Publications

an ecological approach to preventing human infection: vaccinating wild mouse reservoirs intervenes in the lyme disease cycle.	many pathogens, such as the agents of west nile encephalitis and plague, are maintained in nature by animal reservoirs and transmitted to humans by arthropod vectors. efforts to reduce disease incidence usually rely on vector control or immunization of humans. lyme disease, for which no human vaccine is currently available, is a commonly reported vector-borne disease in north america and europe. in a recently developed, ecological approach to disease prevention, we intervened in the natural cycl ...	2004	15608069
ixolaris: a factor xa heparin-binding exosite inhibitor.	ixolaris is a two-kunitz tfpi (tissue factor pathway inhibitor) from the tick salivary gland. in contrast with human tfpi, ixolaris binds tightly to the zymogen fx (factor x) and to dansyl-glu-gly-arg-chloromethyl ketone-treated fxa (degr-fxa; active-site-blocked fxa), indicating that exosites are involved in the fx(a)-ixolaris interaction. here we provide evidence that ixolaris binds specifically to the fxa hbe (heparin-binding exosite), since (i) it markedly decreases the inhibition of fxa by ...	2005	15617517
ehrlichia chaffeensis expresses macrophage- and tick cell-specific 28-kilodalton outer membrane proteins.	ehrlichia chaffeensis, a tick-transmitted rickettsial agent, causes human monocyte/macrophage-tropic ehrlichiosis. in this study, proteomic approaches were used to demonstrate host cell-specific antigenic expression by e. chaffeensis. the differentially expressed antigens include those from the 28-kda outer membrane protein (p28-omp) multigene locus. the proteins expressed in infected macrophages are the products of p28-omp19 and p28-omp20 genes, whereas in tick cells, the protein expressed is t ...	2005	15618143
anaplasma phagocytophilum modulates gp91phox gene expression through altered interferon regulatory factor 1 and pu.1 levels and binding of ccaat displacement protein.	infection of neutrophil precursors with anaplasma phagocytophilum, the causative agent of human granulocytic ehrlichiosis, results in downregulation of the gp91(phox) gene, a key component of nadph oxidase. we now show that repression of gp91(phox) gene transcription is associated with reduced expression of interferon regulatory factor 1 (irf-1) and pu.1 in nuclear extracts of a. phagocytophilum-infected cells. loss of pu.1 and irf-1 correlated with increased binding of the repressor, ccaat disp ...	2005	15618156
spatio-temporal analysis of reinfestation by triatoma infestans (hemiptera: reduviidae) following insecticide spraying in a rural community in northwestern argentina.	the spatio-temporal reinfestation patterns by triatoma infestans following a blanket insecticide spraying in the rural community of amama in northwestern argentina were analyzed using a geographic information system, satellite imagery, and spatial statistics. domestic and peridomestic reinfestation by triatomine bugs was monitored from 1993 to 1997. triatoma infestans was detected at least once in 75% of 2,110 sites evaluated. the prevalence of sites positive at least once for t. infestans durin ...	2004	15642975
allergens of the entomopathogenic fungus beauveria bassiana.	background: beauveria bassiana is an important entomopathogenic fungus currently under development as a bio-control agent for a variety of insect pests. although reported to be non-toxic to vertebrates, the potential allergenicity of beauveria species has not been widely studied. methods: ige-reactivity studies were performed using sera from patients displaying mould hypersensitivity by immunoblot and immunoblot inhibition. skin reactivity to b. bassiana extracts was measured using intradermal s ...	2005	15644142
wildlife as source of zoonotic infections.	zoonoses with a wildlife reservoir represent a major public health problem, affecting all continents. hundreds of pathogens and many different transmission modes are involved, and many factors influence the epidemiology of the various zoonoses. the importance and recognition of wildlife as a reservoir of zoonoses are increasing. cost-effective prevention and control of these zoonoses necessitate an interdisciplinary and holistic approach and international cooperation. surveillance, laboratory ca ...	2004	15663840
tick saliva inhibits differentiation, maturation and function of murine bone-marrow-derived dendritic cells.	haematophagous arthropod vectors such as mosquitoes, tsetse flies, sandflies and ticks have evolved salivary immunomodulatory factors that prevent the vertebrate host from rejecting them meanwhile enhancing pathogen transmission. as dendritic cells (dc) play a major role in host immune responses, we studied the effects of rhipicephalus sanguineus tick saliva on dc differentiation and maturation. flow cytometry analysis revealed that the addition of saliva to bone marrow cells inhibits the differ ...	2005	15667568
molecular differentiation of metastriate tick immatures.	hard ticks, family ixodidae, are divided into two groups, the metastriata and the prostriata, based on morphological differences. in the united states, there are four medically important genera of the ixodidae: ixodes, amblyomma, dermacentor, and rhipicephalus. ixodes is the only genus in and representative of the prostriata, whereas the latter three genera are members of the metastriata. all developmental stages of the prostriata can be easily differentiated from the metastriata using morpholog ...	2004	15682516
genetic variants of anaplasma phagocytophilum infecting dogs in western washington state.	eight dogs from western washington state suspected of being infected with anaplasma phagocytophilum because of the finding of morulae in peripheral blood neutrophils were studied for determination of the etiologic agent of disease. all cases were diagnosed between april 2003 and april 2004. six of the eight dogs had no travel history during the 6 months prior to presentation. two dogs had traveled within the northwest united states and canada. fever, lethargy, and anorexia were the most common c ...	2005	15695682
hypersensitivity to ticks and lyme disease risk.	although residents of lyme disease-endemic regions describe frequent exposure to ticks, lyme disease develops in relatively few. to determine whether people who experience cutaneous hypersensitivity against tick bite have fewer episodes of lyme disease than those who do not, we examined several factors that might restrict the incidence of lyme disease among residents of block island, rhode island. of 1,498 study participants, 27% (95% confidence interval [ci] 23%-31%) reported > or = 1 tick bite ...	2005	15705320
efficacy of a collar impregnated with amitraz and pyriproxyfen for prevention of experimental tick infestations by rhipicephalus sanguineus, ixodes ricinus, and ixodes scapularis in dogs.	to compare the efficacy of collars impregnated with 9% amitraz or 9% amitraz and 0.5% pyriproxyfen (ppf) for control of newly established tick infestations by rhipicephalus sanguineus, ixodes ricinus, and ixodes scapularis in dogs and determine whether egg production by surviving female ticks was decreased.	2005	15706971
