Publications

TitleAbstractYear
Filter
PMID
Filter
distribution and prevalence of spotted fever group rickettsiae in ticks from south carolina, with an epidemiological survey of persons bitten by infected ticks.live ticks removed from human hosts were tested for the presence of spotted fever group rickettsiae from 1974 through 1976. spotted fever group rickettsiae were detected in dermacentor variabilis, amblyomma americanum, amblyomma maculatum, and ixodes scapularis. persons from whom positive ticks were removed in 1974 and 1975 were questioned about ensuing illness. eleven of 51 persons from whom rickettsia-positive d. variabilis were removed reported some unexplained combination of symptoms compati ...1978103448
effects of gulf coast ticks on blood composition and weights of pastured hereford steers.studies conducted in 1975 and 1976 were made of lightweight herefored steers, pastured on native grass pasture and infested with gulf coast ticks, amblyomma maculatum koch. the effects of tick infestations on the blood composition and weights of steers over an 8-week period were measured each year and compared to tick-free animals maintained similarly. by the end of the 8-week study infested animals averaged 8.21 kg less than control animals in 1975 and 12.42 kg less in 1976. of the blood parame ...1978641677
preparation of primary cultures of tick cells.primary cell cultures were prepared from preimaginal bodies from the nymphal ticks, rhipicephalus sanguineus, dermacentor andersoni, and amblyomma maculatum, and from the hemocytes of late-stage nymphal and adult ticks, ornithodoros coriaceus. the dissection methods for obtaining preimaginal bodies and hemocytes for culture are described. a culture mediu, designated rml 375, was used for both culture methods. primary cultures were established with minimal contamination. preimaginal body cultures ...1978697169
comparative test with insecticide-impregnated ear tags against the gulf coast tick. 1978739072
changes in weight and blood composition of hereford and brahman steers in drylot and infested with adult gulf coast ticks. 1978752680
field tests of insecticides for control of the gulf coast tick on cattle. 1977845900
effects of the gulf coast tick on blood composition and weights of drylot hereford steers. 1977858827
prevention of screwworm infestation in cattle by controlling gulf coast ticks with slow release insecticide devices. 1977915072
field trials of insecticides in controlled-release devices for control of the gulf coast tick and prevention of screwworm in cattle. 19761002882
evaluation of co2-baited traps for survey of amblyomma maculatum koch and dermacentor variabilis say (acarina: ixodidae). 19751159725
the effect of host species on the engorgement, molting success, and molted weight of the gulf coast tick, amblyomma maculatum koch (acarina: ixodidae). 19751159746
borrelia sp. in ticks recovered from white-tailed deer in alabama.six hundred sixty-five hunter-killed white-tailed deer (odocoileus virginianus) from 18 counties in alabama (usa) were examined for ticks. most of the collections were made at state-operated wildlife management areas. four species of ticks (n = 4,527) were recovered: the lone star tick amblyomma americanum (n = 482); the gulf coast tick a. maculatum (n = 11); the winter tick dermacentor albipictus (n = 1,242); and the black-legged tick ixodes scapularis (n = 2,792). fifty-six percent of the tick ...19921512879
tick infestations of white-tailed deer in alabama.four species of ticks were collected from 537 white-tailed deer (odocoileus virginianus), examined during the hunting seasons (november to january) of 1988-89 and 1989-90 at selected locations in alabama (usa). ixodes scapularis was the most common tick recovered (2,060 specimens) and infested 54% of the deer. dermacentor albipictus was the second most frequent tick (1,253 specimens) and infested 15% of the deer. amblyomma americanum was the third most frequent tick (315 specimens) and infested ...19911758026
borrelia burgdorferi in ticks (acari: ixodidae) from coastal virginia.ixodid ticks removed from hosts and from vegetation during march-november 1987 at sites in coastal virginia and north carolina were examined for borrelia burgdorferi. b. burgdorferi was evident in nine (22%) ixodes cookei packard removed from rice rats (oryzomys palustris), a white-footed mouse (peromyscus leucopus), and raccoons (procyon lotor); four (6%) amblyomma americanum (l.) removed from raccoons; and two (3%) dermacentor variabilis (say) removed from a raccoon and a rice rat. b. burgdorf ...19911941936
[lymphatic cutaneous rickettsiosis caused by rickettsia conorii in uruguay].three autochthonous cases of cutaneous-ganglionar rickettsiosis transmitted by dogs ticks (amblyomma maculatum in one of them) are reported. two of the three cases were undoubtely produced by rickettsia conorii according to the results of the specific indirect immunofluorescence technique ief-igm anti r. conorii. a third case is included due to the clinical epidemiological similarity, the positive serum reactivity with proteus o x 19 and the rapid response to tetracycline. autochthonous ricketts ...19902135470
