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clustering of genetically defined allele classes in the caenorhabditis elegans daf-2 insulin/igf-1 receptor.the daf-2 insulin/igf-1 receptor regulates development, metabolism, and aging in the nematode caenorhabditis elegans. however, complex differences among daf-2 alleles complicate analysis of this gene. we have employed epistasis analysis, transcript profile analysis, mutant sequence analysis, and homology modeling of mutant receptors to understand this complexity. we define an allelic series of nonconditional daf-2 mutants, including nonsense and deletion alleles, and a putative null allele, m65. ...200818245374
lyme borreliosis spirochete erp proteins, their known host ligands, and potential roles in mammalian infection.lyme borreliae naturally maintain numerous distinct dna elements of the cp32 family, each of which carries a mono- or bicistronic erp locus. the encoded erp proteins are surface-exposed outer membrane lipoproteins that are produced at high levels during mammalian infection but largely repressed during colonization of vector ticks. recent studies have revealed that some erp proteins can serve as bacterial adhesins, binding host proteins such as the complement regulator factor h and the extracellu ...200818248770
evolution of insect proteomes: insights into synapse organization and synaptic vesicle life cycle.the molecular components in synapses that are essential to the life cycle of synaptic vesicles are well characterized. nonetheless, many aspects of synaptic processes, in particular how they relate to complex behaviour, remain elusive. the genomes of flies, mosquitoes, the honeybee and the beetle are now fully sequenced and span an evolutionary breadth of about 350 million years; this provides a unique opportunity to conduct a comparative genomics study of the synapse.200818257909
blood coagulation, inflammation, and malaria.malaria remains a highly prevalent disease in more than 90 countries and accounts for at least 1 million deaths every year. plasmodium falciparum infection is often associated with a procoagulant tonus characterized by thrombocytopenia and activation of the coagulation cascade and fibrinolytic system; however, bleeding and hemorrhage are uncommon events, suggesting that a compensated state of blood coagulation activation occurs in malaria. this article (i) reviews the literature related to blood ...200818260002
co-circulating microorganisms in questing ixodes scapularis nymphs in maryland.ixodes scapularis can be infected with borrelia burgdorferi, anaplasma phagocytophilum, bartonella spp., babesia microti, and rickettsia spp., including spotted-fever group rickettsia. as all of these microorganisms have been reported in maryland, the potential for these ticks to have concurrent infections exists in this region. to assess the frequency of these complex infections, 348 i. scapularis nymphs collected in 2003 were screened for these microorganisms by pcr with positives being confir ...200718260514
host-seeking behavior of ixodes pacificus (acari: ixodidae) nymphs in relation to environmental parameters in dense-woodland and woodland-grass habitats.in the far-western united states, the bacteria that cause lyme disease (borrelia burgdorferi, bb) and human granulocytic anaplasmosis (anaplasma phagocytophilum, ap) are transmitted by the western black-legged tick (ixodes pacificus). in a dense woodland, human behaviors involving contact with wood were recently found to pose greater risk for encountering i. pacificus nymphs than behaviors entailing exclusive exposure to leaf litter. a four-year follow-up study was undertaken in the same woodlan ...200718260527
genomic resources for invertebrate vectors of human pathogens, and the role of vectorbase.high-throughput genome sequencing techniques have now reached vector biology with an emphasis on those species that are vectors of human pathogens. the first mosquito to be sequenced was anopheles gambiae, the vector for plasmodium parasites that cause malaria. further mosquitoes have followed: aedes aegypti (yellow fever and dengue fever vector) and culex pipiens (lymphatic filariasis and west nile fever). species that are currently in sequencing include the body louse pediculus humanus (typhus ...200918262474
salivating for knowledge: potential pharmacological agents in tick saliva. 200818271624
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
anaplasma phagocytophilum msp2(p44)-18 predominates and is modified into multiple isoforms in human myeloid cells.anaplasma phagocytophilum is the etiologic agent of human granulocytic anaplasmosis. msp2(p44), the bacterium's major surface protein, is encoded by a paralogous gene family and has been implicated in a variety of pathobiological processes, including antigenic variation, host adaptation, adhesion, porin activity, and structural integrity. the consensus among several studies performed at the dna and rna levels is that a heterogeneous mix of a limited number of msp2(p44) transcripts is expressed b ...200818285495
isolation, cloning and structural characterisation of boophilin, a multifunctional kunitz-type proteinase inhibitor from the cattle tick.inhibitors of coagulation factors from blood-feeding animals display a wide variety of structural motifs and inhibition mechanisms. we have isolated a novel inhibitor from the cattle tick boophilus microplus, one of the most widespread parasites of farm animals. the inhibitor, which we have termed boophilin, has been cloned and overexpressed in escherichia coli. mature boophilin is composed of two canonical kunitz-type domains, and inhibits not only the major procoagulant enzyme, thrombin, but i ...200818286181
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
a novel mechanism of complement inhibition unmasked by a tick salivary protein that binds to properdin.ixodes scapularis salivary protein 20 (salp20) is a member of the ixodes scapularis anti-complement protein-like family of tick salivary proteins that inhibit the alternative complement pathway. in this study, we demonstrate that the target of salp20 is properdin. properdin is a natural, positive regulator of the alternative pathway that binds to the c3 convertase, stabilizing the molecule. salp20 directly bound to and displaced properdin from the c3 convertase. displacement of properdin acceler ...200818322205
