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differences in the transmissibility of two anaplasma phagocytophilum strains by the north american tick vector species, ixodes pacificus and ixodes scapularis (acari: ixodidae).the etiologic agent of granulocytic anaplasmosis, anaplasma phagocytophilum, has a circum-global distribution within the northern hemisphere and shows a host species predilection that varies by the geographic region in which the disease is found. adaptation by the bacterium to a host species potentially contributes to the variation found worldwide but this is confounded by the bacterium's relationship with its tick vectors, all of which belong to the ixodes ricinus group. we tested the hypothesi ...200616550334
an enzootic transmission cycle of lyme borreliosis spirochetes in the southeastern united states.lyme borreliosis, or lyme disease (ld), is a tick-borne zoonotic infection of biomedical significance, caused by borrelia burgdorferi sensu lato (s.l.) spirochetes and transmitted by ixodes species ticks. it usually circulates among wildlife vertebrate reservoirs and vector ticks but may infect humans, causing multisystem problems. in far western and northern north america, the host reservoirs, tick vectors, and genospecies of borrelia are well known but not so in the southern u.s., where there ...200314500917
molecular cloning and characterization of atx1 cdna from the mole cricket, gryllotalpa orientalis.to search for an insect homologue of antioxidant protein 1 (atx1), a mole cricket, gryllotalpa orientalis, cdna library was screened and a cdna clone, which encodes a 73 amino acid polypeptide with a predicted molecular mass of 8.0 kda and pi of 5.68, was isolated. the g. orientalis atx1 (goatx1) cdna features both a mtcxxc copper-binding site in the n-terminus and a ktgk lysine-rich region in the c-terminus. the deduced amino acid sequence of the goatx1 cdna showed 63% identity to drosophila me ...200616552768
spatial and temporal variability of the glossina palpalis palpalis population in the mbini focus (equatorial guinea).human african trypanosomiasis is a vector-borne parasitic disease. the geographical distribution of the disease is linked to the spatial distribution of the tsetse fly. as part of a control campaign using traps, the spatial and temporal variability is analysed of the glossina populations present in the mbini sleeping sickness foci (equatorial guinea).200717760953
life cycles of seven ixodid tick species (acari: ixodidae) under standardized laboratory conditions.studies of transmission, maintenance, infectivity, virulence, and pathogenicity of tick-borne agents require the use of large numbers of live laboratory-raised ticks. colonies of ixodes scapularis say, ixodes pacificus cooley & kohls, amblyomma americanum (l.), dermacentor occidentalis marx, dermacentor variabilis (say), hemaphysalis leporispalustris (packard), and rhipicephalus sanguineus (latrielle) have been maintained in our laboratory at the centers for disease control and prevention for fi ...200717915502
spatial patterns of lyme disease risk in california based on disease incidence data and modeling of vector-tick exposure.ixodes pacificus, particularly the nymphal life stage, is the primary vector to humans of the lyme disease agent borrelia burgdorferi in california. during 2004, we collected i. pacificus nymphs from 78 woodland sites in ecologically diverse mendocino county, which has a moderately high incidence of lyme disease. within this county, nymphal density was elevated in forested areas with a growing degree day range of 2,600-3,000 (10 degrees c base). using a geographic information systems approach, w ...200617038692
detection of a malaria parasite (plasmodium mexicanum) in ectoparasites (mites and ticks), and possible significance for transmission.two species of sandflies (lutzomyia) are competent vectors of plasmodium mexicanum, a malaria parasite of lizards. the very patchy distribution of sites with high p. mexicanum prevalence in the lizards, and often low or even nil sandfly density at such sites, provoked an evaluation of 2 common lizard ectoparasites, the tick ixodes pacificus and the mite geckobiella occidentalis, as potential passive vectors. plasmodium sp.-specific polymerase chain primers were used to amplify a long segment of ...200616729709
refractoriness of the western fence lizard (sceloporus occidentalis) to the lyme disease group spirochete borrelia bissettii.the western fence lizard, sceloporus occidentalis, is refractory to experimental infection with borrelia burgdorferi sensu stricto, one of several lyme disease spirochetes pathogenic for humans. another member of the lyme disease spirochete complex, borrelia bissettii, is distributed widely throughout north america and a similar, if not identical, spirochete has been implicated as a human pathogen in southern europe. to determine the susceptibility of s. occidentalis to b. bissettii, 6 naïve liz ...200616995383
an insight into the sialome of the soft tick, ornithodorus parkeri.while hard ticks (ixodidae) take several days to feed on their hosts, soft ticks (argasidae) feed faster, usually taking less than 1h per meal. saliva assists in the feeding process by providing a cocktail of anti-hemostatic, anti-inflammatory and immunomodullatory compounds. saliva of hard ticks has been shown to contain several families of genes each having multiple members, while those of soft ticks are relatively unexplored. analysis of the salivary transcriptome of the soft tick ornithodoru ...200818070662