geographic occurrence of ixodes scapularis and amblyomma americanum (acari: ixodidae) infesting white-tailed deer in north carolina.a state-wide survey to determine the occurrence and comparative numbers of ticks infecting white-tailed deer (odocoileus virginianus) was conducted in north carolina (usa). one thousand six hundred twenty nine deer were examined in 60 of 100 counties; with the exception of one county in the piedmont region, all tick-infested deer occurred in the coastal plain. ixodes scapularis (46%) and amblyomma americanum (53%) were the most prevalent species encountered and accounted for more than 98% of the ...19902250335
danger of introducing heartwater onto the american mainland: potential role of indigenous and exotic amblyomma ticks.the existence of heartwater on 3 islands of the central lesser antilles and the presence of an efficient vector originating from africa, amblyomma variegatum, on most of the islands of this region constitute a serious threat for livestock on the american mainland. the disease can be introduced there either by infected animals or infected ticks. the most likely way is probably the transportation of domestic animals which are heavily infested by ticks. due to the low rate of infection of ticks in ...19873329328
chemical control of the heartwater vectors.this paper reviews available literature on the efficacy of acaricides against amblyomma hebraeum and other tick species, and presents information on tests done with registered chemicals in the laboratory. little published information is available on the efficacy of chemicals specifically against a. hebraeum. a host of formulations are registered for use as acaricides on cattle, sheep, and goats in south africa and thus, by implication, against this species. resistance has only been described to ...19873329335
susceptibility of the gulf coast tick (acari: ixodidae) to acaricides. 19883417922
effects of season and area on ectoparasites of white-tailed deer (odocoileus virginianus) in mississippi.nine species of ectoparasites (4 acari, 2 mallophaga, 1 anoplura, 1 diptera, and 1 siphonaptera) were recovered from 126 white-tailed deer collected in northern, central, and southern mississippi. intensity and prevalence of adults of ixodes scapularis and larvae, nymphs, and adults of amblyomma americanum varied significantly over collection periods, but not between host sexes. lipoptena mazamae occurred on deer from only one study area. although individual deer were heavily parasitized by tric ...19873586204
differentiation between three species of amblyomma ticks (acari: ixodidae) by analysis of cuticular hydrocarbons.cuticular lipids were extracted from three species of amblyomma ticks in hexane: dichloromethane and analysed by gas-liquid chromatography using both packed and capillary columns. unlike many of the reported insect hydrocarbons, those of the amblyomma ticks consisted mostly of branched paraffins and olefins and all three species of ticks are well differentiated on the basis of numbers and carbon-chain lengths of the hydrocarbons. amblyomma maculatum has more olefins and a. cajennense has more pa ...19863753063
systemic activity of a benzimidazoline compound in cattle against ticks and biting flies.a benzimidazoline compound [4-nitro-2-(1,1,2,2-tetrafluoroethyl)-6 -(trifluoromethyl)-1h-benzimidazol-2-, 01, sodium salt] referred to as el-979 showed systemic acaricidal and insecticidal activity in cattle against 2 tick species, amblyomma maculatum (gulf coast tick) and dermacentor variabilis (american dog tick) and adult stomoxys calcitrans (stable flies). larvae of black blow fly (phormia regina) were fed serum collected from treated calves. a complete kill of larvae was obtained with a ser ...19854002603
gulf coast tick: susceptibility of engorged nymphs to chlorpyrifos during the postengorgement period. 19734127048
the gulf coast tick: evidence of a pheromone produced by males. 19744855166
mate-seeking by female amblyomma maculatum (acarina: ixodidae) on a bovine. 19714938838
response of ovipositing amblyomma maculatum koch (acarina: ixodidae) to photoperiod. 19715160257
pheromone-induced aggregation of ixodid ticks before host contact.the presence of a pre-feeding aggregation pheromone was demonstrated in the species dermacentor variabilis, dermacentor andersoni, dermacentor parumapertus, amblyomma americanum and haemaphysalis leporispalustris by assay within a petri dish. however, amblyomma maculatum and amblyomma cajennense did not aggregate in the sector containing discs of presumed pheromone within the hour period. d. andersoni and a. americanum recognized each other's pheromone and a. americanum recognized that of h. lep ...19836683667
