Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| interdigital gland substances of white-tailed deer and the response of host-seeking ticks (acari: ixodidae). | host-seeking male and female blacklegged ticks, ixodes scapularis say, exhibited an arrestant response when contacting substances from front and rear interdigital glands of male and female white-tailed deer, odocoileus virginianus (zimmermann). female i. scapularis responded positively to substances from interdigital glands on the fore legs and hind legs of female deer, whereas male i. scapularis responded only to samples from the fore legs of does. these results showed that previously reported ... | 2001 | 11268681 |
| preliminary survey of ticks (acari: ixodidae) parasitizing wild turkeys (aves: phasianidae) in eastern kansas. | during the spring and fall turkey hunting seasons of 1999, hunters and kansas department of wildlife and parks field personnel examined wild turkeys, meleagris gallopavo l., for ticks and submitted them to us for identification. from springtime hunting, we received 113 ticks from 12 turkeys killed in nine counties, all in the eastern one-third of kansas. collectors reported examining three additional wild turkeys on which no ticks were found. all ticks were nymphal lone star ticks, amblyomma ame ... | 2001 | 11268682 |
| prevalence of infection in ticks submitted to the human tick test kit program of the u.s. army center for health promotion and preventive medicine. | in 1997, ticks removed from humans and received alive by the tick-borne disease laboratory of the u.s. army center for health promotion and preventive medicine (usachppm) were tested for pathogens by polymerase chain reaction (pcr). thirty-three of 222 (15%) amblyomma americanum (l.) dnas produced amplicons of the expected size of ehrlichia chaffeensis anderson, dawson & wilson and 26/222 (12%) produced amplicons indicating borrelia burgdorferi johnson, schmid, hyde, steigalt & brenner. five (2% ... | 2001 | 11268694 |
| ticks (acari: ixodidae) and spirochetes (spirochaetaceae: spirochaetales) recovered from birds on a georgia barrier island. | from september 1997 through july 1999, 300 individuals and 46 species of birds were mist-netted and screened for ticks and spirochetes on st. catherine's island, liberty county, ga. seventy-six (25%) of the birds were parasitized by a meal intensity of 4.6 ticks. seasonally, more birds were infested with ticks during the summer (50% in 1998, 34% in 1999) than in spring (15% in 1998, 11% in 1999) or fall (21% in 1997, 20% in 1998), mainly because of severe infestations on some birds by immature s ... | 2001 | 11296828 |
| effects of selected meterological factors on diurnal questing of ixodes scapularis and amblyomma americanum (acari: ixodidade). | the diurnal questing behavior of adult ixodes scapularis say and amblyomma americanum (l.) were monitored in the field to determine whether ticks would be collected with greater frequency during certain times of the day and under certain ambient meteorological conditions. temperature and relative humidity explained a significant amount of the total variation in tick collections. although both species were collected during every period, i. scapularis adults tended to quest earlier and later in th ... | 2001 | 11296842 |
| efficacy of granular deltamethrin against ixodes scapularis and amblyomma americanum (acari: ixodidade) nymphs. | a single barrier application of granular deltamethrin to the woodland edges of a forested residential community in late spring significantly reduced the abundance of ixodes scapularis say nymphs. the application also suppressed the population of amblyomma americanum (l.) nymphs, which recently became established in the study area. the efficacy of deltamethrin is compared with other commonly used acaricides. | 2001 | 11296847 |
| borrelia lonestari infection after a bite by an amblyomma americanum tick. | erythematous rashes that are suggestive of early lyme disease have been associated with the bite of amblyomma americanum ticks, particularly in the southern united states. however, borrelia burgdorferi, the causative agent of lyme disease, has not been cultured from skin biopsy specimens from these patients, and diagnostic serum antibodies usually have not been found. borrelia lonestari sp nov, an uncultured spirochete, has been detected in a. americanum ticks by dna amplification techniques, bu ... | 2001 | 11372036 |
| identification of ehrlichia spp. and borrelia burgdorferi in ixodes ticks in the baltic regions of russia. | the presence and distribution of ehrlichia spp. and borrelia burgdorferi sensu lato was demonstrated among ixodid ticks collected in the baltic regions of russia, where lyme borreliosis is endemic. a total of 3,426 ixodes ricinus and 1,267 ixodes persulcatus specimens were collected, and dark-field microscopy showed that 265 (11.5%) i. ricinus and 333 (26.3%) i. persulcatus ticks were positive. from these samples, 472 dark-field-positive and 159 dark-field-negative ticks were subjected to pcr an ... | 2001 | 11376063 |
