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arthropod-borne disease in canada: a clinician's perspective from the 'cold zone'.arthropod-borne diseases do not occur commonly in canada. nevertheless, canadians run the risk of contracting certain infections within the country during arthropod season, as well as when travelling abroad. therefore, it is important that clinicians are aware of the possible occurrence of arthropod-borne diseases, and consider them in their differential diagnoses. the present review is divided into two sections: arthropod-borne diseases or disease agents documented in canada, and imported arthr ...020177520
ecological niche modeling of lyme disease in british columbia, canada.the purpose of this study was to describe the geographic distribution and model the ecological niche for borrelia burgdorferi (johnson, schmidt, hyde, steigerwaldt & brenner), ixodes pacificus (cooley & kohls), and ixodes angustus (neumann), the bacterium and primary tick vectors for lyme disease, in british columbia (bc), canada. we employed a landscape epidemiology approach using geographic information systems mapping and ecological niche modeling (genetic algorithm for rule-set prediction) to ...201020180315
a 60-year meta-analysis of tick paralysis in the united states: a predictable, preventable, and often misdiagnosed poisoning.tick paralysis (tp) is a neurotoxic poisoning primarily afflicting young girls in endemic regions. recent case series of tp have described increasing misdiagnoses of tp as the guillain-barré syndrome (gbs). a meta-analysis of the scientific literature was conducted using internet search engines to assess the evolving epidemiology of tp. fifty well-documented cases of tp were analyzed over the period 1946-2006. cases were stratified by demographics, clinical manifestations, and outcomes. misdiagn ...201020186584
horizontal and vertical movements of host-seeking ixodes pacificus (acari: ixodidae) nymphs in a hardwood forest.the nymph of the western black-legged tick (ixodes pacificus) is an important bridging vector of the lyme disease spirochete (borrelia burgdorferi) to humans in the far-western united states. the previously unknown dispersal capabilities of this life stage were studied in relation to logs, tree trunks, and adjacent leaf-litter areas in a mixed hardwood forest using mark-release-recapture methods. in two spatially and temporally well-spaced trials involving logs, the estimated mean distances that ...200920352083
community ecology and disease risk: lizards, squirrels, and the lyme disease spirochete in california, usa.vector-borne zoonotic diseases are often maintained in complex transmission cycles involving multiple vertebrate hosts and their arthropod vectors. in the state of california, u.s.a., the spirochete borrelia burgdorferi, which causes lyme disease, is transmitted between vertebrate hosts by the western black-legged tick, ixodes pacificus. several mammalian species serve as reservoir hosts of the spirochete, but levels of tick infestation, reservoir competence, and borrelia-infection prevalence va ...201020380218
uncoordinated phylogeography of borrelia burgdorferi and its tick vector, ixodes scapularis.vector-borne microbes necessarily co-occur with their hosts and vectors, but the degree to which they share common evolutionary or biogeographic histories remains unexplored. we examine the congruity of the evolutionary and biogeographic histories of the bacterium and vector of the lyme disease system, the most prevalent vector-borne disease in north america. in the eastern and midwestern us, ixodes scapularis ticks are the primary vectors of borrelia burgdorferi, the bacterium that causes lyme ...201020394659
genotypic variation and mixtures of lyme borrelia in ixodes ticks from north america and europe.lyme disease, caused by various species of borrelia, is transmitted by ixodes ticks in north america and europe. studies have shown the genotype of borrelia burgdorferi sensu stricto (s.s.) or the species of b. burgdorferi sensu lato (s.l.) affects the ability of the bacteria to cause local or disseminated infection in humans.201020498837
factorial microarray analysis of zebra mussel (dreissena polymorpha: dreissenidae, bivalvia) adhesion.the zebra mussel (dreissena polymorpha) has been well known for its expertise in attaching to substances under the water. studies in past decades on this underwater adhesion focused on the adhesive protein isolated from the byssogenesis apparatus of the zebra mussel. however, the mechanism of the initiation, maintenance, and determination of the attachment process remains largely unknown.201020509938
human ehrlichiosis and anaplasmosis.human ehrlichiosis and anaplasmosis are acute febrile tick-borne diseases caused by various members of the genera ehrlichia and anaplasma (anaplasmataceae). human monocytotropic ehrlichiosis has become one of the most prevalent life-threatening tick-borne disease in the united states. ehrlichiosis and anaplasmosis are becoming more frequently diagnosed as the cause of human infections, as animal reservoirs and tick vectors have increased in number and humans have inhabited areas where reservoir ...201020513551
lyme disease.lyme disease, caused by the spirochete borrelia burgdorferi, is the most common vector-borne disease in the united states. the clinical presentation varies depending on the stage of the illness: early disease includes erthyma migrans, early disseminated disease includes multiple erythema migrans, meningitis, cranial nerve palsies, and carditis; late disease is primarily arthritis. the symptoms and signs of infection resolve in most patients after treatment with appropriate antimicrobials for 2 t ...201020513553
transmission cycles of borrelia burgdorferi and b. bissettii in relation to habitat type in northwestern california.this study was undertaken to determine which rodent species serve as primary reservoirs for the lyme disease spirochete borrelia burgdorferi in commonly occurring woodland types in inland areas of northwestern california, and to examine whether chaparral or grassland serve as source habitats for dispersal of b. burgdorferi- or b. bissettii-infected rodents into adjacent woodlands. the western gray squirrel (sciurus griseus) was commonly infected with b. burgdorferi in oak woodlands, whereas exam ...200920514140
lyme disease in canada: q & a for paediatricians. 200920514158
the expression of genes coding for distinct types of glycine-rich proteins varies according to the biology of three metastriate ticks, rhipicephalus (boophilus) microplus, rhipicephalus sanguineus and amblyomma cajennense.ticks secrete a cement cone composed of many salivary proteins, some of which are rich in the amino acid glycine in order to attach to their hosts' skin. glycine-rich proteins (grps) are a large family of heterogeneous proteins that have different functions and features; noteworthy are their adhesive and tensile characteristics. these properties may be essential for successful attachment of the metastriate ticks to the host and the prolonged feeding necessary for engorgement. in this work, we an ...201020529354