comparative sialomics between hard and soft ticks: implications for the evolution of blood-feeding behavior.ticks evolved various mechanisms to modulate their host's hemostatic and immune defenses. differences in the anti-hemostatic repertoires suggest that hard and soft ticks evolved anti-hemostatic mechanisms independently, but raise questions on the conservation of salivary gland proteins in the ancestral tick lineage. to address this issue, the sialome (salivary gland secretory proteome) from the soft tick, argas monolakensis, was determined by proteomic analysis and cdna library construction of s ...200818070664
immune system responses and fitness costs associated with consumption of bacteria in larvae of trichoplusia ni.insects helped pioneer, and persist as model organisms for, the study of specific aspects of immunity. although they lack an adaptive immune system, insects possess an innate immune system that recognizes and destroys intruding microorganisms. its operation under natural conditions has not been well studied, as most studies have introduced microbes to laboratory-reared insects via artificial mechanical wounding. one of the most common routes of natural exposure and infection, however, is via foo ...200718154650
variability and action mechanism of a family of anticomplement proteins in ixodes ricinus.ticks are blood feeding arachnids that characteristically take a long blood meal. they must therefore counteract host defence mechanisms such as hemostasis, inflammation and the immune response. this is achieved by expressing batteries of salivary proteins coded by multigene families.200818167559
life stage-related differences in density of questing ticks and infection with borrelia burgdorferi sensu lato within a single cohort of ixodes pacificus (acari: ixodidae).the primary aims of this study were to quantify the density of ixodes pacificus cooley and kohls nymphs and adults of the same generational cohort collected within a single year in six oak or madrone leaf litter habitats and to compare the prevalence of infection with borrelia burgdorferi sensu lato (s.l.) in adults originating from nymphal cohorts with a low (<1%) versus high (>10%) infection prevalence. because adult densities were very low both in and adjacent to several sites, direct compari ...200415311473
columbian black-tailed deer (odocoileus hemionus columbianus) as hosts for borrelia spp. in northern california.the prevalence of infection of columbian black-tailed deer (odocoileus hemionus columbianus) with borrelia spp. was evaluated in an area of northwestern california (usa) where lyme disease is endemic and the relapsing-fever group spirochete borrelia coriaceae is enzootic, and in a far-removed comparison area having a disparate climate and lower density of vector ticks. blood samples collected from both deer herds in 1987, 1988, and from 2000-02 were assayed for borrelial infection with microscop ...200515827217
co-detection of bartonella henselae, borrelia burgdorferi, and anaplasma phagocytophilum in ixodes pacificus ticks from california, usa.presence of bartonella dna was explored in 168 questing adult ixodes pacificus ticks from santa cruz county, california. bartonella henselae type i dna was amplified from 11 ticks (6.55%); previously, two (1.19%) were found to be infected with borrelia burgdorferi and five (2.98%) with anaplasma phagocytophilum. detection of b. henselae was not dependent on co-infection. the present study offers additional evidence that ixodes spp. ticks may act as hosts and possibly vectors for b. henselae.200616584332
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
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
geographical distribution patterns and habitat suitability models for presence of host-seeking ixodid ticks in dense woodlands of mendocino county, california.we used drag sampling to examine the geographical distribution patterns of ixodid ticks engaging in open (non-nidicolous) host-seeking behavior in dense woodland habitats of the climatically and ecologically diverse mendocino county in north coastal california. the findings based on this sampling methodology reflect risk of human exposure to host-seeking ticks rather than the true distribution of the ticks. drag sampling in 78 sites yielded 7,860 nymphal or adult ixodes pacificus cooley & kohls, ...200616619628
differential exposure to anaplasma phagocytophilum in rodent species in northern california.anaplasma phagocytophilum is a zoonotic tick-borne rickettsial pathogen that causes granulocytic anaplasmosis (ga) in humans, horses, and dogs. in california, dusky-footed woodrats (neotoma fuscipes) are a putative reservoir host, and ixodes pacificus is a vector for transmission from rodents to humans, dogs, and horses. cases are clustered in coastal and sierra nevada foothill regions, but not necessarily in proximity to infected woodrats. this study was designed to compare exposures and active ...200818047398
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
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
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
sylvatic maintenance of borrelia burgdorferi (spirochaetales) in northern california: untangling the web of transmission.lyme borreliosis is associated with several genospecies of borrelia burgdorferi sensu lato (s.l.) (spirochaetales), but human disease has been associated only with borrelia burgdorferi sensu stricto (s.s.) johnson, schmid, hyde, steigerwalt & brenner in the western united states. restriction fragment length polymorphism (rflp) analysis of rrf-rrl amplicons from 124 tick and mammalian isolates from various habitats yielded 13 rflp patterns. of these patterns, six were patterns previously associat ...200616892634