| borrelia lonestari dna in adult amblyomma americanum ticks, alabama. | polymerase chain reaction analysis of 204 amblyomma americanum and 28 a. maculatum ticks collected in august 1999 near the homes of patients with southern tick-associated rash illness and in control areas in choctaw county, alabama, showed borrelia lonestari flagellin gene sequence from two adult a. americanum. the presence of b. lonestari in a. americanum ticks from alabama suggests that this suspected pathogen may be widespread in the southeastern united states. | 2001 | 11384533 |
| quantitative analyses of variations in the injury of endothelial cells elicited by 11 isolates of rickettsia rickettsii. | eleven isolates of spotted fever group rickettsiae from the blood of patients or ixodid ticks from north and south america were characterized. all isolates were identified as rickettsia rickettsii using restriction fragment length polymorphism analysis of a 532-bp rompa gene fragment obtained by pcr. the ability of the r. rickettsii isolates to elicit cytopathic effects and parameters of oxidative injury were examined in cultured human ea.hy 926 endothelial cells. cytopathic effects were determi ... | 2001 | 11427428 |
| serodiagnosis of human granulocytic ehrlichiosis by using novel combinations of immunoreactive recombinant proteins. | a panel of seven recombinant antigens, derived from ehrlichia phagocytophila (the agent of human granulocytic ehrlichiosis), was evaluated by class-specific enzyme-linked immunosorbent assays (elisas) for utility in the diagnosis of the infection. fourteen genomic fragments, obtained by serologic expression screening, contained open reading frames (orfs) encoding 16 immunodominant antigens. eleven of these antigens were members of the major surface protein (msp) multigene family. alignment of th ... | 2001 | 11427556 |
| genetic heterogeneity of borrelia burgdorferi sensu lato in the southern united states based on restriction fragment length polymorphism and sequence analysis. | fifty-six strains of borrelia burgdorferi sensu lato, isolated from ticks and vertebrate animals in missouri, south carolina, georgia, florida, and texas, were identified and characterized by pcr-restriction fragment length polymorphism (rflp) analysis of rrf (5s)-rrl (23s) intergenic spacer amplicons. a total of 241 to 258 bp of intergenic spacers between tandemly duplicated rrf (5s) and rrl (23s) was amplified by pcr. msei and drai restriction fragment polymorphisms were used to analyze these ... | 2001 | 11427560 |
| molecular and antigenic comparison of ehrlichia canis isolates from dogs, ticks, and a human in venezuela. | we previously culture isolated a strain of ehrlichia canis, the causative agent of canine ehrlichiosis, from a human in venezuela. in the present study, we examined whether dogs and ticks are infected with e. canis in venezuela and, if so, whether this is the same strain as the human isolate. pcr analysis using e. canis-specific primers revealed that 17 of the 55 dog blood samples (31%) and all three pools of four rhipicephalus sanguineus ticks each were positive. an ehrlichial agent (venezuelan ... | 2001 | 11473993 |
| birds disperse ixodid (acari: ixodidae) and borrelia burgdorferi-infected ticks in canada. | a total of 152 ixodid ticks (acari: ixodidae) consisting of nine species was collected from 82 passerine birds (33 species) in 14 locations in canada from 1996 to 2000. the lyme disease spirochete borrelia burgdorferi johnson, schmidt, hyde, steigerwaldt & brenner was cultured from the nymph of a blacklegged tick, ixodes scapularis say, that had been removed from a common yellowthroat, geothlypis trichas l., from bon portage island, nova scotia. as a result of bird movement, a nymphal i. scapula ... | 2001 | 11476328 |
| effects of pyriproxyfen on off-host water-balance and survival of adult lone star ticks (acari: ixodidae). | newly engorged nymphs of the lone star tick, amblyoma americanum (l.), were continuously exposed to 4 microg/cm2 of pyriproxyfen residues in glass vials. treatment of engorged nymphs (n = 285) resulted in significant molting inhibition, with more than one-fourth (26.7%, n = 76) of nymphs dying before or during ecdysis. treatment effects were evident among ticks that molted to the adult stage, with 26.7% (n = 76) of females, and 17.9% (n = 51) of males exhibiting moribund physical characteristics ... | 2001 | 11476341 |