ixodid ticks on feral swine in florida.more than 99% of the 645 feral swine (sus scrofa l.) in southern florida harbored ixodid ticks. dermacentor variabilis (american dog tick) was present on 99.6% of the swine and comprised 82.5% of the ticks collected. amblyomma maculatum (gulf coast tick) occurred on 85.9% of the hosts and 17.4% of the collections were of this species. amblyomma americanum (lone star tick) and ixodes scapularis (black-legged tick) were found infrequently and together constituted less than 0.1% of the ticks. pigs ...19846737605
experimental transmission of cowdria ruminantium by the gulf coast tick amblyomma maculatum: danger of introducing heartwater and benign african theileriasis onto the american mainland.the tick amblyomma maculatum proved to be an experimental vector of cowdria ruminantium, the cause of heartwater of ruminants. transstadial transmission from larva to nymph and from larva through nymph to adult was successful; however, an experiment on transovarial transmission gave negative results. neither a americanum nor a cajennense transmitted the infection. there is a potential danger of the disease gaining access to the american mainland from the caribbean where it is known to occur and ...19826808870
performance of ticks fed on rabbits inoculated with extracts derived from homogenized ticks amblyomma maculatum koch (acarina: ixodidae). 19807365638
evidence of common and genus-specific epitopes on ornithodoros spp. tick (acari: argasidae) salivary proteins.new zealand white rabbits were repeatedly infested with ornithodoros turicata (duges), ornithodoros talaje (guérin-méneville), and ornithodoros coriaceus (koch) at 2-wk intervals. blood samples were taken from each animal 10 d after each infestation and the titer of anti-tick antibody was determined by enzyme-linked immunosorbent assay. subsequent cross-reactivity studies demonstrated that the antitick antisera nonspecifically bound to salivary gland extract proteins prepared from several other ...19957544412
physiological responses of beef cattle to gulf coast tick (acari: ixodidae) infestations.nine yearling crossbred beef steers, bos taurus l., were used to examine physiological responses to gulf coast tick, amblyomma maculatum koch, infestation. steers were stanchioned indoors in individual environmentally controlled rooms. on day 0, each animal received 0, 25, or 75 pairs of ticks. physiological variables measured daily were feed intake, heart rates, rectal temperatures, and respiration rates. blood samples were collected from each animal on days 7, 21, and 42 for serum constituent ...19957722083
cytosystematics of five north american amblyomma (acarina: ixodidae) species.the karyotypes of 5 species of amblyomma ticks found in north america were examined for the presence and location of constitutive heterochromatin (c-bands). all specimens examined had 20 autosomes and an xx:xo sex-determining system, with the x being the largest element in the karyotype. except as noted in text, the autosomes of all species were acrocentric and heterochromatin was restricted to the centromeric region. the third largest autosome in 4 of the 5 species displayed a consistent band o ...19957876973
ixodid ticks from panthers and bobcats in florida.ixodid ticks were present in all 189 samples examined from 53 florida panthers (felis concolor coryi, 104 collections) and 85 bobcats (felis rufus floridana) in florida (usa) between 1974 and 1991. we identified 3,251 ticks from panthers and 918 from bobcats. specimens of dermacentor variabilis, ixodes scapularis, i. affinis, amblyomma maculatum, and a. americanum were present on 49, 39, 17, seven, and two of the 53 florida panthers, respectively, and comprised 36%, 55%, 7%, 1%, and < 1% of the ...19958592378
ticks parasitizing humans in georgia and south carolina.from 1990 through 1995, 913 ticks removed from 460 human patients in georgia or south carolina were identified and recorded. the majority of these specimens (758, 83.0%) were lone star ticks, amblyomma americanum. one hundred and four (11.4%) american dog ticks dermacentor variabilis, 36 (3.9%) blacklegged ticks ixodes scapularis, 9 (1.0%) gulf coast ticks amblyomma maculatum, and 6 (0.7%) brown dog ticks rhipicephalus sanguineus were also recovered. all active stages (larvae, nymphs, and adults ...19968636862
ectoparasites (acari, mallophaga, anoplura, diptera) of white-tailed deer, odocoileus virginianus, from southern florida.during a 7-yr period (1984-1990), 300 white-tailed deer, odocoileus virginianus (zimmermann), from 7 localities in collier, dade, and monroe counties in southern florida were examined for ectoparasites. eight species were identified: 4 ticks [ixodes scapularis say, i. affinis neumann, amblyomma maculatum (koch), and dermacentor variabilis (say)], 1 chigger mite [eutrombicula splendens (ewing)], 1 ked (lipoptena mazamae rondani), 1 chewing louse [tricholipeurus lipeuroides (megnin)], and 1 suckin ...19968906911