a tightly regulated surface protein of borrelia burgdorferi is not essential to the mouse-tick infectious cycle.borrelia burgdorferi synthesizes a variety of differentially regulated outer surface lipoproteins in the tick vector and in vertebrate hosts. among these is ospd, a protein that is highly induced in vitro by conditions that mimic the tick environment. using genetically engineered strains in which ospd is deleted, we demonstrate that this protein is not required for b. burgdorferi survival and infectivity in either the mouse or the tick. however, examination of both transcript levels and protein ...200818332210
climate change and infectious diseases in north america: the road ahead.global climate change is inevitable--the combustion of fossil fuels has resulted in a buildup of greenhouse gases within the atmosphere, causing unprecedented changes to the earth's climate. the fourth assessment report of the intergovernmental panel on climate change suggests that north america will experience marked changes in weather patterns in coming decades, including warmer temperatures and increased rainfall, summertime droughts and extreme weather events (e.g., tornadoes and hurricanes) ...018332386
rna interference in infectious tropical diseases.introduction of double-stranded rna (dsrna) into some cells or organisms results in degradation of its homologous mrna, a process called rna interference (rnai). the dsrnas are processed into short interfering rnas (sirnas) that subsequently bind to the rna-induced silencing complex (risc), causing degradation of target mrnas. because of this sequence-specific ability to silence target genes, rnai has been extensively used to study gene functions and has the potential to control disease pathogen ...018344671
profiling of proteolytic enzymes in the gut of the tick ixodes ricinus reveals an evolutionarily conserved network of aspartic and cysteine peptidases.abstract:200818348719
expression and porin activity of p28 and omp-1f during intracellular ehrlichia chaffeensis development.ehrlichia chaffeensis, an obligatory intracellular gram-negative bacterium, must take up various nutrients and metabolic compounds because it lacks many genes involved in metabolism. nutrient uptake by a gram-negative bacterium occurs primarily through pores or channels in the bacterial outer membrane. here we demonstrate that isolated e. chaffeensis outer membranes have porin activities, as determined by a proteoliposome swelling assay. the activity was partially blocked by an antibody that rec ...200818359808
characterization and growth of polymorphic rickettsia felis in a tick cell line.morphological differentiation in some arthropod-borne bacteria is correlated with increased bacterial virulence, transmission potential, and/or as a response to environmental stress. in the current study, we utilized an in vitro model to examine rickettsia felis morphology and growth under various culture conditions and bacterial densities to identify potential factors that contribute to polymorphism in rickettsiae. we utilized microscopy (electron microscopy and immunofluorescence), genomic (pc ...200818359823
rnai-mediated gene silencing in tick synganglia: a proof of concept study.progress in generating comprehensive est libraries and genome sequencing is setting the stage for reverse genetic approaches to gene function studies in the blacklegged tick (ixodes scapularis). however, proving that rnai can work in nervous tissue has been problematic. developing an ability to manipulate gene expression in the tick synganglia likely would accelerate understanding of tick neurobiology. here, we assess gene silencing by rna interference in the adult female black-legged tick synga ...200818366768
a possible canine tick-bite reaction to ixodes muris.an airedale terrier became acutely ill following attachment of an ixodes muris tick. clinical signs waned within hours of tick removal, similar to a pattern previously documented in animals harboring i. muris. this supports the theory that i. muris can induce a noninfectious, severe inflammatory reaction in domestic animals.200818390101
phlebotomine salivas inhibit immune inflammation-induced neutrophil migration via an autocrine dc-derived pge2/il-10 sequential pathway.in the present study, we investigated whether saliva from phlebotomus papatasi and phlebotomus duboscqi inhibited antigen-induced neutrophil migration and the mechanisms involved in these effects. the pretreatment of immunized mice with salivary gland extracts (sge) of both phlebotomines inhibited ova challenge-induced neutrophil migration and release of the neutrophil chemotactic mediators, mip-1alpha, tnf-alpha, and leukotriene b4 (ltb4). furthermore, sge treatment enhanced the production of a ...200818390928
herbivore benefits from vectoring plant virus through reduction of period of vulnerability to predation.herbivores can profit from vectoring plant pathogens because the induced defence of plants against pathogens sometimes interferes with the induced defence of plants against herbivores. plants can also defend themselves indirectly by the action of the natural enemies of the herbivores. it is unknown whether the defence against pathogens induced in the plant also interferes with the indirect defence against herbivores mediated via the third trophic level. we previously showed that infection of pla ...200818392858
a novel sine family occurs frequently in both genomic dna and transcribed sequences in ixodid ticks of the arthropod sub-phylum chelicerata.reassociation kinetics and flow cytometry data indicate that ixodid tick genomes are large, relative to most arthropods, containing>or=10(9) base pairs. the molecular basis for this is unknown. we have identified a novel small interspersed element with features of a trna-derived sine, designated ruka, in genomic sequences of rhipicephalus appendiculatus and boophilus (rhipicephalus) microplus ticks. the sine was also identified in expressed sequence tag (est) databases derived from several tissu ...200818394826
presence of multiple variants of borrelia burgdorferi in the natural reservoir peromyscus leucopus throughout a transmission season.white-footed mice (peromyscus leucopus) serve as the principal reservoir for borrelia burgdorferi and have been shown to remain infected for life. complex infections with multiple genetic variants of b. burgdorferi occur in mice through multiple exposures to infected ticks or through exposure to ticks infected with multiple variants of b. burgdorferi. using a combination of cloning and single strand conformation polymorphism (sscp), b. burgdorferi ospc variation was assessed in serial samples co ...200818399776
