Publications

an in vivo rodent model for identifying and characterizing acaricides.	evaluation of candidate acaricides in livestock or companion animals is expensive, time-consuming, and usually requires large quantities of test material. to identify promising substances at the earliest possible stage of the development process, robust and predictive surrogate animal models, capable of rapidly characterizing potency with minimal compound requirements, are necessary. the objective of this study was to generate an in vivo surrogate animal bioassay capable of rapidly and accuratel ...	2006	16739411
a novel real-time pcr assay for the speciation of medically important ticks.	the identification of ticks using morphological characters is a well-established practice, however specimens that are small or damaged are often difficult to speciate. a novel, rapid real-time pcr assay, which targets the second internal transcribed spacer (its2) region in the nuclear ribosomal dna gene, was developed for identification of four tick species of utmost medical importance in the united states: ixodes scapularis, i. pacificus, dermacentor variabilis, and amblyomma americanum. comput ...	2006	16796512
relative abundance and survival of the tick amblyomma americanum collected from sunlit and shaded habitats.	the population density of host-searching nymphal and adult lone star ticks, amblyomma americanum (l.) (acari: ixodidae), was determined at the robinson tract of the kansas ecological reserves and a private farm 5 km north-west of the robinson tract using standard drag cloth methods. nymphs, males and females were counted and collected weekly from shaded habitats and adjacent sunlit habitats from mid-may through late july, 2003. of the 1598 nymphs and 549 males collected by drag sampling, 74.0% a ...	2006	16796613
inferring the population structure and demographic history of the tick, amblyomma americanum linnaeus.	a hierarchial population genetic study was conducted on 703 individual amblyomma americanum from nine populations in georgia, u.s.a. populations were sampled from the coastal plain, midland piedmont region, and the upper piedmont region. twenty-nine distinct haplotypes were found. a minimum spanning tree was constructed that indicated these haplotypes comprised two lineages, the root of which was distinctly star-like. the majority of the variation found was among ticks within each population, in ...	2006	16859107
lymph node hemophagocytosis in rickettsial diseases: a pathogenetic role for cd8 t lymphocytes in human monocytic ehrlichiosis (hme)?	human monocytic ehrlichiosis (hme) and rocky mountain spotted fever (rmsf) are caused by ehrlichia chaffeensis and rickettsia rickettsii, respectively. the pathogenesis of rmsf relates to rickettsia-mediated vascular injury, but it is unclear in hme.	2006	16859547
efficacy of imidacloprid (8.8% w/w) plus permethrin (44% w/w) spot-on topical solution against amblyomma americanum infesting dogs using a natural tick exposure model.	this study evaluated the efficacy of an imidacloprid 8.8% w/w + permethrin 44% w/w spot-on topical solution (k9 advantix, bayer animal health) against amblyomma americanum using a natural field exposure model. sixteen beagles were divided into two groups of eight dogs each. one group of dogs was treated with k9 advantix and the other group served as untreated controls. on day -1 and at 3, 7, 14, 21 and 28 days after treatment, the dogs were walked for 80 minutes in an a. americanum-infested habi ...	2006	16871491
isolation and identification of rickettsia massiliae from rhipicephalus sanguineus ticks collected in arizona.	twenty rhipicephalus sanguineus ticks collected in eastern arizona were tested by pcr assay to establish their infection rate with spotted fever group rickettsiae. with a nested pcr assay which detects a fragment of the rickettsia genus-specific 17-kda antigen gene (htra), five ticks (25%) were found to contain rickettsial dna. one rickettsial isolate was obtained from these ticks by inoculating a suspension of a triturated tick into monolayers of vero e6 monkey kidney cells and xtc-2 clawed toa ...	2006	16885311
the emerging diversity of rickettsia.	the best-known members of the bacterial genus rickettsia are associates of blood-feeding arthropods that are pathogenic when transmitted to vertebrates. these species include the agents of acute human disease such as typhus and rocky mountain spotted fever. however, many other rickettsia have been uncovered in recent surveys of bacteria associated with arthropods and other invertebrates; the hosts of these bacteria have no relationship with vertebrates. it is therefore perhaps more appropriate t ...	2006	16901827
unique macrophage and tick cell-specific protein expression from the p28/p30-outer membrane protein multigene locus in ehrlichia chaffeensis and ehrlichia canis.	ehrlichia chaffeensis and ehrlichia canis are tick-transmitted rickettsial pathogens that cause human and canine monocytic ehrlichiosis respectively. we tested the hypothesis that these pathogens express unique proteins in response to their growth in vertebrate and tick host cells and that this differential expression is similar in closely related ehrlichia species. evaluation of nine e. chaffeensis isolates and one e. canis isolate demonstrated that protein expression was host cell-dependent. t ...	2006	16922866
confirmation of tick bite by detection of antibody to ixodes calreticulin salivary protein.	ticks introduce a variety of pharmacologically active molecules into their host during attachment and feeding in order to obtain a blood meal. people who are repeatedly exposed to ticks may develop an immune response to tick salivary proteins. despite this response, people usually are unaware of having been bitten, especially if they are not repeatedly exposed to ticks. in order to develop a laboratory marker of tick exposure that would be useful in understanding the epidemiology of tick-borne i ...	2006	16928887