attempted transmission of human granulocytotropic ehrlichia (hge) by amblyomma americanum and amblyomma maculatum.transstadial transmission of human granulocytotrophic ehrlichia (hge) was attempted in dogs using amblyomma americanum (l.) and a. maculatum koch, two species that, as adults, feed readily on human beings. larvae and nymphs were acquisition-fed on a dog that was parasitemic with hge. two months later, following digestion of the blood meal and subsequent molting to nymphal or adult stage, these ticks were fed to repletion on hge-naive dogs. none of the dogs developed clinical evidence of ehrlichi ...19979195722
ticks (acari: ixodida) uncommonly found biting humans in north carolina.collection records are presented that document human-biting by otobius megnini, amblyomma maculatum, haemaphysalis leporispalustris, ixodes cookei, ixodes dentatus, and rhipicephalus sanguineus in north carolina. these species are either extremely rare in north carolina or they are normally considered non-human feeders. the record of otobius megnini represents the first collection of this species in north carolina in over 50 years. it is proposed that immature rhipicephalus sanguineus feed on hu ...19979221733
taxonomic relationships among spotted fever group rickettsiae as revealed by antigenic analysis with monoclonal antibodies.the spotted fever group (sfg) is made up of more than 20 different rickettsial species and strains. study of the taxonomic relationships among the group has been attempted by phenotypic, genotypic, and phylogenetic analyses. in this study, we determined taxonomic relationships among the sfg rickettsiae by comparative analysis of immunogenic epitopes reactive against a panel of monoclonal antibodies. a total of 98 monoclonal antibodies, which were directed against epitopes on the major immunodomi ...19989542904
phylogenetic placement of rickettsiae from the ticks amblyomma americanum and ixodes scapularis.a rickettsial isolate (isolate moaa) belonging to the spotted fever group (sfg) was obtained from the lone star tick amblyomma americanum. we used pcr to characterize the genes for the rickettsial outer membrane proteins rompa and rompb. we sequenced the pcr products (domains i of both the rompa gene and the rompb gene) of moaa and wb-8-2, another rickettsial isolate from a. americanum. to place moaa and wb-8-2 and two other nonpathogenic isolates (rickettsia rickettsii hip2 and rickettsia monta ...19989574696
in vitro susceptibilities of 27 rickettsiae to 13 antimicrobials.the mics of 13 antibiotics (doxycycline, thiamphenicol, rifampin, amoxicillin, gentamicin, co-trimoxazole, ciprofloxacin, pefloxacin, ofloxacin, erythromycin, josamycin, clarithromycin, and pristinamycin) were determined for 27 available rickettsial species or strains. we used two in vitro cell culture methods described previously: the plaque assay and the microplaque colorimetric assay. our results confirm the susceptibilities of rickettsiae to doxycycline, thiamphenicol, and fluoroquinolones. ...19989660979
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 ...19989673934
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 ...19989701932
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 ...19989701938
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 ...19989877066
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 ...199910073352
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 ...199910337108
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 ...199910384901
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. ...199910647032
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 ...199910672552
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 ...200010682757
genetic and antigenic evidence supports the separation of hepatozoon canis and hepatozoon americanum at the species level.recognition of hepatozoon canis and hepatozoon americanum as distinct species was supported by the results of western immunoblotting of canine anti-h. canis and anti-h. americanum sera against h. canis gamonts. sequence analysis of 368 bases near the 3' end of the 18s rrna gene from each species revealed a pairwise difference of 13.59%.200010699047
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 ...200010701562
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 ...200010747140
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 ...200010780541
attempted transmission of ehrlichia chaffeensis among white-tailed deer by amblyomma maculatum.a deer was needle-exposed intravenously to ehrlichia chaffeensis (rickettsiales: ehrlichieae) in canine macrophage (dh82) cells and 7 days later was infested with laboratory-reared amblyomma maculatum (koch) (acari:ixodidae) nymphs for acquisition feeding. after molting, the adult ticks were allowed to feed on a naive deer. the organism was reisolated from the needle-exposed deer by cell culture and e. chaffeensis dna was detected in the deer's blood by pcr. similar isolation/recovery techniques ...200010941753
