Publications

range expansion of the tick amblyomma triguttatum triguttatum, an australian vector of q fever.	the tick amblyomma triguttatum triguttatum has previously been reported from western australia, queensland and new south wales. a viable population of this species, including all developmental stages, has now been discovered on the southern end of yorke peninsula, south australia. species determination was carried out morphologically and using 18s and 16s rrna. the data for 16s rrna are the first published for this species. amblyomma t. triguttatum is significant through its involvement in the n ...	2000	10899523
ultrastructure studies on post-oocyst development of the lizard hemogregarine hemolivia mariae in the tick amblyomma limbatum.	the ultrastructural features of the development of hemolivia mariae, a blood parasite of the australian lizard, tiliqua rugosa, from sporokinetes to sporozoites in their vector tick amblyomma limbatum are described. sporokinetes, released from oocysts, re-establish themselves in tick-gut epithelial cells within a parasitophorous vacuole, the wall of which becomes evaginating and anastomosing and is underlined extensively by endoplasmic reticulum. the sporozoites forming within the encysting spor ...	2000	10894472
report on ticks collected in the southeast and mid-west regions of brazil: analyzing the potential transmission of tick-borne pathogens to man.	specimens of ticks were collected in 1993, 1996, 1997, and 1998, mostly from wild and domestic animals in the southeast and mid-west regions of brazil. nine species of amblyommidae were identified: anocentor nitens, amblyomma cajennense, amblyomma ovale, amblyomma fulvum, amblyomma striatum, amblyomma rotundatum, boophilus microplus, boophilus annulatus, and rhipicephalus sanguineus. the potential of these tick species as transmitters of pathogens to man was analyzed. a flaviviridade flavivirus ...	1999	10881097
[isolation of rickettsia in vero cell culture].	the diagnosis of spotted fever is based on characteristic signs and symptoms but requires laboratorial confirmation because of the possible differential diagnosis from other diseases like leptospirosis, enterovirus, meningococcemia and typhoid fever. laboratorial confirmation may be done by detection of specific antibodies which is possible only 5-10 days after the onset of the symptoms or by the isolation of rickettsiae from blood and/or skin biopsy and from ticks collected in the patient or in ...	1999	10881078
identification of ehrlichia chaffeensis by nested pcr in ticks from southern china.	a total of 717 ticks collected from southern china were examined by nested pcr for the presence of ehrlichia chaffeensis. sixteen (55. 2%) of 29 adult amblyomma testudinarium ticks and 28 (11.7%) of 240 adult and at least 4.2% of 215 nymphal (pooled specimens) haemaphysalis yeni ticks tested positive. four other species of ticks were negative. selected positive amplicons were confirmed by dna sequencing.	2000	10878087
isolation and molecular cloning of a secreted immunosuppressant protein from dermacentor andersoni salivary gland.	a 36-kda immunosuppressant protein (da-p36) was isolated from salivary glands of feeding female ixodid ticks dermacentor andersoni, using its affinity for ultralink biosupport medium (pierce, rockford, illinois)/protein complexes. using a nested set of forward degenerate oligonucleotide primers corresponding to da-p36 n-terminal amino acids, a cdna encoding the immunosuppressant protein was isolated by 3' rapid amplification of cdna ends. the resulting 772-base pair cdna encodes a novel protein ...	2000	10864249
competence of the african tortoise tick, amblyomma marmoreum (acari: ixodidae), as a vector of the agent of heartwater (cowdria ruminantium).	the ability of the african tortoise tick, amblyomma marmoreum, to acquire and transmit cowdria ruminantium infection was investigated experimentally with transmission trials and with a c. ruminantium-specific polymerase chain reaction (pcr) detection assay. laboratory-reared a. marmoreum larvae and nymphs were fed on small ruminants with clinical heartwater. after molting, the resultant nymphs were fed on cowdria ruminantium-naive sheep (n = 3), and the adults were ground and inoculated intraven ...	2000	10864237
short report: study on the efficacy of a new long-acting formulation of n, n-diethyl-m-toluamide (deet) for the prevention of tick attachment.	the beneficial effects of n, n-diethyl-m-toluamide (deet) against biting insects of human and animals appear to last <6 hr after a single application to the skin. to prolong the repellent effects of deet, recently we developed a new long-acting formulation of deet called lipodeet. this preparation was retained in the skin for a longer duration of time with minimal systemic absorption. in this study, we have evaluated the protective effect of three compounds (deet, lipodeet, and morpel 220) again ...	2000	10813468
tick infestations of birds in coastal georgia and alabama.	mist-netted birds were examined for ticks on jekyll island, glynn co., georgia (32 bird species) in 1996-1998, and at fort morgan, baldwin co., alabama (36 species) in 1998 during fall migration. sixty-two (14.7%) of 423 birds from jekyll island and 22 (13.3%) of 165 birds from fort morgan were infested with ticks. the mean number of ticks per infested bird was 2.0 on jekyll island and 6.3 at fort morgan. ten species of birds were infested with ticks on jekyl1 island where 87% of all ticks were ...	2000	10780541
detection of the agent of heartwater, cowdria ruminantium, in amblyomma ticks by pcr: validation and application of the assay to field ticks.	we have previously reported that the pcs20 pcr detection assay for cowdria ruminantium, the causative agent of heartwater disease of ruminants, is more sensitive than xenodiagnosis and the pcs20 dna probe for the detection of infection in the vector amblyomma ticks. here, we further assessed the reliability of the pcr assay and applied it to field ticks. the assay detected dna of 37 isolates of c. ruminantium originating from sites throughout the distribution of heartwater and had a specificity ...	2000	10747140
molecular individuality: polymorphism of salivary gland proteins in three species of ixodid tick.	pooled tissue samples are frequently used in biochemical studies involving parasites in order to ensure that there is sufficient material for experimentation. a pooled sample is considered to represent the overall phenotypic characteristics of the investigated population. however, this will not be the case if there is a significant degree of molecular polymorphism among individuals in the sampled population. here we demonstrate marked differences in the protein profile of salivary glands among i ...	1999	10737731
prevalence of ehrlichia chaffeensis (rickettsiales: rickettsiaceae) in amblyomma americanum (acari: ixodidae) from the georgia coast and barrier islands.	human monocytic ehrlichiosis is an emerging zoonosis caused by infection with ehrlichia chaffeensis anderson, dawson, jones & wilson, which is transmitted to mammals by ixodid ticks. prevalence of infected ticks and distribution of infection foci indicate relative risk of human exposure to ehrlichiosis and may be influenced by factors such as geographic isolation, human disturbance, and the availability of suitable mammalian reservoir hosts. to test, this, individual and pooled lone star ticks, ...	2000	10730500