identification of rickettsia felis in the salivary glands of cat fleas.rickettsia felis, a flea-associated rickettsial pathogen, has been identified in many tissues, including the digestive and reproductive tissues, within the cat flea, ctenocephalides felis. we utilized transmission electron microscopy and polymerase chain reaction to identify r. felis in the salivary glands of fed fleas and further define the distribution of r. felis within the arthropod host. we identified rickettsia-like organisms in salivary glands using electron microscopy. sequence analysis ...200818399779
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
emerging pathogens: challenges and successes of molecular diagnostics.more than 50 emerging and reemerging pathogens have been identified during the last 40 years. until 1992 when the institute of medicine issued a report that defined emerging infectious diseases, medicine had been complacent about such infectious diseases despite the alarm bells of infections with human immunodeficiency virus. molecular tools have proven useful in discovering and characterizing emerging viruses and bacteria such as sin nombre virus (hantaviral pulmonary syndrome), hepatitis c vir ...200818403608
cellular and molecular characterization of an embryonic cell line (bme26) from the tick rhipicephalus (boophilus) microplus.the cellular and molecular characteristics of a cell line (bme26) derived from embryos of the cattle tick rhipicephalus (boophilus) microplus were studied. the cells contained glycogen inclusions, numerous mitochondria, and vesicles with heterogeneous electron densities dispersed throughout the cytoplasm. vesicles contained lipids and sequestered palladium meso-porphyrin (pd-mp) and rhodamine-hemoglobin, suggesting their involvement in the autophagic and endocytic pathways. the cells phagocytose ...200818405834
genome-wide screen for temperature-regulated genes of the obligate intracellular bacterium, rickettsia typhi.the ability of rickettsiae to survive in multiple eukaryotic host environments provides a good model for studying pathogen-host molecular interactions. rickettsia typhi, the etiologic agent of murine typhus, is a strictly intracellular gram negative alpha-proteobacterium, which is transmitted to humans by its arthropod vector, the oriental rat flea, xenopsylla cheopis. thus, r. typhi must cycle between mammalian and flea hosts, two drastically different environments. we hypothesize that temperat ...200818412961
the evolution of protostome gata factors: molecular phylogenetics, synteny, and intron/exon structure reveal orthologous relationships.invertebrate and vertebrate gata transcription factors play important roles in ectoderm and mesendoderm development, as well as in cardiovascular and blood cell fate specification. however, the assignment of evolutionarily conserved roles to gata homologs requires a detailed framework of orthologous relationships. although two distinct classes, gata123 and gata456, have been unambiguously recognized among deuterostome gata genes, it has been difficult to resolve exact orthologous relationships a ...200818412965
enhanced spatial models for predicting the geographic distributions of tick-borne pathogens.disease maps are used increasingly in the health sciences, with applications ranging from the diagnosis of individual cases to regional and global assessments of public health. however, data on the distributions of emerging infectious diseases are often available from only a limited number of samples. we compared several spatial modelling approaches for predicting the geographic distributions of two tick-borne pathogens: ehrlichia chaffeensis, the causative agent of human monocytotropic ehrlichi ...200818412972
immunity to distinct sand fly salivary proteins primes the anti-leishmania immune response towards protection or exacerbation of disease.leishmania parasites are transmitted in the presence of sand fly saliva. together with the parasite, the sand fly injects biologically active salivary components that favorably change the environment at the feeding site. exposure to bites or to salivary proteins results in immunity specific to these components. mice immunized with phlebotomus papatasi salivary gland homogenate (sgh) or pre-exposed to uninfected bites were protected against leishmania major infection delivered by needle inoculati ...200818414648
significantly improved accuracy of diagnosis of early lyme disease by peptide enzyme-linked immunosorbent assay based on the borreliacidal antibody epitope of borrelia burgdorferi ospc.highly specific borreliacidal antibodies are induced by infection with borrelia burgdorferi, and the immunodominant response during early lyme disease is specific for an epitope within the 7 amino acids nearest the c terminus of ospc. we evaluated the ability of an enzyme-linked immunosorbent assay (elisa) based on a synthetic peptide (ospc7) that matched the region to detect the response and compared the sensitivity during early lyme disease to that for an fda-approved western blot. when the op ...200818417666
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
comparative analysis of septic injury-inducible genes in phylogenetically distant model organisms of regeneration and stem cell research, the planarian schmidtea mediterranea and the cnidarian hydra vulgaris.the planarian schmidtea mediterranea and the cnidarian hydra vulgaris have emerged as valuable model organisms in regeneration and stem cell research because of their prominent ability to regenerate a complete organism from any small body fragment. under natural conditions wounding may result from predator attacks. these injuries open their innermost to a wide array of microbes present in the environment. therefore, we established the hypothesis that regeneration processes may be linked to or at ...200818439314
structure, function, and evolution of biogenic amine-binding proteins in soft ticks.two highly abundant lipocalins, monomine and monotonin, have been isolated from the salivary gland of the soft tick argas monolakensis and shown to bind histamine and 5-hydroxytryptamine (5-ht), respectively. the crystal structures of monomine and a paralog of monotonin were determined in the presence of ligands to compare the determinants of ligand binding. both the structures and binding measurements indicate that the proteins have a single binding site rather than the two sites previously des ...200818445596