analysis of the first australian strains of bartonella quintana reveals unique genotypes.bartonella quintana is increasingly recognized as a cause of clinical disease in various geographical locations. we characterized three australian strains associated with endocarditis, using established molecular-typing techniques, the 16s/23s rrna intergenic spacer (its) region, and multispacer typing (mst). all strains examined demonstrated novel its and/or mst genotypes. further characterization of australian strains is required to determine whether there is an association between genotype an ...200717428928
clinical, epidemiologic, and environmental surveillance for ehrlichiosis and anaplasmosis in an endemic area of northern california.two forms of tick-borne leukocytotropic rickettsioses have been recognized in california since the mid-1990s: human monocytic ehrlichiosis (hme) caused by ehrlichia chaffeensis and human granulocytic anaplasmosis (hga) caused by anaplasma phagocytophilum. between 1997 and 1999, two cases of hme and four cases of hga were diagnosed in residents of southern humboldt county, california. environmental followup at case-patients' residences revealed dense populations of ixodes pacificus ticks, particu ...200516007950
myd88 deficiency enhances acquisition and transmission of borrelia burgdorferi by ixodes scapularis ticks.borrelia burgdorferi strains exhibit various degrees of infectivity and pathogenicity in mammals, which may be due to their relative ability to evade initial host immunity. innate immune cells recognize b. burgdorferi by toll-like receptors (tlrs) that use the intracellular molecule myd88 to mediate effector functions. to determine whether impaired tlr signaling enhances ixodes scapularis acquisition of b. burgdorferi, we fed nymphs on wild-type (wt) and myd88-/- mice previously infected with tw ...200616552045
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
coinfections acquired from ixodes ticks.the pathogens that cause lyme disease (ld), human anaplasmosis, and babesiosis can coexist in ixodes ticks and cause human coinfections. although the risk of human coinfection differs by geographic location, the true prevalence of coinfecting pathogens among ixodes ticks remains largely unknown for the majority of geographic locations. the prevalence of dually infected ixodes ticks appears highest among ticks from regions of north america and europe where ld is endemic, with reported prevalences ...200617041141
spatial dynamics of lyme disease: a review.lyme disease (ld), the most frequently reported vector-borne disease in the united states, requires that humans, infected vector ticks, and infected hosts all occur in close spatial proximity. understanding the spatial dynamics of ld requires an understanding of the spatial determinants of each of these organisms. we review the literature on spatial patterns and environmental correlates of human cases of ld and the vector ticks, ixodes scapularis in the northeastern and midwestern united states ...200818787920
habitat-related variation in infestation of lizards and rodents with ixodes ticks in dense woodlands in mendocino county, california.during the spring and early summer of 2002, we examined the relative importance of borrelia-refractory lizards (sceloporus occidentalis, elgaria spp.) versus potential borrelia burgdorferi sensu lato (s.l.)-reservoirs (rodents) as hosts for ixodes pacificus immatures in 14 woodland areas (six oak, five mixed oak/douglas fir, and three redwood/tanoak areas) distributed throughout mendocino county, california. lizards were estimated to serve as hosts for 93-98% of all larvae and > or =99.6% of all ...200415347025
wild turkey (meleagris gallopavo) as a host of ixodid ticks, lice, and lyme disease spirochetes (borrelia burgdorferi sensu lato) in california state parks.rio grande wild turkeys (meleagris gallopavo intermedia) were evaluated as potential hosts of ixodid ticks, lice, and lyme disease spirochetes (borrelia burgdorferi sensu lato [s.l.]) in three state parks in sonoma county, california, usa, during 2003 and 2004. in total, 113 birds were collected, 50 (44.2%) of which were found to be infested by 361 ixodid ticks representing three species: the western black-legged tick (ixodes pacificus, n=248), the rabbit tick (haemaphysalis leporispalustris, n= ...200617255442
high-resolution genetic fingerprinting of european strains of anaplasma phagocytophilum by use of multilocus variable-number tandem-repeat analysis.anaplasma phagocytophilum is a widely distributed tick-borne pathogen of humans, livestock, and companion animals. we used in silico methods to identify 10 variable-number tandem-repeat (vntr) loci within the genome sequence of the a. phagocytophilum hz strain and used these data to develop a multilocus vntr-based typing scheme for the species. having confirmed the stability of four of the loci in replicates of the a. phagocytophilum strain that had been subjected to different numbers of passage ...200717442796
purine salvage pathways among borrelia species.genome sequencing projects on two relapsing fever spirochetes, borrelia hermsii and borrelia turicatae, revealed differences in genes involved in purine metabolism and salvage compared to those in the lyme disease spirochete borrelia burgdorferi. the relapsing fever spirochetes contained six open reading frames that are absent from the b. burgdorferi genome. these genes included those for hypoxanthine-guanine phosphoribosyltransferase (hpt), adenylosuccinate synthase (pura), adenylosuccinate lya ...200717502392