tick-borne rickettsial pathogens in ticks and small mammals in korea.	in order to investigate the prevalence of tick-borne infectious agents among ticks, ticks comprising five species from two genera (hemaphysalis spp. and ixodes spp.) were screened using molecular techniques. ticks (3,135) were collected from small wild-caught mammals or by dragging/flagging in the republic of korea (rok) and were pooled into a total of 1,638 samples (1 to 27 ticks per pool). from the 1,638 tick samples, species-specific fragments of anaplasma phagocytophilum (1 sample), anaplasm ...	2006	16957192
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
orally active acaricidal peptide toxins from spider venom.	numerous species of ticks and mites (collectively known as acarines) are serious pests of animals, humans, and crops. there are few commercially available acaricides and major classes of these chemicals continue to be lost from the marketplace due to resistance development or deregistration by regulatory agencies. there is consequently a pressing need to isolate new and safe acaricidal compounds. in this study, we show that two families of peptide neurotoxins isolated from the venom of the austr ...	2006	16330063
ehrlichia under our noses and no one notices.	ehrlichia chaffeensis, an obligately intracellular bacterium, resides within a cytoplasmic vacuole in macrophages, establishes persistent infection in natural hosts such as white-tailed deer and canids, and is transmitted transstadially and during feeding by ticks, particularly amblyomma americanum. ehrlichial cell walls contain glycoproteins and a family of divergent 28 kda proteins, but no peptidoglycan or lipopolysaccharide. the dense-cored ultrastructural form preferentially expresses certai ...	2005	16358425
capillary tube feeding system for studying tick-pathogen interactions of dermacentor variabilis (acari: ixodidae) and anaplasma marginale (rickettsiales: anaplasmataceae).	a capillary tube feeding (ctf) system was adapted for studying the interaction between dermacentor variabilis (say) and the rickettsial cattle pathogen anaplasma marginale theiler. a. marginale undergoes a complex developmental cycle in ticks that begins in midguts and ends by transmission from salivary glands. in this ctf system, male d. variabilis were fed a. marginale-infected blood or cultured tick cells. ticks that fed on highly rickettsemic calves developed midgut and salivary gland infect ...	2005	16366000
distribution of borreliae among ticks collected from eastern states.	lyme disease is the most commonly reported vector-borne disease in the united states and is transmitted by borrelia burgdorferi-infected ixodes species. the disease is typically characterized by an erythema migrans (em) rash at the site of tick feeding. em rashes have also been associated with feeding by amblyomma americanum ticks despite evidence suggesting that they are incompetent vectors for lyme disease. in 1996, a borrelia organism only recently cultivated in the laboratory was described i ...	2005	16417434
theileriosis in a white-tailed deer (odocoileus virginianus) fawn.	a white-tailed deer (odocoileus virginianus) fawn was collected in missouri (usa) and submitted for diagnostic evaluation. necropsy and histologic examination revealed severe amblyomma americanum infestation, pronounced icterus, and marked hemosiderin deposition in the liver and spleen. whole blood evaluation revealed a normocytic normochromic anemia and a piroplasm parasitemia of approximately 70%. the piroplasm was identified as theileria cervi by polymerase chain reaction and sequencing of th ...	2005	16456174
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
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
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
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
ticks (acari: ixodoidea: argasidae, ixodidae) of chile.	the tick species recorded from chile can be listed under the following headings: (1) endemic or established: argas keiransi estrada-peña, venzal and gonzalez-acuña, a. neghmei kohls and hoogstraal; ornithodoros amblus chamberlin; otobius megnini (dugès); amblyomma parvitarsum neumann; a. tigrinum koch; ixodes auritulus neumann; i. chilensis kohls; i. cornuae arthur, i. sigelos keirans, clifford and corwin; i. stilesi neumann; i. uriae white; rhipicephalus sanguineus koch. (2) probably establishe ...	2005	15777007
comparison of in vitro and in vivo ectoparasiticide activity of experimental benzimidazole-carbamate with permethrin and amitraz.	a series of in vitro and in vivo bioassays were conducted to assess the ectoparasiticide activity of isopropyl-4-nitro-2,6-bis(trifluoromethyl)-1-benzimidazole-carbamate, an experimental benzimidazole-carbamate class compound. this compound was less potent than permethrin against ectoparasiticide-susceptible larvae of the lone star tick, amblyomma americanum (l.) (acari: ixodidae); larvae of the southern cattle tick, boophilus microplus (canestrini); and adult stable fly, stomoxys calcitrans (l. ...	2005	15799532
anointing chemicals and ectoparasites: effects of benzoquinones from millipedes on the lone star tick, amblyomma americanum.	many mammals and birds roll on or rub themselves with millipedes that discharge benzoquinones. chemicals transferred from millipedes onto the integument of anointing animals are thought to deter ectoparasites. we tested the lone star tick, amblyomma americanum (l.), for responses to three widespread components of millipede defensive secretions, 1,4-benzoquinone; 2-methyl-1,4-benzoquinone (toluquinone); and 2-methoxy-3-methyl-1,4-benzoquinone (mmb). in toxicity tests, ticks were confined for 1 hr ...	2005	15839480
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
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
the fc fragment mediates the uptake of immunoglobulin c from the midgut to hemolymph in the ixodid tick amblyomma americanum (acari: ixodidae).	the phenomenon of immunoglobulin uptake from the midgut into the hemolymph has been observed in both argasid and ixodid ticks, but the mechanism of the uptake is not known. using capillary feeding of adult amblyomma americanum (l.) female ticks, we investigated the role of immunoglobulin g fc and fab fragments in the uptake process. intact igg and fragments labeled with 125i were introduced alone or as a mixture with a 10-fold molar excess of unlabeled compounds into ticks, and then the concentr ...	2005	15962788