stage-specific gene expression during urediniospore germination in puccinia striiformis f. sp tritici.puccinia striiformis f. sp. tritici is an obligate biotrophic pathogen that causes leaf stripe rust on wheat. although it is critical to understand molecular mechanisms of pathogenesis in the wheat stripe rust fungus for developing novel disease management strategies, little is known about its genome and gene functions due to difficulties in molecular studies with this important pathogen. to identify genes expressed during early infection stages, in this study we constructed a cdna library with ...200818447959
lyme disease in oregon.the incidence of lyme disease in oregon is calculated from cases reported to the oregon state health division. we reviewed the exposure history of reported cases of lyme disease and performed field surveys for infected ixodes pacificus ticks. the incidence of lyme disease correlated with the distribution of infected i. pacificus ticks.200818448697
essential protective role attributed to the surface lipoproteins of borrelia burgdorferi against innate defences.to initiate infection, a microbial pathogen must be able to evade innate immunity. here we show that the lyme disease spirochete borrelia burgdorferi depends on its surface lipoproteins for protection against innate defences. the deficiency for ospc, an abundantly expressed surface lipoprotein during early infection, led to quick clearance of b. burgdorferi after inoculation into the skin of scid mice. increasing expression of any of the four randomly chosen surface lipoproteins, ospa, ospe, vls ...200818452586
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
biology of infection with borrelia burgdorferi.the spirochete borrelia burgdorferi is a tick-borne obligate parasite whose normal reservoir is a variety of small mammals. although infection of these natural hosts does not lead to disease, infection of humans can result in lyme disease as a consequence of the human immunopathologic response to b burgdorferi. consistent with the pathogenesis of lyme disease, bacterial products that allow b burgdorferi to replicate and survive seem to be primarily what is required for the bacterium to cause dis ...200818452798
molecular detection of bartonella schoenbuchensis from ectoparasites of deer in massachusetts.deer keds (lipoptena cervi) are thought to have been introduced into new england from europe during the 1800 s. we sought to determine whether l. cervi from massachusetts deer contained evidence of infection by bartonella schoenbuchensis, which appears to be maintained by l. cervi in europe. five of 6 keds were found to contain b. schoenbuchensis dna, and 2 deer ticks cofeeding on deer with such keds did as well. the detection of bartonella dna in deer ticks probably represents contamination by ...200818454595
the propensity of different borrelia burgdorferi sensu stricto genotypes to cause disseminated infections in humans.lineages of borrelia burgdorferi, the bacterium that causes lyme disease, can be characterized by distinct alleles at the outer surface protein c (ospc) locus. the lineages marked by ospc genotypes have been shown to be differentially invasive in different species of mammals, including humans; genotypes a, b, i, and k effectively disseminate to human blood and cerebrospinal fluid. in this report, we extend the sample of genotypes isolated from human blood to include genotypes n, h, c, m, and d, ...200818458317
verification and dissection of the ospc operator by using flab promoter as a reporter in borrelia burgdorferi.the lyme disease spirochete borrelia burgdorferi must repress expression of outer surface protein c (ospc) to effectively evade specific humoral immunity and to establish persistent infection. this ability largely relies upon a regulatory element, the only operator that has been reported in spirochetal bacteria. immediately upstream of the ospc promoter, two sets of inverted repeats (irs) constitute small and large palindromes, in which the right ir of the large palindrome contains the left ir o ...200818479884
a cysteine protease is critical for babesia spp. transmission in haemaphysalis ticks.vector ticks possess a unique system that enables them to digest large amounts of host blood and to transmit various animal and human pathogens, suggesting the existence of evolutionally acquired proteolytic mechanisms. we report here the molecular and reverse genetic characterization of a multifunctional cysteine protease, longipain, from the babesial parasite vector tick haemaphysalis longicornis. longipain shares structural similarity with papain-family cysteine proteases obtained from invert ...200818483546
bioinformatic analysis suggests that the orbivirus vp6 cistron encodes an overlapping gene.the genus orbivirus includes several species that infect livestock - including bluetongue virus (btv) and african horse sickness virus (ahsv). these viruses have linear dsrna genomes divided into ten segments, all of which have previously been assumed to be monocistronic.200818489030
insight into the sialome of the castor bean tick, ixodes ricinus.in recent years, there have been several sialome projects revealing transcripts expressed in the salivary glands of ticks, which are important vectors of several human diseases. here, we focused on the sialome of the european vector of lyme disease, ixodes ricinus.200818489795
transfusion-associated babesiosis with an atypical time course after nonmyeloablative transplantation for sickle cell disease. 018490697
neuropeptide discovery in ixodoidea: an in silico investigation using publicly accessible expressed sequence tags.the ixodoidea (ticks) are important vectors in the transmission of many human diseases; for example, the blacklegged tick ixodes scapularis is the major vector in the transmission of lyme disease, the most frequently reported vector-borne illness in the united states. the development of expressed sequence tags (ests) for ixodoidean cdna libraries, and their public deposition, has generated a rich resource for protein discovery in members of this taxon, thereby providing an opportunity for better ...200818495123