production of pheromones by artificially fed males of the tick amblyomma maculatum (acari: ixodidae).aggregation-attachment pheromones are produced only by male ticks of the genus amblyomma that have imbibed blood for at least 8 d from their mammalian hosts. this report demonstrates that production and release of aggregation-attachment pheromones by amblyomma maculatum (koch) males can be induced in vitro by using nonblood media, artificially introduced through capillary tubes, into the male ticks. the presence of these pheromones is demonstrated by using both biological observations on bovine ...200011004791
ectoparasites and gastrointestinal helminths of southern flying squirrels in southeast georgia.southern flying squirrels (glaucomys volans) from southeastern georgia were examined for ectoparasites and gastrointestinal helminths. ten species of ectoparasites were recovered, including 3 species of sucking lice (hoplopleura trispinosa, microphthirus uncinatus, and neohaematopinus sciuropteri), 1 species of flea (orchopeas howardi), 2 species of ticks (amblyomma maculatum and ixodes scapularis), 3 species of mesostigmatid mites (androlaelaps casalis, a. fahrenholzi, and haemogamasus ambulans ...200011128479
american canine hepatozoonosis. an emerging disease in the new world.hepatozoon canis was first described from dogs in 1905 in india and rhipicephalus sanguineus was identified as the vector. dogs on the texas gulf coast were recognized in 1978 to have hepatozoonosis, and it was thought that h. canis had entered the new world. later, it was realized that american canine hepatozoonosis (ach) is more debilitating than its old world counterpart, often resulting in death. when the malady and parasite were characterized, a new species, h. americanum, was described, in ...200011193705
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 ...200111296828
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 ...200111427428
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. ...200111469190
larval gulf coast ticks (amblyomma maculatum) [acari: ixodidae] as host for hepatozoon americanum [apicomplexa: adeleorina].laboratory-reared larval gulf coast ticks (gcts) (amblyomma maculatum) were exposed experimentally and found to acquire hepatozoon americanum infection while feeding on parasitemic dogs. these ticks supported gamogonic and sporogonic development of the apicomplexan, and oocysts from newly molted nymphs were infectious for a dog. other nymphs from this cohort that were allowed to feed on a blood-parasite naive sheep molted normally; the resulting adult ticks contained oocysts that were infectious ...200211750999
host associations of ticks parasitizing rodents at borrelia burgdorferi enzootic sites in south carolina.a total of 237 rodents was collected in 4 regions of south carolina from july 1994 through december 1995. eight species were collected, including cotton mouse, hispid cotton rat, eastern woodrat, marsh rice rat, white-footed mouse, eastern harvest mouse, golden mouse, and black rat. of the 1,514 ticks recovered from these hosts, ixodes minor neumann, including larvae, nymphs, and adults, was the most abundant species, representing 54% of the total. only immature stages of other tick species were ...200111780825
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 ...200211931241
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 ...200212038138
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 ...200212144294
detection of rickettsia prowazekii in body lice and their feces by using monoclonal antibodies.in order to identify rickettsia prowazekii in lice, we developed a panel of 29 representative monoclonal antibodies selected from 187 positive hybridomas made by fusing splenocytes of immunized mice with sp2/0-ag14 myeloma cells. immunoblotting revealed that 15 monoclonal antibodies reacted with the lipopolysaccharide-like (lps-l) antigen and 14 reacted with the epitopes of a 120-kda protein. only typhus group rickettsiae reacted with the monoclonal antibodies against lps-l. r. felis, a recently ...200212202579
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 ...200312517884
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 ...200312525424
antigenic classification of rickettsia felis by using monoclonal and polyclonal antibodies.rickettsia felis is a flea-transmitted rickettsia. there is a discrepancy between its reported phylogenic and phenotypic identifications. following the first report of r. felis, it was considered by tests with serologic reagents to be closely related to another recognized flea-transmitted rickettia, r. typhi. subsequently, it appeared to be more closely related to spotted fever group (sfg) rickettsiae by genetic analysis. in the present work, r. felis was studied by microimmunofluorescence (mif) ...200312626446