failure of ticks to transmit scopulariopsis brevicaulis (deuteromycota), a common filamentous fungal commensal of ticks.	the capacity of ticks to transmit a fungus was examined by analyzing tick saliva, host tissue from feeding sites, and host blood for presence of scopulariopsis brevicaulis (sacc.) bainier, an internal mycosymbiont of the american dog tick, dermacentor variabilis (say), and lone star tick, amnblyomma americanum (l.). although >85% of ticks were infected with s. brevicaulis, conidia presence was low (0-5% of samples) in microscopic observations and mycological culturing of saliva expressed from la ...	2005	15962791
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
sequence variation of the ribosomal dna second internal transcribed spacer region in two spatially-distinct populations of amblyomma americanum (l.) (acari: ixodidae).	sequence analysis of the ribosomal dna second internal transcribed spacer (its 2) region in 2 spatially distinct populations of amblyomma americanum (l.) revealed intraspecific variation. nucleotide sequences from multiple dna extractions and several polymerase chain reaction amplifications of eggs from mixed-parentage samples from both populations of ticks revealed that 12 of 1,145 (1.0%) sites varied. three of the 12 sites of variation were distinct between the 2 a. americanum populations, whi ...	2005	15986597
polymerase chain reaction detection of cytauxzoon felis from field-collected ticks and sequence analysis of the small subunit and internal transcribed spacer 1 region of the ribosomal rna gene.	cytauxzoon felis produces a disease in domestic cats in the midwest (u.s.a.), which often leads to a fatal outcome. although the clinical disease process is well described, there are still many unanswered questions about this organism. for example, it is unknown whether species of ticks other than dermacentor variabilis can serve as vectors for transmission. with recent reports of surviving cats from limited geographic areas, another relevant question is the potential for genetically less virule ...	2005	15986625
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
possible tick-borne human enterovirus resulting in aseptic meningitis.	enterovirus-specific genetic sequences were isolated from two amblyomma americanum tick pools. identical genetic sequences were later obtained from cerebrospinal fluid of a patient with aseptic meningitis and a recent history of tick attachment. these observations suggest the possibility of an emerging tick-borne human enterovirus associated with aseptic meningitis.	2005	16000481
rapid detection methods and prevalence estimation for borrelia lonestari glpq in amblyomma americanum (acari: ixodidae) pools of unequal size.	dna was extracted from pools of amblyomma americanum ticks collected from vegetation at two sites in fort leonard wood, missouri and tested for the presence of borrelia spp. two new methods were developed to detect borrelia lonestari dna by targeting the glycerophosphodiester phosphodiesterase (glpq) gene. the first method detected b. lonestari dna using a sybr green i melting curve analysis of the pcr product obtained with glpq gene primers. the second method, a glpq taqman assay, detected and ...	2005	16011431
detection of ehrlichia spp. in raccoons (procyon lotor) from georgia.	raccoons (procyonis lotor) and opossums (didelphis virginianus) acquired from six contiguous counties in the piedmont physiographic region of georgia were investigated for their potential role in the epidemiology of ehrlichial and anaplasmal species. serum was tested by indirect fluorescent antibody (ifa) assay for the presence of antibodies reactive to ehrlichia chaffeensis, e. canis, and anaplasma phagocytophilum (hga agent). nested polymerase chain reaction (pcr) assay was used to test whole ...	2005	16011433
rnai-mediated gene silencing to assess the role of synaptobrevin and cystatin in tick blood feeding.	in addition to being the conduit for pathogens into hosts, tick saliva contains a broad array of secretory products that facilitate prolonged tick attachment and blood feeding. proteins found in tick saliva modulate host hemostasis and immune responses. however, it is not clear whether ticks manipulate the immune responses of their hosts by disrupting the antigen-processing pathways of the hosts. protein secretion into tick saliva from the salivary glands is due to exocytosis of vesicular membra ...	2005	16040003
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
ehrlichial infection in cameroonian canines by ehrlichia canis and ehrlichia ewingii.	ehrlichia chaffeensis and ehrlichia ewingii are agents of emerging human ehrlichioses in north america and are transmitted primarily by amblyomma americanum ticks, while ehrlichia canis is the globally distributed cause of canine monocytic ehrlichiosis (cme) and is transmitted by the brown dog tick, rhipicephalus sanguineus. although e. canis and ehrlichia ruminantium are endemic in africa, the presence of ehrlichial agents in dogs and ticks in cameroon has not been investigated. the objective o ...	2005	16181750
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
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
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
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
microbiologic evaluation of patients from missouri with erythema migrans.	borrelia lonestari infects amblyomma americanum, the tick species that is the most common cause of tick bites in southeast and south-central united states, and this spirochete has been detected in an erythema migrans (em)-like skin rash in 1 patient. therefore, b. lonestari is considered to be a leading candidate for the etiologic agent of em in this region.	2005	15668867