risk maps for range expansion of the lyme disease vector, ixodes scapularis, in canada now and with climate change.lyme disease is the commonest vector-borne zoonosis in the temperate world, and an emerging infectious disease in canada due to expansion of the geographic range of the tick vector ixodes scapularis. studies suggest that climate change will accelerate lyme disease emergence by enhancing climatic suitability for i. scapularis. risk maps will help to meet the public health challenge of lyme disease by allowing targeting of surveillance and intervention activities.200818498647
molecular evolution of cide family proteins: novel domain formation in early vertebrates and the subsequent divergence.cide family proteins including cidea, cideb and cidec/fsp27, contain an n-terminal cide-n domain that shares sequence similarity to the n-terminal cad domain (ncd) of dna fragmentation factors dffa/dff45/icad and dffb/dff40/cad, and a unique c-terminal cide-c domain. we have previously shown that cide proteins are newly emerged regulators closely associated with the development of metabolic diseases such as obesity, diabetes and liver steatosis. they modulate many metabolic processes such as lip ...200818500987
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
gene silencing in phlebotomine sand flies: xanthine dehydrogenase knock down by dsrna microinjections.lutzomyia longipalpis are vectors of medically important visceral leishmaniasis in south america. blood-fed adult females digest large amounts of protein, and xanthine dehydrogenase is thought to be a key enzyme involved in protein catabolism through the production of urate. large amounts of heme are also released during digestion with potentially damaging consequences, as heme can generate oxygen radicals that damage lipids, proteins and nucleic acids. however, urate is an antioxidant that may ...200818510977
pattern of proinflammatory cytokine induction in raw264.7 mouse macrophages is identical for virulent and attenuated borrelia burgdorferi.lyme disease pathogenesis results from a complex interaction between borrelia burgdorferi and the host immune system. the intensity and nature of the inflammatory response of host immune cells to b. burgdorferi may be a determining factor in disease progression. gene array analysis was used to examine the expression of genes encoding cytokines, chemokines, and related factors in the joint tissue of infected c3h/hej mice and in a murine macrophage-like cell line in response to a disseminating or ...200818523297
intracellular infection of tick cell lines by the entomopathogenic fungus metarhizium anisopliae.several fungal pathogens are able to enter and persist within eukaryotic cells as part of their infectious life cycle. metarhizium anisopliae is a saprophytic entomopathogenic fungus virulent towards numerous tick species, including those within the genera ixodes and amblyomma. infection of the target organism by this fungus proceeds via several steps, including adhesion and penetration of the host cuticle, proliferation within tissues and the haemolymph, and eventual eruption through the host c ...200818524924
estimating populations of adult ixodes scapularis in mississippi using a sequential bayesian algorithm.a sequential bayesian algorithm and accompanying computer program were developed and validated to estimate population numbers of adult blacklegged tick, ixodes scapularis say, using mark-release-recapture methodology in field plots in central mississippi. in fieldwork, data taken in february 2005 in a 1-ha plot yielded an estimate of 317 adult i. scapularis per ha data from another field plot in 2006, 3 km away, yielded an estimate of 280 adult i. scapularis per ha the number of ticks collected ...200818533452
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
transcriptome analysis of loxosceles laeta (araneae, sicariidae) spider venomous gland using expressed sequence tags.the bite of spiders belonging to the genus loxosceles can induce a variety of clinical symptoms, including dermonecrosis, thrombosis, vascular leakage, haemolysis, and persistent inflammation. in order to examine the transcripts expressed in venom gland of loxosceles laeta spider and to unveil the potential of its products on cellular structure and functional aspects, we generated 3,008 expressed sequence tags (ests) from a cdna library.200818547439
essential role of the response regulator rrp2 in the infectious cycle of borrelia burgdorferi.alteration of surface lipoprotein profiles is a key strategy that the lyme disease pathogen, borrelia burgdorferi, has evolved to be maintained within its enzootic cycle between arthropods and mammals. accumulated evidence indicates that the central regulatory pathway controlling differential gene expression by b. burgdorferi is the rpon-rpos pathway (the sigma(54)-sigma(s) sigma factor cascade). it was previously shown that activation of the rpon-rpos pathway is controlled by rrp2, a two-compon ...200818573895
novel peptide marker corresponding to salivary protein gsg6 potentially identifies exposure to anopheles bites.in order to improve malaria control, and under the aegis of who recommendations, many efforts are being devoted to developing new tools for identifying geographic areas with high risk of parasite transmission. evaluation of the human antibody response to arthropod salivary proteins could be an epidemiological indicator of exposure to vector bites, and therefore to risk of pathogen transmission. in the case of malaria, which is transmitted only by anopheline mosquitoes, maximal specificity could ...200818575604
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
expressed sequence tags from peromyscus testis and placenta tissue: analysis, annotation, and utility for mapping.mice of the genus peromyscus are found in nearly every habitat from alaska to central america and from the atlantic to the pacific. they provide an evolutionary outgroup to the mus/rattus lineage and serve as an intermediary between that lineage and humans. although peromyscus has been studied extensively under both field and laboratory conditions, research has been limited by the lack of molecular resources. genes associated with reproduction typically evolve rapidly and thus are excellent sour ...200818577228
transmission of bartonella henselae by ixodes ricinus.bartonella spp. are facultative intracellular bacteria associated with several emerging diseases in humans and animals. b. henselae causes cat-scratch disease and is increasingly associated with several other syndromes, particularly ocular infections and endocarditis. cats are the main reservoir for b. henselae and the bacteria are transmitted to cats by cat fleas. however, new potential vectors are suspected of transmitting b. henselae, in particular, ixodes ricinus, the most abundant ixodid ti ...200818598628