reduced variation among northern deer tick populations at an autosomal microsatellite locus.	to determine whether genes flow freely between populations of the ixodes ricinus-like ticks of eastern north america, and to determine whether the abundant northerly populations of these vectors of lyme disease and other zoonotic infections may have arisen recently from a small cohort of ancestral founders, we characterized the nuclear ir27 microsatellite alleles in ticks sampled from the geographic extremes of their ranges. these microsatellite alleles differentiated populations located in the ...	2004	15707282
the roles of birds, lizards, and rodents as hosts for the western black-legged tick ixodes pacificus.	we compared the infestation by ixodid ticks of lizards, rodents, and birds collected simultaneously within areas representing common habitat types in mendocino county, ca. lizards were infested only by ixodes pacificus cooley and kohls, birds by i. pacificus and haemaphysalis leporispalustris (packard), and rodents by i. pacificus, i. spinipalpis hadwen and nuttall, i. woodi bishopp, dermacentor occidentalis marx, and d. variabilis (say). infestation by i. pacificus larvae and nymphs of lizards ...	2004	15709249
ectoparasites and other epifaunistic arthropods of sympatric cotton mice and golden mice: comparisons and implications for vector-borne zoonotic diseases.	ectoparasite and epifaunistic arthropod biodiversity and infestation parameters were compared between 2 sympatric small rodent species, the cotton mouse (peromyscus gossypinus (le conte)) and golden mouse (ochrotomys nuttalli (harlan)), in southern georgia from 1992 to 2003. because the cotton mouse is known to be a reservoir of more vector-borne zoonotic pathogens than the golden mouse, we hypothesized that it would be parasitized by more ectoparasites that are known to be vectors of these path ...	2004	15715219
interactions of ospa monoclonal antibody c3.78 with borrelia burgdorferi within ticks.	the borrelia burgdorferi outer surface protein a (ospa) vaccine induces antibodies that prevent transmission from the tick to the host. here we describe studies with an ospa monoclonal antibody (c3.78) to understand the mechanism by which antibodies entering the tick block borrelia transmission. host complement in the tick's blood meal did not contribute to protection because the antibody was equally effective whether infected ticks fed on normal or complement-deficient mice. antibody-mediated c ...	2005	15731064
borrelia burgdorferi sigma54 is required for mammalian infection and vector transmission but not for tick colonization.	previous studies have shown that a sigma54-sigma(s) cascade regulates the expression of a few key lipoproteins in borrelia burgdorferi, the agent of lyme disease. here, we demonstrate that these sigma factors, both together and independently, regulate a much more extensive number of genes and cellular processes. microarray analyses of sigma54 and sigma(s) mutant strains identified 305 genes regulated by sigma54 and 145 regulated by sigma(s), whereas the sigma54-sigma(s) regulatory cascade appear ...	2005	15743918
identification of a new borrelia species among small mammals in areas of northern spain where lyme disease is endemic.	the role of small mammals as reservoir hosts for borrelia burgdorferi was investigated in several areas where lyme disease is endemic in northern spain. a low rate of infestation by ixodes ricinus nymphs was found in the small mammal populations studied that correlated with the near-absence of b. burgdorferi sensu lato in 184 animals tested and with the lack of transmission of b. burgdorferi sensu lato to i. ricinus larvae that fed on them. in contrast, questing ticks collected at the same time ...	2005	15746336
detection and identification of ehrlichia spp. in ticks collected in tunisia and morocco.	a broad-range 16s rrna gene pcr assay followed by partial sequencing of the 16s rrna gene was used for the detection of members of the family anaplasmataceae in ticks in north africa. a total of 418 questing ixodes ricinus ticks collected in tunisia and morocco, as well as 188 rhipicephalus ticks from dogs and 52 hyalomma ticks from bovines in tunisia, were included in this study. of 324 adult i. ricinus ticks, 16.3% were positive for ehrlichia spp., whereas only 3.4 and 2.8% of nymphs and larva ...	2005	15750072
sequence analysis of the msp4 gene of anaplasma phagocytophilum strains.	the causative agent of human granulocytic ehrlichiosis was recently reclassified as anaplasma phagocytophilum, unifying previously described bacteria that cause disease in humans, horses, dogs, and ruminants. for the characterization of genetic heterogeneity in this species, the homologue of anaplasma marginale major surface protein 4 gene (msp4) was identified, and the coding region was pcr amplified and sequenced from a variety of sources, including 50 samples from the united states, germany, ...	2005	15750101
borreliacidal activity of saliva of the tick amblyomma americanum.	amblyomma americanum (linneaus) (acari: ixodidae), an important tick vector of human and animal disease, is not a competent vector of the bacterial agent of lyme disease, borrelia burgdorferi, although its range overlaps the geographical distribution of lyme disease within the united states. a possible mechanism that could prevent acquisition of b. burgdorferi spirochetes from infected hosts is the toxic effect of a. americanum saliva on b. burgdorferi. the data presented here indicate that afte ...	2005	15752182
repellency of deet and ss220 applied to skin involves olfactory sensing by two species of ticks.	responses of host-seeking nymphs of the blacklegged tick, ixodes scapularis say and lone star tick, amblyomma americanum (linnaeus) (acari: ixodidae) to the repellents n,n-diethyl-3-methylbenzamide (deet) and (1s, 2's)-2-methylpiperidinyl-3-cyclohexene-1-carboxamide (ss220) were studied using fingertip laboratory bioassays. ethanol solutions of both compounds applied to the skin strongly repelled both species of ticks at 0.8 and 1.6 micromole of compound/cm2 skin. the ticks were also repelled wh ...	2005	15752184
improving the specificity of 16s rdna-based polymerase chain reaction for detecting borrelia burgdorferi sensu lato-causative agents of human lyme disease.	16s rdna sequences of borrelia burgdorferi sensu lato were aligned with the 16s rdna sequences of borrelia hermsii, borrelia turicatae, and borrelia lonestari in order to identify primers that might be used to more specifically identify agents of human lyme disease in ticks in human skin samples.	2005	15752343
babesia microti, upstate new york.	five cases of human babesiosis were reported in the lower hudson valley region of new york state in 2001. an investigation to determine if babesia microti was present in local ixodes scapularis ticks yielded 5 positive pools in 123 pools tested, the first detection of b. microti from field-collected i. scapularis in upstate new york.	2005	15757571