francisella tularensis in the united states.	the causative agent of tularemia, francisella tularensis, is a formidable biologic agent that occurs naturally throughout north america. we examined genetic and spatial diversity patterns among 161 us f. tularensis isolates by using a 24-marker multiple-locus variable-number tandem repeat analysis (mlva) system. mlva identified 126 unique genotypes. phylogenetic analyses showed patterns similar to recently reported global-scale analyses. we observed clustering by subspecies, low genetic diversit ...	2005	16485467
bartonella henselae in porpoise blood.	we report detection of bartonella henselae dna in blood samples from 2 harbor porpoises (phocoena phocoena). by using real-time polymerase chain reaction, we directly amplified bartonella species dna from blood of a harbor porpoise stranded along the northern north carolina coast and from a pre-enrichment blood culture from a second harbor porpoise. the second porpoise was captured out of habitat (in a low-salinity canal along the northern north carolina coast) and relocated back into the ocean. ...	2005	16485476
novel spotted fever group rickettsiae (sfgr) infecting amblyomma americanum ticks in ohio, usa.		2005	16481541
overcoming barriers to the transformation of the genus ehrlichia.	while bacterial transformation has evolved since the early 20th century to allow for the genetic manipulation of a variety of microbial agents, rickettsial organisms have proved resistant to such advances until only recently. the ehrlichia are small, gram-negative, obligately intracellular bacterial parasites, which belong to the family anaplasmataceae and cause a variety of infections in human and animal hosts. e. chaffeensis is the causative agent of human monocytotropic ehrlichiosis and is tr ...	2005	16481548
tick infestations of the eastern cottontail rabbit (sylvilagus floridanus) and small rodentia in northwest alabama and implications for disease transmission.	studies were conducted over a four-county area of northwest alabama to determine the association of eastern cottontail rabbits with dermacentor variabilis, the eastern united states vector of rocky mountain spotted fever. a secondary objective was to compare infestations of this tick on rabbits with infestations on commonly encountered rodent species as a means of determining the relative importance of each in the disease transmission cycle. these epidemiologic surveys were conducted in response ...	2005	16599149
ehrlichia chaffeensis: a prevalent, life-threatening, emerging pathogen.	ehrlichia chaffeensis are small, obligately intracellular, endosomal bacteria with tropism for macrophages. persistent infection in reservoir white-tailed deer is transmitted by lone star ticks. flu-like illness can progress to severe multisystem disease with toxic shock-like syndrome, meningitis, or ards. the case-fatality rate is 2.7%. leukopenia and thrombocytopenia are diagnostically useful. granulomas are associated with control of the infection. ehrlichial proteins and glycoproteins have b ...	2004	17060980
evaluation of immunocompetent and immunocompromised mice (mus musculus) for infection with ehrlichia chaffeensis and transmission to amblyomma americanum ticks.	experiments on the natural history of ehrlichia chaffeensis, the agent of human monocytic ehrlichiosis (hme), would be facilitated by the availability of a laboratory animal model for transmission to vector ticks. five strains of mice were evaluated for their susceptibility to infection with e. chaffeensis and transmission competence: c57bl/6 mice, inducible nitric oxide synthase (inos) deficient mice, mhc i deficient (beta2m /) mice, mhc ii deficient mice (abb /), and b and t cell deficient (ra ...	2004	15671738
lack of susceptibility of guinea pigs and gerbils to experimental infection with ehrlichia chaffeensis.	guinea pigs and mongolian gerbils were experimentally infected with ehrlichia chaffeensis (st. vincent strain, 10 passages in vitro). the infection was monitored by serial blood sampling for pcr and by xenodiagnosis with amblyomma americanum larvae. exposure to the pathogen was confirmed using serology. neither guinea pigs nor gerbils were susceptible to infection with e. chaffeensis, and ticks fed upon these animals did not become infected with the pathogen.	2004	15682515
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
evaluation of antibiotic susceptibilities of ehrlichia canis, ehrlichia chaffeensis, and anaplasma phagocytophilum by real-time pcr.	we determined mics of antibiotics against anaplasma phagocytophilum, ehrlichia chaffeensis, and ehrlichia canis by real-time quantitative pcr. the doubling times of the organisms were established: 19 h for e. chaffeensis, 26 h for a. phagocytophilum, and 28 h for e. canis. in comparison to the reference method for determining sensitivities, which uses diff-quick staining, our pcr assay was very sensitive and specific. we confirmed that doxycycline and rifampin are highly active against these bac ...	2004	15561862
an in vitro larval immersion microassay for identifying and characterizing candidate acaricides.	we have optimized a larval immersion microassay (lim) that offers superior sensitivity, flexibility to accommodate multiple formulations, and a robust capability for rapidly screening many compounds with a minimal requirement of test article for evaluation. dose-response studies were conducted for representative members from the organophosphate, pyrethroid, pyrazole, carbamate, macrocyclic lactone, and formamidine chemistries against amblyomma americanum (l.). time-response experiments revealed ...	2004	15605642
detection of ehrlichia chaffeensis in adult and nymphal amblyomma americanum (acari: ixodidae) ticks from long island, new york.	the lone star tick, amblyomma americanum (l.), has increased in abundance in several regions of the northeastern united states, including areas of long island, ny. adult and nymphal stage a. americanum collected from several sites on long island were evaluated for infection with ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis (hme), by using a nested polymerase chain reaction assay. fifty-nine (12.5%) of 473 adults and eight of 113 pools of five nymphs each (estimated ...	2004	15605650