a spatially-explicit model of acarological risk of exposure to borrelia burgdorferi-infected ixodes pacificus nymphs in northwestern california based on woodland type, temperature, and water vapor.in the far-western united states, the nymphal stage of the western black-legged tick, ixodes pacificus, has been implicated as the primary vector to humans of borrelia burgdorferi sensu stricto (hereinafter referred to as b. burgdorferi), the causative agent of lyme borreliosis in north america. in the present study, we sought to determine if infection prevalence with b. burgdorferi in i. pacificus nymphs and the density of infected nymphs differ between dense-woodland types within mendocino cou ...201020532183
geographic differences in genetic locus linkages for borrelia burgdorferi.borrelia burdorferi genotype in the northeastern united states is associated with lyme borreliosis severity. analysis of dna sequences of the outer surface protein c gene and rrs-rrla intergenic spacer from extracts of ixodes spp. ticks in 3 us regions showed linkage disequilibrium between the 2 loci within a region but not consistently between regions.201020587192
differential impact of west nile virus on california birds.the strain of west nile virus (wnv) currently epidemic in north america contains a genetic mutation elevating its virulence in birds, especially species in the family corvidae. although dead american crows (corvus brachyrhynchos) have been the hallmark of the epidemic, the overall impact of wnv on north america's avifauna remains poorly understood and has not been addressed thoroughly in california. here, we evaluate variation by species in the effect of wnv on california birds from 2004 to 2007 ...200920589226
survival rates of immature ixodes pacificus (acari: ixodidae) ticks estimated using field-placed enclosures.granulocytic anaplasmosis (ga) and lyme borreliosis are emerging tick-borne diseases caused by infection with anaplasma phagocytophilum and borrelia burgdorferi, respectively, and maintained in rodent-ixodes spp. tick cycles, including i. pacificus in the western u.s. ixodes pacificus has a multiple-year life cycle and b. burgdorferi and a. phagocytophilum are transstadially, but not transovarially, transmitted within ticks, thus ticks function importantly in maintaining infection in nature. in ...201020618646
detection of lyme disease spirochete, borrelia burgdorferi sensu lato, including three novel genotypes in ticks (acari: ixodidae) collected from songbirds (passeriformes) across canada.lyme disease is reported across canada, but pinpointing the source of infection has been problematic. in this three-year, bird-tick-pathogen study (2004-2006), 366 ticks representing 12 species were collected from 151 songbirds (31 passerine species/subspecies) at 16 locations canada-wide. of the 167 ticks/pools tested, 19 (11.4%) were infected with borrelia burgdorferi sensu lato (s.l.). sequencing of the rrf-rrl intergenic spacer gene revealed four borrelia genotypes: b. burgdorferi sensu stri ...201020618658
invasion of mosquito salivary glands by malaria parasites: prerequisites and defense strategies.the interplay between vector and pathogen is essential for vector-borne disease transmission. dissecting the molecular basis of refractoriness of some vectors may pave the way to novel disease control mechanisms. a pathogen often needs to overcome several physical barriers, such as the peritrophic matrix, midgut epithelium and salivary glands. additionally, the arthropod vector elicites immune responses that can severely limit transmission success. one important step in the transmission of most ...201020621627
comparative microarray analysis of rhipicephalus (boophilus) microplus expression profiles of larvae pre-attachment and feeding adult female stages on bos indicus and bos taurus cattle.rhipicephalus (boophilus) microplus is an obligate blood feeder which is host specific to cattle. existing knowledge pertaining to the host or host breed effects on tick transcript expression profiles during the tick - host interaction is poor.201020637126
the dusky-footed woodrat (neotoma fuscipes) is susceptible to infection by anaplasma phagocytophilum originating from woodrats, horses, and dogs.the dusky-footed woodrat (neotoma fuscipes) is the putative reservoir for anaplasma phagocytophilum in the western united states based on high prevalence of a. phagocytophilum genetic material detected by polymerase chain reaction (pcr), high antibody prevalence, and infestation with the vector tick ixodes pacificus. following inoculation of nine wild-caught woodrats with woodrat-, canine-, or equine-origin a. phagocytophilum, all became pcr-positive and seroconverted. however, when pcr-positive ...201020688687
human granulocytic anaplasmosis: first reported case in canada.human granulocytic anaplasmosis (hga) is a tick-borne rickettsial infection of peripheral blood neutrophils caused by anaplasma phagocytophilum. while this infection is increasingly recognized as endemic throughout much of the united states, no canadian cases have been previously described, despite the agent being identified in canadian ticks. herein we present a case of hga acquired in an urban alberta centre. canadian physicians must be aware of the possibility of tick-borne rickettsial diseas ...200920808448
evolution and distribution of the ospc gene, a transferable serotype determinant of borrelia burgdorferi.borrelia burgdorferi, an emerging bacterial pathogen, is maintained in nature by transmission from one vertebrate host to another by ticks. one of the few antigens against which mammals develop protective immunity is the highly polymorphic ospc protein, encoded by the ospc gene on the cp26 plasmid. intragenic recombination among ospc genes is known, but the extent to which recombination extended beyond the ospc locus itself is undefined. we accessed and supplemented collections of dna sequences ...201020877579
effects of an invasive forest pathogen on abundance of ticks and their vertebrate hosts in a california lyme disease focus.invasive species, including pathogens, can have important effects on local ecosystems, including indirect consequences on native species. this study focuses on the effects of an invasive plant pathogen on a vertebrate community and ixodes pacificus, the vector of the lyme disease pathogen (borrelia burgdorferi) in california. phytophthora ramorum, the causative agent of sudden oak death, is a non-native pathogen killing trees in california and oregon. we conducted a multi-year study using a grad ...201020941513
rhipicephalus microplus salivary gland molecules induce differential cd86 expression in murine macrophages.abstract:201021054882
multilocus sequence analysis of borrelia bissettii strains from north america reveals a new borrelia species, borrelia kurtenbachii.using multilocus sequence analyses (mlsa), we investigated the phylogenetic relationship of spirochaete strains from north america previously assigned to the genospecies borrelia bissettii. we amplified internal fragments of 8 housekeeping genes (clpa, clpx, nifs, pepx, pyrg, recg, rplb, and uvra) located on the main linear chromosome by polymerase chain reaction. phylogenetic analysis of concatenated sequences of the 8 loci showed that the b. bissettii clade consisted of 4 closely related clust ...201021157575