comparison of efficacy of american and african amblyomma ticks as vectors of heartwater (cowdria ruminantium) infection by molecular analyses and transmission trials.	the ability of amblyomma americanum, amblyomma cajennense, amblyomma maculatum, and amblyomma variegatum to acquire and transmit cowdria ruminantium infection was investigated. uninfected nymphs were fed on clinically reacting c. ruminantium-infected sheep and then analyzed for infection by specific dna detection assays and by tick transmission trials. by polymerase chain reaction (pcr), the mean infection prevalence of a. maculatum ticks (50.7%) was similar to that of a. variegatum, elevage str ...	2000	10701562
naturally occurring and experimentally transmitted hepatozoon americanum in coyotes from oklahoma.	twenty free-ranging coyotes (canis latrans) in oklahoma (usa) were examined for the presence of naturally occurring infections with hepatozoon americanum and to determine if bone lesions attributable to h. americanum were present. although eight of the 20 free-ranging coyotes were found to be naturally infected with h. americanum, no bone lesions were detected. in addition, two coyote pups were exposed to h. americanum oocysts collected from experimentally infected ticks and the course of the re ...	2000	10682757
ticks of south carolina (acari: ixodoidea).	county and host records are reported for 19 species of ticks from south carolina: amblyomma americanum, amblyomma maculatum, amblyomma tuberculatum, aponomma latum, boophilus annulatus, boophilus microplus, dermacentor albipictus, dermacentor variablis, haemaphysalis leporispalustris, ixodes affinis, ixodes brunneus, ixodes cookei, ixodes marxi, ixodes minor, ixodes scapularis, ixodes texanus, ixodes woodi, rhipicephalus sanguineus, and ornithodoros capensis. ixodes woodi is recorded from south ...	1999	10672552
responses of the tropical bont tick, amblyomma variegatum (fabricius), to its aggregation-attachment pheromone presented in an air stream on a servosphere.	male amblyomma variegatum ticks feeding on a host release a mixture of o-nitrophenol and methyl salicylate which serves to attract conspecifics. the behavioural responses of a. variegatum on a servosphere to these volatiles presented in an air stream are detailed here. in still air, ticks walked on all eight legs, but with long halts. in contrast, the air stream caused continuous walking and induced a reaching response where the forelegs actively sampled the air. such reaching increased the angu ...	2000	10659046
sporogonic development of hepatozoon americanum (apicomplexa) in its definitive host, amblyomma maculatum (acarina).	light microscopic observations of the sporogonic development of hepatozoon americanum are described in its acarine host, amblyomma maculatum. laboratory-reared nymphal ticks were fed on 2 dogs infected with h. americanum. nymphal ticks were sampled daily, starting 3 days after being placed on a parasitemic dog, until 18 days after infestation (pi), and then every 3 or 4 days until replete nymphs molted. ticks were examined as unstained wet mounts and hematoxylin-eosin-stained paraffin sections. ...	1999	10647032
the occurrence of theileria and cowdria parasites in african buffalo (syncerus caffer) and their associated amblyomma hebraeum ticks.	the polymerase chain reaction and oligonucleotide probing were used to detect theileria and cowdria species in dna extracted from blood and ticks recovered from 24 african buffalo during a gamecapture operation in the kruger national park, south africa. species-specific probing indicated that all but one of the buffalo were carrying at least one theileria species. indirect fluorescent antibody (ifa) serology indicated that all animals had been exposed to theileria parva infection but only 33% we ...	1999	10631711
parasites of domestic and wild animals in south africa. xxxvii. ixodid ticks on cattle on kikuyu grass pastures and in valley bushveld in the eastern cape province.	individual calves, exposed to infestation for 14 d on dry-land kikuyu grass pastures on the coast near alexandria, were slaughtered at approximately monthly intervals over a period of 2 years and examined for ticks. although seven species were recovered total tick burdens were for the most part low. changing the acaricide with which other cattle on the farm, but not the survey calves, were treated from an organophosphate-based compound to a synthetic pyrethroid resulted in a marked sustained red ...	1999	10631707
parasites in cross-bred pigs in the upper east region of ghana.	a cross-sectional study was carried out in the upper east region (uer) of ghana in order to estimate the prevalence of parasitic infections in local cross-bred pigs. out of 60 villages with a human population of 200-1000 inhabitants, 10 villages were randomly selected for the study. the number of pigs varied from 50 to 200 pigs per village. in total 259 faecal samples from growers were collected and examined. ninety-one percent of the animals excreted parasite eggs. among these the prevalence of ...	1999	10628701
infection rates of amblyomma americanum (acari: ixodidae) by ehrlichia chaffeensis (rickettsiales: ehrlichieae) and prevalence of e. chaffeensis-reactive antibodies in white-tailed deer in southern indiana, 1997.	to monitor the percentage and stability of ehrlichia chaffeensis-infected ticks in southern indiana over time, pools of amblyomma americanum (l.) ticks were screened for infection in southern indiana for a 2nd time. nested polymerase chain reaction (with 6% dmso included only in the 2nd reaction) was performed on 920 ticks in pools of 5 individuals from 9 sites (5 sites previously examined and 4 new ones) in 6 counties. the average minimum infection rate for all sites for 1997 was 1.6%, lower th ...	1999	10593071
ticks feeding on humans: a review of records on human-biting ixodoidea with special reference to pathogen transmission.	in this article, literature records of argasid and ixodid ticks feeding on humans worldwide are provided in view of increased awareness of risks associated with tick bites. ticks can cause paralyses, toxicoses, allergic reactions and are vectors of a broad range of viral, rickettsial, bacterial and protozoan pathogens. approximately 12 argasid species (argas and ornithodos) are frequently found attached to humans who intrude into tick-infested caves and burrows. over 20 ixodid tick species are o ...	1999	10581710
prevalence of cowdria ruminantium infection in amblyomma hebraeum ticks from heartwater-endemic areas of zimbabwe.	analysis of the transmission dynamics of cowdria ruminantium, the tick-borne rickettsial agent of heartwater in ruminants, requires accurate measures of infection in vector populations. to obtain these, amblomnia hebraeum ticks were collected at two heartwater-endemic locations in the lowveld and highveld regions of zimbabwe and assessed for c. ruminantium infection with specific polymerase chain reaction (pcr) and dna probe detection assays. at the lowveld site, 11.2% (50/446) of adult ticks an ...	1999	10579452
ticks and antibodies to borrelia burgdorferi from mammals at cape hatteras, nc and assateague island, md and va.	results of a survey for ixodid ticks and/or serum antibodies to borrelia burgdorferi from 14 species of small to large mammals from eastern coastal areas of the united states are presented. most samples were obtained from july 1987 through june 1989 (excluding december-march) at 3 locales: assateague is. national seashore, worcester co., md., and accomack co., va. (approximately 38 degrees 05' n 75 degrees 10' w), and cape hatteras national seashore, dare co., nc (approximately 35 degrees 30' n ...	1999	10534951