| different activities and footwear influence exposure to host-seeking nymphs of ixodes scapularis and amblyomma americanum (acari: ixodidae). | the relative potential for a person accidentally acquiring host-seeking nymphs of the blacklegged tick, ixodes scapularis say, and lone star tick, amblyomma americanum (l.), while wearing either of two types of footwear, walking, crawling on hands and knees, and sitting on large fallen logs in deciduous woods, was evaluated. although flag samples indicated substantial populations of i. scapularis nymphs and low to moderate numbers of a. americanum at the study sites, relatively few i. scapularis ... | 2001 | 11476342 |
| effects of habitat structure on the retention of ixodes scapularis and amblyomma americanum (acari: ixodidae) adults during drag sampling surveys. | the ability of ixodes scapularis say and amblyomma americanum (l.) to remain on drags, once acquired, was tested in sparse and dense shrub layer vegetation. when placed on bottoms of drags, adults of both species remained attached for distances three to four times greater in sparse vegetation compared with dense vegetation. when attached to the tops of drags, the differences in retention of ticks on drags between vegetation densities were significant only for a. americanum. in dense vegetation, ... | 2001 | 11476345 |
| risk of lyme disease: perceptions of residents of a lone star tick-infested community. | lone star ticks (amblyomma americanum) have been suggested as a vector of the agent of lyme disease (borrelia burgdorferi sensu lato) in the usa, based on associations with an infection manifesting mainly as erythema migrans. in laboratory experiments, however, they failed to transmit b. burgdorferi sensu stricto. | 2001 | 11693973 |
| lone-star tick bite of the conjunctiva. | 2001 | 11735801 | |
| identification and characterization of a homologue of the pro-inflammatory cytokine macrophage migration inhibitory factor in the tick, amblyomma americanum. | studying tick feeding and digestion, we discovered in a cdna library from partially fed amblyomma americanum ticks the first known arthropod homologue of a human cytokine, the pro-inflammatory macrophage migration inhibitory factor (mif). the tick origin of the mif cdna clone was confirmed by sequencing a genomic fragment that contained the full-length tick mif gene with two introns. antiserum to a tick mif-specific peptide as well as antiserum to complete tick mif revealed the expression of tic ... | 2001 | 11520355 |
| western blot analysis of sera reactive to human monocytic ehrlichiosis and human granulocytic ehrlichiosis agents. | laboratory diagnosis of human ehrlichioses is routinely made by an indirect immunofluorescence assay (ifa) using cultured ehrlichia-infected whole cells as antigen. concern has been raised that incorrect diagnoses of human monocytic ehrlichiosis (hme) or human granulocytic ehrlichiosis (hge) may be made on the basis of serologic cross-reactivity between ehrlichia chaffeensis and the agent of hge. the present study examined whether two recombinant major outer membrane proteins, rp30 and rp44, tha ... | 2001 | 11682518 |
| isolation of a spotted fever group rickettsia, rickettsia peacockii, in a rocky mountain wood tick, dermacentor andersoni, cell line. | an embryonic cell line (dae100) of the rocky mountain wood tick, dermacentor andersoni, was observed by microscopy to be chronically infected with a rickettsialike organism. the organism was identified as a spotted fever group (sfg) rickettsia by pcr amplification and sequencing of portions of the 16s rrna, citrate synthase, rickettsia genus-specific 17-kda antigen, and sfg-specific 190-kda outer membrane protein a (rompa) genes. sequence analysis of a partial rompa gene pcr fragment and indirec ... | 2001 | 11157215 |
| sensitive detection of ehrlichia chaffeensis in cell culture, blood, and tick specimens by reverse transcription-pcr. | ehrlichia chaffeensis is an obligatory intracellular bacterium of monocytes and macrophages and the etiologic agent of human monocytic ehrlichiosis, an emerging zoonosis. the lone star tick (amblyomma americanum) has been implicated as the primary vector of e. chaffeensis. the present study examined the sensitivity of the nested reverse transcription (rt)-pcr based on the 16s rrna gene relative to that of the nested pcr for detection of e. chaffeensis in infected dh82 cells, experimentally infec ... | 2001 | 11158090 |
| lone star tick-infecting borreliae are most closely related to the agent of bovine borreliosis. | although borrelia theileri, the agent of bovine borreliosis, was described at the turn of the century (in 1903), its relationship with borreliae causing lyme disease or relapsing fever remains undescribed. we tested the previously published hypothesis that spirochetes infecting lone star ticks (amblyomma americanum) may comprise b. theileri by analyzing the 16s ribosomal dnas (rdnas) and flagellin genes of these spirochetes. b. theileri, the amblyomma agent, and b. miyamotoi formed a natural gro ... | 2001 | 11158095 |