a comparison of visual and flagging methods for estimating adult ixodes pacificus (acari: ixodidae) tick abundance. 201021175953
genetic diversity of borrelia burgdorferi and detection of b. bissettii-like dna in serum of north-coastal california residents.in north america, lyme borreliosis (lb) is a tick-borne disease caused by infection with the spirochete borrelia burgdorferi. we studied the genetic diversity of lb spirochetes in north-coastal california residents. spirochete dna was detected in 23.7% (27/114) of the study subjects using a pcr protocol optimized for increased sensitivity in human sera. californians were most commonly infected with b. burgdorferi ospc genotype a, a globally widespread spirochete associated with high virulence in ...201021177909
transfusion-transmitted babesia spp.: bull's-eye on babesia microti.babesia spp. are intraerythrocytic protozoan parasites of animals and humans that cause babesiosis, a zoonotic disease transmitted primarily by tick vectors. although a variety of species or types of babesia have been described in the literature as causing infection in humans, the rodent parasite babesia microti has emerged as the focal point of human disease, especially in the united states. not only has b. microti become established as a public health concern, this agent is increasingly being ...201121233506
diverse borrelia burgdorferi strains in a bird-tick cryptic cycle.the blacklegged tick ixodes scapularis is the primary vector of the most prevalent vector-borne zoonosis in north america, lyme disease (ld). enzootic maintenance of the pathogen borrelia burgdorferi by i. scapularis and small mammals is well documented, whereas its "cryptic" maintenance by other specialist ticks and wildlife hosts remains largely unexplored because these ticks rarely bite humans. we quantified b. burgdorferi infection in a cryptic bird-rabbit-tick cycle. furthermore, we explore ...201121257811
impact of the experimental removal of lizards on lyme disease risk.the distribution of vector meals in the host community is an important element of understanding and predicting vector-borne disease risk. lizards (such as the western fence lizard; sceloporus occidentalis) play a unique role in lyme disease ecology in the far-western united states. lizards rather than mammals serve as the blood meal hosts for a large fraction of larval and nymphal western black-legged ticks (ixodes pacificus-the vector for lyme disease in that region) but are not competent reser ...201121325326
influence of abiotic and environmental factors on the density and infection prevalence of ixodes pacificus (acari:ixodidae) with borrelia burgdorferi.the abiotic and biotic factors that govern the spatial distribution of lyme disease vectors are poorly understood. this study addressed the influence of abiotic and biotic environmental variables on ixodes pacificus cooley & kohls (acari:ixodidae) nymphs, because it is the primary vector of borrelia burgdorferi johnson, schmidt, hyde, steigerwaldt & brenner in the far-western united states. three metrics of lyme disease risk were evaluated: the density of nymphs, the density of infected nymphs, ...201121337944
differences in prevalence of borrelia burgdorferi and anaplasma spp. infection among host-seeking dermacentor occidentalis, ixodes pacificus, and ornithodoros coriaceus ticks in northwestern california.previous studies revealed that the pacific coast tick (dermacentor occidentalis) is infected occasionally with the agents of lyme disease (borrelia burgdorferi) or human granulocytic anaplasmosis (anaplasma phagocytophilum) and that it is an inefficient experimental vector of b. burgdorferi. the relationship of the pajahuello tick (ornithodoros coriaceus) to each of these bacterial zoonotic agents has not been reported. the primary bridging vector of both bacterial zoonotic agents to humans is t ...201021359090
molecular detection and identification of rickettsia species in ixodes pacificus in california.we amplified 16s rrna, glta, and ompa genes from ixodes pacificus by polymerase chain reaction. sequencing, blast analysis, and phylogenetic constructions indicated that two rickettsia phylotypes are present in i. pacificus. while phylotype g021 has high homology to ixodes scapularis endosymbiotic rickettsia, phylotype g022 is a deeply branched novel spotted fever group rickettsia.201121413886
nidicolous ticks of small mammals in anaplasma phagocytophilum-enzootic sites in northern california.ixodes spp. tick-borne zoonotic diseases are present across the holarctic in humans, domestic animals, and wildlife. small mammals are reservoirs for the rickettsial pathogen anaplasma phagocytophilum and tick vectors may include catholic-feeding bridge vectors as well as host-specialist or nidicolous ticks. far western north american communities in which a. phagocytophilum is maintained are complex ecologically, with multiple reservoir host and tick species, multiple strains of the bacterial pa ...201121686062
increasing incidence of ehrlichia chaffeensis and anaplasma phagocytophilum in the united states, 2000-2007.ehrlichia chaffeensis causes human monocytic ehrlichiosis, and anaplasma phagocytophilum causes human granulocytic anaplasmosis. these related tick-borne rickettsial organisms can cause severe and fatal illness. during 2000-2007, the reported incidence rate of e. chaffeensis increased from 0.80 to 3.0 cases/million persons/year. the case-fatality rate was 1.9%, and the hospitalization rate was 49%. during 2000-2007, the reported incidence of a. phagocytophilum increased from 1.4 to 3.0 cases/mil ...201121734137
mechanisms of obligatory intracellular infection with anaplasma phagocytophilum.anaplasma phagocytophilum persists in nature by cycling between mammals and ticks. human infection by the bite of an infected tick leads to a potentially fatal emerging disease called human granulocytic anaplasmosis. a. phagocytophilum is an obligatory intracellular bacterium that replicates inside mammalian granulocytes and the salivary gland and midgut cells of ticks. a. phagocytophilum evolved the remarkable ability to hijack the regulatory system of host cells. a. phagocytophilum alters vesi ...201121734244
temporal patterns of tick-borne granulocytic anaplasmosis in california.granulocytic anaplasmosis (ga) is a tick-borne emerging infectious disease caused by the bacterium anaplasma phagocytophilum. from fall 2005 to spring 2007, a. phagocytophilum infection prevalence in small mammals and tick abundance were monitored at 4 study sites in coastal california. the abundance of different life stages of questing ixodes pacificus ticks fluctuated seasonally with the number of adults peaking december to february, nymphs peaking may to july, and larvae peaking april to june ...201121771541