exploring the mialome of ticks: an annotated catalogue of midgut transcripts from the hard tick, dermacentor variabilis (acari: ixodidae).ticks are obligate blood feeders. the midgut is the first major region of the body where blood and microbes ingested with the blood meal come in contact with the tick's internal tissues. little is known about protein expression in the digestive tract of ticks. in this study, for analysis of global gene expression during tick attachment and feeding, we generated and sequenced 1,679 random transcripts (ests) from cdna libraries from the midguts of female ticks at varying stages of feeding.200819021911
gray foxes (urocyon cinereoargenteus) as a potential reservoir of a bartonella clarridgeiae-like bacterium and domestic dogs as part of a sentinel system for surveillance of zoonotic arthropod-borne pathogens in northern california.two species of bartonella, a novel bartonella clarridgeiae-like bacterium and b. vinsonii subsp. berkhoffii, were isolated from rural dogs and gray foxes in northern california. a novel b. clarridgeiae-like species was isolated from 3 (1.7%) of 182 dogs and 22 (42%) of 53 gray foxes, while b. vinsonii subsp. berkhoffii was isolated from 1 dog (0.5%) and 5 gray foxes (9.4%). pcr and dna sequence analyses of the citrate synthase (glta) gene and the 16s-23s intergenic spacer region suggested that s ...200717553970
dermatologic changes induced by repeated ixodes scapularis bites and implications for prevention of tick-borne infection.previous studies in rodents and people have demonstrated that repeated tick exposure is associated with reduced borrelia burgdorferi transmission but the mechanism of prevention remains unclear. we examined the acute histopathologic reactions to initial and repeated ixodes scapularis bites in balb/c mice and in people. skin biopsies of balb/c mice infested for the first time by i. scapularis nymphs revealed vascular dilatation and an accumulation of inflammatory cells adjacent to the bite site b ...200919196014
feeding preferences of the immature stages of three western north american ixodid ticks (acari) for avian, reptilian, or rodent hosts.larval and nymphal ixodes pacificus cooley and kohls, i. (ixodes) jellisoni cooley and kohls, and dermacentor occidentalis marx were tested for host preference when simultaneously presented with a deer mouse (peromyscus maniculatus wagner), california kangaroo rat (dipodomys californicus merriam), western fence lizard (sceloporus occidentalis baird and girard), and california towhee (pipilo crissalis vigors) in an experimental apparatus. differences were observed in the preferences among the thr ...200919198525
migratory songbirds disperse ticks across canada, and first isolation of the lyme disease spirochete, borrelia burgdorferi, from the avian tick, ixodes auritulus.during a 3-yr comprehensive study, 196 ixodid ticks (9 species) were collected from 89 passerine birds (32 species) from 25 localities across canada to determine the distribution of avian-associated tick species and endogenous lyme disease spirochetes, borrelia burgdorferi johnson, schmid, hyde, steigerwalt, and brenner. we report the following first records of tick parasitism on avian hosts: the rabbit-associated tick, ixodes dentatus marx, from manitoba and ontario; the mouse tick, ixodes muri ...200517089744
ability of transstadially infected ixodes pacificus (acari: ixodidae) to transmit west nile virus to song sparrows or western fence lizards.the hypothesis that ixodes pacificus cooley & kohls (acari: ixodidae) may serve as a reservoir and vector of west nile virus (family flaviviridae, genus flavivirus, wnv) in california was tested by determining the ability of this tick species to become infected with the ny99 strain of wnv while feeding on viremic song sparrows, to maintain the infection transstadially, and then to transmit wnv to recipient naive song sparrows and western fence lizards during the nymphal stage. the percentage of ...200717427704
ectoparasite diversity and exposure to vector-borne disease agents in wild rodents in central coastal california.a survey of wild rodents was performed in the morro bay area of central coastal california to determine serological and polymerase chain reaction (pcr) prevalence of anaplasma phagocytophilum dumler, barbet, bekker, dasch, palmer, ray, rikihisa, and rurangirwa, borrelia burgdorferi johnson, schmidt, hyde, steigerwalt, and brenner, francisella tularensis mccoy, and yersinia pestis yersin; to describe the ectoparasitic fauna on important vector-borne disease hosts; and to determine whether pathoge ...200717427705
reviewing molecular adaptations of lyme borreliosis spirochetes in the context of reproductive fitness in natural transmission cycles.lyme borreliosis (lb) is caused by a group of pathogenic spirochetes - most often borrelia burgdorferi, b. afzelii, and b. garinii - that are vectored by hard ticks in the ixodes ricinus-persulcatus complex, which feed on a variety of mammals, birds, and lizards. although lb is one of the best-studied vector-borne zoonoses, the annual incidence in north america and europe leads other vector-borne diseases and continues to increase. what factors make the lb system so successful, and how can resea ...200919368764
prevalence of anaplasma phagocytophilum in domestic felines in the united states.anaplasma phagocytophilum is among the more common tick-borne disease agents in the united states. it is of veterinary and public health significance as dogs, cats, and human beings are known to be susceptible. a. phagocytophilum is transmitted trans-stadially by either nymphs or adults of either the black-legged tick (ixodes scapularis) or the western black-legged tick (ixodes pacificus). little information is available regarding either the prevalence of this agent in cats or the dynamics of ve ...200717493756