susceptibility of mice (mus musculus) to repeated infestation with amblyomma americanum (acari: ixodidae) ticks.	laboratory mice, mus musculus (l.), balb/c strain, were assessed for their ability to develop resistance to repeated infestation by amblyomma americanum (l.) ticks. mice were infested five consecutive times with a. americanum nymphs. no decrease in tick viability was seen after five infestations, suggesting that balb/c mice do not develop immune-mediated resistance to a. americanum. in contrast, tick viability was significantly reduced in the second infestation of a new zealand white rabbit, a l ...	2004	15605656
ectoparasites of gray squirrels in two different habitats and screening of selected ectoparasites for bartonellae.	gray squirrels, sciurus carolinensis, were livetrapped in 2 different habitat types, woodland (67 squirrels) and parkland (53 squirrels), in southeastern georgia. ectoparasites were recovered from anesthetized squirrels and compared between hosts from the 2 habitats. because of the absence of low vegetation in parkland habitats, it was hypothesized that the ectoparasite fauna, especially ticks and chiggers, would be more diverse on woodland squirrels. the results were generally in agreement with ...	2004	15270090
disease agents in amblyomma americanum from northeastern georgia.	amblyomma americanum (lone star tick) is known or suspected to vector several organisms that are implicated as human pathogens, including ehrlichia chaffeensis, e. ewingii, and borrelia lonestari. these three agents have also been detected in white-tailed deer (odocoileus virginianus). because northeastern georgia has a high abundance of both lone star ticks and white-tailed deer, and one of these organisms, e. chaffeensis, is already known to be endemic in the area, we assayed individual adult ...	2004	15311471
histologic, serologic, and molecular analysis of persistent ehrlichiosis in a murine model.	human monocytotropic ehrlichiosis caused by ehrlichia chaffeensis was reported in 1987. an animal model to study acute fatal ehrlichiosis in mice that has been developed closely resembles the fatal form of human monocytotropic ehrlichiosis. however, animal models for persistent infection in the genus ehrlichia in immunocompetent mice have not been characterized. we report the histopathological progression of ehrlichia muris infection in immunocompetent mice (akr and c57bl/6 strains) correlated w ...	2004	15331423
ehrlichia prevalence in amblyomma americanum, central texas.		2004	15338551
water relations in eggs of the lone star tick, amblyomma americanum, with experimental work on the capacity for water vapor absorption.	this study shows that water stress is not countered in eggs of the lone star tick, amblyomma americanum (l.), using water vapor, and suggests involvement of liquid water as a developmental cue. eggs fail to maintain an equilibrium water content in subsaturated air, hence, gain not equal to loss, with net water losses occurring at relative humidities near saturation and these eggs exhibit a three-fold drop in viability, but not incubation period, as compared to eggs held in saturated air. amblyom ...	2004	15347026
typing of borrelia relapsing fever group strains.	partial sequencing of the 16s-23s rdna intergenic spacer showed two to four genotypes each for borrelia hermsii and b. turicatae, both relapsing fever agents transmitted by argasid ticks, and for b. miyamotoi and b. lonestari, transmitted by ixodid ticks. field surveys of ixodes ticks in connecticut and sweden showed limited local diversity for b. miyamotoi.	2004	15498172
characterization of the b-cell inhibitory protein factor in ixodes ricinus tick saliva: a potential role in enhanced borrelia burgdoferi transmission.	we recently described the inhibition of host b lymphocytes by ixodes ricinus tick saliva. in this study, we characterized the factor responsible for this activity and examined the modulation of lipopolysaccharide (lps)- and borrelia burgdorferi outer surface protein (osp)-induced proliferation of naive murine b lymphocytes by an enriched fraction of this factor. the b-lymphocyte inhibitory activity was destroyed by trypsin treatment, indicating that a proteinaceous factor was responsible for thi ...	2004	15500628
amblyomma americanum salivary gland homolog of nsec1 is essential for saliva protein secretion.	soluble n-ethylmaleimide-sensitive factor attachment protein receptor proteins assemble in tight core complexes which promote fusion of carrier vesicles with target compartments. members of this class of proteins are expressed in all eukaryotic cells and distributed in distinct subcellular compartments. all vesicle transport mechanisms known to date have an essential requirement for a member of the sec1 protein family, including the nsec1 in regulated exocytosis. a homolog of nsec1 was cloned an ...	2004	15504350
sequence and expression analysis of the ompa gene of rickettsia peacockii, an endosymbiont of the rocky mountain wood tick, dermacentor andersoni.	the transmission dynamics of rocky mountain spotted fever in montana appears to be regulated by rickettsia peacockii, a tick symbiotic rickettsia that interferes with transmission of virulent rickettsia rickettsii. to elucidate the molecular relationships between the two rickettsiae and glean information on how to possibly exploit this interference phenomenon, we studied a major rickettsial outer membrane protein gene, ompa, presumed to be involved in infection and pathogenesis of spotted fever ...	2004	15528527
borrelia species in host-seeking ticks and small mammals in northern florida.	the aim of this study was to improve understanding of several factors related to the ecology and environmental risk of borrelia infection in northern florida. small mammals and host-seeking adult ticks were collected at several sites, and specimens were tested for the presence of borrelia species, primarily by pcr amplification. tissues from some vertebrates and ticks were initially cultured in bsk-h medium to isolate spirochetes, but none were recovered. however, comparison of partial flagellin ...	2004	15528699