| animal model of fatal human monocytotropic ehrlichiosis. | human monocytotropic ehrlichiosis caused by ehrlichia chaffeensis is a life-threatening, tick-borne, emerging infectious disease for which no satisfactory animal model has been developed. strain hf565, an ehrlichial organism closely related to e. chaffeensis isolated from ixodes ovatus ticks in japan, causes fatal infection of mice. c57bl/6 mice became ill on day 7 after inoculation and died on day 9. the liver revealed confluent necrosis, ballooning cell injury, apoptosis, poorly formed granulo ... | 2001 | 11159213 |
| ixodid ticks on white-tailed deer and feral swine in florida. | a state-wide survey was conducted in florida during the 1997-99 hunting seasons to examine white-tailed deer (odocoileus virginianus) and feral swine (sus scrofa) for potential indigenous vectors of the rickettsial agent of heartwater, cowdria ruminantium. a total of 504 white-tailed deer and 166 feral swine was examined from 30 wildlife management areas across the state. amblyomma maculatum, an experimental vector of c. ruminantium, was common on both deer and feral swine throughout the state. ... | 2001 | 11469190 |
| developmental profiles of ecdysteroids, ecdysteroid receptor mrnas and dna binding properties of ecdysteroid receptors in the ixodid tick amblyomma americanum (l.). | total body ecdysteroid titers were determined at specific stages during the larval and nymphal life of amblyomma americanum (l.). one ecdysteroid peak was observed following the completion of larval apolysis. however, two distinct ecdysteroid peaks occurred at a comparable stage in the nymphal molting cycle. the first occurred following apolysis and the second peak occurred at about the time of ecdysis. when whole body profiles of ecr and rxr mrnas were examined during the molting cycle using rt ... | 2002 | 11886781 |
| comparison of differentially expressed genes in the salivary glands of male ticks, amblyomma americanum and dermacentor andersoni. | genes expressed differentially in the salivary glands of unfed and fed male ticks, amblyomma americanum (l.), were identified, cloned and sequenced, and some were compared with those expressed in the salivary glands of dermacentor andersoni. total protein and rna increased sixfold in the salivary glands of fed male a. americanum, while in fed male d. andersoni salivary glands, rna increased approximately 3.5 times. feeding d. andersoni in the presence of females increased total rna by 25% over t ... | 2002 | 12020839 |
| analysis of serum and whole blood values in relation to helminth and ectoparasite infections of feral pigs in texas. | in the summers of 1996 and 1997, 60 wild pigs (sus scrofa) were necropsied from three sites in south texas (usa) to test the hypothesis that serum and whole blood parameters vary significantly (p < or = 0.05) with the prevalence and intensity of parasites infecting wild pigs. we found ten parasite species: five nematodes (metastrongylus salmi, metastrongylus pudentotectus, stephanurus dentatus, oesophagostomum dentatum, and physocephalus sexalatus); four ixodid ticks (amblyomma cajennense, ambly ... | 2002 | 12038138 |
| ticks parasitizing dogs in northwestern georgia. | from january 1998 through september 1999, 324 dogs in three northwestern georgia counties were examined for ticks. six species of ticks were recovered. the three most commonly collected ticks were the american dog tick, dermacentor variabilis (say) (310 male male, 352 female female; prevalence, 97%; mean intensity 2.1); the brown dog tick, rhipicephalus sanguineus (latreille) (118 male male, 119 female female, 38 nymphs; prevalence, 22%; mean intensity, 3.8); and the lone star tick, amblyomma am ... | 2002 | 11931241 |
| a survey for nymphs of host-seeking ixodes scapularis and amblyomma americanum (acari: ixodidae) on tree trunks in deciduous forests. | trunks of 83 trees in a mixed deciduous forests in maryland were sampled for the presence of nymphs of the blacklegged tick, ixodes scapularis say, and the lone star tick, amblyomma americanum (l.). although one or more nymphs of either i. scapularis or a. americanum was found in leaf litter and substrate < or = 1 m from the bases of 47% of the trees sampled, a total of 6 i. scapularis nymphs was found on the trunks of only five trees. no nymphs were found on the trunks of 12 dead trees. no a. a ... | 2002 | 11931264 |