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 ...200212853269
persistence of hepatozoon americanum (apicomplexa: adeleorina) in a naturally infected dog.to determine the persistence of hepatozoon americanum in a naturally infected dog, skeletal muscle biopsies were performed at approximately 6-mo intervals over a period of 5.5 yr, and the samples were examined for presence of lesions of american canine hepatozoonosis (ach). nymphal amblyomma maculatum (gulf coast tick) were allowed to feed to repletion on the dog periodically over the 5.5-yr period, and adult ticks were dissected and examined for presence of h. americanum oocysts. with 3 excepti ...200312880267
american canine hepatozoonosis.american canine hepatozoonosis is an emerging, tick-transmitted infection of domestic dogs caused by a recently recognized species of apicomplexan parasite, hepatozoon americanum. the known definitive host of the protozoan is the gulf coast tick, amblyomma maculatum. presently recognized intermediate hosts include the domestic dog and the coyote, canis latrans. laboratory-reared larval or nymphal a. maculatum can be infected readily by feeding to repletion on a parasitemic intermediate host; spo ...200312885206
american canine hepatozoonosis.hepatozoon americanum infection is an emerging tickborne disease in the southern united states. this organism causes a very different and much more severe disease than does hepatozoon canis, the etiologic agent of canine hepatozoonosis in the rest of the world. h americanum is transmitted through ingestion of the definitive host, amblyomma maculatum (the gulf coast tick). clinical signs of american canine hepatozoonosis tend to wax and wane over time and may include lameness, weakness, pain, mus ...200312910749
the possible role of ticks as vectors of leptospire. ii. infection of the ixodid ticks, dermacentor andersoni and amblyomma maculatum, with leptospira pomona. 195913806052
[rectification of diagnosis: amblyomma tigrinum koch in place of amblyomma maculatum koch]. 195913836584
an enzootic transmission cycle of lyme borreliosis spirochetes in the southeastern united states.lyme borreliosis, or lyme disease (ld), is a tick-borne zoonotic infection of biomedical significance, caused by borrelia burgdorferi sensu lato (s.l.) spirochetes and transmitted by ixodes species ticks. it usually circulates among wildlife vertebrate reservoirs and vector ticks but may infect humans, causing multisystem problems. in far western and northern north america, the host reservoirs, tick vectors, and genospecies of borrelia are well known but not so in the southern u.s., where there ...200314500917
american canine hepatozoonosis.american canine hepatozoonosis (ach) is a tick-borne disease that is spreading in the southeastern and south-central united states. characterized by marked leukocytosis and periosteal bone proliferation, ach is very debilitating and often fatal. dogs acquire infection by ingesting nymphal or adult gulf coast ticks (amblyomma maculatum) that, in a previous life stage, ingested the parasite in a blood meal taken from some vertebrate intermediate host. ach is caused by the apicomplexan hepatozoon a ...200314557294
tick paralysis; implicating amblyomma maculatum. 195114806800
rickettsia parkeri: a newly recognized cause of spotted fever rickettsiosis in the united states.ticks, including many that bite humans, are hosts to several obligate intracellular bacteria in the spotted fever group (sfg) of the genus rickettsia. only rickettsia rickettsii, the agent of rocky mountain spotted fever, has been definitively associated with disease in humans in the united states. herein we describe disease in a human caused by rickettsia parkeri, an sfg rickettsia first identified >60 years ago in gulf coast ticks (amblyomma maculatum) collected from the southern united states ...200414999622
occurrence of the gulf coast tick (acari: ixodidae) on wild and domestic mammals in north-central oklahoma.parasitic life stages of amblyomma maculatum koch were collected from domestic cattle and several species of wild mammals during a 3.5-yr study (may 1998-october 2001) in north-central oklahoma. adult ticks were the predominant life stage collected from cattle, white-tailed deer, coyotes, and raccoons, whereas only immature ticks were collected from cotton rats and white-footed mice. the prevalence of adult a. maculatum on white-tailed deer (n = 15) examined in june, july, and august 1998 was 80 ...200415061275
phylogenetic analysis of the francisella-like endosymbionts of dermacentor ticks.bacterial endosymbionts with significant homology to francisella tularensis (gamma-proteobacteria) have been described from at least five species of ticks in three different genera, including two north american dermacentor species [d. andersoni stiles and d. variabilis (say)]. the evolutionary relationships among the francisella-like endosymbionts (fle) from different hosts and between fle and the arthropod-borne pathogen f. tularensis are not known. a 1,169-base fragment of the 16s rdna and a 7 ...200415185926