[african rickettsia infections].	epidemiology: african rickettsiasis is transmitted by rickettsia africae, a cattle tick. amblyomma spp. is an emerging rickettsiasis in sub-sehalian afric described in 1992. seroepidemiology studies conducted in africa show that it is probably the most widespread rickettsiasis in the sorld. in addition, the development of tourist activities in southern african countries has led to an increase in the number of reported cases in subjects returning from endemic areas. a high serprevalence of anti r ...	1999	10518970
cowdria ruminantium infection in ticks in the kruger national park.	adult amblyomma hebraeum ticks, the principle vector of heartwater (cowdriosis) of domestic ruminants in southern africa, were collected in pheromone traps placed in kruger national park, an exclusively wildlife sanctuary in south africa. these ticks transmitted cowdria ruminantium, the rickettsial agent causing heartwater, to a susceptible goat, resulting in acute, fatal disease. c ruminantium was isolated in bovine endothelial cell culture from the plasma of this animal during the febrile stag ...	1999	10515616
serologic study of the prevalence of rickettsiosis in yucatán: evidence for a prevalent spotted fever group rickettsiosis.	because of the discovery of a spotted fever group rickettsiosis with signs and symptoms similar to dengue fever in yucatan, mexico, immunofluorescence assay (ifa) serology was performed on sera from 390 persons selected from a representative geographic distribution of rural yucatan to detect antibodies reactive with rickettsia rickettsii, r. akari, a thai strain (tt-118) that is most closely related to a rickettsia identified in amblyomma cajennense ticks in southern texas, and r. typhi. the ifa ...	1999	10497980
transmission of the blood parasite hemolivia mariae between its lizard and tick hosts.	the haemogregarine hemolivia mariae is found in the erythrocytes of a natural population of the lizard tiliqua rugosa. it infects two tick species, amblyomma limbatum and aponomma hydrosauri, which parasitise lizards. in laboratory experiments, engorged amb. limbatum nymphs from infected lizards transmitted the haemogregarine to uninfected lizards significantly more often than engorged ap. hydrosauri nymphs. dissections of larvae and nymphs of both species fed on the same infected hosts showed t ...	1999	10494815
toxicity of neem seed oil (azadiracta indica) against the larvae of amblyomma variegatum a three-host tick in cattle.	the in vitro toxicity of neem seed oil (azadiracta indica, family: meliaceae, 'dogon yaro' in hausa -language) was tested against the larvae of a three-host tick, amblyomma variegatum (family: ixodidae or hard tick) parasitic to cattle commonly found in nigeria. undiluted neem oil (100% concentration) was found to kill all (100% mortality) the larvae after 48 h. the toxicity was concentration and time dependent.	1999	10479769
squalene: a naturally abundant mammalian skin secretion and long distance tick-attractant (acari: ixodidae).	squalene is a naturally occurring lipid on mammalian skin and is an attractant to the lone star tick, amblyomma americanum (l.). in this study, we compared squalene to the standard tick-attractants, benzaldehyde, isobutyric acid, methyl salicylate, nonanoic acid, and o-nitrophenol identified as active ingredients of tick aggregation-attachment pheromones and determined its effectiveness in field and laboratory settings at varying distances. squalene was detected from 1/4 m greater than the stand ...	1999	10467784
comparison of methods for introducing and producing artificial infection of ixodid ticks (acari: ixodidae) with ehrlichia chaffeensis.	only 29.5 +/- 8.91% of engorged amblyomma americanum (l.) nymphs that we inoculated with ehrlichia chaffeensis molted successfully to adults compared with 75.8 +/- 7.46% of engorged nymphs that were not inoculated. however, 65.4 +/- 6.02% of unfed nymphs of this species were exposed for 2 h to e. chaffeensis suspension introduced to them through glass capillaries gained weight. these nymphs were placed on rabbits, and approximately 50% of them completed their feeding and molted successfully to a ...	1999	10467766
evidence of rickettsial spotted fever and ehrlichial infections in a subtropical territory of jujuy, argentina.	between november 1993 and march 1994, a cluster 6 pediatric patients with acute febrile illnesses associated with rashes was identified in jujuy province, argentina. immunohistochemical staining of tissues confirmed spotted fever group rickettsial infection in a patient with fatal disease, and testing of serum of a patient convalescing from the illness by using an indirect immunofluorescence assay (ifa) demonstrated antibodies reactive with spotted fever group rickettsiae. a serosurvey was condu ...	1999	10463693
theileria sp. infections associated with bovine fatalities in the united states confirmed by small-subunit rrna gene analyses of blood and tick samples.	theileria sp.-specific small subunit (ssu) rrna gene amplification confirmed the presence of the organism in cattle and in amblyomma americanum and dermacentor variabilis ticks collected from a cattle herd in missouri. blood from the index animal had type a and type d theileria ssu rrna genes. the type d gene was also found in blood from two cohort cattle and tick tissues. the type a ssu rrna gene was previously reported from bovine theileria isolates from texas and north carolina; the type d ge ...	1999	10449501
seroepidemiologic studies on babesia equi and babesia caballi infections in brazil.	horses from six stud farms representing the most frequent types of horse breeding in brazil were tested for babesia antibodies by the ifa test. the farms are located at the tropic of capricorn at an altitude of 472-715 m where temperatures below 0 degrees c may occur. horses of conventional stud farms were infested with dermacentor nitens, amblyomma cajennense, and boophilus microplus. infestation with bo. microplus was associated with direct or indirect contact of horses with cattle, and was no ...	1999	10447188
wild birds as hosts of amblyomma cajennense (fabricius, 1787) (acari: ixodidae).	we evaluated the prevalence, mean intensity and relative density of ticks in 467 wild birds of 67 species (12 families) from forest and cerrado habitats at two protected areas of minas gerais, between march and september 1997. ticks collected (n=177) were identified as larvae and nymphs of amblyomma cajennense and four other species of amblyomma. we report for the first time 28 bird species as hosts of the immature stages of a. cajennense, demonstrating the lack of host specificity of the larvae ...	1999	10419381
tick-borne rickettiosis in guadeloupe, the french west indies: isolation of rickettsia africae from amblyomma variegatum ticks and serosurvey in humans, cattle, and goats.	twenty-seven rickettsiae were isolated and/or detected from 100 amblyomma variegatum ticks collected on guadeloupe in the french west indies. in this study, the polymerase chain reaction procedure appeared to be more sensitive in detecting rickettsiae in ticks than the shell-vial technique. sequencing a portion of the outer membrane protein a-encoding gene showed that these rickettsiae appeared to be identical to rickettsia africae, a member of the spotted fever group rickettsiae recently descri ...	1999	10403315