distinct ecologically relevant strains of anaplasma phagocytophilum. 200919402993
predicting density of ixodes pacificus nymphs in dense woodlands in mendocino county, california, based on geographic information systems and remote sensing versus field-derived data.ixodes pacificus nymphs are the primary vectors to humans of borrelia burgdorferi, the etiologic agent of lyme disease, in california. we used a supervised classification model, based on remote sensing (rs) data from multi-seasonal landsat tm 5 images, to identify the key habitat in mendocino county where humans are exposed to i. pacificus nymphs (woodlands carpeted with leaf litter). the model, based on the normalized difference vegetation index (ndvi), brightness, and wetness, separated the ny ...200616606998
distantly related lipocalins share two conserved clusters of hydrophobic residues: use in homology modeling.lipocalins are widely distributed in nature and are found in bacteria, plants, arthropoda and vertebra. in hematophagous arthropods, they are implicated in the successful accomplishment of the blood meal, interfering with platelet aggregation, blood coagulation and inflammation and in the transmission of disease parasites such as trypanosoma cruzi and borrelia burgdorferi. the pairwise sequence identity is low among this family, often below 30%, despite a well conserved tertiary structure. under ...200818190694
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
comprehensive seroprofiling of sixteen b. burgdorferi ospc: implications for lyme disease diagnostics design.early diagnosis of lyme disease (ld) is critical to successful treatment. however, current serodiagnostic tests do not reliably detect antibodies during early infection. ospc induces a potent early immune response and is also one of the most diverse proteins in the borrelia proteome. yet, at least 70% of the amino acid sequence is conserved among all 21 known ospc types. we performed a series of comprehensive seroprofiling studies to select the ospc types that have the most cross-reactive immuno ...200919576856
current management of human granulocytic anaplasmosis, human monocytic ehrlichiosis and ehrlichia ewingii ehrlichiosis.anaplasma phagocytophilum, ehrlichia chaffeensis and ehrlichia ewingii are emerging tick-borne pathogens and are the causative agents of human granulocytic anaplasmosis, human monocytic ehrlichiosis and e. ewingii ehrlichiosis, respectively. collectively, these are referred to as human ehrlichioses. these obligate intracellular bacterial pathogens of the family anaplasmataceae are transmitted by ixodes spp. or amblyomma americanum ticks and infect peripherally circulating leukocytes to cause inf ...200919681699
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
the low seroprevalence of tick-transmitted agents of disease in dogs from southern ontario and quebec.infectious diseases caused by pathogens transmitted by ticks and other insect vectors are an important cause of morbidity and mortality in both dogs and humans throughout north america. the purpose of this study was to determine the seroprevalence of selected vector-transmitted pathogens in southern ontario and quebec. samples submitted to the vector borne disease diagnostic laboratory (vbddl) at the north carolina state university college of veterinary medicine were evaluated for antibodies to ...200617217089
survey for zoonotic rickettsial pathogens in northern flying squirrels, glaucomys sabrinus, in california.epidemic typhus, caused by rickettsia prowazekii, is maintained in a southern flying squirrel (glaucomys volans) sylvatic cycle in the southeastern united states. the northern flying squirrel (glaucomys sabrinus) has not been previously associated with r. prowazekii transmission. a second rickettsial pathogen, anaplasma phagocytophilum, infects dusky-footed woodrats (neotoma fuscipes) and tree squirrels in northern california. because northern flying squirrels or their ectoparasites have not bee ...200717984264
delineation of a new species of the borrelia burgdorferi sensu lato complex, borrelia americana sp. nov.analysis of borrelia isolates collected from ticks, birds, and rodents from the southeastern united states revealed the presence of well-established populations of borrelia burgdorferi sensu stricto, borrelia bissettii, borrelia carolinensis, and borrelia sp. nov. multilocus sequence analysis of five genomic loci from seven samples representing borrelia sp. nov. isolated from nymphal ixodes minor collected in south carolina showed their close relatedness to california strains known as genomospec ...200919846628
granulocytic anaplasmosis in three dogs from saskatoon, saskatchewan.three dogs from saskatoon, saskatchewan were diagnosed with acute granulocytic anaplasmosis. fever, lethargy, inappetence, vomiting, diarrhea, and lameness were reported. lymphopenia, thrombocytopenia, and splenomegaly were identified in all dogs. inclusions were identified within the cytoplasm of blood neutrophils, and infection with anaplasma phagocytophilum was confirmed by polymerase chain reaction.200919881921
evaluation of squirrels (rodentia: sciuridae) as ecologically significant hosts for anaplasma phagocytophilum in california.granulocytic anaplasmosis (ga), caused by anaplasma phagocytophilum, is a potentially fatal, emerging rickettsial disease of humans, domestic animals, and wildlife. the purpose of this study was to determine whether sciurids from multiple areas of northern california were infested with ticks or exposed to or infected with a. phagocytophilum using polymerase chain reaction (pcr) and indirect-fluorescent antibody (ifa) serology. sciurids of nine different tree- and ground-dwelling species were ass ...200818714881