flab gene as a molecular marker for distinct identification of borrelia species in environmental samples by the pcr-restriction fragment length polymorphism method.a new protocol employing nested pcr-restriction fragment length polymorphism (rflp) based on the flab gene and two restriction enzymes was worked out. this protocol allows the identification of all borrelia species transmitted by ixodes ricinus in europe, including borrelia miyamotoi and 3 genetic variants of b. garinii. a dendrogram of flab sequence similarity was in accordance with rflp variants.201121841027
avian hosts of ixodes pacificus (acari: ixodidae) and the detection of borrelia burgdorferi in larvae feeding on the oregon junco.larval and nymphal western blacklegged tick, ixodes pacificus cooley & kohls (acari: ixodidae), were collected from birds, rodents, and lizards at quail ridge reserve located in napa county in northwestern california. species from three vertebrate classes were sampled simultaneously from two transects during two consecutive spring seasons. feeding larval and nymphal ticks were removed and preserved for counting, examination and testing for the presence of borrelia burgdorferi johnson, schmid, hy ...201121845945
An insight into the sialotranscriptome and proteome of the coarse bontlegged tick, Hyalomma marginatum rufipes.Ticks are mites specialized in acquiring blood from vertebrates as their sole source of food and are important disease vectors to humans and animals. Among the specializations required for this peculiar diet, ticks evolved a sophisticated salivary potion that can disarm their host's hemostasis, inflammation, and immune reactions. Previous transcriptome analysis of tick salivary proteins has revealed many new protein families indicative of fast evolution, possibly due to host immune pressure. The ...201121851864
tick cell lines for study of crimean-congo hemorrhagic fever virus and other arboviruses.abstract continuous cell lines derived from many of the vectors of tick-borne arboviruses of medical and veterinary importance are now available. their role as tools in arbovirus research to date is reviewed and their potential application in studies of tick cell responses to virus infection is explored, by comparison with recent progress in understanding mosquito immunity to arbovirus infection. a preliminary study of propagation of the human pathogen crimean-congo hemorrhagic fever virus (cc ...201121955214
Infection prevalences of common tick-borne pathogens in adult lone star ticks (Amblyomma americanum) and American dog ticks (Dermacentor variabilis) in Kentucky.Rocky Mountain spotted fever, Lyme disease, and ehrlichiosis are tick-borne diseases that are reported annually in Kentucky. We conducted a survey to describe infection prevalence of tick-borne pathogens in Amblyomma americanum and Dermacentor variabilis ticks collected in Kentucky. During 2007-2008, we collected 287 ticks (179 D. variabilis and 108 A. americanum) from canine, feral hog, horse, raccoon, white-tailed deer, and human hosts in six counties in Kentucky. Ticks were screened for Ricke ...201121976578
Seroprevalence of Borrelia burgdorferi, Anaplasma phagocytophilum, Ehrlichia canis, and Dirofilaria immitis among dogs in Canada.The seropositivity of dogs to Borrelia burgdorferi, Anaplasma phagocytophilum, and Ehrlichia canis antibodies, and Dirofilaria immitis antigen was assessed in Canada. Borrelia burgdorferi had the highest seroprevalence, while that of Dirofilaria immitis has not changed significantly in the past 20 y. The risk for these vector-borne infectious agents in Canadian dogs is low but widespread with foci of higher prevalence.201122043075
granulocytic anaplasmosis in a horse from nova scotia caused by infection with anaplasma phagocytophilum.a 16-year-old paint stallion was presented with intermittent fever, inappetance, lethargy, icterus, distal limb edema, and submandibular lymphadenopathy. the horse was native to nova scotia and had never left that province. morulae were detected in granulocytes. ananaplasma phagocytophilum infection was confirmed by serology and polymerase chain reaction (pcr). the horse responded to treatment with oxytetracycline.201122043078
novel exposure sites for nymphal ixodes pacificus within picnic areas.risk of exposure to nymphal ixodes pacificus cooley and kohls ticks was investigated at 7 picnic areas in tilden regional park, a heavily used recreation area of over 2000 acres in northwestern california, east of san francisco bay. wooden picnic tables, tree trunks, logs, leaf litter, surrounding vegetation, and rock walls were checked for ticks using standard 1-m(2) flannel tick flags at biweekly intervals from march to august 2008. results indicate that nymphal i. pacificus were commonly foun ...201122108011
lysophosphatidylcholine: a novel modulator of trypanosoma cruzi transmission.lysophosphatidylcholine is a bioactive lipid that regulates a large number of cellular processes and is especially present during the deposition and infiltration of inflammatory cells and deposition of atheromatous plaque. such molecule is also present in saliva and feces of the hematophagous organism rhodnius prolixus, a triatominae bug vector of chagas disease. we have recently demonstrated that lpc is a modulator of trypanosoma cruzi transmission. it acts as a powerful chemoattractant for inf ...201222132309
whole-genome sequences of borrelia bissettii, borrelia valaisiana, and borrelia spielmanii.it has been known for decades that human lyme disease is caused by the three spirochete species borrelia burgdorferi, borrelia afzelii, and borrelia garinii. recently, borrelia valaisiana, borrelia spielmanii, and borrelia bissettii have been associated with lyme disease. we report the complete genome sequences of b. valaisiana vs116, b. spielmanii a14s, and b. bissettii dn127.201222207749
of ticks, mice and men: understanding the dual-host lifestyle of lyme disease spirochaetes.in little more than 30 years, lyme disease, which is caused by the spirochaete borrelia burgdorferi, has risen from relative obscurity to become a global public health problem and a prototype of an emerging infection. during this period, there has been an extraordinary accumulation of knowledge on the phylogenetic diversity, molecular biology, genetics and host interactions of b. burgdorferi. in this review, we integrate this large body of information into a cohesive picture of the molecular and ...201222230951
evolution, expansion and expression of the kunitz/bpti gene family associated with long-term blood feeding in ixodes scapularis.abstract: background: recent studies of the tick saliva transcriptome have revealed the profound role of salivary proteins in blood feeding. kunitz/bpti proteins are abundant in the salivary glands of ticks and perform multiple functions in blood feeding, such as inhibiting blood coagulation, regulating host blood supply and disrupting host angiogenesis. however, kunitz/bpti proteins in soft and hard ticks have different functions and molecular mechanisms. how these differences emerged and whet ...201222244187