wide distribution of a high-virulence borrelia burgdorferi clone in europe and north america.the a and b clones of borrelia burgdorferi sensu stricto, distinguished by outer surface protein c (ospc) gene sequences, are commonly associated with disseminated lyme disease. to resolve phylogenetic relationships among isolates, we sequenced 68 isolates from europe and north america at 1 chromosomal locus (16s-23s ribosomal rna spacer) and 3 plasmid loci (ospc,dbpa, and bbd14). the ospc-a clone appeared to be highly prevalent on both continents, and isolates of this clone were uniform in dna ...200818598631
growth of tick-borne encephalitis virus (european subtype) in cell lines from vector and non-vector ticks.we undertook a comparative study of the susceptibility of different tick cell lines to infection with the european subtype of tick-borne encephalitis virus (tbev), prototype strain neudoerfl. the growth of tbev was investigated in lines derived from vector ixodes ricinus l. ticks (ire/ctvm18, 19, and 20), as well as non-vector ticks, namely ixodes scapularis say (ide2), boophilus microplus canestrini (bme/ctvm2), hyalomma anatolicum anatolicum koch (hae/ctvm9), rhipicephalus appendiculatus neuma ...200818602711
a survey for infection with dirofilaria immitis, ehrlichia canis, borrelia burgdorferi, and babesia canis in feral and client-owned dogs in the turks and caicos islands, british west indies.the frequency of infection with dirofilaria immitis and babesia canis and seropositivity to ehrlichia canis and borrelia burgdorferi in feral and client-owned dogs was determined. feral dogs were 14.8 and 11.2 times more likely to be seropositive to d. immitis and e. canis, respectively, than were client-owned dogs. none of the dogs tested positive for b. burgdorferi or b. canis.200818624070
suppression of cell proliferation and cytokine expression by hl-p36, a tick salivary gland-derived protein of haemaphysalis longicornis.previously, a putative immunosuppressant-coding gene was identified from a complementary dna library derived from the salivary glands of partially-fed haemaphysalis longicornis. using real-time polymerase chain reaction, the gene was shown to be predominantly expressed during blood feeding with the site of expression being mainly in the salivary glands; this was confirmed by western blotting analysis. to investigate the function of this novel protein, in this study, we examined the proliferative ...200918624730
outlining eicosanoid biosynthesis in the crustacean daphnia.eicosanoids are biologically active, oxygenated metabolites of three c20 polyunsaturated fatty acids. they act as signalling molecules within the autocrine or paracrine system in both vertebrates and invertebrates mainly functioning as important mediators in reproduction, the immune system and ion transport. the biosynthesis of eicosanoids has been intensively studied in mammals and it is known that they are synthesised from the fatty acid, arachidonic acid, through either the cyclooxygenase (co ...200818625039
bartonella sp. bacteremia in patients with neurological and neurocognitive dysfunction.we detected infection with a bartonella species (b. henselae or b. vinsonii subsp. berkhoffii) in blood samples from six immunocompetent patients who presented with a chronic neurological or neurocognitive syndrome including seizures, ataxia, memory loss, and/or tremors. each of these patients had substantial animal contact or recent arthropod exposure as a potential risk factor for bartonella infection. additional studies should be performed to clarify the potential role of bartonella spp. as a ...200818632903
oral immunization with recombinant lactobacillus plantarum induces a protective immune response in mice with lyme disease.mucosal immunization is advantageous over other routes of antigen delivery because it can induce both mucosal and systemic immune responses. our goal was to develop a mucosal delivery vehicle based on bacteria generally regarded as safe, such as lactobacillus spp. in this study, we used the lyme disease mouse model as a proof of concept. we demonstrate that an oral vaccine based on live recombinant lactobacillus plantarum protects mice from tick-transmitted borrelia burgdorferi infection. our me ...200818632920
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
relapsing fever spirochetes retain infectivity after prolonged in vitro cultivation.borrelia hermsii and borrelia burgdorferi, two closely related spirochetes, are the etiological agents of tick-borne relapsing fever and lyme disease, respectively. previous studies have shown the loss of infectivity of b. burgdorferi is associated with in vitro cultivation. this diminished infectivity of b. burgdorferi has occurred as early as three in vitro passages, and the loss of plasmids have been observed with these less virulent to noninfective cultures. the effects of long-term in vitro ...200818637723
north american encephalitic arboviruses.arboviruses continue to be a major cause of encephalitis in north america, and west nile virus neuroinvasive disease is now the dominant cause of encephalitis. transmission to humans of north american arboviruses occurs by infected mosquitoes or ticks. most infections are asymptomatic or produce a flulike illness. rapid serum or cerebrospinal fluid igm antibody capture elisa assays are available to diagnosis the acute infection for all north american arboviruses. unfortunately, no antiviral drug ...200818657724
differential expression of a putative card-like transcriptional regulator, ltpa, in borrelia burgdorferi.the availability of microbial genome information has provided a fruitful opportunity for studying regulatory networks in a variety of pathogenic bacteria. in an initial effort to elucidate regulatory networks potentially involved in differential gene expression by the lyme disease pathogen borrelia burgdorferi, we have been investigating the functions and regulation of putative transcriptional regulatory factors predicted to be encoded within the b. burgdorferi genome. herein we report the regul ...200818663002
whole genome transcription profiling of anaplasma phagocytophilum in human and tick host cells by tiling array analysis.anaplasma phagocytophilum (ap) is an obligate intracellular bacterium and the agent of human granulocytic anaplasmosis, an emerging tick-borne disease. ap alternately infects ticks and mammals and a variety of cell types within each. understanding the biology behind such versatile cellular parasitism may be derived through the use of tiling microarrays to establish high resolution, genome-wide transcription profiles of the organism as it infects cell lines representative of its life cycle (tick; ...200818671858