a dynamic population model to investigate effects of climate on geographic range and seasonality of the tick ixodes scapularis.	a dynamic population model of ixodes scapularis, the vector of a number of tick-borne zoonoses in north america, was developed to simulate effects of temperature on tick survival and seasonality. tick development rates were modelled as temperature-dependent time delays, calculated using mean monthly normal temperature data from specific meteorological stations. temperature also influenced host-finding success in the model. using data from stations near endemic populations of i. scapularis, the m ...	2005	15777914
the ixodes scapularis genome project: an opportunity for advancing tick research.	the ixodes scapularis genome project (igp), the first to sequence a tick genome, will provide an unparalleled resource for studying tick biology and tick-host-pathogen relationships, and identifying novel targets for tick and tick-borne disease control. the igp will be the first genomic analysis of a member of the subphylum chelicerata and will accelerate the pace of tick research. the challenge for scientists is to translate igp data into public health benefits.	2005	15780833
genome size and organization in the blacklegged tick, ixodes scapularis and the southern cattle tick, boophilus microplus.	genome sizes and the organization of repetitive dna were determined in the hard ticks ixodes scapularis and boophilus microplus using reassociation kinetics. the i. scapularis genome contains approximately 2.15 pg (2.1x10(3) mbp) of dna and consists of no foldback (fb), 27% highly repetitive (hr), 39% moderately repetitive (mr), and 34% unique dna. the b. microplus genome contains 7.5 pg (7.1x10(3) mbp) dna, and consists of 0.82% fb, 31% hr, 38% mr, and 30% unique dna. in both species, repetitiv ...	2005	15796755
expression of the bmpb gene of borrelia burgdorferi is modulated by two distinct transcription termination events.	bmp gene family 36 of borrelia burgdorferi, the agent of lyme disease, comprises four paralogs: bmpa, bmpb, bmpc, and bmpd. the bmpa and bmpb genes constitute an operon. all four genes have been found to be transcribed in cultured spirochetes. expression from the bmpab operon results in three distinct transcripts of 1.1, 1.6, and 2.4 kb, and the relative expression of bmpa mrna is three- to fourfold greater than that of bmpb mrna. however, thus far only expression of the bmpa protein has been de ...	2005	15805505
analysis of fluorescent protein expression in transformants of rickettsia monacensis, an obligate intracellular tick symbiont.	we developed and applied transposon-based transformation vectors for molecular manipulation and analysis of spotted fever group rickettsiae, which are obligate intracellular bacteria that infect ticks and, in some cases, mammals. using the epicentre ez::tn transposon system, we designed transposons for simultaneous expression of a reporter gene and a chloramphenicol acetyltransferase (cat) resistance marker. transposomes (transposon-transposase complexes) were electroporated into rickettsia mona ...	2005	15812043
passive prophylaxis with permethrin-treated tents reduces mosquito bites among north american summer campers.	over 2 million adolescents participate in summer-camp experiences, placing themselves at risk for mosquito-borne illness. insect repellent is recommended but often not used. it is unknown whether permethrin treatment of a location, such as a campsite, provides passive prophylaxis reducing mosquito bites among all persons in the immediate vicinity.	0	15813141
the role of seasonality in the dynamics of deer tick populations.	in this paper, we formulate a nonlinear system of difference equations that models the three-stage life cycle of the deer tick over four seasons. we study the effect of seasonality on the stability and oscillatory behavior of the tick population by comparing analytically the seasonal model with a non-seasonal one. the analysis of the models reveals the existence of two equilibrium points. we discuss the necessary and sufficient conditions for local asymptotic stability of the equilibria and anal ...	2005	15820738
rna interference screening in ticks for identification of protective antigens.	ticks are ectoparasites of wild and domestic animals and humans, and are considered to be the most important arthropod vector of pathogens in north america. development of vaccines directed against tick proteins may effect reduction of tick infestations and transmission of tick-borne pathogens. the limiting step for the development of tick vaccines has been the identification of tick protective antigens. reverse vaccinology approaches aimed at reducing animal experimentation while allowing for t ...	2005	15824899
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 ...	2005	15827217
relapsing fever spirochetes contain chromosomal genes with unique direct tandemly repeated sequences.	genome sequencing of the relapsing fever spirochetes borrelia hermsii and borrelia turicatae identified three open reading frames (orfs) on the chromosomes that contained internal, tandemly repeated amino acid sequences that were absent in the lyme disease spirochete borrelia burgdorferi. the predicted amino acid sequences of these genes (bh0209, bh0512, and bh0553) have hydrophobic n termini, indicating that these proteins may be secreted. b. hermsii transcribed the three orfs in vitro, and the ...	2005	15845510
bpta (bbe16) is essential for the persistence of the lyme disease spirochete, borrelia burgdorferi, in its natural tick vector.	borrelia burgdorferi (bb), the agent of lyme disease, is a zoonotic spirochetal bacterium that depends on arthropod (ixodes ticks) and mammalian (rodent) hosts for its persistence in nature. the quest to identify borrelial genes responsible for bb's parasitic dependence on these two diverse hosts has been hampered by limitations in the ability to genetically manipulate virulent strains of bb. despite this constraint, we report herein the inactivation and genetic complementation of a linear plasm ...	2005	15860579
molecular identification and analysis of borrelia burgdorferi sensu lato in lizards in the southeastern united states.	lyme borreliosis (lb) group spirochetes, collectively known as borrelia burgdorferi sensu lato, are distributed worldwide. wild rodents are acknowledged as the most important reservoir hosts. ixodes scapularis is the primary vector of b. burgdorferi sensu lato in the eastern united states, and in the southeastern united states, the larvae and nymphs mostly parasitize certain species of lizards. the primary aim of the present study was to determine whether wild lizards in the southeastern united ...	2005	15870353
antibody testing and lyme disease risk.	lyme disease test results for >9,000 dogs were collected from participating veterinary clinics. testing was conducted by using the idexx 3dx kit, used widely by maine veterinarians to screen clinically normal dogs during heartworm season. this study demonstrates how this test can be a valuable public health disease surveillance tool.	2005	15890128