serum antibodies to whole-cell and recombinant antigens of borrelia burgdorferi in cottontail rabbits.archived serum samples, from 95 eastern cottontail rabbits (sylvilagus floridanus) captured in new york, new york, usa and millbrook, new york, usa, during 1985-86, were analyzed in solid-phase enzyme-linked immunosorbent assays (elisa) for total and class-specific immunoglobulin (ig) m antibodies to whole-cell or recombinant antigens of borrelia burgdorferi sensu stricto. using a polyvalent conjugate, rabbit sera contained antibodies to whole-cell and recombinant antigens (protein [p]35, p37, o ...201222247369
immunoregulation of bovine macrophages by factors in the salivary glands of rhipicephalus microplus.alternative strategies are required to control the southern cattle tick, rhipicephalus microplus, due to evolving resistance to commercially available acaricides. this invasive ectoparasite is a vector of economically important diseases of cattle such as bovine babesiosis and anaplasmosis. an understanding of the biological intricacies underlying vector-host-pathogen interactions is required to innovate sustainable tick management strategies that can ultimately mitigate the impact of animal and ...201222333193
clinical findings and diagnosis in human granulocytic anaplasmosis: a case series from massachusetts.to describe clinical findings and the use of a tick-associated pathogen panel in a series of patients with human granulocytic anaplasmosis (hga) at a suburban boston hospital.201222386178
how do host sex and reproductive state affect host preference and feeding duration of ticks?parasitism is one of the most notable forms of symbiosis in the biological world, with nearly all organisms hosting parasites. in many vertebrates, males have higher ectoparasite burdens than females, especially when testosterone concentrations are elevated. furthermore, reproductive females may have higher ectoparasite burdens than non-reproductive females. it is possible that testosterone-stimulated behaviors in males and offspring investment by females incur energetic costs that inhibit immun ...201222526292
consensus conference on lyme disease. 199122529708
field studies on lyme disease in north america.the primary tick vector of borrelia burgdorferi in eastern and central north america is ixodes dammini; in western north america, ixodes pacificus. searching for the appropriate vector is the first step in determining whether a region is endemic and enzootic for the spirochete b burgdorferi, the etiological agent of lyme disease, followed by examination of the ticks (questing or already attached to hosts) and wildlife for the spirochete. questing ticks can be collected through a variety of metho ...199122529709
association of bartonella spp bacteremia with chagas cardiomyopathy, endocarditis and arrhythmias in patients from south america.infection with bartonella spp may cause cardiac arrhythmias, myocarditis and endocarditis in humans. the aim of the present study was to evaluate a possible association between bartonella spp bacteremia and endocarditis, arrhythmia and chagas cardiomyopathy in patients from brazil and argentina. we screened for the presence of bacterial 16s rrna in human blood by pcr using oligonucleotides to amplify a 185-bp bacterial dna fragment. blood samples were taken from four groups of subjects in brazil ...201222584639
modelling transmission of vector-borne pathogens shows complex dynamics when vector feeding sites are limited.the relationship between species richness and the prevalence of vector-borne disease has been widely studied with a range of outcomes. increasing the number of host species for a pathogen may decrease infection prevalence (dilution effect), increase it (amplification), or have no effect. we derive a general model, and a specific implementation, which show that when the number of vector feeding sites on each host is limiting, the effects on pathogen dynamics of host population size are more compl ...201222590597
impacts of an introduced forest pathogen on the risk of lyme disease in california.global changes such as deforestation, climate change, and invasive species have the potential to greatly alter zoonotic disease systems through impacts on biodiversity. this study examined the impact of the invasive pathogen that causes sudden oak death (sod) on the ecology of lyme disease in california. the lyme disease bacterium, borrelia burgdorferi, is maintained in the far western united states by a suite of animal reservoirs including the dusky-footed woodrat (neotoma fuscipes) and deer mo ...201222607076
biomarkers for exposure to sand flies bites as tools to aid control of leishmaniasis.intense research efforts so far have not been sufficient to reduce leishmaniasis burden worldwide. this disease is transmitted by bites of infected sand flies, which inject saliva in the host skin in an attempt to obtain a blood meal. sand fly saliva has an array of proteins with diverse pharmacological properties that modulates the host homeostatic and immune responses. some of these proteins are also immunogenic and can induce both cellular and humoral immune responses. recently, the use of sa ...201222661974
natural product studies of u.s. endangered plants: volatile components of lindera melissifolia (lauraceae) repel mosquitoes and ticks.the number of endangered plant species in the u.s. is significant, yet studies aimed towards utilizing these plants are limited. ticks and mosquitoes are vectors of significant pathogenic diseases of humans. repellents are critical means of personal protection against biting arthropods and disease transmission. the essential oil and solvent extracts from lindera melissifolia (walt.) blume (lauraceae) (pondberry) drupes were gathered and analyzed by gc and gc-ms. the essential oil obtained from t ...201222704653
two boundaries separate borrelia burgdorferi populations in north america.understanding the spread of infectious diseases is crucial for implementing effective control measures. for this, it is important to obtain information on the contemporary population structure of a disease agent and to infer the evolutionary processes that may have shaped it. here, we investigate on a continental scale the population structure of borrelia burgdorferi, the causative agent of lyme borreliosis (lb), a tick-borne disease, in north america. we test the hypothesis that the observed po ...201222729536
lyme disease: knowledge, beliefs, and practices of physicians in a low-endemic area.to determine physicians' level of awareness and knowledge of lyme disease (ld) in a low-prevalence area and whether physicians' practices align with current guidelines for treatment of ld.201222734172
disintegrins from hematophagous sources.bloodsucking arthropods are a rich source of salivary molecules (sialogenins) which inhibit platelet aggregation, neutrophil function and angiogenesis. here we review the literature on salivary disintegrins and their targets. disintegrins were first discovered in snake venoms, and were instrumental in our understanding of integrin function and also for the development of anti-thrombotic drugs. in hematophagous animals, most disintegrins described so far have been discovered in the salivary gland ...201222778902