first culture isolation of borrelia lonestari, putative agent of southern tick-associated rash illness.	southern tick-associated rash illness (stari) is a lyme disease-like infection described in patients in the southeastern and south-central united states, where classic lyme disease is relatively rare. stari develops following the bite of a lone star tick (amblyomma americanum) and is thought to be caused by infection with an "uncultivable" spirochete tentatively named borrelia lonestari. in this study, wild lone star ticks collected from an area where b. lonestari is endemic were cocultured in a ...	2004	15004069
how much pilocarpine contaminates pilocarpine-induced tick saliva?	pilocarpine is often applied or injected into ticks to induce salivation, and the resulting saliva used to test for various pharmacological, biochemical and immunological activities. to measure the amount of pilocarpine in pilocarpine-induced tick saliva, an hplc-ms/ms method, based on capillary strong cation exchange chromatography online with an ion trap mass spectrometer, was used to measure pilocarpine in the pg to ng range. results indicate large concentrations of pilocarpine in ixodes scap ...	2004	15009442
amblyomma americanum salivary glands: double-stranded rna-mediated gene silencing of synaptobrevin homologue and inhibition of pge2 stimulated protein secretion.	protein secretion into the saliva from the tick salivary glands is due to exocytosis of vesicular membrane bound granular material regulated by snare complex proteins after salivary gland stimulation by pge2 [insect biochem. mol. biol. 32 (2002) 1711]. proteins associated with vesicles (v-snares) are essential components of the exocytotic process. synaptobrevin is a key v-snare in all secreting cells studied to date. a vesicle-associated synaptobrevin cdna fragment homologue from the salivary gl ...	2004	15041024
development of a p28-based pcr assay for ehrlichia chaffeensis.	detection of ehrlichia chaffeensis is necessary to study interactions between the parasite and its vertebrate and invertebrate hosts. the purpose of this study was to develop a sensitive, specific pcr assay for e. chaffeensis based on the outer membrane protein gene, p28. candidate primer sets were identified and ranked based on annealing scores, similarities to three major p28 sequence clusters, dissimilarity to e. canis p30, an ortholog of p28, and the proximities of flanking primer sequences ...	2004	15051120
transgenic expression of reca of the spirochetes borrelia burgdorferi and borrelia hermsii in escherichia coli revealed differences in dna repair and recombination phenotypes.	after unsuccessful attempts to recover a viable reca-deficient mutant of the lyme borreliosis agent borrelia burgdorferi, we characterized the functional activities of reca of b. burgdorferi, as well as reca of the relapsing fever spirochete borrelia hermsii and the free-living spirochete leptospira biflexa, in a reca mutant of escherichia coli. as a control, e. coli reca was expressed from the same plasmid vector. dna damage repair activity was assessed after exposure of the transgenic cells to ...	2004	15060027
comparative activity of deet and ai3-37220 repellents against the ticks ixodes scapularis and amblyomma americanum (acari: ixodidae) in laboratory bioassays.	the repellents n,n-diethyl-3-methylbenzamide (deet) and racemic 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (ai3-37220) were evaluated using two different laboratory bioassays to determine their relative effectiveness against host-seeking nymphs of the blacklegged tick, ixodes scapularis say, and the lone star tick, amblyomma americanum (l.). in a petri dish bioassay, ticks were released within a ring of repellent on a horizontal filter paper disk. in the second bioassay, ticks were allowed ...	2004	15061285
invasion of the central nervous system by intracellular bacteria.	infection of the central nervous system (cns) is a severe and frequently fatal event during the course of many diseases caused by microbes with predominantly intracellular life cycles. examples of these include the facultative intracellular bacteria listeria monocytogenes, mycobacterium tuberculosis, and brucella and salmonella spp. and obligate intracellular microbes of the rickettsiaceae family and tropheryma whipplei. unfortunately, the mechanisms used by intracellular bacterial pathogens to ...	2004	15084504
detection of pathogenic ehrlichia in ticks collected at acquisition sites of human ehrlichiosis in missouri.	we collected 385 ticks from sites in missouri associated with human monocytic ehrlichiosis. using pcr, we detected e. chaffeensis or e. ewingii in 2 of 19 pools of adult amblyomma americanum, 0 of 32 pools of dermacentor variabilis, and 6 (18%) of 39 pools of unspeciated nymphal ticks from 3 of 6 sites associated with disease and one site not associated with disease. we also detected a variant of a. phagocytophila in one nymph pool.	2004	15119113
glycerophosphodiester phosphodiesterase gene (glpq) of borrelia lonestari identified as a target for differentiating borrelia species associated with hard ticks (acari:ixodidae).	a glpq ortholog was identified in dna from borrelia lonestari-positive amblyomma americanum, providing further evidence that b. lonestari is more closely related to the relapsing fever group spirochetes than to borreliae that cause lyme disease. this finding provides a basis for developing diagnostic assays to differentiate species of borrelia transmitted by hard ticks.	2004	15131225
a proteomics approach to characterizing tick salivary secretions.	the saliva of ticks contains a complex mixture of bioactive molecules including proteins that modulate host responses ensuring successful feeding. the limited amount of saliva that can be obtained from ticks has hampered characterization of salivary proteins using traditional protein chemistry. recent improvements in two-dimensional gel electrophoresis, mass spectrometry, and bioinformatics provide new tools to characterize small amounts of protein. these methods were employed to characterize sa ...	2004	15198089