targeting exosites on blood coagulation proteases.	the high specificity of blood coagulation proteases has been attributed not only to residues surrounding the active site but also to other surface domains that are involved in recognizing and interacting with macromolecular substrates and inhibitors. specific blood coagulation inhibitors obtained from exogenous sources such as blood sucking salivary glands and snake venoms have been identified. some of these inhibitors interact with exosites on coagulation enzymes. two examples are discussed in ...	2005	15895163
histopathological studies of experimental lyme disease in the dog.	experimental borrelia infection was induced in 62 specific--pathogen-free beagle dogs by exposure to ixodes scapularis ticks harbouring the spirochaete borrelia burgdorferi. clinical signs of lyme disease occurred in 39/62 dogs, the remaining 23 being subclinically infected. clinical signs consisted of one to six episodes of transitory lameness with joint swelling and pain, most commonly affecting the elbow or shoulder joints. the polymerase chain reaction and culture demonstrated that the dogs ...	2005	15904927
immunoglobulin-regulated expression of borrelia burgdorferi outer surface protein a in vivo.	borrelia burgdorferi, the agent of lyme disease, down-regulates outer surface protein a (ospa), which is abundantly expressed in ticks, during infection of the mammalian host. in this study we examined the signals that may be responsible for maintaining the ospa-negative state of spirochetes during infection. transcription of ospa mrna was found in tissues of c3h-severe combined immunodeficient (c3h-scid) mice, but not immunocompetent c3h mice, inoculated with cultured b. burgdorferi, tick-borne ...	2005	15908357
birds, migration and emerging zoonoses: west nile virus, lyme disease, influenza a and enteropathogens.	wild birds are important to public health because they carry emerging zoonotic pathogens, either as a reservoir host or by dispersing infected arthropod vectors. in addition, bird migration provides a mechanism for the establishment of new endemic foci of disease at great distances from where an infection was acquired. birds are central to the epidemiology of west nile virus (wnv) because they are the main amplifying host of the virus in nature. the initial spread of wnv in the u.s. along the ea ...	2003	15931279
borreliacidal ospc antibodies specific for a highly conserved epitope are immunodominant in human lyme disease and do not occur in mice or hamsters.	humans produce highly specific borreliacidal antibodies against outer surface protein c (ospc) shortly after infection with borrelia burgdorferi sensu stricto. we previously demonstrated the epitope recognized by immunoglobulin m (igm) and igg ospc borreliacidal antibodies was located within the 50 amino acids nearest the carboxy (c) terminus. in this study, we show the immunodominant epitope is located in the highly conserved region within the seven c-terminal amino acids. six early lyme diseas ...	2005	15939749
transstadial and intrastadial experimental transmission of ehrlichia canis by male rhipicephalus sanguineus.	the acquisition and transmission of rickettsial pathogens by different tick developmental stages has important epidemiological implications. the purpose of this study was to determine if male rhipicephalus sanguineus can experimentally acquire and transmit ehrlichia canis in the absence of female ticks. two trials were performed where nymphal and male r. sanguineus were simultaneously acquisition fed on the same infected donor hosts, and transstadially or intrastadially exposed male ticks were f ...	2005	15941624
influence of meso- and microscale habitat structure on focal distribution of sympatric ixodes scapularis and amblyomma americanum (acari: ixodidae).	we compared the distribution of sympatric ixodes scapularis say and amblyomma americanum (l.) within several suitable forested habitats at different spatial scales and characterized differences in microhabitat features accounting for the observed distribution of questing ticks. we used automatic data loggers placed in the shrub and litter layers to contrast mesoclimate and microclimate conditions experienced by questing ticks. larger numbers of i. scapularis were collected at sites where the for ...	2005	15962776
oxalic acid as a fungal acaracidal virulence factor.	cell-free culture supernatants of the entomopathogenic fungus beauveria bassiana (bals.) vuillemin were able to induce mortality in several tick species, including adult ambylomma americanum (l.), ambylomma maculatum koch, and ixodes scapularis say. four lines of experimental evidence support the hypothesis that oxalic acid secretion by b. bassiana, coupled to a reduction in the ph of the medium, act as potent acaricidal factors during pathogenesis. 1) acaracidal activity of culture supernatants ...	2005	15962786
use of novel compounds for pest control: insecticidal and acaricidal activity of essential oil components from heartwood of alaska yellow cedar.	laboratory bioassays were conducted to determine the activity of 15 natural products isolated from essential oil components extracted from the heartwood of alaska yellow cedar, chamaecyparis nootkatensis (d. don) spach., against ixodes scapularis say nymphs, xenopsylla cheopis (rothchild), and aedes aegypti (l.) adults. four of the compounds from the essential oil have been identified as monoterpenes, five as eremophilane sesquiterpenes, five as eremophilane sesquiterpene derivatives from valenc ...	2005	15962787
western gray squirrel (rodentia: sciuridae): a primary reservoir host of borrelia burgdorferi in californian oak woodlands?	in california, dense woodlands have been recognized as important biotopes where humans are exposed to the nymphal stage of the western blacklegged tick, ixodes pacificus cooley & kohls, the primary vector of the lyme disease spirochete borrelia burgdorferi sensu stricto (s.s.), in the far-western united states. to identify the principal reservoir host(s) of this spirochete, and of closely related spirochetes in the b. burgdorferi sensu lato (s.l.) complex, in dense woodlands in mendocino county, ...	2005	15962792
relative encounter frequencies and prevalence of selected borrelia, ehrlichia, and anaplasma infections in amblyomma americanum and ixodes scapularis (acari: ixodidae) ticks from central new jersey.	to evaluate their relative importance in tick-borne disease transmission in new jersey, host-seeking amblyomma americanum (l.) and ixodes scapularis say adults and nymphs were collected during spring activity periods in 2003 and 2004 to determine relative frequencies at which these ticks were encountered from an area known to be hyperendemic for lyme disease. although similar numbers of the two species were encountered during early spring of both years, a. americanum were encountered more often ...	2005	15962799
