the middle phalanx of a forefinger and t ... | 2007 | 17380408 |
| borrelia burgdorferi binding of host complement regulator factor h is not required for efficient mammalian infection. | the causative agent of lyme disease, borrelia burgdorferi, is naturally resistant to its host's alternative pathway of complement-mediated killing. several different borrelial outer surface proteins have been identified as being able to bind host factor h, a regulator of the alternative pathway, leading to a hypothesis that such binding is important for borrelial resistance to complement. to test this hypothesis, the development of b. burgdorferi infection was compared between factor h-deficient ... | 2007 | 17420242 |
| prince edward island. lyme disease vector, ixodes dammini (the northern deer tick), identified in prince edward island. | | 1990 | 17423542 |
| duration of exposure to suboptimal atmospheric moisture affects nymphal blacklegged tick survival. | the biological processes affecting ixodes scapularis say survival are complex. understanding these processes will be beneficial for predicting tick distribution and population dynamics. this research shows that the duration for which nymphal ticks are exposed to drying air is an important factor for their survival. experimental analysis of variance results show that duration of exposure to dry air (duration) is as important as vapor pressure deficit (relative humidity) (duration, relative humidi ... | 2007 | 17427711 |
| rickettsia peacockii, an endosymbiont of dermacentor andersoni, does not elicit or inhibit humoral immune responses from immunocompetent d. andersoni or ixodes scapularis cell lines. | ixodes scapularis and dermacentor andersoni cell lines were stimulated with heat-killed escherichia coli and micrococcus luteus to investigate whether infection by rickettsia peacockii, an endosymbiont of d. andersoni, modifies humoral immune responses. radial diffusion assays, western blotting, flow cytometry, and quantitative reverse-transcription pcr were used to determine if expression of bacteriolytic peptides, including lysozyme and defensin, was upregulated by bacterial stimulation or inf ... | 2007 | 17428539 |
| the bursicon gene in mosquitoes: an unusual example of mrna trans-splicing. | the bursicon gene in anopheles gambiae is encoded by two loci. burs124 on chromosome arm 2l contains exons 1, 2, and 4, while burs3 on arm 2r contains exon 3. exon 3 is efficiently spliced into position in the mature transcript. this unusual gene arrangement is ancient within mosquitoes, being shared by aedes aegypti and culex pipiens. | 2007 | 17435221 |
| an insight into the sialome of the oriental rat flea, xenopsylla cheopis (rots). | the salivary glands of hematophagous animals contain a complex cocktail that interferes with the host hemostasis and inflammation pathways, thus increasing feeding success. fleas represent a relatively recent group of insects that evolved hematophagy independently of other insect orders. | 2007 | 17437641 |
| borrelia burgdorferi intercepts host hormonal signals to regulate expression of outer surface protein a. | the borrelia burgdorferi infectious cycle requires that the organism adapt to vast differences in environmental conditions found in its tick and mammalian hosts. previous studies have shown that b. burgdorferi accomplishes this accommodation in part by regulating expression of its surface proteins. outer surface protein a (ospa) is a borrelial protein important in colonization of the tick midgut. ospa is up-regulated when the organism is in its tick host and down-regulated when it is in a mammal ... | 2007 | 17438273 |
| high-resolution genetic fingerprinting of european strains of anaplasma phagocytophilum by use of multilocus variable-number tandem-repeat analysis. | anaplasma phagocytophilum is a widely distributed tick-borne pathogen of humans, livestock, and companion animals. we used in silico methods to identify 10 variable-number tandem-repeat (vntr) loci within the genome sequence of the a. phagocytophilum hz strain and used these data to develop a multilocus vntr-based typing scheme for the species. having confirmed the stability of four of the loci in replicates of the a. phagocytophilum strain that had been subjected to different numbers of passage ... | 2007 | 17442796 |
| variation in genome size of argasid and ixodid ticks. | the suborder ixodida includes many tick species of medical and veterinary importance, but little is known about the genomic characteristics of these ticks. we report the first study to determine genome size in two species of argasidae (soft ticks) and seven species of ixodidae (hard ticks) using flow cytometry analysis of fluorescent stained nuclei. our results indicate a large haploid genome size (1c>1000 mbp) for all ixodida with a mean of 1281 mbp (1.31+/-0.07 pg) for the argasidae and 2671 m ... | 2007 | 17456435 |
| biocidal activity of three wood essential oils against ixodes scapularis (acari: ixodidae), xenopsylla cheopis (siphonaptera: pulicidae), and aedes aegypti (diptera: culicidae). | the biocidal activity of three steam distilled wood essential oils-incense cedar, calocedrus decurrens (torr.) florin; port-orford-cedar, chamaecyparis lawsoniana (a. murr.) parl.; and western juniper, juniperus occidentalis (hook)--were evaluated against adult aedes aegypti (l.) (diptera: culicidae) and xenopsylla cheopis (rothchild) (siphonaptera: pulicidae) and nymphal ixodes scapularis say (acari: ixodidae). in vitro laboratory bioassays were conducted to establish baseline dose-mortality da ... | 2007 | 17461093 |
| determinants of the geographic distribution of puumala virus and lyme borreliosis infections in belgium. | vector-borne and zoonotic diseases generally display clear spatial patterns due to different space-dependent factors. land cover and land use influence disease transmission by controlling both the spatial distribution of vectors or hosts, and the probability of contact with susceptible human populations. the objective of this study was to combine environmental and socio-economic factors to explain the spatial distribution of two emerging human diseases in belgium, puumala virus (puuv) and lyme b ... | 2007 | 17474974 |
| isolation and propagation of the ap-variant 1 strain of anaplasma phagocytophilum in a tick cell line. | the first tissue culture isolates of the unique anaplasma phagocytophilum strain, ap-variant 1, were obtained in the ixodes scapularis tick-derived cell line ise6. two isolates were from goat blood samples: one from a goat infected with i. scapularis ticks from rhode island and a second from a goat infected by serial passage of blood from the first infected goat. eight isolates were made directly from i. scapularis ticks collected from white-tailed deer in minnesota and represent the first isola ... | 2007 | 17475757 |