molecular identification of salp15, a key salivary gland protein in the transmission of lyme disease spirochetes, from ixodes persulcatus and ixodes pacificus (acari: ixodidae).salp15 is a multifunctional protein, vital to the tick in its need to obtain vertebrate host blood without stimulating a host inflammatory and immune response. the salpl5 protein from both ixodes scapularis say and ixodes ricinus (l.), the principal vectors of the lyme disease spirochete in eastern north america and europe, respectively, have been well characterized and found to bind the murine cd4 receptor, dc-sign, and the ospc protein of borrelia burgdorferi. in the current study, we characte ...200919960697
niche partitioning of borrelia burgdorferi and borrelia miyamotoi in the same tick vector and mammalian reservoir species.the lyme borreliosis agent borrelia burgdorferi and the relapsing fever group species borrelia miyamotoi co-occur in the united states. we used species-specific, quantitative polymerase chain reaction to study both species in the blood and skin of peromyscus leucopus mice and host-seeking ixodes scapularis nymphs at a connecticut site. bacteremias with b. burgdorferi or b. miyamotoi were most prevalent during periods of greatest activity for nymphs or larvae, respectively. whereas b. burgdorferi ...200919996447
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
molecular and clinical evidence of ehrlichia chaffeensis infection in cameroonian patients with undifferentiated febrile illness.in the u.s.a., human monocytotropic ehrlichiosis (hme) caused by ehrlichia chaffeensis is an emerging tick-transmitted zoonosis. in cameroon, where e. canis, e. chaffeensis and e. ewingii have recently been detected in dogs and/or ticks (rhipicephalus sanguineus), the potential exists for human infections. patients from the coastal region of cameroon who had acute fevers of unknown aetiology were therefore checked for ehrlichial infection, using a real-time pcr that amplifies part of a genus-spe ...200920030996
relative importance of ixodes ricinus and ixodes trianguliceps as vectors for anaplasma phagocytophilum and babesia microti in field vole (microtus agrestis) populations.the importance of ixodes ricinus in the transmission of tick-borne pathogens is well recognized in the united kingdom and across europe. however, the role of coexisting ixodes species, such as the widely distributed species ixodes trianguliceps, as alternative vectors for these pathogens has received little attention. this study aimed to assess the relative importance of i. ricinus and i. trianguliceps in the transmission of anaplasma phagocytophilum and babesia microti among united kingdom fiel ...200818820068
[ehrlichiosis/anaplasmosis].ehrlichiosis and anaplasmosis are zoonoses caused by bacteria from the family anaplasmataceae, including human and animal pathogens. the human pathogens are ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis (hme), anaplasma phagocytophilum, the pathogen causing human granulocytic anaplasmosis (hga), e. ewingii and neorickettsia sennetsu, granulocytotropic and monocytotropic ehrlichia species, respectively. ehrlichia spp. are small, gram-negative, obligate intracellular b ...200920077398
coinfection of western gray squirrel (sciurus griseus) and other sciurid rodents with borrelia burgdorferi sensu stricto and anaplasma phagocytophilum in california.overlapping geographic distributions of tick-borne disease agents utilizing the same tick vectors are common, and coinfection of humans, domestic animals, wildlife, and ticks with both borrelia burgdorferi and anaplasma phagocytophilum has been frequently reported. this study was undertaken in order to evaluate the prevalence of both b. burgdorferi sensu stricto (hereinafter referred to as b. burgdorferi) and a. phagocytophilum in several species of sciurid rodents from northern california, usa. ...201020090047
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
evaluation of the recombinant vlse-based liaison chemiluminescence immunoassay for detection of borrelia burgdorferi and diagnosis of lyme disease.recent efforts to improve the serologic diagnosis of lyme disease have included the use of a synthetic peptide (c6) that reproduces the sequence of invariable region 6 of vlse, the variable surface antigen of borrelia burgdorferi. in the present study, the diagnostic performance of diasorin's recombinant vlse-based chemiluminescence immunoassay in 1,947 human serum samples was evaluated. sensitivity was determined using two serum panels from the cdc. for panel i, we observed sensitivities of 68. ...200818945880
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
reservoir competence of the redwood chipmunk (tamias ochrogenys) for anaplasma phagocytophilum.granulocytic anaplasmosis (ga) is an emerging tick-transmitted disease that persists in rodent- ixodes ricinus-complex tick cycles across the holarctic. although the putative reservoir for anaplasmosis in the western united states is the dusky-footed woodrat (neotoma fuscipes), this rodent was not shown reservoir-competent because of failure of infection from woodrats to other animals via ticks. redwood chipmunks are common in habitats where anaplasma phagocytophilum is common, have high pcr- an ...200919327022