presence of borrelia burgdorferi (spirochaetales: spirochaetaceae) in southern kettle moraine state forest, wisconsin, and characterization of strain w97f51.	lyme disease, caused by borrelia burgdorferi johnson, schmidt, hyde, steigerwalt & brenner; babesiosis, caused by babesia microti franca; and human granulocytic ehrlichiosis, caused by anaplasma phagocytophilum bakken & dumler have been reported in wisconsin, mainly in the endemic areas of the northwestern part of the state. people exposed to blacklegged ticks, ixodes scapularis say, from this region can potentially contract one or all of these diseases concurrently. within the past several year ...	2005	15962800
differential infectivity of the lyme disease spirochete borrelia burgdorferi derived from ixodes scapularis salivary glands and midgut.	blood fed nymphal ixodes scapularis say infected with borrelia burgdorferi were dissected to obtain salivary gland and midgut extracts. extracts were inoculated into c3h/hej mice, and ear, heart, and bladder were cultured to determine comparative infectivity. aliquots of extracts were then analyzed by quantitative polymerase chain reaction to determine the number of spirochetes inoculated into mice. a comparative median infectious dose (id50) was determined for both salivary gland and midgut ext ...	2005	15962807
pathogenicity of metarhizium anisopliae (deuteromycetes) and permethrin to ixodes scapularis (acari: ixodidae) nymphs.	effectiveness of the entomopathogenic fungus metarhizium anisopliae, for controlling nymphal ixodes scapularis, was tested in laboratory and field trials. in the laboratory, m. anisopliae (metschnikoff) sorokin strain esc1 was moderately pathogenic, with an lc50 of 10(7) spores/ml and induced 70% mortality at 10(9) spores/ml. in a field study, however, 10(9) spores/ml m. anisopliae did not effectively control questing i. scapularis nymphs, and significant differences were not detected in pre- an ...	2005	15969463
nairovirus rna sequences expressed by a semliki forest virus replicon induce rna interference in tick cells.	we report the successful infection of the cell line ise6 derived from ixodes scapularis tick embryos by the tick-borne hazara virus (hazv), a nairovirus in the family bunyaviridae. using a recombinant semliki forest alphavirus replicon that replicates in these cells, we were able to inhibit replication of hazv, and we showed that this blockage is mediated by the replication of the semliki forest alphavirus replicon; the vector containing the hazv nucleoprotein gene in sense or antisense orientat ...	2005	15994788
transcription analysis of the major antigenic protein 1 multigene family of three in vitro-cultured ehrlichia ruminantium isolates.	ehrlichia ruminantium, an obligate intracellular bacterium transmitted by ticks of the genus amblyomma, causes heartwater disease in ruminants. the gene coding for the major antigenic protein map1 is part of a multigene family consisting of a cluster containing 16 paralogs. in the search for differentially regulated genes between e. ruminantium grown in endothelial and tick cell lines that could be used in vaccine development and to determine if differences in the map1 gene cluster exist between ...	2005	15995193
analysis of the ospc regulatory element controlled by the rpon-rpos regulatory pathway in borrelia burgdorferi.	outer surface lipoprotein c (ospc) is a key virulence factor of borrelia burgdorferi. ospc is differentially regulated during borrelial transmission from ticks to rodents, and such regulation is essential for maintaining the spirochete in its natural enzootic cycle. recently, we showed that the expression of ospc in b. burgdorferi is governed by a novel alternative sigma factor regulatory network, the rpon-rpos pathway. however, the precise mechanism by which the rpon-rpos pathway controls ospc ...	2005	15995197
characterization of three ixodes scapularis cdnas protective against tick infestations.	cdna expression library immunization (eli) and analysis of expressed sequenced tags (est) in a mouse model of tick infestations was used to identified cdna clones that affected i. scapularis. three protective antigens against larval tick infestations, 4f8, with homology to a nucleotidase, and 4d8 and 4e6 of unknown function, were selected for further characterization. all three antigens were expressed in all i. scapularis stages and localized in adult tick tissues. 4d8 was shown to be conserved ...	2005	16005748
effectiveness of metarhizium anisopliae (deuteromycetes) against ixodes scapularis (acari: ixodidae) engorging on peromnyscus leucopus.	with the incidence of lyme disease increasing throughout the united states, reducing risk of exposure to the disease is of the utmost concern. in the northeastern u.s., the blacklegged tick, ixodes scapularis, is the primary vector and the white-footed mouse, (peromyscus leucopus), the primary reservoir for borrelia burgdorteri, the bacterium causing lyme disease. targeting i. scapularis engorging on white-footed mice with an effective biological control agent, such as the fungus metarhizium ani ...	2005	16007961
diagnosis of lyme borreliosis.	a large amount of knowledge has been acquired since the original descriptions of lyme borreliosis (lb) and of its causative agent, borrelia burgdorferi sensu stricto. the complexity of the organism and the variations in the clinical manifestations of lb caused by the different b. burgdorferi sensu lato species were not then anticipated. considerable improvement has been achieved in detection of b. burgdorferi sensu lato by culture, particularly of blood specimens during early stages of disease. ...	2005	16020686
effects of barrier application of granular deltamethrin on subadult ixodes scapularis (acari: ixodidae) and nontarget forest floor arthropods.	we evaluated the effects of a single application of granular deltamethrin made against nymphal ixodes scapularis say on the diversity and abundance of forest arthropods taken in pitfall traps in oak forest sites for 16 wk after treatment in central new jersey. control of i. scapularis subadults on treated plots ranged between 97 and 100% and continued at least 12 wk postapplication. significant short-term changes in arthropod assemblages were detected at one of three study sites within 4 wk post ...	2005	16025588
third borrelia species in white-footed mice.		2005	16032795
capillary feeding of specific dsrna induces silencing of the isac gene in nymphal ixodes scapularis ticks.	ixodes scapularis transmits several pathogens including borrelia burgdorferi. bioactive compounds in tick saliva support tick feeding and influence pathogen transmission to the mammalian host. these studies utilized oral delivery of dsrna to silence an anticomplement gene (isac) in i. scapularis nymphs. silencing of isac significantly reduced fed-tick weight compared to delivery of control lacz dsrna, and immunoblots specific for flab protein indicated a reduction in spirochete load in isac-sile ...	2005	16033437
the lyme disease agent exploits a tick protein to infect the mammalian host.	the lyme disease agent, borrelia burgdorferi, is maintained in a tick-mouse cycle. here we show that b. burgdorferi usurps a tick salivary protein, salp15 (ref. 3), to facilitate the infection of mice. the level of salp15 expression was selectively enhanced by the presence of b. burgdorferi in ixodes scapularis, first indicating that spirochaetes might use salp15 during transmission. salp15 was then shown to adhere to the spirochaete, both in vitro and in vivo, and specifically interacted with b ...	2005	16049492