susceptibility and carrier status of impala, sable, and tsessebe for cowdria ruminantium infection (heartwater).	three species of wild african ruminants, impala (aepyceros melampus), sable (hippotragus equinus), and tsessebe (damaliscus lunatus), were experimentally inoculated with in vitro culture-derived cowdria ruminantium organisms, the tick-borne causative agent of heartwater in domestic ruminants, to determine their susceptibility to infection. no clinical disease was observed in any of the ruminants. however, c. ruminantium was detected in the sable by the transmission of heartwater to susceptible s ...	1999	10386439
canine hepatozoonosis: comparison of lesions and parasites in skeletal muscle of dogs experimentally or naturally infected with hepatozoon americanum.	we report previously undescribed, early lesions in skeletal muscle of dogs experimentally infected with hepatozoon americanum by ingestion of laboratory-reared, infected amblyomma maculatum. the earliest muscle lesion was recognized at the first interval of examination 3 weeks following exposure. the lesion consisted of a large, modified host cell whose cytoplasm frequently contained a demonstrable parasite. in skeletal muscle, the cell was consistently located between muscle fibers or in loose ...	1999	10384901
immune responses to dermatophilus congolensis infections.	complex mechanisms underly the establishment of dermatophilosis, an exudative and proliferative skin disease of ruminants. this multicomponent system involves the bacterium dermatophilus congolensis, transmission by various routes including flies, host genetic factors and immunosuppression by amblyomma variegatum ticks. here, nick ambrose and colleagues summarize recent evidence for an association between a. variegatum and severe chronic dermatophilosis in cattle. breed-based differences in resi ...	1999	10377534
the life cycle of amblyomma neumanni ribaga, 1902 (acari: ixodidae) in the laboratory.	a colony of amblyomma neumanni was started with engorged females collected from cattle in the province of salta (24 degrees 51's, 65 degrees 33'w), argentina. the larvae and nymphs were fed on rabbits and the adults on calves. the non-parasitic stages were maintained in darkness at 27 +/- 1 degrees c and 83-86% rh. the life cycle (pre-feeding period not tested) had a mean duration of 205.7 days. the mean time (days) for the different phases of the cycle were as follows: feeding of females 8.8, p ...	1999	10356766
evaluation of 16s, map1 and pcs20 probes for detection of cowdria and ehrlichia species.	a panel of 16s ribosomal rna gene probes has been developed for the study of the epidemiology of heartwater; five of these detect different cowdria genotypes, one detects five distinct genotypes; one detects any group iii ehrlichia species other than cowdria and one detects any group ii ehrlichia species. these probes have been used on pcr-amplified rickettsial 16s rrna genes from over 200 amblyomma hebraeum ticks. control ticks were laboratory-reared and either uninfected or fed on sheep experi ...	1999	10355799
population dynamics of ticks on indigenous cattle in a pastoral dry to semi-arid rangeland zone of uganda.	studies on seasonality and population dynamics of ticks on indigenous cattle and their crosses (calves) were carried out in buruli ranching scheme, nabiswera, luwero district of uganda on three treatment groups of animals: group 1 (twice a week dipping), group 2 (once a month dipping) and group 3 (no tick control). during this study, four major species of ticks of economic importance were recorded in decreasing order of abundance: rhipicephalus appendiculatus, rhipicephalus evertsi evertsi, ambl ...	1999	10353189
palp-splaying behavior and a specific mouthpart site associated with active water vapor uptake in amblyomma americanum (acari: ixodidae).	ticks actively absorb water vapor from unsaturated air via their mouthparts. a wax technique was used to cover select areas of the mouthparts of the lone star tick, amblyomma americanum (l.), to examine whether a specific site is involved in uptake. covering dorsal, ventral, and distal regions failed to inhibit uptake, whereas wax applied to the proximal region, specifically the hypostome-cheliceral junction, blocked water absorption. a novel occurrence of a palp-splaying behavior was observed d ...	1999	10337109
attachment sites of four tick species (acari: ixodidae) parasitizing humans in georgia and south carolina.	from june 1995 through january 1998, 677 tick specimens were submitted by 521 humans from 14 states. analysis was limited to specimens originating in georgia and south carolina, representing 87.3% of total submissions. attachment sites were specified in 367 specimens (62.3%). the american dog tick, dermacentor variabilis (say), a vector of the agent of rocky mountain spotted fever, favored the head and neck in 59% of attached specimens. the lone star tick, amblyomma americanum (l.), a strongly i ...	1999	10337108
responses of three species of adult ticks (acari: ixodidae) to chemicals in the coats of principal and minor hosts.	in laboratory bioassays, host-seeking adult blacklegged ticks, ixodes scapularis say, lone star ticks, amblyomma americanum (l.), and american dog ticks, dermacentor variabilis (say), were exposed to substances from the pelage of dogs and white-tailed deer, odocoileus virginianus (zimmermann). male a. americanum exhibited an arrestant response to all samples of deer tarsal gland substances tested, whereas female a. americanum, female i. scapularis, and male and female d. variabilis responded to ...	1999	10337091
[experimental transmission of crimean-congo hemorrhagic fever virus: role of 3 vector species in the maintenance and transmission cycles in senegal].	in this article, we published the role of three species of ticks amblyomma variegatum (fabricius, 1974), hyalomma marginatum rufipes (koch, 1844) and hyalomma truncatum (koch, 1844) in the maintenance and transmission of the cchf virus. the imagos of these species were infected by intracoelomic route. vertical transmission (transtasial and transovarial) and horizontal transmission for different stases were studied by isolation on newborn mice, polymerase chain reaction, indirect immunofluorescen ...	1999	10229934
molecular cloning and characterization of the ehrlichia chaffeensis variable-length pcr target: an antigen-expressing gene that exhibits interstrain variation.	a clone expressing an immunoreactive protein with an apparent molecular mass of 44 kda was selected from an ehrlichia chaffeensis arkansas genomic library by probing with anti-e. chaffeensis hyperimmune mouse ascitic fluid. nucleotide sequencing revealed an open reading frame (orf) capable of encoding a 198-amino-acid polypeptide. the orf contained four imperfect, direct, tandem 90-bp repeats. the nucleotide and deduced amino acid sequences did not show close homologies to entries in the molecul ...	1999	10203503
phylogeny of the hard ticks (ixodidae) inferred from 18s rrna indicates that the genus aponomma is paraphyletic.	we examined the phylogeny of ticks (acari:parasitiformes:ixodida) and their closest known mite relatives (acari:parasitiformes:mesostigmata and holothyrida) using 18s rrna sequences. in our analyses, we included sequences from 36 taxa. sequences for 13 hard ticks (family ixodidae), 5 soft ticks (family argasidae), and 2 mesostigmatid mites were obtained from the genbank database and we generated sequences for 15 hard ticks and 1 holothyrid mite. ten of these tick species were endemic to australi ...	1999	10191073