serological characteristics of a pathogenic rickettsia occurring in amblyomma maculatum. 194915398100
characterization of spotted fever group rickettsiae in flea and tick specimens from northern peru.evidence of spotted fever group (sfg) rickettsiae was obtained from flea pools and individual ticks collected at three sites in northwestern peru within the focus of an outbreak of febrile disease in humans attributed, in part, to sfg rickettsia infections. molecular identification of the etiologic agents from these samples was determined after partial sequencing of the 17-kda common antigen gene (htra) as well as pairwise nucleotide sequence homology with one or more of the following genes: glt ...200415528680
observations on distribution and seasonal activity of the gulf coast tick in mississippi.medical importance of the gulf coast tick, amblyomma maculatum koch, has been highlighted with the recent discovery of a new rickettsial pathogen associated with this tick. accordingly, distribution and seasonal collection records of a. maculatum were assessed in mississippi by using three sources of data: sampling of experimental field plots, national tick collection records, and mississippi department of health human tick biting records. a. maculatum was collected in 17/82 (21%) mississippi co ...200515799527
the amblyomma maculatum koch, 1844 (acari: ixodidae: amblyomminae) tick group: diagnostic characters, description of the larva of a. parvitarsum neumann, 1901, 16s rdna sequences, distribution and hosts.a review of the largely confused amblyomma maculatum koch, 1844 tick group of the subgenus anastosiella santos dias, 1963 (a. neumanni ribaga, 1902, a. maculatum, a. parvitarsum neumann, 1901, a. tigrinum koch, 1844 and a. triste koch, 1844) is presented together with a discussion of the diagnostic characters used for the determination of adults, nymphs and, to a lesser extent, larvae. a key for this tick group is produced, including the description of the larva of a. parvitarsum, 1901. sequence ...200515841347
feeding predilection of gulf coast tick, amblyomma maculatum koch, nymphs on cattle.gulf coast tick nymphs successfully attached and fed on cattle after being freely released. six hereford heifers were each infested with approximately 2000 gulf coast tick nymphs, three with a strain originating from refugio co., tx, and three with ticks from osage co., ks by free release on the head and legs to simulate field acquisition of questing nymphs. two re-infestations were conducted, the first at 7 days and the second at 28 days. nymph dispersal was estimated by daily inspection of 22 ...200515993001
tick-borne rickettsioses around the world: emerging diseases challenging old concepts.during most of the 20th century, the epidemiology of tick-borne rickettsioses could be summarized as the occurrence of a single pathogenic rickettsia on each continent. an element of this paradigm suggested that the many other characterized and noncharacterized rickettsiae isolated from ticks were not pathogenic to humans. in this context, it was considered that relatively few tick-borne rickettsiae caused human disease. this concept was modified extensively from 1984 through 2005 by the identif ...200516223955
experimental infection of adult and juvenile coyotes with domestic dog and wild coyote isolates of hepatozoon americanum (apicomplexa: adeleorina).each of five adult and four juvenile coyotes (canis latrans) was exposed to an oral dose of 50 hepatozoon americanum oocysts recovered from amblyomma maculatum ticks that previously fed on either naturally infected domestic dogs (canis familiaris) or naturally infected wild coyotes. all coyotes exposed to h. americanum became infected, regardless of isolate source, and all exhibited mild to moderate clinical disease that simulated american canine hepatozoonosis in naturally infected dogs. at 100 ...200516244069
discrimination between francisella tularensis and francisella-like endosymbionts when screening ticks by pcr.the presence of francisella-like endosymbionts in tick species known to transmit tularemia poses a potential diagnostic problem for laboratories that screen tick samples by pcr for francisella tularensis. tick samples initially considered positive for f. tularensis based on standard 16s rrna gene pcr were found to be positive only for francisella-like endosymbionts using a multitarget f. tularensis taqman assay (isftu2, tul4, and iglc) and 16s rrna gene sequencing. specificity of pcr-based diagn ...200516269811