evidence of the role of tick subolesin in gene expression.subolesin is an evolutionary conserved protein that was discovered recently in ixodes scapularis as a tick protective antigen and has a role in tick blood digestion, reproduction and development. in other organisms, subolesin orthologs may be involved in the control of developmental processes. because of the profound effect of subolesin knockdown in ticks and other organisms, we hypothesized that subolesin plays a role in gene expression, and therefore affects multiple cellular processes. the ob ...200818673577
a novel clade of cysteinyl leukotriene scavengers in soft ticks.inflammation is an important vertebrate defense mechanism against ecto-parasites for which ticks have evolved numerous mechanisms of modulation. am-33 and tsgp4, related lipocalins from the soft ticks argas monolakensis and ornithodoros savignyi bind cysteinyl leukotrienes with high affinity as measured by isothermal titration calorimetry. this was confirmed in a smooth muscle bioassay that measured contraction of guinea pig ileum induced by leukotriene c4 where both proteins inhibited contracti ...200818675910
identification of residual blood proteins in ticks by mass spectrometry proteomics.mass spectrometry-based proteomics of individual ticks demonstrated persistence of mammalian host blood components, including alpha- and beta-globin chains, histones, and mitochondrial enzymes, in ixodes scapularis and amblyomma americanum ticks for months after molting. residual host proteins may identify sources of infection for ticks.200818680654
function, mechanism and evolution of the moubatin-clade of soft tick lipocalins.the "moubatin-clade" of soft tick lipocalins, although monophyletic, shows clear signs of paralogy as indicated by the various functions associated with this protein family. this includes anti-platelet (moubatin), anti-complement (omci) and toxic (tsgp2) activities in the vertebrate host. in order to understand the evolution of function and how it relates to the various paralogs in this clade, we characterized a number of different proteins in regard to undefined function and mechanism. by utili ...200818694828
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
relaxation of selective constraints causes independent selenoprotein extinction in insect genomes.selenoproteins are a diverse family of proteins notable for the presence of the 21st amino acid, selenocysteine. until very recently, all metazoan genomes investigated encoded selenoproteins, and these proteins had therefore been believed to be essential for animal life. challenging this assumption, recent comparative analyses of insect genomes have revealed that some insect genomes appear to have lost selenoprotein genes.200818698431
total, membrane, and immunogenic proteomes of macrophage- and tick cell-derived ehrlichia chaffeensis evaluated by liquid chromatography-tandem mass spectrometry and maldi-tof methods.ehrlichia chaffeensis, a tick-transmitted rickettsial, is the causative agent of human monocytic ehrlichiosis. to examine protein expression patterns, we analyzed total, membrane, and immunogenic proteomes of e. chaffeensis originating from macrophage and tick cell cultures. total proteins resolved by one-dimensional gel electrophoresis and subjected to liquid chromatography-electrospray ionization ion trap mass spectrometry allowed identification of 134 and 116 proteins from macrophage- and tic ...200818710870
borrelia burgdorferi complement regulator-acquiring surface protein 2 does not contribute to complement resistance or host infectivity.borrelia burgdorferi, the pathogen of lyme disease, cycles in nature through ixodes ticks and mammalian hosts. at least five complement regulator-acquiring surface proteins (bbcrasps) are produced by b. burgdorferi, which are thought to assist spirochetes in host immune evasion. recent studies established that bbcrasp-2 is preferentially expressed in mammals, and elicits robust antibody response in infected hosts, including humans. we show that bbcrasp-2 is ubiquitously expressed in diverse muri ...200818714378
evidence of the importance of host habitat use in predicting the dilution effect of wild boar for deer exposure to anaplasma spp.foci of tick-borne pathogens occur at fine spatial scales, and depend upon a complex arrangement of factors involving climate, host abundance and landscape composition. it has been proposed that the presence of hosts that support tick feeding but not pathogen multiplication may dilute the transmission of the pathogen. however, models need to consider the spatial component to adequately explain how hosts, ticks and pathogens are distributed into the landscape. in this study, a novel, lattice-deri ...200818714379
prolonged efficacy of ir3535 repellents against mosquitoes and blacklegged ticks in north america.here i report the first findings of consistently high, long-duration efficacy of ir3535 (ethyl butyl acetyl aminopropionate) formulations in the united states. i tested novel, controlled-release formulations of ir3535, at 10% in lotion and at 20% in pump spray and aerosol, against mosquitoes in the field and blacklegged ticks in the laboratory. these were also the first studies to be conducted under the authority of the u.s. environmental protection agency's human studies rule of 2006, and the p ...200818714871
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
establishment of a large semi-field system for experimental study of african malaria vector ecology and control in tanzania.medical entomologists increasingly recognize that the ability to make inferences between laboratory experiments of vector biology and epidemiological trends observed in the field is hindered by a conceptual and methodological gap occurring between these approaches which prevents hypothesis-driven empirical research from being conducted on relatively large and environmentally realistic scales. the development of semi-field systems (sfs) has been proposed as the best mechanism for bridging this ga ...200818715508