disruption of ixodes scapularis anticoagulation by using rna interference.	ixodes scapularis ticks transmit many pathogens, including borrelia burgdorferi, anaplasma phagocytophilum, and babesia microti. vaccines directed against arthropod proteins injected into the host during tick engorgement could prevent numerous infectious diseases. salp14, a salivary anticoagulant, poses a key target for such intervention. salp14 is the prototypic member of a family of potential i. scapularis anticoagulants, expressed and secreted in tick saliva during tick feeding. rna interfere ...	2004	14745044
evaluation of transovarial transmission and transmissibility of ehrlichia chaffeensis (rickettsiales: anaplasmataceae) in amblyomma americanum (acari: ixodidae).	it has long been assumed that ehrlichia chaffeensis (anderson, dawson & wilson), is not transmitted transovarially in the lone star tick vector amblyomma americanum (l.). to test this hypothesis, three beagle dogs, canis familiaris (l.) (carnivora: canidae), were subcutaneously infected with e. chaffeensis (arkansas strain). uninfected nymphal lone star ticks were placed on the infected dogs and allowed to feed to repletion. these nymphal ticks were allowed to molt, and five of five adult female ...	2003	14765684
practical uses for ecdysteroids in mammals including humans: an update.	ecdysteroids are widely used as inducers for gene-switch systems based on insect ecdysteroid receptors and genes of interest placed under the control of ecdysteroid-response elements. we review here these systems, which are currently mainly used in vitro with cultured cells in order to analyse the role of a wide array of genes, but which are expected to represent the basis for future gene therapy strategies. such developments raise several questions, which are addressed in detail. first, the met ...	2003	15844229
experimental infection of lone star ticks, amblyomma americanum (l.), with rickettsia parkeri and exposure of guinea pigs to the agent.	the maculatum agent, rickettsia parkeri (a member of the spotted fever group rickettsiae), was inoculated into a colony of the lone star tick, amblyomma americanum, and followed for two tick generations. in addition, guinea pigs were exposed to the agent by direct injection and by feeding infected ticks on them. eighty (53%) of 150 nymphal a. americanum that were inoculated with suspensions of r. parkeri were positive by hemolymph test and fluorescent antibody test for rickettsial infection when ...	2003	14596284
a cautionary note: survival of nymphs of two species of ticks (acari: ixodidae) among clothes laundered in an automatic washer.	host-seeking ticks often remain on clothing of persons returning home from work or recreation in tick habitats, and can pose at least a temporary risk to people and pets in these homes. laundering clothing has been one of the recommendations to reduce tick exposure. host-seeking lone star tick, amblyomma americanum (l.), and blacklegged tick, ixodes scapularis say, nymphs confined in polyester mesh packets, were included with laundry in cold, warm, and hot wash cycles of an automatic clothes was ...	2003	14596290
molecular variation in the variable-length pcr target and 120-kilodalton antigen genes of ehrlichia chaffeensis from white-tailed deer (odocoileus virginianus).	genes encoding two surface-expressed antigens of ehrlichia chaffeensis, the variable-length pcr target (vlpt) and the 120-kda antigen, which contain variable numbers of tandem repeats, were characterized for e. chaffeensis from white-tailed deer (odocoileus virginianus). both genes from infected deer contained numbers of repeats similar to those reported in genes from humans and ticks, although a new variant of the 120-kda antigen gene containing five repeat units and coinfection with multiple v ...	2003	14605163
detection of antibodies to anaplasma phagocytophilum and ehrlichia chaffeensis antigens in sera of korean patients by western immunoblotting and indirect immunofluorescence assays.	two hundred seventy one serum samples from south korean patients were tested to detect antibodies against anaplasma phagocytophilum (the human granulocytic ehrlichiosis agent) and ehrlichia chaffeensis (the human monocytic ehrlichiosis agent) by indirect fluorescent-antibody assay (ifa) and the western blot assay. these sera were collected from patients with symptoms of high fever. the rate of seropositivity for orientia tsutsugamushi was 50.9% by ifa at the public health & environmental researc ...	2003	14607867
evaluation of a pcr assay for quantitation of rickettsia rickettsii and closely related spotted fever group rickettsiae.	a spotted fever rickettsia quantitative pcr assay (sq-pcr) was developed for the detection and enumeration of rickettsia rickettsii and other closely related spotted fever group rickettsiae. the assay is based on fluorescence detection of sybr green dye intercalation in a 154-bp fragment of the rompa gene during amplification by pcr. as few as 5 copies of the rompa gene of r. rickettsii can be detected. sq-pcr is suitable for quantitation of r. rickettsii and 10 other genotypes of spotted fever ...	2003	14662926
evidence of borrelia lonestari dna in amblyomma americanum (acari: ixodidae) removed from humans.	we used a nested pcr with borrelia flagellin gene (flab) primers and dna sequencing to determine if borrelia lonestari was present in amblyomma americanum ticks removed from military personnel and sent to the tick-borne disease laboratory of the u.s. army center for health promotion and preventive medicine. in our preliminary investigation, we detected borrelia sequences in 19 of 510 a. americanum adults and nymphs from ft. a. p. hill, va. during the 2001 tick season, the flab primers were used ...	2003	14662940