| a ten-year study of tick biting in mississippi: implications for human disease transmission. | to determine exactly which tick species bit people in mississippi, information was gathered on ticks involved in human biting cases for the ten-year period, january 1, 1990-december 31, 1999. specimens were identified by the author and, in most cases, confirmed by personnel at the institute of arthropodology and parasitology, georgia southern university. a total of 119 ticks were recovered from 73 humans during the study period. seven tick species were represented; most common included the lone ... | 2002 | 12853269 |
| identity and synthesis of prostaglandins in the lone star tick, amblyomma americanum (l.), as assessed by radio-immunoassay and gas chromatography/mass spectrometry. | high concentrations of pge(2) and pgf(2alpha) were identified by radio-immunoassay (ria) and/or gas chromatography/mass spectrometry (gc/ms) in the hemolymph, salivary glands and saliva of the lone star tick amblyomma americanum (l.). binding studies indicated that pge(2) was free and not bound to any proteins in the hemolymph. a small amount of 6-keto-pgf(1alpha) (breakdown product of pgi(2); prostacyclin) was also found in the salivary glands but not in the hemolymph or saliva. neither pgd(2) ... | 2002 | 11804805 |
| effect of deer exclusion by fencing on abundance of amblyomma americanum (acari: ixodidae) on fire island, new york, usa. | the effects of deer exclusion on northern populations of lone star ticks, amblyomma americanum, were tested at the lighthouse tract, fire island, ny, usa, where densities of this species have increased recently. game fencing was erected to exclude deer from two sites of roughly one ha each, and populations of nymphal and adult a. americanum within were compared with those at control sites outside the exclosures. percent control of nymphs within vs. outside the exclosures averaged 48.4% in the fo ... | 2002 | 12546457 |
| infection rates of amblyomma americanum and dermacentor variabilis by ehrlichia chaffeensis and ehrlichia ewingii in southwest missouri. | both ehrlichia chaffeensis and ehrlichia ewingii are causative agents of human ehrlichiosis. both pathogens are transmitted to humans through the bite of an infected lone star tick (amblyomma americanum). since missouri has a high incidence of human monocytic ehrlichiosis, we investigated the prevalence of e. chaffeensis- and e. ewingii-infected a. americanum and dermacentor variabilis (american dog tick) ticks to help assess the relative risk for humans exposed to these vectors. we used a neste ... | 2002 | 12653298 |
| ehrlichia ewingii infection in white-tailed deer (odocoileus virginianus). | two closely related zoonotic ehrlichiae, ehrlichia chaffeensis and e. ewingii, are transmitted by amblyomma americanum, the lone star tick. because white-tailed deer (odocoileus virginianus) are critical hosts for all mobile stages of a. americanum and are important vertebrate reservoirs of e. chaffeensis, we investigated whether deer may be infected with e. ewingii, a cause of granulocytotropic ehrlichiosis in humans and dogs. to test for e. ewingii infection, we used polymerase chain reaction ... | 2002 | 12095432 |
| the omp-1 major outer membrane multigene family of ehrlichia chaffeensis is differentially expressed in canine and tick hosts. | sixteen of 22 omp-1 paralogs encoding 28-kda-range immunodominant outer membrane proteins of ehrlichia chaffeensis were transcribed in blood monocytes of dogs throughout a 56-day infection period. only one paralog was transcribed by e. chaffeensis in three developmental stages of amblyomma americanum ticks before or after e. chaffeensis transmission to naïve dogs. | 2002 | 12117987 |
| transmission of hepatozoon americanum (apicomplexa: adeleorina) by ixodids (acari: ixodidae). | american canine hepatozoonosis (ach) caused by hepatozoon americanum vincent-johnson, macintire, lindsay, lenz, baneth, and shkap is an emerging, often fatal, tick-borne protozoal disease of dogs in the united states of america. dogs acquire infection by ingesting ticks that contain oocysts. to understand the invertebrate (definitive) host range of h. americanum, experiments were carried out using four ixodids, rhipicephalus sanguineus (latreille), dermacentor variabilis say, amblyomma americanu ... | 2002 | 12144294 |
| dermacentor variabilis and boophilus microplus (acari: ixodidae): experimental vectors of babesia equi to equids. | the experimental vector competence of five laboratory-reared ixodid tick species representing three genera [amblyomma americanum (l.), boophilus microplus (canestrini), d. andersoni stiles, d. occidentalis marx, and d. variabilis (say)] for babesia equi (laveran 1901) was evaluated by delayed transfer of male ticks from infected to susceptible equids or by infesting the latter animals with adult ticks previously fed as nymphs on infected equids. after feeding for 5, 6, or 13 d on acquisition hos ... | 2002 | 12144301 |