serum antibodies to west nile virus in naturally exposed and vaccinated horses.a polyvalent elisa and plaque reduction neutralization tests (prnts) were used to measure serum antibodies to west nile virus (wnv) in horses naturally exposed to or vaccinated against this flavivirus in connecticut and new york state, usa. relying on a prnt as a 'gold standard', the main objective was to validate a modified elisa containing a recombinant wnv envelope protein antigen. it was also important to assess specificity by testing sera from horses that had other, undiagnosed illnesses. s ...200818719177
transgene expression and silencing in a tick cell line: a model system for functional tick genomics.the genome project of the black legged tick, ixodes scapularis, provides sequence data for testing gene function and regulation in this important pathogen vector. we tested sleeping beauty (sb), a tc1/mariner group transposable element, and cationic lipid-based transfection reagents for delivery and genomic integration of transgenes into i. scapularis cell line ise6. plasmid dna and dsrna were effectively transfected into ise6 cells and they were successfully transformed to express a red fluores ...200818722527
transcriptional up-regulation of disk abalone selenium dependent glutathione peroxidase by h(2)o(2) oxidative stress and vibrio alginolyticus bacterial infection.selenium dependent glutathione peroxidase (se-gpx) belongs to the family of selenoprotein, which acts mainly as an antioxidant in the cellular defence system. we have identified se-gpx full length cdna from disk abalone (haliotis discus discus) designated as abse-gpx. it has a characteristic codon at (223)tga(225) that corresponds to selenocysteine (sec) amino acid as u(75). the full length cdna consists of 675 bp, an open reading frame encoding 225 amino acids. sequence characterization reveale ...200818722791
the multiple-wing-hairs gene encodes a novel gbd-fh3 domain-containing protein that functions both prior to and after wing hair initiation.the frizzled signaling/signal transduction pathway controls planar cell polarity (pcp) in both vertebrates and invertebrates. epistasis experiments argue that in the drosophila epidermis multiple wing hairs (mwh) acts as a downstream component of the pathway. the pcp proteins accumulate asymmetrically in pupal wing cells where they are thought to form distinct protein complexes. one is located on the distal side of wing cells and a second on the proximal side. this asymmetric protein accumulatio ...200818723886
multiple causes of variable tick burdens on small-mammal hosts.blood meals by blacklegged ticks (ixodes scapularis) on vertebrate hosts serve to transmit the agents of several zoonotic diseases, including lyme disease, human babesiosis, and human granulocytic anaplasmosis, between host and tick. if ticks are aggregated on hosts, a small proportion of hosts may be responsible for most transmission events. therefore, a key element in understanding and controlling the transmission of these pathogens is identifying the group(s) or individuals feeding a dispropo ...200818724736
effect of borrelia burgdorferi genotype on the sensitivity of c6 and 2-tier testing in north american patients with culture-confirmed lyme disease.a potential concern with any serologic test to detect antibodies to borrelia burgdorferi is whether the epitopes incorporated in the test provide sufficient cross-reactivity to detect infection with all of the pathogenic strains of the species. this is a particular concern for the c6 test, which is based on reactivity to a single peptide.200818724824
borrelia burgdorferi lipoprotein bmpa activates pro-inflammatory responses in human synovial cells through a protein moiety.borrelia burgdorferi invasion of mammalian joints results in genesis of lyme arthritis. other than spirochete lipids, existence of protein antigens, which are abundant in joints and participate in b. burgdorferi-induced host inflammatory response, is unknown. here, we report that major products of the b. burgdorferi basic membrane protein (bmp) a/b operon that are induced in murine and human joints, possess inflammatory properties. compared to the wild type b. burgdorferi, an isogenic bmpa/b mut ...200818725314
an insight into the salivary transcriptome and proteome of the soft tick and vector of epizootic bovine abortion, ornithodoros coriaceus.the salivary glands of blood-sucking arthropods contain a redundant 'magic potion' that counteracts their vertebrate host's hemostasis, inflammation, and immunity. we here describe the salivary transcriptome and proteomics (sialome) of the soft tick ornithodoros coriaceus. the resulting analysis helps to consolidate the classification of common proteins found in both soft and hard ticks, such as the lipocalins, kunitz, cystatin, basic tail, hebraein, defensin, til domain, metalloprotease, 5'-nuc ...200818725333
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
prevention of lyme disease and other tick-borne infections.prevention is the best method for avoiding potentially serious complications of lyme and other tick-borne diseases. in this article, we discuss preventative measures that can be used by individuals or communities. among the topics discussed are personal protective measures, tick reduction, reservoir reduction, and vaccination. additionally, new preventative measures that are in development-including new lyme disease vaccines, antitick vaccines, and reservoir-targeted vaccination-are discussed.200818755380
tick-borne relapsing fever.each year, many residents of and visitors to endemic regions of the western united states are exposed to the tick vectors of tick-borne relapsing fever (tbrf), ornithodoros hermsi, ornithodoros turicata, or ornithodoros parkeri. this disease is remarkable because the human host is unaware of the tick bite, usually becomes very ill, may experience an exacerbation of symptoms rather than improvement shortly after beginning appropriate treatment, and, despite often high numbers of the etiologic org ...200818755384
human babesiosis.human babesiosis is an emerging intraerythrocytic infection caused by protozoal parasites transmitted by ixodid ticks. babesiosis is endemic in the northeastern and upper midwestern regions of the united states and is found sporadically in other parts of the united states, europe, asia, africa, and south america. babesial infections range from asymptomatic to severe and occasionally are fatal. specific laboratory diagnosis of babesial infection is made by morphologic examination of giemsa-staine ...200818755385
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