role of borrelia burgdorferi linear plasmid 25 in infection of ixodes scapularis ticks.	the tick-borne bacterium borrelia burgdorferi has over 20 different circular and linear plasmids. some b. burgdorferi plasmids are readily lost during in vitro culture or genetic manipulation. linear plasmid 25, which is often lost in laboratory strains, is required for the infection of mice. strains missing linear plasmid 25 (lp25(-)) are able to infect mice if the bbe22 gene on lp25 is provided on a shuttle vector. in this study, we examined the role of lp25 and bbe22 in tick infections. we te ...	2005	16077125
lyme disease agent borrows a practical coat.		2005	16079876
experimental infection of white-tailed deer with anaplasma phagocytophilum, etiologic agent of human granulocytic anaplasmosis.	serologic and molecular evidence of anaplasma phagocytophilum has been demonstrated in white-tailed deer (wtd; odocoileus virginianus), and deer are an important host for the tick vector ixodes scapularis. in this study, we describe experimental infection of wtd with a. phagocytophilum. we inoculated four wtd with a human isolate of a. phagocytophilum propagated in tick cells. two additional deer served as negative controls. all inoculated deer developed antibodies (titers, > or =64) to a. phago ...	2005	16081884
epidemiology and transmission dynamics of west nile virus disease.	from 1937 until 1999, west nile virus (wnv) garnered scant medical attention as the cause of febrile illness and sporadic encephalitis in parts of africa, asia, and europe. after the surprising detection of wnv in new york city in 1999, the virus has spread dramatically westward across the united states, southward into central america and the caribbean, and northward into canada, resulting in the largest epidemics of neuroinvasive wnv disease ever reported. from 1999 to 2004, >7,000 neuroinvasiv ...	2005	16102302
the transcriptome of the salivary glands of the female western black-legged tick ixodes pacificus (acari: ixodidae).	sequencing of an ixodes pacificus salivary gland cdna library yielded 1068 sequences with an average undetermined nucleotide of 1.9% and an average length of 487 base pairs. assembly of the expressed sequence tags yielded 557 contigs, 138 of which appear to code for secreted peptides or proteins based on translation of a putative signal peptide. based on the blastx similarity of these contigs to 66 matches of ixodes scapularis peptide sequences, only 58% sequence identity was found, indicating a ...	2005	16102420
tick saliva is a potent inhibitor of endothelial cell proliferation and angiogenesis.	we report for the first time that saliva of the hard tick and lyme disease vector, ixodes scapularis, is a potent inhibitor of angiogenesis. saliva (< or = 1:500 dilutions) or salivary gland (0.1-0.5 pairs/assay) dose-dependently inhibits microvascular endothelial cell (mvec) proliferation. inhibition was also detected with the saliva of the cattle tick boophilus microplus but not with the salivary gland of anopheles gambiae, an. stephensi, lutzomyia longipalpis, phlebotomus papatasi, aedes aegy ...	2005	16113800
spatiotemporal patterns of reinfestation by triatoma guasayana (hemiptera: reduviidae) in a rural community of northwestern argentina.	triatoma guasayana (wygodzinsky & abalos) is a secondary vector of trypanosoma cruzi (chagas), the etiologic agent of chagas disease, in the chaco region of argentina, bolivia, and paraguay. the spatial distribution of t. guasayana in a rural community in northwestern argentina is described and analyzed using very high spatial resolution satellite imagery, geographic information systems, and spatial statistics. since a 1992 residual spraying with insecticides of all houses, site-specific domesti ...	2005	16119545
seasonality in diurnal locomotory patterns of adult blacklegged ticks (acari: ixodidae).	we continuously recorded the activity of adult and nymphal blacklegged ticks, ixodes scapularis say, exposed to diurnal light and temperature cycles in a laboratory test chamber by using a digital camera controlled by an intervalometer. adult ticks collected and tested in the fall exhibited a bimodal pattern of activity, with peaks shortly after lights on and shortly after lights off, and substantial daytime activity. however, adult ticks collected in the winter and early spring exhibited a unim ...	2005	16119546
defining plasmids required by borrelia burgdorferi for colonization of tick vector ixodes scapularis (acari: ixodidae).	maintenance in nature of borrelia burgdorferi, the pathogenic bacterium that causes lyme disease, requires transmission through an infectious cycle that includes a tick vector and a mammalian host. the genetic requirements for persistence in these disparate environments have not been well defined. b. burgdorferi has a complex genome composed of a chromosome and >20 plasmids. previous work has demonstrated that b. burgdorferi requires two plasmids, lp25 and lp28-1, in the mammalian host. to inves ...	2005	16119559
detection of babesia microti dna in ixodes scapularis (acari: ixodidae) by use of chelex 100 resin and polymerase chain reaction.	a rapid and sensitive protocol using chelex 100 resin for dna extraction and the polymerase chain reaction for detection of babesia microti franca within its vector ixodes scapularis say is described. the level of detection of this protocol was determined to be the approximate equivalent of one parasite.	2005	16119561
new gammaproteobacteria associated with blood-feeding leeches and a broad phylogenetic analysis of leech endosymbionts.	many monophagous animals have coevolutionary relationships with bacteria that provide unavailable nutrients to the host. frequently, these microbial partners are vertically inherited and reside in specialized structures or tissues. here we report three new lineages of bacterial symbionts of blood-feeding leeches, one from the giant amazonian leech, haementeria ghilianii, and two others from placobdelloides species. these hosts each possess a different mycetome or esophageal organ morphology wher ...	2005	16151107
vaccination with recombinant tick antigens for the control of ixodes scapularis adult infestations.	antigens protective against ixodes scapularis infestations were identified by cdna expression library immunization (eli) and analysis of expressed sequenced tags (est). three cdnas protective against larval tick infestations, 4f8, with homology to a nucleotidase, and 4d8 and 4e6 of unknown function, were characterized and obtained as recombinant proteins for immunization studies. vaccination trials with recombinant proteins demonstrated an effect of these antigens against i. scapularis larvae in ...	2005	16153760
antiviral silencing in animals.	rna silencing or rna interference (rnai) refers to the small rna-guided gene silencing mechanism conserved in a wide range of eukaryotic organisms from plants to mammals. as part of this special issue on the biology, mechanisms and applications of rnai, here we review the recent advances on defining a role of rnai in the responses of invertebrate and vertebrate animals to virus infection. approximately 40 mirnas and 10 rnai suppressors encoded by diverse mammalian viruses have been identified. a ...	2005	16154568