| simultaneous detection of anaplasma marginale and a new ehrlichia species closely related to ehrlichia chaffeensis by sequence analyses of 16s ribosomal dna in boophilus microplus ticks from tibet. | to identify ehrlichial agents in boophilus microplus ticks, dna samples of b. microplus collected from the tibet autonomous region and sichuan province of china were screened by a nested pcr. sixteen of 43 (37%) dna samples of b. microplus from tibet were positive in nested pcr analysis. all 27 samples from sichuan were negative. the screen identified two ehrlichial agents based on different 16s rrna genes that were found after amplifying and sequencing the 5'-end fragments of the 16s rrna genes ... | 2002 | 12202567 |
| determination of novel borrelia genospecies in swedish ixodes ricinus ticks. | a total of 301 adult questing ixodes ricinus ticks were collected at 15 different locations along the south and east coasts of sweden to determine the borrelia genospecies diversity. thirty-two ticks (11%) were found to be positive by nested pcr with borrelia burgdorferi sensu lato-specific primers. species determination was based on partial sequencing of the 16s rrna gene and the flagellin gene. five different borrelia species were found. the nucleotide sequence of the borrelia dna found in two ... | 2002 | 12202571 |
| prevalence of ectoparasites in a population of feral cats from north central florida during the summer. | ectoparasites are a common and important cause of skin disorders in cats. ectoparasites are capable of disease transmission and can cause life-threatening anemia in young or debilitated animals. the objective of this study was to determine the potential feline ectoparasites in domestic cats by using a cohort of feral cats from north central florida that have not received veterinary care and have no known exposure to insecticide application. a total of 200 feral cats were randomly selected for th ... | 2002 | 12383632 |
| identification of snare and cell trafficking regulatory proteins in the salivary glands of the lone star tick, amblyomma americanum (l.). | prostaglandin e(2) (pge(2)) stimulates secretion of tick salivary gland proteins via a phosphoinositide signaling pathway and mobilization of intracellular ca(2+) (). highly conserved intracellular snare (soluble nsf attachment protein receptors) complex proteins are associated with the mechanism of protein secretion in vertebrate and invertebrate neuronal and non-neuronal cells. proteins in the salivary glands of partially fed female lone star ticks cross-react individually with antibodies to s ... | 2002 | 12429123 |
| naturally occurring ehrlichia chaffeensis infection in two prosimian primate species: ring-tailed lemurs (lemur catta) and ruffed lemurs (varecia variegata). | a naturally occurring infection of ehrlichia chaffeensis in lemurs is described. dna of ehrlichia chaffeensis was identified by polymerase chain reaction in peripheral blood from six of eight clinically ill lemurs. organisms were cultured from the blood of one lemur exhibiting clinical and hematologic abnormalities similar to those of humans infected with e. chaffeensis. | 2002 | 12498671 |
| 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 ... | 2002 | 14570118 |
| how specific are host-produced kairomones to host-seeking ixodid ticks? | ixodid ticks respond to host-produced substances (kairomones) that influence the ticks' host-finding behavior. in the laboratory adult blacklegged ticks, ixodes scapularis say, lone star ticks, amblyomma americanum l., and american dog ticks, dermacentor variabilis (say) became akinetic on residues rubbed from their principal hosts (deer for the former two species and dogs for the latter). however, arrestment also occurred when adults of these species were tested using the same method bioassay, ... | 2002 | 14570126 |
| control of ixodes scapularis and amblyomma americanum through use of the '4-poster' treatment device on deer in maryland. | deer self-treatment devices ('4-posters') were evaluated for their efficacy in reducing populations of blacklegged ticks, ixodes scapularis, and lone star ticks, amblyomma americanum. at each of three locations in maryland, 25 '4-posters' were operated in study areas of approximately 5.18 km2. populations of host-seeking ticks were monitored by flagging of treated areas and similar untreated control areas without '4-posters.' from 1998 to 2002 the percent mortalities achieved were 69, 75.8 and 8 ... | 2002 | 14570143 |