anticoagulant rodenticides on our public and community lands: spatial distribution of exposure and poisoning of a rare forest carnivore.anticoagulant rodenticide (ar) poisoning has emerged as a significant concern for conservation and management of non-target wildlife. the purpose for these toxicants is to suppress pest populations in agricultural or urban settings. the potential of direct and indirect exposures and illicit use of ars on public and community forest lands have recently raised concern for fishers (martes pennanti), a candidate for listing under the federal endangered species act in the pacific states. in an invest ...201222808110
antigen variability in anaplasma phagocytophilum during chronic infection of a reservoir host.anaplasma phagocytophilum is an obligately intracellular, tick-transmitted, bacterial pathogen of humans and other animals. in order to evade host immunity during the course of infection, a. phagocytophilum utilizes gene conversion to shuffle approximately 100 functional pseudogenes into a single expression cassette of the msp2(p44) gene, which encodes the major surface antigen, major surface protein 2 (msp2). the role and extent of msp2(p44) recombination in a reservoir host for a. phagocytophi ...201222859615
identification of endosymbionts in ticks by broad-range polymerase chain reaction and electrospray ionization mass spectrometry.many organisms, such as insects, filarial nematodes, and ticks, contain heritable bacterial endosymbionts that are often closely related to transmissible tickborne pathogens. these intracellular bacteria are sometimes unique to the host species, presumably due to isolation and genetic drift. we used a polymerase chain reaction/electrospray ionization-mass spectrometry assay designed to detect a wide range of vectorborne microorganisms to characterize endosymbiont genetic signatures from amblyomm ...201222897044
borrelia burgdorferi infections in the united states.it is becoming increasingly evident that the clinical presentation of infection with borrelia burgdorferi varies greatly between different parts of the world. a growing number of european and asian isolates of lyme borreliae, differing from the american strain of borrelia burgdorferi, have been identified in several different disorders. in light of the increasing number of reports describing an association between various cutaneous disorders and infection with borrelia burgdorferi and the contro ...201222916311
evolving perspectives on lyme borreliosis in canada.with cases now documented in every province, lyme borreliosis (lb) is emerging as a serious public health risk in canada. controversy over the contribution of lb to the burden of chronic disease is maintained by difficulty in capturing accurate canadian statistics, especially early clinical cases of lb. the use of dogs as sentinel species demon-strates that potential contact with borrelia burgdorferi spirochetes, as detected by c6 peptide, extends across the country. dissemination of infected ti ...201223091570
analysis of an ordered, comprehensive stm mutant library in infectious borrelia burgdorferi: insights into the genes required for mouse infectivity.the identification of genes important in the pathogenesis of lyme disease borrelia has been hampered by exceedingly low transformation rates in low-passage, infectious organisms. using the infectious, moderately transformable b. burgdorferi derivative 5a18np1 and signature-tagged versions of the himar1 transposon vector pgkt, we have constructed a defined transposon library for the efficient genome-wide investigation of genes required for wild-type pathogenesis, in vitro growth, physiology, morp ...201223133514
tick cell culture isolation and growth of rickettsia raoultii from dutch dermacentor reticulatus ticks.tick cell lines play an important role in research on ticks and tick-borne pathogenic and symbiotic microorganisms. in an attempt to derive continuous dermacentor reticulatus cell lines, embryo-derived primary cell cultures were set up from eggs laid by field ticks originally collected as unfed adults in the netherlands and maintained for up to 16 months. after several months, it became evident that cells in the primary cultures were infected with a rickettsia-like intracellular organism. supern ...201223140894
anopheles salivary gland proteomes from major malaria vectors.antibody responses against anopheles salivary proteins can indicate individual exposure to bites of malaria vectors. the extent to which these salivary proteins are species-specific is not entirely resolved. thus, a better knowledge of the diversity among salivary protein repertoires from various malaria vector species is necessary to select relevant genus-, subgenus- and/or species-specific salivary antigens. such antigens could be used for quantitative (mosquito density) and qualitative (mosqu ...201223148599
structure of the type iv secretion system in different strains of anaplasma phagocytophilum.anaplasma phagocytophilum is an intracellular organism in the order rickettsiales that infects diverse animal species and is causing an emerging disease in humans, dogs and horses. different strains have very different cell tropisms and virulence. for example, in the u.s., strains have been described that infect ruminants but not dogs or rodents. an intriguing question is how the strains of a. phagocytophilum differ and what different genome loci are involved in cell tropisms and/or virulence. t ...201223190684
outer surface protein c peptide derived from borrelia burgdorferi sensu stricto as a target for serodiagnosis of early lyme disease.current serodiagnostic assays for lyme disease are inadequate at detecting early infection due to poor sensitivity and nonspecificity that arise from the use of whole bacteria or bacterial proteins as assay targets; both targets contain epitopes that are cross-reactive with epitopes found in antigens of other bacterial species. tests utilizing peptides that contain individual epitopes highly specific for borrelia burgdorferi as diagnostic targets are an attractive alternative to current assays. ...201323365204
vaccination against lyme disease: past, present, and future.lyme borreliosis is a zoonotic disease caused by borrelia burgdorferi sensu lato bacteria transmitted to humans and domestic animals by the bite of an ixodes spp. tick (deer tick). despite improvements in diagnostic tests and public awareness of lyme disease, the reported cases have increased over the past decade to approximately 30,000 per year. limitations and failed public acceptance of a human vaccine, comprised of the outer surface a (ospa) lipoprotein of b. burgdorferi, led to its demise, ...201323407755
prevalence and burden of two rickettsial phylotypes (g021 and g022) in ixodes pacificus from california by real-time quantitative pcr.the western black-legged tick, ixodes pacificus cooley and kohls, commonly bites humans in the far western u.s. in addition to transmitting lyme borreliosis and anaplasmosis, it is a host of nonpathogenic bacteria as well as some of unknown pathogenicity. in this study, we report the detection, prevalence, and burden of 2 rickettsial phylotypes with unknown pathogenicity in i. pacificus ticks from 6 california counties using real-time quantitative pcr with phylotype-specific primers and probes. ...201323522936