tick exposure and lyme disease at a summer camp in maryland.	after investigating an outbreak of lyme disease among counselors at a summer camp in kent county, maryland in 1994, we wanted to determine the incidence of lyme disease (ld) at the camp the following summer and identify risk factors for tick exposure. any ticks that were detected on campers' skin or clothing were collected by the camp nurse and we studied them for infection with borrelia burgdorferi. in addition, we sent detailed questionnaires home with the 1,623 campers. a total of 537 campers ...	2005	16161531
the abcs of lyme disease spirochaetes in ticks.		2005	16168758
variable tick protein in two genomic groups of the relapsing fever spirochete borrelia hermsii in western north america.	borrelia hermsii is the primary cause of tick-borne relapsing fever in north america. when its tick vector, ornithodoros hermsi, acquires these spirochetes from the blood of an infected mammal, the bacteria switch their outer surface from one of many bloodstream variable major proteins (vmps) to a unique protein, vtp (vsp33). vtp may be critical for successful tick transmission of b. hermsii; however, the gene encoding this protein has been described previously in only one isolate. here we ident ...	2005	16177341
forest fragmentation predicts local scale heterogeneity of lyme disease risk.	fragmentation of the landscape has been proposed to play an important role in defining local scale heterogeneity in lyme disease risk through influence on mammalian host density and species composition. we tested this observed relationship in a suburban region around lyme, connecticut, where we collected data on the density of the tick vector, ixodes scapularis and prevalence of the lyme bacterium, borrelia burgdorferi at 30 sites. analysis of the landscape pattern of forest patches was performe ...	2005	16187106
geographic distribution of ticks (acari: ixodidae) in iowa with emphasis on ixodes scapularis and their infection with borrelia burgdorferi.	in iowa, public concern regarding lyme disease has increased markedly over the last decade. in response to these concerns, a statewide surveillance program was initiated in 1990 based on ticks received by the department of entomology at iowa state university. ticks were received from health care professionals, state government agencies, and the general public. a total of 5,343 ticks from all 99 iowa counties were identified during the 12 years of this study. dermacentor variabilis was the most n ...	2005	16187889
oral vaccine that breaks the transmission cycle of the lyme disease spirochete can be delivered via bait.	borrelia burgdorferi causes lyme disease, a potentially debilitating human disease for which no vaccine is currently available. we developed an oral bait delivery system for an anti-b. burgdorferi vaccine based in ospa. mice were immunized orally via gavage and bait feeding. challenge was performed via ixodes scapularis field nymphs carrying multiple b. burgdorferi strains. vaccination protected 89% of the mice and the systemic immune response was skewed toward igg2a/2b production. moreover, thi ...	2006	16198456
serologic cross-reactivity between anaplasma marginale and anaplasma phagocytophilum.	in the context of a serosurvey conducted on the anaplasma marginale prevalence in swiss cattle, we suspected that a serological cross-reactivity between a. marginale and a. phagocytophilum might exist. in the present study we demonstrate that cattle, sheep and horses experimentally infected with a. phagocytophilum not only develop antibodies to a. phagocytophilum (detected by immunofluorescent-antibody assay) but also to a. marginale (detected by a competitive enzyme-linked immunosorbent assay). ...	2005	16210480
tick modulation of the in-vitro expression of adhesion molecules by skin-derived endothelial cells.	as a tick feeds, its saliva induces innate and acquired immune responses in the host, including leucocyte infiltration into the bite site. tick salivary glands produce molecules, however, that counteract many host defences against blood feeding. the effects of salivary-gland extracts (sge) of dermacentor andersoni and ixodes scapularis on the expression of various adhesion molecules [e-selectin, p-selectin, intercellular adhesion molecule 1 (icam-1) and vascular cell adhesion molecule 1 (vcam-1) ...	2005	16212800
tick-borne rickettsioses around the world: emerging diseases challenging old concepts.	during most of the 20th century, the epidemiology of tick-borne rickettsioses could be summarized as the occurrence of a single pathogenic rickettsia on each continent. an element of this paradigm suggested that the many other characterized and noncharacterized rickettsiae isolated from ticks were not pathogenic to humans. in this context, it was considered that relatively few tick-borne rickettsiae caused human disease. this concept was modified extensively from 1984 through 2005 by the identif ...	2005	16223955
climate change and the potential for range expansion of the lyme disease vector ixodes scapularis in canada.	we used an ixodes scapularis population model to investigate potential northward spread of the tick associated with climate change. annual degree-days >0 degrees c limits for i. scapularis establishment, obtained from tick population model simulations, were mapped using temperatures projected for the 2020s, 2050s and 2080s by two global climate models (the canadian cgcm2 and the uk hadcm3) for two greenhouse gas emission scenario enforcings 'a2'and 'b2' of the intergovernmental panel on climate ...	2006	16229849
anaplasma phagocytophilum infection (granulocytic anaplasmosis) in a dog from vancouver island.	a 7-year-old labrador retriever had nonspecific clinical signs that included lethargy, malaise, and difficult ambulation. the dog was native to vancouver island, british columbia, and had never left this area. morulae were identified in polymorphonuclear cells. serologic studies and polymerase chain reaction (pcr) testing confirmed canine anaplasmosis caused by anaplasma phagocytophilum. the dog recovered after treatment with tetracycline.	2005	16231653
expression library immunization: a road map for discovery of vaccines against infectious diseases.		2005	16239502
association of linear plasmid 28-1 with an arthritic phenotype of borrelia burgdorferi.	borrelia burgdorferi, the lyme disease spirochete, has a genome comprised of a linear chromosome and up to 21 plasmids. loss of plasmids is associated with decreased infectivity and pathogenicity. sixteen transformants were generated by transforming the noninfectious clone 5a13 with the recombinant plasmid pbbe22. the transformants were classified into nine groups based on plasmid content analysis. an infectivity study revealed that all nine transformants examined, each of which represented one ...	2005	16239515