| structure-based analysis of the ultraspiracle protein and docking studies of putative ligands. | the ultraspiracle protein (usp) is the insect ortholog of the mammalian retinoid x receptor (rxr). fundamental questions concern the functional role of usp as the heterodimerization partner of insect nuclear receptors such as the ecdysone receptor. the crystallographic structures of the ligand binding domain of usps of heliothis virescens and drosophila melanogaster solved recently show that helix 12 is locked in an antagonist conformation raising the question whether usps could adopt an agonist ... | 2002 | 15455059 |
| abstracts of the fourth international symposium on molecular insect science. may 28-june 2, 2002. tucson, arizona, usa. | 2002 | 15455051 | |
| evolution of moth sex pheromones via ancestral genes. | mate finding in most moth species involves long-distance signaling via female-emitted sex pheromones. there is a great diversity of pheromone structures used throughout the lepidoptera, even among closely related species. the conundrum is how signal divergence has occurred. with strong normalizing selection pressure on blend composition and response preferences, it is improbable that shifts to pheromones of diverse structures occur through adaptive changes in small steps. here, we present data s ... | 2002 | 12237399 |
| the p53-dependent effects of macrophage migration inhibitory factor revealed by gene targeting. | macrophage migration inhibitory factor (mif) is a mediator of host immunity and functions as a high, upstream activator of cells within the innate and the adaptive immunological systems. recent studies have suggested a potentially broader role for mif in growth regulation because of its ability to antagonize p53-mediated gene activation and apoptosis. to better understand mif's activity in growth control, we generated and characterized a strain of mif-knockout (mif-ko) mice in the inbred, c57bl/ ... | 2003 | 12878730 |
| 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 |
| 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 |
| 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 |
| 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 |
| ehrlichia chaffeensis infections among hiv-infected patients in a human monocytic ehrlichiosis-endemic area. | manifestations of human monocytic ehrlichiosis (hme), a tick-borne infection caused by ehrlichia chaffeensis, range from asymptomatic disease to fulminant infection and may be particularly severe in persons infected with hiv. we conducted a serologic study to determine the epidemiology of hme in hiv-positive patients residing in an hme-endemic area. we reviewed charts from a cohort of 133 hiv-positive patients who were seen during the 1999 tick season with symptoms compatible with hme (n=36) or ... | 2003 | 14519250 |
| rna interference in ticks: a study using histamine binding protein dsrna in the female tick amblyomma americanum. | rna interference (rnai), a gene silencing process, has been recently exploited to determine gene function by degrading specific mrnas in several eukaryotic organisms. we constructed a double stranded rna (dsrna) from a previously cloned putative amblyomma americanum histamine binding protein (hbp) to test the significance of using this methodology in the assessment of the function and importance of gene products in ectoparasitic ticks. the female salivary glands incubated in vitro with hbp dsrna ... | 2003 | 12752664 |
| efficacy of two 65% permethrin spot-on formulations against induced infestations of ctenocephalides felis (insecta: siphonaptera) and amblyomma americanum (acari: ixodidae) on beagles. | the efficacy of two formulations of a topically applied 65% permethrin spot-on (defend exspot treatment for dogs, schering-plough animal health) was evaluated against experimental infestations of the cat flea ctenocephalides felis and the lone star tick amblyomma americanum in dogs. eighteen dogs were randomly assigned to treatment with 65% permethrin in either diethylene glycol monomethyl ether (dgme; original formulation) or propylene glycol monomethyl ether (pgme) or to be untreated as a cont ... | 2003 | 12756635 |
| comprehensive analysis of the factor h binding capabilities of borrelia species associated with lyme disease: delineation of two distinct classes of factor h binding proteins. | some lyme disease spirochete isolates can bind complement regulatory protein factor h (fh), a process that may allow evasion of complement-mediated killing. here we demonstrate significant differences in the fh binding capabilities of species of the borrelia burgdorferi sensu lato complex. the percentages of b. burgdorferi, b. afzelii, and b. garinii bacteria that bound fh in either enzyme-linked immunosorbent assays or affinity ligand binding immunoblot assays were 100, 83, and 29%, respectivel ... | 2003 | 12761145 |
| 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 |