novel ehrlichia organism (rickettsiales: ehrlichieae) in white-tailed deer associated with lone star tick (acari: ixodidae) parasitism.	polymerase chain reaction (pcr) evidence of a novel ehrlichia organism was found recently in wild white-tailed deer, odocoileus virginianus zimmermann, and lone star ticks, amblyomma americanum l., from the southeastern united states. to evaluate whether lone star tick parasitism was associated with the presence of this novel ehrlichia organism in deer, 2 retrospective studies were conducted using specific nested pcr to test archived deer serum samples. the 1st study of 150 serum samples collect ...	1999	10083757
naturally occurring hepatozoonosis in coyotes from oklahoma.	nine of 16 free-ranging coyotes (canis latrans) from central oklahoma (usa) had naturally acquired infections of hepatozoon americanum. infections were confirmed by recognition of tissue stages closely resembling h. americanum in skeletal and cardiac muscle. at the time coyotes were collected they were infested with a variety of ticks, including adult gulf coast ticks (amblyomma maculatum). we propose that the high prevalence of h. americanum in this small sample of free-ranging coyotes and the ...	1999	10073352
molecular cloning of camp-dependent protein kinase catalytic subunit isoforms from the lone star tick, amblyomma americanum (l.).	the salivary glands of ixodid ticks are central to tick feeding and to survival during off-host periods. they produce and secrete a number of molecules critical to maintaining the complex host-vector interface and to maintaining osmotic balance. we have previously shown that a cyclic amp-dependent protein kinase (capk) is involved in the mechanism of salivary gland secretion. we have now cloned cdnas encoding three isoforms of the catalytic subunit (capk-c) of the capk from amblyomma americanum, ...	1999	10070744
profile of the ecdysteroid hormone and its receptor in the salivary gland of the adult female tick, amblyomma hebraeum.	we examined the hemolymph ecdysteroid titer (by radioimmunoassay) and profile of the ecdysteroid receptor (ecr/usp; by [3h]ponasterone a binding, gel mobility shift assay, western blot) in the salivary gland of the ixodid tick, amblyomma hebraeum koch (acari: ixodidae) throughout the tick feeding period and first 6 days post-engorgement. throughout the slow phase of feeding, the hemolymph ecdysteroid titer was approximately 18 pg/microliter. the titer peaked at approximately 52 pg/microliter dur ...	1999	10070743
distributions of the vectors of heartwater, amblyomma hebraeum and amblyomma variegatum (acari: ixodidae), in zimbabwe.	the tick vectors of heartwater (cowdria ruminantium infection) in zimbabwe, amblyomma hebraeum and amblyomma variegatum, historically were believed to be confined to the low-lying regions of the south and north-west of the country. however, country-wide surveys performed in 1975-1980 and 1988-1991 demonstrated that both species were also established in western parts of the highveld plateau and had started to encroach on the predominantly heartwater-free central and eastern highveld regions. to d ...	1998	10030008
population genetic structure of a three-host tick, amblyomma dissimile, in eastern venezuela.	patterns of genetic variation for the tick amblyomma dissimile were analyzed from a total of 200 ticks collected on 12 toads (bufo marinus), 14 snakes (boa constrictor), and 8 lizards (iguana iguana) at 11 localities. the analyses were performed on electrophoretic data from 8 isozyme loci. mean heterozygosity per locus was 6% (+/-3.1) per population. differences in allelic frequencies among ticks from different individual hosts were the major source of genetic variability in this study. host spe ...	1998	9920303
[two cases of spotted fever group rickettsiosis contracted in southern parts of africa].	a 40-year-old japanese male stayed in zimbabwe and developed a fever above 38 degrees c during which he noted a typical eschar in the lumbar region and also regional inguinal lymphadenopathy. although not conspicuous, erythematous eruptions accompanied by itching were observed on the face, trunk and lower extremities. after returning to japan and visiting our hospital, he was suspected of rickettsiosis and put on minocycline which gradually led to the improvement of the symptoms. immunofluoresce ...	1998	9916419
dna binding properties of the ecdysteroid receptor in the salivary gland of the female ixodid tick, amblyomma hebraeum.	salivary gland degeneration in the female tick, amblyomma hebraeum koch (acari: ixodidae) is controlled by an ecdysteroid hormone. in an earlier study (mao, h., mcblain, w.a., kaufman, w.r., 1995. some properties of the ecdysteroid receptor in the salivary gland of the ixodid tick, amblyomma hebraeum. gen. comp. endocrinol. 99, 340-348), we demonstrated that a protein component of a salivary gland extract binds to ponasterone a (pon a) with high affinity (kd-1 nm), suggesting a tick ecdysteroid ...	1998	9887511
experimental transmission of hepatozoon americanum vincent-johnson et al., 1997 to dogs by the gulf coast tick, amblyomma maculatum koch.	experimental transmission of hepatozoon americanum to dogs was attempted with four ixodid ticks, viz., rhipicephalus sanguineus, amblyomma americanum, amblyomma maculatum and dermacentor variabilis. ticks that dogs ingested included some that were laboratory-reared and experimentally fed as nymphs on a dog with naturally occurring hepatozoonosis; other ticks were collected as replete or partially engorged larvae, nymphs and adults from dogs that had hepatozoonosis and natural infestations of tic ...	1998	9877066
encephalitozoon-like microsporidia in the ticks amblyomma cajennense and anocentor nitens (acari: ixodidae).	a encephalitozoon-like microsporidia was found in epithelial cells of the midgut and the salivary glands of amblyomma cajennense (f.) and anocentor nitens (neumann) that had fed on rabbits. ultrastructural studies demonstrated that all stages of the life cycle of the parasite occur in parasitophorous vacuoles and contain only 1 nucleus. the sporonts detach from the limiting membrane of the vacuole and divide by binary fission to produce the sporoblasts, each presenting a thickened electron-dense ...	1998	9835698
a molecular and serologic survey of ehrlichia canis, e. chaffeensis, and e. ewingii in dogs and ticks from oklahoma.	polymerase chain reaction and southern hybridization were used to survey for the presence of ehrlichia canis, ehrlichia chaffeensis, and ehrlichia ewingii in blood samples of 65 dogs that harbored ticks from northcentral and northeastern oklahoma. dog blood samples were also examined for antibodies against e. canis and e. chaffeensis, using an immunofluorescent antibody test. ten of 65 dogs (15.4%) examined were positive for ehrlichia spp. by pcr. four (6.2%) were positive for e. ewingii, 2 (3.1 ...	1998	9831955
comment on "a possible explanation of the apparent breed-related resistance in cattle to bont tick (amblyomma hebraeum) infestations" by m.i. meltzer, veterinary parasitology 67 (1996) 275-279.		1998	9823067
parasites of domestic and wild animals in south africa. xxxv. ixodid ticks and bot fly larvae in the bontebok national park.	ixodid ticks were collected during february of each year from 1983-1992 from bontebok and grey rhebok in the bontebok national park, western cape province. when available other mammals as well as ground-nesting birds and leopard tortoises were examined. eleven tick species were recovered. rhipicephalus nitens followed by rhipicephalus glabroscutatum and an ixodes sp. (near i. pilosus) were the most abundant, while amblyomma marmoreum infested the widest host range. the larvae of three bot files ...	1998	9809325
the distribution of heartwater in the highveld of zimbabwe, 1980-1997.	heartwater, the tick-borne disease caused by the rickettsia cowdria ruminantium has historically been confined to the southern and western lowvelds of zimbabwe. since 1986, however, cases of heartwater have been diagnosed with increasing frequency in the central and eastern regions of the previously heartwater-free highveld plateau. during the same period, collections of the two major tick vectors of heartwater in zimbabwe, amblyomma hebraeum and amblyomma variegatum, were made for the first tim ...	1998	9809322
natural coinfection of a white-tailed deer (odocoileus virginianus) population with three ehrlichia spp.	the ticks amblyomma americanum and ixodes scapularis, strongly implicated vectors of ehrlichia chaffeensis and the human granulocytic ehrlichiosis (hge) agent, respectively, commonly are found on white-tailed deer (odocoileus virginianus). as deer can be infected with e. chaffeensis, the hge agent, and another ehrlichia-like organism, a deer population parasitized by both tick species in coastal georgia was tested for evidence of ehrlichia spp. infection using serologic, molecular, and culture t ...	1998	9794627
ehrlichia chaffeensis in missouri ticks.	a nested polymerase chain reaction specific for ehrlichia chaffeensis was used to attempt to amplify dna from extracts of 100 individual ticks collected from 13 counties in central missouri. seventeen of 59 amblyomma americanum and six of 41 dermacentor variabilis ticks exhibited the characteristic 389-basepair product. this supports the hypothesis that these tick species may be vectors of human monocytic ehrlichiosis.	1998	9790445
geographic distribution of ticks (acari: ixodidae) in michigan, with emphasis on ixodes scapularis and borrelia burgdorferi.	a 12-yr (1985-1996) passive survey in michigan based upon tick submissions from citizens yielded 4,755 ticks of 21 species, 16 of which were probably indigenous in the state. three species of dermacentor [most common, d. variabilis say and d. albipictus (packard)]; 2 species of amblyomma [most common, a. americanum (l.)]; and 12 species of ixodes (most common, i. cookei packard and i. scapularis say), as well as haemaphysalis leporispalustris (packard), rhipicephalus sanguineus latreille, and th ...	1998	9775623
kinetics and cross-species comparisons of host antibody responses to lone star ticks and american dog ticks (acari: ixodidae).	understanding of the animal antibody response to tick salivary gland proteins is necessary to identify candidate antibodies that may have use as species- and feeding-duration-specific biomarkers of tick exposure in humans. the kinetics of the humoral immune response of rabbits to challenge feeding by 2 tick species [amblyomma americanum (l.) and dermacentor variabilis (say)] was characterized by both enzyme-linked immunosorbent assay and immunoblot. western blot analysis revealed that rabbits pr ...	1998	9775620
establishment of the tortoise tick amblyomma marmoreum (acari: ixodidae) on a reptile-breeding facility in florida.	the tortoise tick amblyomma marmoreum koch was found to be established on a reptile facility in central florida. over a 5-mo period, 443 ticks were collected from tortoises, dogs, and vegetation. collections from hosts were primarily from 3 species of exotic tortoises, including leopard tortoises, aldabra tortoises, and yellow-footed tortoises. the total numbers of ticks present, the presence of all life stages, and the slow development of this species indicate that this is not a recent infestat ...	1998	9775582
ixodid tick infestations of wild birds and mammals on a game ranch in central province, zambia.	ticks were collected at irregular intervals from december 1995 to november 1996 from wildlife on mtendere game ranch in the chisamba district of central province, zambia. total collections were made from two species of ground-nesting birds and 20 species of small and large mammals. thirteen species/subspecies of ixodid ticks were recovered. rhipicephalus appendiculatus was the most abundant, followed by boophilus decoloratus and rhipicephalus evertsi evertsi. small numbers of immature ticks of o ...	1998	9741055
immunization of rabbits with amblyomma hebraeum nymphal homogenates and implications for the host amplification system.	immunochemical mechanisms involved in tick rejection by a host are not well documented. the role of serum globulins, and that played by the amplification system's humoral products (thrombin from the coagulation, plasmin from the fibrinolytic, and kallikrein from the kinin systems) in tick-resistant animal hosts have not yet been demonstrated. it is known, however, that factors c1, c3 and c5 of the complement system play a role in tick rejection, and that factors c3a and c5a are anaphylatoxins ca ...	1998	9741053
a review of heartwater and the threat of introduction of cowdria ruminantium and amblyomma spp. ticks to the american mainland.	heartwater, caused by the rickettsial agent cowdria ruminantium, is one of the most devastating livestock diseases in sub-saharan africa. in addition to domestic cattle, sheep, and goats, a variety of nondomestic species can acquire subclinical and clinical infections. recent epidemiologic findings that demonstrate a long-term host carrier state in domestic and wild ruminants, intrastadial transmission by the tick vectors (amblyomma spp.), vertical transmission of the agent from cows to their ca ...	1998	9732023
physician-diagnosed erythema migrans and erythema migrans-like rashes following lone star tick bites.	to differentiate cases of physician-diagnosed erythema migrans and erythema migrans-like rashes associated with lone star tick (amblyomma americanum) bites.	1998	9722725
antibody to a cdna-derived calreticulin protein from amblyomma americanum as a biomarker of tick exposure in humans.	the antibody responses of human and animal hosts were studied to determine the utility of antibody against recombinant tick calreticulin (rtc), a cdna-derived protein isolated from salivary glands of amblyomma americanum l., as a biologic marker of tick exposure. rabbits fed upon by either a. americanum or dermacentor variabilis say developed significant anti-rtc antibody responses, as measured by both elisa and immunoblot assay. in contrast, gerbils exposed to aedes aegypti did not develop anti ...	1998	9715947
outbreak of rickettsia africae infections in participants of an adventure race in south africa.	african tick-bite fever, caused by rickettsia africae and transmitted by amblyomma ticks, is an emerging rickettsiosis in southern africa. because of increased tourism to this area, several cases in tourists have been reported recently. we report 13 cases of r. africae infection diagnosed in france that occurred in competitors returning from an adventure race in south africa and compare our data with previously reported findings. most of our patients presented with fever, headache, multiple inoc ...	1998	9709882
the travels of a lone star tick.	a lone-star tick, amblyomma americanum, was found as a pedunculated lesion on the back of the arm of an 84 year old man in northern ireland. this was acquired on a visit to the usa. the tick is found mainly in texas and the ozark mountains of missouri, with scattered foci in other parts of southern usa. it is the vector of rocky mountain spotted fever. as worldwide travel becomes increasingly common, exotic parasites make occasional appearances in northern europe.	1998	9708212
demonstration of a carrier state for cowdria ruminantium in wild ruminants from africa.	four wild african ruminants, eland (taurotragus oryx), giraffe (giraffa camelopardalis), kudu (tragephalus strepsiceros strepsiceros), and blue wildebeest (connochaetes taurinus), were experimentally infected with the rickettsia cowdria ruminantium, the tickborne agent causing heartwater in domestic ruminants. the infections were established, and c. ruminantium was transmitted to naive small ruminants by the vector amblyomma hebraeum when transmission attempts were made at days 128 (eland and wi ...	1998	9706566
isolation of two functional retinoid x receptor subtypes from the ixodid tick, amblyomma americanum (l.).	retinoid x receptors (rxr) play a central role in a variety of nuclear signaling pathways in both vertebrates and invertebrates. vertebrate rxrs are encoded by a multigene family whereas the insect rxr homologue, ultraspiracle (usp), is encoded by a single gene. to determine if acarines possess an rxr homologue similar to insect usps, we isolated cdnas encoding two distinct rxr genes, aamrxr1 and aamrxr2, from the ixodid tick, amblyomma americanum (l.). the dna binding domains share 95 and 87% i ...	1998	9705073
interaction of entomopathogenic nematodes (steinernematidae) with selected species of ixodid ticks (acari: ixodidae).	entomopathogenic nematodes, currently used for biological control of various insect pests, were tested for their ability to penetrate and kill replete females of several species of ticks including dermacentor variabilis (say), rhipicephalus sanguineus (latreille), amblyomma maculatum koch, and a. cajennense (f.). these species were found to be susceptible to the entomopathogenic nematodes, steinernema feltiae (filipjev) or s. riobravus (cabanillas & poinar), shown in previous studies in our labo ...	1998	9701938
phospholipase a2 activity in salivary glands and saliva of the lone star tick (acari: ixodidae) during tick feeding.	phospholipase a2 (pla2) activity levels in tick [amblyomma americanum (l.)] salivary glands and saliva were examined during tick feeding by using 14c-phosphatidylcholine as the substrate. saliva produced by stimulating female ticks to salivate with dopamine contains pla2 (ts-pla2) activity. the ts-pla2 activity level in saliva did not change significantly during tick feeding except for a decrease in the last rapid feeding phase (> 200 mg) and in replete ticks. phospholipase a2 activity was highe ...	1998	9701935
illustrated key to nymphs of the tick genus amblyomma (acari: ixodidae) found in the united states.	a dichotomous identification key, with important characters illustrated by scanning electron micrographs, is provided for nymphs of the 9 species of the genus amblyomma occurring in the united states. species included are a. americanum (l.), a. cajennense (f.), a. dissimile koch, a. imitator kohls, a. inornatum (banks), a. longirostre (koch), a maculatum koch, a. rotundatum koch, and a. tuberculatum marx. notes on the geographical distributions, medical and veterinary importance, and nymphal sta ...	1998	9701933
population dynamics of immature amblyomma maculatum (acari: ixodidae) and other ectoparasites on meadowlarks and northern bobwhite quail resident to the coastal prairie of texas.	a survey of ectoparasites from 219 meadowlarks conducted during 2 consecutive fall-winter periods in a coastal prairie found immature amblyomma maculatum koch to be the most abundant parasite. peak larval infestations occurred in december with 80-100% of collected birds infested and with a monthly mean of up to 34 larvae per bird. peak nymphal infestations occurred in february or march with 95-100% of birds infested and with a monthly mean of up to 11 nymphs per bird. seasonal dynamics of these ...	1998	9701932
detection of a spotted fever group rickettsia in amblyomma cajennense (acari: ixodidae) in south texas.	thai tick typhus rickettsia (strain tt-118), a spotted fever group rickettsia of indeterminant pathogenicity, was isolated from a mixed pool of larval ixodes and rhipicephalus ticks collected from thailand in 1962. here we report the surprising finding of a spotted fever group rickettsia with closest sequence homology to the thai tick typhus rickettsia in amblyomma cajennense (f.) ticks from south texas. sequence analysis was performed on segments of 3 genes that differentiate rickettsial specie ...	1998	9701930
host specificity of amblyomma cajennense (fabricius, 1787) (acari: ixodidae) with comments on the drop-off rhythm.	the parasitic specificity of larval, nymph and adult amblyomma cajennense on six different host species: oryctolagus cuniculus, rattus norvegicus, gallus gallus domesticus, anas platyrhynchus, coturnix coturnix and streptopelia decorata is described. in terms of the numbers of larvae and nymphs recovered, o. cuniculus was the best host species. the modal day for drop-off of larvae and nymphs was day three for the mammal hosts, but variable in the birds. we conclude that adult a. cajennense have ...	1998	9698869
investigating the epidemiology of heartwater (cowdria ruminantium infection) by means of a transmission dynamics model.	a mathematical model of the transmission dynamics of cowdria ruminantium by the ixodid tick amblyomma hebraeum in the bovine host is developed and used to investigate the epidemiology of heartwater across a range of vector challenge. the processes described are supported by empirical data. the pattern of outcome measures (incidence, case-fatality and proportion of infected hosts) predicted agrees with those described anecdotally from field experience and empirical observation, and demonstrates t ...	1998	9695100
prostaglandin e2 in the salivary glands of the female tick, amblyomma americanum (l.): calcium mobilization and exocytosis.	a cholera toxin-sensitive, prostaglandin e2 (pge2) specific receptor has been identified in the plasma membrane fraction of tick salivary glands. in the present study, we report that stimulation of dispersed salivary glands of the lone star tick amblyomma americanum (l.) with 1 nm to 10 microm pge2 increased the intracellular concentration of inositol trisphosphate (ip3) in a dose-dependent manner. incubation of dispersed tissue with 1 nm to 10 microm pge2 also stimulated release of 45ca2+ from ...	1998	9684330
distribution, abundance, and seasonal activities of ticks collected from rodents and vegetation in south carolina.	ixodid ticks were collected from live-trapped rodents and by flagging vegetation at sites in the piedmont, sandhills, coastal plain, and coastal zone of south carolina from may 1994 through december 1995. a total of 1,514 ticks was recovered from 237 live-trapped rodents. host-attached species included ixodes minor neumann (n = 818), dermacentor variabilis (say) (n = 346), amblyomma maculatum koch (n = 209), ixodes affinis neumann (n = 89), and ixodes scapularis say (n = 52). species of questing ...	1998	9673934
seasonal variation of ticks on cattle in burkina faso.	cattle of the sahel zebu peuhl breed from traditionally managed livestock herds in a representative area of north soudanese savana (with 400-900 mm of rainfall/year from may to september) located in the central land of burkina faso, were monitored over 12 months for tick and blood parasite. two species of ticks were found: amblyomma variegatum and hyalomma marginatum rufipes. h. m. rufipes was found on cattle all year round with a highest infestation rate in june characterized by means of 10 +/- ...	1998	9668496
repeatability of the level of infestation by amblyomma variegatum ticks on creole cattle.		1998	9668494
attempts to feed amblyomma variegatum ticks on artificial membranes.	feeding jars were used to feed nymphs of amblyomma variegatum on blood of goats or cattle. sterile blood was collected daily or weekly (kept at 4 degrees c or frozen until use), with addition either of heparin alone or of heparin and antibiotics/fungicide or of heparin, adenosine triphosphate and glutathione. membranes were made of a thin (0.12-0.32 mm) film of silicone mastic. blood in the jars was replaced twice a day, and reached a temperature of 39 degrees c in a waterbath before it became a ...	1998	9668493
a trial to control or eradicate amblyomma hebraeum ticks and heartwater on three ranches in zimbabwe.		1998	9668492
entomopathogenic nematodes as a potential biological control method for ticks.	entomopathogenic nematodes have been used for biological control of certain insect pests. in these studies the nematodes were tested as a possible biological control agent for engorged female ticks. five species of infective juveniles (ijs) were tested initially for their ability to penetrate and kill ticks, including steinernema glaseri (sg), s. riobravus (sr), s. carpocapsae (dt), s. feltiae (sf) and heterorhabiditis bacteriophora (hp88). infective juveniles (ijs) of srs and sfs appeared to be ...	1998	9668486
successes and failures in the tropical bont tick eradication campaigns in the french antilles.	the amblyomma variegatum eradication campaigns, based on three phases and a 5-year program, as in other islands of the caribbean, started in the french antilles in april 1994 with various financial inputs. the progress of the campaigns in the two islands of guadeloupe and martinique contrast sharply. owing to a shortage and inadequacy of results with regard to the initial objectives, particularly in organization, communication efforts, cattle identification, and application of acaricides on live ...	1998	9668485
the caricom/fao/iica caribbean amblyomma program.	the objective of the caribbean amblyomma program is to eradicate the tropical bont tick (tbt), amblyomma variegatum, from the caribbean. field activities directed to eradication of the tbt were initiated in may 1995 commencing in northern caribbean islands. plans have been finalized for the remaining islands to the south to start eradication activities in early 1997. the components of the program include tick control and surveillance, adaptive research, training, communications, and extension. d ...	1998	9668484
pcr detection of cowdria ruminantium infection in ticks and animals from heartwater-endemic regions of zimbabwe.	the development of a pcr assay for the detection of cowdria ruminantium infection in ticks has been previously described. here we report a further evaluation of this assay by comparison with a dna probe and with the mouse inoculation assay (mia). application of the pcr assay in determining the prevalence of infection in ruminants and ticks from heartwater-endemic areas of zimbabwe is also described. one hundred uninfected and 120 infected amblyomma hebraeum ticks were analyzed by pcr, dna probe ...	1998	9668453
comparative evaluation of 16s, map1 and pcs20 probes for the detection of cowdria and ehrlichia species in ticks.	we have developed a panel of 16s ribosomal rna gene probes for heartwater epidemiology; five of these detect different cowdria genotypes (ball3, senegal, omatjenne, crystal springs, and mara 87/7); one detects all five of these genotypes; one detects any group iii ehrlichia species other than cowdria; one detects any group ii ehrlichia species. we have used these probes on pcr-amplified rickettsial 16s rrna genes from over 200 amblyomma ticks. control ticks were laboratory-reared and either unin ...	1998	9668452
delivery of ivermectin by injectable microspheres.	a bioabsorbable, injectable microsphere formulation containing ivermectin in poly-(lactide-co-glycolide) copolymer (pla/pga) was developed to provide long-lasting delivery of the drug for control of livestock pests. a solvent-evaporation technique was used to produce the spherical beads containing approximately 30% ivermectin and ranging in size from 25-250 microns. the pattern of delivery of the drug into the blood stream of spanish goats was characterized for a 50:50 pla/pga, a 90:10 pla/pga c ...	1998	9650514
first records of amblyomma americanum, ixodes (ixodes) dentatus, and ixodes (ceratixodes) uriae (acari: ixodidae) from maine.	the first records of 3 ixodid tick species collected in the state of maine are reported. a total of 23 records of the lone star tick, amblyomma americanum (l., 1758), in 11 counties from hosts with no history of travel outside the state demonstrates that this tick is now a resident of maine. ixodes dentatus marx, 1899 is recorded from waldo and lincoln counties, and ixodes uriae white, 1852 is recorded from matinicus rock in knox county. this is the first report of i. uriae from the eastern unit ...	1998	9645873
development, reproductive capacity and survival of amblyomma variegatum and boophilus decoloratus in relation to host resistance and climatic factors under field conditions.	to determine the developmental periods, fecundity and survival of amblyomma variegatum and boophilus decoloratus and the effect of host resistance, a study was carried out in the field at abernossa ranch in ethiopia using three breeds of cattle: arssi, boran and boran x friesian crossbreed. the investigation took place between october 1991 and september 1992. the developmental periods of both tick species were recorded. the hatching periods of larvae, engorgement, larvo-nymphal and nympho-adult ...	1998	9637226
dynamics of free-living ixodid ticks on a game ranch in the central province, zambia.	free-living ixodid ticks were collected at monthly intervals from january to december 1996 by dragsampling the vegetation of mtendere game ranch in the chisamba district of the central province, zambia. ticks belonging to 11 species were recovered. rhipicephalus appendiculatus was most abundant, comprising 90% of the total number collected. all life stages of this tick showed a definite seasonal pattern of activity. the adults were present mainly during the rainy season (february and march), the ...	1998	9629590
efficacy of tags impregnated with pheromone and acaricide for control of amblyomma variegatum.	the efficacy of tags impregnated with pheromone and acaricide for control of amblyomma variegatum on cattle in guadeloupe was determined for a 13-week trial. comparisons were made between untreated cattle and cattle with tags containing either pheromones alone (o-nitrophenol, methyl salicylate, 2,6-dichlorophenol and phenylacetaldehyde), pheromones plus acaricide (cyfluthrin or deltamethrin), or acaricide alone. tags were fastened to cattle both on collars on the neck and with adhesive to tail h ...	1998	9622367
effect of controlling natural field-tick infestation on the growth of n'dama and gobra zebu cattle in the gambia.	the effect of tick infestations on liveweight gain (lwg) was assessed by comparison of weight changes in flumethrin-treated n'dama and gobra zebu cattle (16-20 months old) with respective control groups submitted to natural tick challenge over 1 year. flumethrin was applied monthly, fortnightly or weekly. preventive treatments against anaplasmosis, babesiosis and trypanosomosis were given. mortality rate was recorded and post-mortem examinations carried out. in both treated and control animals, ...	1998	9604263