hybridization in natural sympatric populations of dermacentor ticks in northwestern north america.hybridization in ticks has been described in a handful of species and mostly as a result of laboratory experiments. we used 148 aflp loci to describe putative hybridization events between d. andersoni and d. variabilis in sympatric populations from northwestern north america. recently, d. variabilis has expanded its range westward into the natural range of d. andersoni. using a sample of 235 d. andersoni and 62 d. variabilis, we identified 31 individuals as putative hybrids: four f2 individuals ...201323531531
what is the risk for exposure to vector-borne pathogens in united states national parks?united states national parks attract > 275 million visitors annually and collectively present risk of exposure for staff and visitors to a wide range of arthropod vector species (most notably fleas, mosquitoes, and ticks) and their associated bacterial, protozoan, or viral pathogens. we assessed the current state of knowledge for risk of exposure to vector-borne pathogens in national parks through a review of relevant literature, including internal national park service documents and organismal ...201323540107
serum antibodies to borrelia burgdorferi, anaplasma phagocytophilum, and babesia microti in recaptured white-footed mice.a mark-release-recapture study was conducted during 2007 through 2010 in six, tick-infested sites in connecticut, united states to measure changes in antibody titers for borrelia burgdorferi sensu stricto, anaplasma phagocytophilum, and babesia microti in peromyscus leucopus (white-footed mice). there was an overall recapture rate of 40%, but only four tagged mice were caught in ≥2 yr. sera from 561 mice were analyzed for total antibodies to b. burgdorferi and a. phagocytophilum by using whole-c ...201323568904
bartonella henselae infection in a family experiencing neurological and neurocognitive abnormalities after woodlouse hunter spider bites.bartonella species comprise a group of zoonotic pathogens that are usually acquired by vector transmission or by animal bites or scratches.201323587343
the use of deer vehicle accidents as a proxy for measuring the degree of interaction between human and deer populations and its correlation with the incidence rate of lyme disease.the study described in this article examined the relationship between the incidence rate of deer vehicle accidents (dvas), a proxy for measuring the interaction between populations of humans and deer, and human lyme disease incidence rate. the authors also examined the relationship between deer population density and human lyme incidence rate. they analyzed data from connecticut's department of environmental protection and the department of public health from 1999 through 2008 by deer management ...201323621054
comparison of a real-time pcr method with serology and blood smear analysis for diagnosis of human anaplasmosis: importance of infection time course for optimal test utilization.anaplasmosis and ehrlichiosis are emerging tick-borne diseases with clinically similar presentations caused by closely related pathogens. currently, laboratories rely predominantly on blood smear analysis (for the detection of intracellular morulae) and on serologic tests, both of which have recognized limitations, for diagnostic purposes. we compared the performance of a published real-time pcr assay that incorporates melt curve analysis to differentiate anaplasma and ehrlichia species with blo ...201323637292
eco-epidemiological factors contributing to the low risk of human exposure to ixodid tick-borne borreliae in southern california, usa.little is known about the eco-epidemiology of lyme disease in southern california, a region where the incidence is much lower than it is in northern california. here, we sought to discover the previously unknown microhabitats of nymphs of the primary vector, the western black-legged tick (ixodes pacificus), in 3 moderately to heavily-utilized state parks in the santa monica mountains in los angeles county; to elucidate the seasonal distribution and abundance of adults of i. pacificus and another ...201323643357
brief, recurrent, and spontaneous episodes of loss of consciousness in a healthy young male.lyme disease is caused by bacterial spirochete borrelia burgdorferi and is transmitted by ixodes scapularis and ixodes pacificus ticks, which get infected while feeding on the reservoir host of the bacteria.1 about 248,074 cases of lyme disease were reported by the us centers for disease control and prevention from 1992-2006.2 over 95% of these cases are reported from the northeastern and upper midwestern united states.3 carditis is usually a clinical manifestation/complication of lyme disease a ...201023754893
effect of host lizard anemia on host choice and feeding rate of larval western black-legged ticks (ixodes pacificus).although ticks are known to exhibit preferences among host species, there is little evidence that ticks select hosts within a species based on physiological condition. it may be beneficial for ticks to choose hosts that are easier to feed upon if the ticks can perceive indicative chemical or other signals from the host. for example, if ticks can detect host hematocrit they may choose hosts with high hematocrit, facilitating a faster blood meal. it may similarly be adaptive for ticks to avoid ane ...201323760685
host blood meal-dependent growth ensures transovarial transmission and transstadial passage of rickettsia sp. phylotype g021 in the western black-legged tick (ixodes pacificus).in this study, we explored the growth dynamics of rickettsia sp. phylotype g021 during transovarial transmission and transstadial passage by ixodes pacificus using real-time quantitative pcr. four parental engorged i. pacificus females were allowed to complete their developmental stages until the f2-generation eggs yielded unfed larvae. all eggs, larvae, nymphs, and adults tested through 2 generations were found to be infected with phylotype g021. hence, we conclude that the efficiency of transo ...201323876278
anaplasma phagocytophilum--a widespread multi-host pathogen with highly adaptive strategies.the bacterium anaplasma phagocytophilum has for decades been known to cause the disease tick-borne fever (tbf) in domestic ruminants in ixodes ricinus-infested areas in northern europe. in recent years, the bacterium has been found associated with ixodes-tick species more or less worldwide on the northern hemisphere. a. phagocytophilum has a broad host range and may cause severe disease in several mammalian species, including humans. however, the clinical symptoms vary from subclinical to fatal ...201323885337
de novo ixodes ricinus salivary gland transcriptome analysis using two next-generation sequencing methodologies.tick salivary gland (sg) proteins possess powerful pharmacologic properties that facilitate tick feeding and pathogen transmission. for the first time, sg transcriptomes of ixodes ricinus, an important disease vector for humans and animals, were analyzed using next-generation sequencing. sgs were collected from different tick life stages fed on various animal species, including cofeeding of nymphs and adults on the same host. four cdna samples were sequenced, discriminating tick sg transcriptome ...201323964076