meteorologically mediated diurnal questing of ixodes scapularis and amblyomma americanum (acari: ixodidae) nymphs.	questing ixodes scapularis say and amblyomma americanum (l.) nymphs were collected in the field by drag sampling to determine whether ticks would be collected in greater numbers during certain times of the day and under certain ambient meteorological conditions. ticks were collected hourly for 16 h on 4 d and counts were contrasted with simultaneous measurements of ambient temperature and relative humidity, and with similar measurements made within the leaf litter. peak numbers of questing i. sc ...	2003	14680102
transstadial transfer of west nile virus by three species of ixodid ticks (acari: ixodidae).	larvae and/or nymphs of four species of ixodid ticks, ixodes scapularis say, amblyomma americanum (l.), dermacentor andersoni stiles, and dermacentor variabilis say, were fed to completion on laboratory hamsters or mice which had been inoculated with a west nile (wn) virus isolate from culex pipiens l. captured in connecticut usa. maximum titers in mice and hamsters were approximately 5 and two logs, respectively, lower than recorded (10 logs) in a naturally infected american crow, corvus brachy ...	2003	14680122
dna evidence of borrelia lonestari in amblyomma americanum (acari: ixodidae) in southeast missouri.	amblyomma americanum collected near lake wappapello, missouri, tested positive for borrelia lonestari using polymerase chain reaction and sequence analyses of b. lonestari 16s rrna and flagellin (flab) genes. twelve pools containing a total of 214 nymph or adult ticks contained evidence of infection with b. lonestari (minimum prevalence 5.6%). these data suggest that persons in southeast missouri are at risk for exposure to b. lonestari after a. americanum tick bite, a possible cause of erythema ...	2003	14680133
survey of ticks collected in mississippi for rickettsia, ehrlichia, and borrelia species.	from november 1999 through october 2000, we tested ticks collected from vegetation as well as from deer, dogs, and humans for spotted fever group (sfg) rickettsiae, ehrlichia chaffeensis, and borrelia spp. spirochetes. a total of 149 adult ticks representing four species was collected from 11 collection sites from southwestern to northern mississippi. amblyomma americanum was most commonly collected (n=68), followed by ixodes scapularis (n=53). the bird tick, ixodes brunneus (usually rare), was ...	2003	14714667
human monocytotropic ehrlichiosis, missouri.	to determine the incidence, clinical and laboratory characteristics, and utility of molecular diagnosis of human monocytotropic ehrlichiosis (hme) in the primary care setting, we conducted a prospective study in an outpatient primary care clinic in cape girardeau, missouri. one hundred and two patients with a history of fever for 3 days (>37.7 degrees c), tick bite or exposure, and no other infectious disease diagnosis were enrolled between march 1997 and december 1999. hme was diagnosed in 29 p ...	2003	14720399
evaluation of a prototype ehrlichia chaffeensis surveillance system using white-tailed deer (odocoileus virginianus) as natural sentinels.	the natural history of ehrlichia chaffeensis, the causative agent of human monocytotropic ehrlichiosis, includes the lone star tick (lst, amblyomma americanum) as a vector and white-tailed deer (wtd; odocoileus virginianus) as both a natural reservoir of e. chaffeensis and a major host of lst. the goal of the current study was to implement and evaluate a prototype surveillance system to delineate the geographic distribution of e. chaffeensis using wtd as natural sentinels. to accomplish this goa ...	2003	14733672
the ascendancy of amblyomma americanum as a vector of pathogens affecting humans in the united states.	until the 1990s, amblyomma americanum was regarded primarily as a nuisance species, but a tick of minor importance as a vector of zoonotic pathogens affecting humans. with the recent discoveries of ehrlichia chaffeensis, ehrlichia ewingii, and "borrelia lonestari," the public health relevance of lone star ticks is no longer in question. during the next 25 years, the number of cases of human disease caused by a. americanum-associated pathogens will probably increase. based on current trajectories ...	2003	12414740
detection of borrelia lonestari, putative agent of southern tick-associated rash illness, in white-tailed deer (odocoileus virginianus) from the southeastern united states.	to determine if white-tailed deer may serve as a reservoir host for borrelia lonestari, we used a nested pcr for the borrelia flagellin gene to evaluate blood samples collected from deer from eight southeastern states. seven of 80 deer (8.7%) from 5 of 17 sites (29.4%) had sequence-confirmed evidence of a b. lonestari flagellin gene by pcr, indicating that deer are infected with b. lonestari or another closely related borrelia species. our findings expand the known geographic range of b. lonesta ...	2003	12517884
ehrlichia chaffeensis: a prototypical emerging pathogen.	ehrlichia chaffeensis is an obligately intracellular, tick-transmitted bacterium that is maintained in nature in a cycle involving at least one and perhaps several vertebrate reservoir hosts. the moderate to severe disease caused by e. chaffeensis in humans, first identified in 1986 and reported for more than 1,000 patients through 2000, represents a prototypical "emerging infection." knowledge of the biology and natural history of e. chaffeensis, and of the epidemiology, clinical features, and ...	2003	12525424
detection of borrelia lonestari in amblyomma americanum (acari: ixodidae) from tennessee.	genetic sequences characteristic of borrelia lonestari (barbour et al. 1996) were detected in two pools of adult amblyomma americanum (l.) from tennessee, corresponding to an estimated minimum field infection rate of 8.4 infected ticks/1000 adults. dna amplification was conducted using primers derived from the b. lonestari flagellin gene that would also amplify borrelia burgdorferi (johnson, schmid, hyde, steigerwalt, and brenner). species-specific, internal probes were then used to differentiat ...	2003	12597661