ecology of anaplasma phagocytophilum infection in gray foxes (urocyon cinereoargenteus) in northwestern california.although granulocytic anaplasmosis, caused by infection of anaplasma phagocytophilum, is an emerging human and domestic animal disease, the ecology and natural history of the parasite is not well understood. gray foxes (urocyon cinereoargenteus) are relatively common, occasionally peri-urban mesocarnivores whose geographic distribution overlaps the reported distribution of granulocytic anaplasmosis in humans and domestic animals in north america. we evaluated the potential of foxes as hosts and ...200919395744
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
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
effect of climate change on lyme disease risk in north america.an understanding of the influence of climate change on ixodes scapularis, the main vector of lyme disease in north america, is a fundamental component in assessing changes in the spatial distribution of human risk for the disease. we used a climate suitability model of i. scapularis to examine the potential effects of global climate change on future lyme disease risk in north america. a climate-based logistic model was first used to explain the current distribution of i. scapularis in north amer ...200519008966
distribution of the lyme disease spirochete borrelia burgdorferi in naturally and experimentally infected western gray squirrels (sciurus griseus).the dynamics of borrelia burgdorferi infections within its natural hosts are poorly understood. we necropsied four wild-caught western gray squirrels (sciurus griseus) that were acquired during a previous study that evaluated the reservoir competence of this rodent for the lyme disease spirochete. one animal was infected experimentally, whereas the others were infected in the wild before capture. to investigate dissemination of b. burgdorferi and concurrent histopathologic lesions in different t ...201020017717
ixodes ricinus tick lipocalins: identification, cloning, phylogenetic analysis and biochemical characterization.during their blood meal, ticks secrete a wide variety of proteins that interfere with their host's defense mechanisms. among these proteins, lipocalins play a major role in the modulation of the inflammatory response.200819096708
rrp1, a cyclic-di-gmp-producing response regulator, is an important regulator of borrelia burgdorferi core cellular functions.two-component systems (tcs) are universal among bacteria and play critical roles in gene regulation. our understanding of the contributions of tcs in the biology of the borrelia is just now beginning to develop. borrelia burgdorferi, a causative agent of lyme disease, harbours a tcs comprised of open reading frames (orfs) bb0419 and bb0420. bb0419 encodes a response regulator designated rrp1, and bb0420 encodes a hybrid histidine kinase-response regulator designated hpk1. rrp1, which contains a ...200919210621
functional characterization and novel rickettsiostatic effects of a kunitz-type serine protease inhibitor from the tick dermacentor variabilis.here we report the novel bacteriostatic function of a five-domain kunitz-type serine protease inhibitor (kpi) from the tick dermacentor variabilis. as ticks feed, they release anticoagulants, anti-inflammatory and immunosuppressive molecules that mediate the formation of the feeding lesion on the mammalian host. a number of kpis have been isolated and characterized from tick salivary gland extracts. interestingly, we observe little d. variabilis kpi gene expression in the salivary gland and abun ...200818779339
vertebrate hosts of ixodes pacificus (acari: ixodidae) in california.the western black-legged tick, ixodes pacificus cooley & kohls, is an important parasite and vector of disease agents that affect human and animal health in the western united states. this paper presents a review of all published california host records for i. pacificus. unpublished data from public health, academic, and vector control agencies and researchers were reviewed as well. host species were identified for each active life stage (larvae, nymph and adult). a total of 108 vertebrate speci ...200717633435
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
divergent evolution of arrested development in the dauer stage of caenorhabditis elegans and the infective stage of heterodera glycines.the soybean cyst nematode heterodera glycines is the most important parasite in soybean production worldwide. a comprehensive analysis of large-scale gene expression changes throughout the development of plant-parasitic nematodes has been lacking to date.200717919324
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
meningitis due to a "bartonella washoensis"-like human pathogen.we report the second human case of infection caused by an organism identified as the proposed bartonella species, "b. washoensis." the organism was isolated from a blood sample from a patient presenting with meningitis and early sepsis. oropsylla montana fleas were implicated as the vector for disease transmission in this case.200919439538
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
the diversity of reproductive parasites among arthropods: wolbachia do not walk alone.inherited bacteria have come to be recognised as important components of arthropod biology. in addition to mutualistic symbioses, a range of other inherited bacteria are known to act either as reproductive parasites or as secondary symbionts. whilst the incidence of the alpha-proteobacterium wolbachia is relatively well established, the current knowledge of other inherited bacteria is much weaker. here, we tested 136 arthropod species for a range of inherited bacteria known to demonstrate reprod ...200818577218