borrelia burgdorferi regulates expression of complement regulator-acquiring surface protein 1 during the mammal-tick infection cycle.	during the natural mammal-tick infection cycle, the lyme disease spirochete borrelia burgdorferi comes into contact with components of the alternative complement pathway. b. burgdorferi, like many other human pathogens, has evolved the immune evasion strategy of binding two host-derived fluid-phase regulators of complement, factor h and factor h-like protein 1 (fhl-1). the borrelial complement regulator-acquiring surface protein 1 (crasp-1) is a surface-exposed lipoprotein that binds both factor ...	2005	16239539
factors influencing in vitro infectivity and growth of rickettsia peacockii (rickettsiales: rickettsiaceae), an endosymbiont of the rocky mountain wood tick, dermacentor andersoni (acari, ixodidae).	rickettsia peacockii, a spotted fever group rickettsia, is a transovarially transmitted endosymbiont of rocky mountain wood ticks, dermacentor andersoni. this rickettsia, formerly known as the east side agent and restricted to female ticks, was detected in a chronically infected embryonic cell line, dae100, from d. andersoni. we examined infectivity, ability to induce cytopathic effect (cpe) and host cell specificity of r. peacockii using cultured arthropod and mammalian cells. aposymbiotic dae1 ...	2005	16288906
early transcriptional response of human neutrophils to anaplasma phagocytophilum infection.	anaplasma phagocytophilum, an unusual obligate intracellular pathogen that persists within neutrophils, causes human anaplasmosis (previously known as human granulocytic ehrlichiosis). to study the effects of this pathogen on the transcriptional profile of its host cell, we performed a comprehensive dna microarray analysis of the early (4-h) transcriptional response of human neutrophils to a. phagocytophilum infection. a. phagocytophilum infection resulted in the up- and down-regulation of 177 a ...	2005	16299303
protective efficacy of an oral vaccine to reduce carriage of borrelia burgdorferi (strain n40) in mouse and tick reservoirs.	lyme disease is caused by the spirochete borrelia burgdorferi, which is transmitted through the bite of infected ixodes ticks. vaccination of mice with outer surface protein a (ospa) of b. burgdorferi has been shown to both protect mice against b. burgdorferi infection and reduce carriage of the organism in feeding ticks. here we report the development of a murine-targeted ospa vaccine utilizing vaccinia virus to interrupt transmission of disease in the reservoir hosts, thus reducing incidence o ...	2006	16300863
anaplasma phagocytophilum in white-tailed deer.	we examined the reservoir potential of white-tailed deer for anaplasma phagocytophilum. results suggest that white-tailed deer harbor a variant strain not associated with human infection, but contrary to published reports, white-tailed deer are not a reservoir for strains that cause human disease. these results will affect surveillance studies of vector and reservoir populations.	2005	16318705
anaplasma phagocytophilum-infected ticks, japan.	we report anaplasma phagocytophilum infection of ixodes persulcatus and i. ovatus ticks in japan. unique p44/msp2 paralogs (and/or 16s rrna genes) were detected in tick tissues, salivary glands, and spleens of experimentally infected mice. these findings indicate the public health threat of anaplasmosis in japan.	2005	16318739
the molecular and biological analysis of ixodid ticks histamine release factors.	we previously described a dermacentor varibialis (dv) cdna that encodes a ubiquitously expressed and tick saliva-secreted functional histamine release factor (hrf) homolog. in this study gene specific primers based on dvhrf open reading frame nucleotide sequence were utilized to amplify three orthologs, from the wood tick, d. andersoni (da), the black legged tick, the southern cattle tick, boophilus microplus (bm) and the lone star tick, amblyomma americanum (aa). at nucleotide level, sequence c ...	2005	16323052
seroprevalence of antibodies against borrelia burgdorferi and anaplasma phagocytophilum in cats.	to determine whether cats in the northeastern united states develop serum antibodies against antigens of borrelia burgdorferi and anaplasma phagocytophilum and whether coinfection with the 2 organisms occurs.	2005	16334946
a defensin-like gene expressed in the black-legged tick, ixodes scapularis.	the black-legged tick ixodes scapularis linnaeus (acari: ixodidae) is an important vector of microbial pathogens. knowledge of the tick's innate immune response, particularly defensin and other antimicrobial peptides, is important for understanding how microbes survive in this tick. a defensin gene (slna) from i. scapularis was obtained by reverse transcription-polymerase chain reaction (rt-pcr) using mrna extracted from tissues of female ticks. rt-pcr indicated the gene was expressed in the mid ...	2005	16336297
invhogen: a database of homologous invertebrate genes.	classification of proteins into families of homologous sequences constitutes the basis of functional analysis or of evolutionary studies. here we present invertebrate homologous genes (invhogen), a database combining the available invertebrate protein genes from uniprot (consisting of swiss-prot and trembl) into gene families. for each family invhogen provides a multiple protein alignment, a maximum likelihood based phylogenetic tree and taxonomic information about the sequences. it is possible ...	0	16381884
fas ligand deficiency impairs host inflammatory response against infection with the spirochete borrelia burgdorferi.	lyme disease represents a complex response to borrelia burgdorferi that involves both bacterial factors as well as host responses. this results in an inflammatory reaction at several sites, including the synovial lining of joints. synovial tissues of inflamed joints contain cells expressing high levels of fas and fas ligand (fasl). although fas stimulation is typically associated with cell death, it can also transmit stimulatory signals to certain cell types. among these are dendritic cells and ...	2006	16428764
reservoir competency of goats for the ap-variant 1 strain of anaplasma phagocytophilum.	field-collected ticks were used to infect goats with either ap-ha, a strain associated with human disease, or a variant strain, ap-variant 1, of anaplasma phagocytophilum. goats were shown to be competent as a reservoir for ap-variant 1, and challenge and immunosuppression studies were used to further examine infection in the goat model.	2006	16428787
an annotated catalog of salivary gland transcripts from ixodes scapularis ticks.	over 8000 expressed sequence tags from six different salivary gland cdna libraries from the tick ixodes scapularis were analyzed. these libraries derive from feeding nymphs infected or not with the lyme disease agent, borrelia burgdorferi, from unfed adults, and from adults feeding on a rabbit for 6-12 h, 18-24 h, and 3-4 days. comparisons of the several libraries led to identification of several significantly differentially expressed transcripts. additionally, over 500 new predicted protein seq ...	2006	16431279