tick salivary compounds: their role in modulation of host defences and pathogen transmission.ticks require blood meal to complete development and reproduction. multifunctional tick salivary glands play a pivotal role in tick feeding and transmission of pathogens. tick salivary molecules injected into the host modulate host defence responses to the benefit of the feeding ticks. to colonize tick organs, tick-borne microorganisms must overcome several barriers, i.e., tick gut membrane, tick immunity, and moulting. tick-borne pathogens co-evolved with their vectors and hosts and developed m ...201323971008
unique strains of anaplasma phagocytophilum segregate among diverse questing and non-questing ixodes tick species in the western united states.the emerging tick-borne pathogen anaplasma phagocytophilum infects humans, domestic animals, and wildlife throughout the holarctic. in the western us, the ecology of a. phagocytophilum is particularly complex, with multiple pathogen strains, tick vectors, and reservoir hosts. a recent phylogenetic analysis of a. phagocytophilum strains isolated from various small mammal hosts in california documented distinct clustering of woodrat strains separate from sciurid (chipmunk and squirrel) strains. he ...201323994335
temporal and spatial variation in anaplasma phagocytophilum infection in swedish moose (alces alces).the occurrence of anaplasma phagocytophilum was investigated in spleen and serum samples from swedish moose (alces alces) in southern sweden (island and mainland). samples were analysed for presence of a. phagocytophilum dna by real-time pcr (n = 263), and for anaplasma antibodies with elisa serology (n = 234). all serum samples had antibodies against a. phagocytophilum. the mean dna-based prevalence was 26·3%, and significant (p < 0·01) temporal, and spatial variation was found. island moose ha ...201324001524
multilocus sequence typing of borrelia burgdorferi suggests existence of lineages with differential pathogenic properties in humans.the clinical manifestations of lyme disease, caused by borrelia burgdorferi, vary considerably in different patients, possibly due to infection by strains with varying pathogenicity. both rrna intergenic spacer and ospc typing methods have proven to be useful tools for categorizing b. burgdorferi strains that vary in their tendency to disseminate in humans. neither method, however, is suitable for inferring intraspecific relationships among strains that are important for understanding the evolut ...201324069170
update on tick-borne rickettsioses around the world: a geographic approach.tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus rickettsia. these zoonoses are among the oldest known vector-borne diseases. however, in the past 25 years, the scope and importance of the recognized tick-associated rickettsial pathogens have increased dramatically, making this complex of diseases an ideal paradigm for the understanding of emerging and reemerging infections. several species of tick-borne rickettsiae that wer ...024092850
emerging antigens involved in allergic responses.new allergic diseases can 'emerge' because of exposure to a novel antigen, because the immune responsiveness of the subject changes, or because of a change in the behavior of the population. novel antigens have entered the environment as new pests in the home (e.g., asian lady beetle or stink bugs), in the diet (e.g., prebiotics or wheat isolates), or because of the spread of a biting arthropod (e.g., ticks). over the last few years, a significant new disease has been identified, which has chang ...201324095162
host specialization in ticks and transmission of tick-borne diseases: a review.determining patterns of host use, and the frequency at which these patterns change, are of key importance if we are to understand tick population dynamics, the evolution of tick biodiversity, and the circulation and evolution of associated pathogens. the question of whether ticks are typically host specialists or host generalists has been subject to much debate over the last half-century. indeed, early research proposed that morphological diversity in ticks was linked to host specific adaptation ...201324109592
single-tube real-time pcr assay for differentiation of ixodes affinis and ixodes scapularis.ixodes affinis neumann (1899) and ixodes scapularis say (1821) are tick vectors of the etiologic agent of lyme disease, borrelia burgdorferi sensu stricto. ixodes affinis and i. scapularis are morphologically very similar, and as they are sympatric in the mid- and south-atlantic u.s. coastal states, their accurate identification is crucial to studies of disease and vector ecology in this area. this work describes a rapid, single-tube sybr(®) green-based real-time pcr assay for differentiation of ...201324192510
first isolation of the relapsing fever spirochete, borrelia hermsii, from a domestic dog.in north america, tick-borne relapsing fever of humans is most frequently caused by infection with the spirochete borrelia hermsii. prior to our investigation, this spirochete was not known to infect dogs although another species, borrelia turicatae, has been isolated from domestic canids in florida and texas. a clinically ill dog in washington, usa, was spirochetemic upon examination. spirochetes were isolated from the dog's serum and examined by pcr and multi-locus sequence typing. dna sequenc ...201324252262
molecular epidemiology of the emerging zoonosis agent anaplasma phagocytophilum (foggie, 1949) in dogs and ixodid ticks in brazil.anaplasma phagocytophilum is an emerging pathogen of humans, dogs and other animals, and it is transmitted by ixodid ticks. the objective of the current study was a) detect a. phagocytophilum in dogs and ixodid ticks using real-time polymerase chain reaction (qpcr); and b) determine important variables associated to host, environment and potential tick vectors that are related to the presence of a. phagocytophilum in dogs domiciled in rio de janeiro, brazil.201324330631
insecticide/acaricide resistance in fleas and ticks infesting dogs and cats.this review defines insecticide/acaricide resistance and describes the history, evolution, types, mechanisms, and detection of resistance as it applies to chemicals currently used against fleas and ticks of dogs and cats and summarizes resistance reported to date. we introduce the concept of refugia as it applies to flea and tick resistance and discuss strategies to minimize the impact and inevitable onset of resistance to newer classes of insecticides. our purpose is to provide the veterinary p ...201424393426
on the potential roles of ticks and migrating birds in the ecology of west nile virus.mosquitoes are the primary vectors of west nile virus (wnv). ticks have, however, been suggested to be potential reservoirs of wnv. in order to investigate their role in the spread of the virus, ticks, which had been collected from birds migrating northwards from africa to europe, were analyzed for the potential presence of wnv-rna.201424455105
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