characterization of stages of hepatozoon americanum and of parasitized canine host cells.american canine hepatozoonosis is caused by hepatozoon americanum, a protozoan parasite, the definitive host of which is the tick, amblyomma maculatum. infection of the dog follows ingestion of ticks that harbor sporulated h. americanum oocysts. following penetration of the intestinal mucosa, sporozoites are disseminated systemically and give rise to extensive asexual multiplication in cells located predominantly in striated muscle. the parasitized canine cells in "onion skin" cysts and in granu ...200516301575
rickettsia parkeri as a paradigm for multiple causes of tick-borne spotted fever in the western hemisphere.among the many contributions made to rickettsiology by entomologist and rickettsiologist ralph r. parker was his discovery in 1937 of a novel rickettsia isolated from the gulf coast tick, amblyomma maculatum. this bacterium was subsequently characterized as a unique rickettsial species in 1965 and named rickettsia parkeri in honor of its discoverer. during the next several decades r. parkeri was generally considered as one of several "nonpathogenic" spotted fever group (sfg) rickettsiae that res ...200516481534
phylogenetic analysis of a novel molecular isolate of spotted fever group rickettsiae from northern peru: candidatus rickettsia andeanae.phylogenetic analysis of five rickettsial genes (17-kda gene, glta, ompb, ompa, and sca4) from two molecular isolates of candidatus rickettsia andeanae from two ticks (amblyomma maculatum and ixodes boliviensis) collected from two domestic horses living in two separate locations in northern peru (coletas and naranjo) was conducted to more clearly characterize this recently reported novel spotted fever group (sfg) rickettsia. following nested polymerase chain reaction (pcr) amplification of the 1 ...200516481537
epidemic spread of lyme borreliosis, northeastern united states.we examined the degree of host specialization of different strains of borrelia burgdorferi, the tickborne pathogen that causes lyme borreliosis in the northeastern united states. we first assessed the genetic population structures of b. burgdorferi in ticks obtained from different mammalian host species and in questing ticks sampled in a woodland ecosystem in connecticut. by comparing the patterns found in our study with data from another cross-sectional study, we demonstrate that b. burgdorferi ...200616704808
mating success of two geographically distinct populations of gulf coast ticks, amblyomma maculatum koch.gulf coast ticks collected from refugio co., tx and osage co., ks are reproductively compatible despite differences in genetic haplotypes, geographic separation and seasonal phenologies. two heifers per mating combination (tx males x tx females, ks males x ks females, tx males x ks females, ks males x tx females) were each infested with 360 pairs of gulf coast ticks. only mean pre-oviposition and mean egg conversion efficiency index for the texas male-kansas female mating were significantly diff ...200616713094
isolation and identification of rickettsia massiliae from rhipicephalus sanguineus ticks collected in arizona.twenty rhipicephalus sanguineus ticks collected in eastern arizona were tested by pcr assay to establish their infection rate with spotted fever group rickettsiae. with a nested pcr assay which detects a fragment of the rickettsia genus-specific 17-kda antigen gene (htra), five ticks (25%) were found to contain rickettsial dna. one rickettsial isolate was obtained from these ticks by inoculating a suspension of a triturated tick into monolayers of vero e6 monkey kidney cells and xtc-2 clawed toa ...200616885311
isolation of rickettsia rhipicephali and rickettsia bellii from haemaphysalis juxtakochi ticks in the state of são paulo, brazil.in the present study, attempts to isolate rickettsia in cell culture were performed individually in seven specimens of haemaphysalis juxtakochi ticks collected in the state of são paulo (southeastern brazil). rickettsia was successfully isolated by the shell vial technique and established in vero cell culture from six ticks (six isolates). dna extracted from infected cells of these isolates was tested by pcr and dna sequencing, using genus-specific rickettsia primers targeting the genes glta, ht ...200717142361
gulf coast ticks (amblyomma maculatum) and rickettsia parkeri, united states.geographic distribution of rickettsia parkeri in its us tick vector, amblyomma maculatum, was evaluated by pcr. r. parkeri was detected in ticks from florida, georgia, kentucky, mississippi, oklahoma, and south carolina, which suggests that a. maculatum may be responsible for additional cases of r. parkeri rickettsiosis throughout much of its us range.200717553257
rickettsia parkeri in brazil.we report finding rickettsia parkeri in brazil in 9.7% of amblyomma triste ticks examined. an r. parkeri isolate was successfully established in vero cell culture. molecular characterization of the agent was performed by dna sequencing of portions of the rickettsial genes glta, htra, ompa, and ompb.200718214195
Displaying items 1 - 100 of 314