a comparison of visual and flagging methods for estimating adult ixodes pacificus (acari: ixodidae) tick abundance. 201021175953
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
the immunomodulatory action of sialostatin l on dendritic cells reveals its potential to interfere with autoimmunity.sialostatin l (sialol) is a secreted cysteine protease inhibitor identified in the salivary glands of the lyme disease vector ixodes scapularis. in this study, we reveal the mechanisms of sialol immunomodulatory actions on the vertebrate host. lps-induced maturation of dendritic cells from c57bl/6 mice was significantly reduced in the presence of sialol. although ova degradation was not affected by the presence of sialol in dendritic cell cultures, cathepsin s activity was partially inhibited, l ...200919494265
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
reptile infection with anaplasma phagocytophilum, the causative agent of granulocytic anaplasmosis.granulocytic anaplasmosis (ga) is a potentially fatal tick-borne rickettsial disease that occurs sporadically in the far western united states. we evaluated the prevalence of anaplasma phagocytophilum in multiple species of lizards and snakes from enzootic sites in northern california, described the infestation prevalence of its tick vector ixodes pacificus on reptiles, and conducted an experimental challenge of western fence lizards (sceloporus occidentalis) and pacific gopher snakes (pituophis ...200919281295
population structure of the lyme borreliosis spirochete borrelia burgdorferi in the western black-legged tick (ixodes pacificus) in northern california.factors potentially contributing to the lower incidence of lyme borreliosis (lb) in the far-western than in the northeastern united states include tick host-seeking behavior resulting in fewer human tick encounters, lower densities of borrelia burgdorferi-infected vector ticks in peridomestic environments, and genetic variation among b. burgdorferi spirochetes to which humans are exposed. we determined the population structure of b. burgdorferi in over 200 infected nymphs of the primary bridging ...200919783741
destruction of spirochete borrelia burgdorferi round-body propagules (rbs) by the antibiotic tigecycline.persistence of tissue spirochetes of borrelia burgdorferi as helices and round bodies (rbs) explains many erythema-lyme disease symptoms. spirochete rbs (reproductive propagules also called coccoid bodies, globular bodies, spherical bodies, granules, cysts, l-forms, sphaeroplasts, or vesicles) are induced by environmental conditions unfavorable for growth. viable, they grow, move and reversibly convert into motile helices. reversible pleiomorphy was recorded in at least six spirochete genera (>1 ...200919843691
identifying the reservoir hosts of the lyme disease spirochete borrelia burgdorferi in california: the role of the western gray squirrel (sciurus griseus).we investigated the role of the western gray squirrel (sciurus griseus) as a reservoir host of the lyme disease spirochete borrelia burgdorferi. a survey of 222 western gray squirrels in california showed an overall prevalence of b. burgdorferi infection of 30%, although at a county level, prevalence of infection ranged from 0% to 50% by polymerase chain reaction. laboratory trials with wild-caught western gray squirrels indicated that squirrels were competent reservoir hosts of the lyme disease ...200818840740
effect of prescribed fire for tick control in california chaparral.prescribed fire was investigated as a method for controlling ixodid and argasid ticks in chaparral habitats in northern california. two experimental and two adjacent control plots within a wildlife preserve were monitored for 1 yr postburn. ticks were collected by flagging vegetation, by co2-baited pitfall trap, and by live-trapping rodents. twice as many rodents were caught at control sites compared with burn sites and no dusky-footed woodrats, neotoma fuscipes baird, were found in the treatmen ...200919769046
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
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
[morphofunctional changes in the midgut of ticks of the genus ixodes (acarina: ixodidae) during life cycle].morphofunctional investigations of five ixodes species (ixodes pacificus, i. pavlovsky, i. persulcatus, i. ricinus and i. scapularis) were carried out. it was established, that the change of midgut epithelium lags at the each next developmental stage, and it is not synchronized with general processes of metamorphosis and organogenesis during molts. the midgut epithelium of a previous phase of the life cycle persists and functions during the feeding stage at the next phase.200919957908
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
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
prevalence of bartonella henselae and borrelia burgdorferi sensu lato dna in ixodes ricinus ticks in europe.bartonella spp. can cause persistent bloodstream infections in humans and animals. to determine whether bartonella henselae is present in questing ixodes ricinus ticks, we analyzed the prevalence of b. henselae dna among tick stages compared to the prevalence of dna from borrelia burgdorferi sensu lato, the pathogen most frequently transmitted by ticks. b. henselae dna was present with a prevalence of up to approximately 40% in tick populations sampled in four european sites (eberdingen, germany ...201020061459
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
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
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