| endocannabinoids and related fatty acid amides, and their regulation, in the salivary glands of the lone star tick. | the salivary glands and saliva from the lone star tick amblyomma americanum (l.) were analyzed for the presence of the two endogenous agonists of cannabinoid receptors, n-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol (2-ag), as well as of the anandamide congener, n-palmitoylethanolamine (pea), an anti-inflammatory and analgesic mediator that is inactive at cannabinoid receptors. two very sensitive mass-spectrometric techniques were used for this purpose. both 2-ag and pea, as ... | 2003 | 12842196 |
| survival, replication, and antibody susceptibility of ehrlichia chaffeensis outside of host cells. | ehrlichia chaffeensis, an obligate intracellular, tick-transmitted bacterium, is susceptible to antibody-mediated host defense, but the mechanism by which this occurs is not understood. one possible explanation is that antibodies directly access the bacteria in the extracellular environment of the host, perhaps during bacterial intercellular transfer. accordingly, we investigated whether bacteria could be found outside of host cells during infection. host cell-free plasma obtained from infected ... | 2003 | 12874298 |
| molecular genetics and evolution of pheromone biosynthesis in lepidoptera. | a great diversity of pheromone structures are used by moth species (insecta: lepidoptera) for long-distance mating signals. the signal/response channel seems to be narrow for each species, and a major conundrum is how signal divergence has occurred in the face of strong selection pressures against small changes in the signal. observations of various closely related and morphologically similar species that use pheromone components biosynthesized by different enzymes and biosynthetic routes unders ... | 2003 | 12876197 |
| enzootic transmission of anaplasma bovis in nantucket cottontail rabbits. | serological studies of cottontail rabbits sampled from nantucket island, mass., have suggested exposure to at least two ehrlichiae. the agent of human granulocytic ehrlichiosis (anaplasma phagocytophilum) is intensely enzootic in rabbits there, but the identity of the other ehrlichial infection remains undescribed. we sampled rabbits over five transmission seasons and tested their blood and tissues for evidence of infection using pcr targeting an ehrlichia genus-wide 16s rdna target. sequence an ... | 2003 | 12904385 |
| isolation of an anaplasma sp. organism from white-tailed deer by tick cell culture. | we used tick cell culture to isolate a bacterium previously referred to as the "white-tailed deer (wtd) agent" from two captive fawns inoculated with blood from wild wtd (odocoileus virginianus). buffy coat cells were added to ise6 tick cell cultures and incubated at 34 degrees c, and 8 days later, anaplasma-like inclusions were demonstrated in giemsa-stained culture samples. the microbes became established and could be continuously passaged in tick cells. the identity of a culture isolate desig ... | 2003 | 12958265 |
| development of a polyclonal competitive enzyme-linked immunosorbent assay for detection of antibodies to ehrlichia ruminantium. | a polyclonal competitive enzyme-linked immunosorbent assay (pc-elisa) is described for detection of antibodies to ehrlichia (cowdria) ruminantium by using a soluble extract of endothelial cell culture-derived e. ruminantium as the antigen and biotin-labeled polyclonal goat immunoglobulins as the competitor. for goats, the diagnostic sensitivity and specificity were both 100% with a cutoff of 80% inhibition (80 pi), with detection of antibodies for 550 days postinfection. for cattle, diagnostic s ... | 2003 | 12965926 |
| 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 |
| quantitative real-time pcr assay for detection of ehrlichia chaffeensis. | a real-time pcr assay was developed for the detection of ehrlichia chaffeensis. the assay is species specific and provides quantitative results in the range 10 to 10(10) gene copies. the assay is not inhibited by the presence of tick, human, or mouse dna and is compatible with high sample throughput. the assay was compared with previously described assays for e. chaffeensis. | 2003 | 12904406 |
| a method for extraction and analysis of high quality genomic dna from ixodid ticks. | currently, no published methods describe the extraction of high molecular weight genomic dna from ixodid ticks (acari: ixodidae) and commonly used methods of extraction are not well adapted for use with members of this family. a method for extraction of minimally degraded genomic dna from ixodid ticks that can be completed in one or two days is described. the method produces dna which is of sufficient size (>24 kb) for use in southern analysis and which is readily digestible by restriction endon ... | 2003 | 12823841 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |