| experimental transmission of ehrlichia canis (rickettsiales: ehrlichieae) by dermacentor variabilis (acari: ixodidae). | four trials were conducted in which laboratory-reared dermacentor variabilis nymphs were exposed to ehrlichia canis by feeding on experimentally infected dogs as soon as classical morulae were detected in peripheral blood monocytes. after molting 25, 50 or 90 adult tick pairs were permitted to feed on 7 ehrlichia-naive dogs. transmission occurred in trials 1 (1/1 dog), 3 (1/1 dog) and 4 (2/2 dogs) but not in trial 2 (0/3 dogs), with 4 of 7 dogs becoming infected. successful transstadial transmis ... | 1998 | 9561712 |
| antibody response to hepatozoon canis in experimentally infected dogs. | canine hepatozoonosis is a disease caused by the tick-borne protozoan hepatozoon canis. five puppies were inoculated by ingestion of rhipicephalus sanguineus ticks experimentally infected with h. canis, and all became infected with h. canis: gametocytes were detected in blood smears from four dogs and schizonts were observed in the spleen and bone marrow of the fifth. antibodies reactive with h. canis gametocytes were detected by the indirect fluorescent antibody test (ifa), with igm detected in ... | 1998 | 9561714 |
| 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 ... | 1998 | 9574696 |
| transmission of tick-borne bunyaviruses by cofeeding ixodid ticks. | palma and bhanja bunyaviruses replicated in dermacentor marginatus, d. reticulatus, rhipicephalus sanguineus, r. appendiculatus and ixodes ricinus ticks after parenteral inoculation and appropriate incubation and feeding. palma virus was transmitted to d. marginatus and d. reticulatus males, d. reticulatus and r. sanguineus females, and r. appendiculatus nymphs while cofeeding with infected ticks on laboratory mice. bhanja virus was transmitted to d. marginatus males and r. appendiculatus nymphs ... | 1997 | 9607090 |
| production and characterization of ehrlichia risticii, the agent of potomac horse fever, from snails (pleuroceridae: juga spp.) in aquarium culture and genetic comparison to equine strains. | we report on the production and characterization of ehrlichia risticii, the agent of potomac horse fever (phf), from snails (pleuroceridae: juga spp.) maintained in aquarium culture and compare it genetically to equine strains. snails were collected from stream waters on a pasture in siskiyou county, calif., where phf is enzootic and were maintained for several weeks in freshwater aquaria in the laboratory. upon exposure to temperatures above 22 degrees c the snails released trematode cercariae ... | 1998 | 9620368 |
| 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. ... | 1998 | 9660979 |
| 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 |
| survey of tick-borne diseases in dogs infested with rhipicephalus sanguineus at a kennel in okayama prefecture, japan. | serological tests were performed to investigate extent of tick-borne diseases in dogs infested with rhipicephalus sanguineus at a kennel in okayama prefecture. three of 22 dogs (13.6%) were positive for ehrlichia canis. two of 19 dogs (10.5%) were positive for rickettsia japonica. three of 22 dogs (13.6%) were positive for babesia gibsoni. none of these animals were positive for coxiella burnetii or hepatozoon canis. a microfilaria was detected in a drop smear of hemolymph from an engorged femal ... | 1998 | 9673953 |
| detection of ehrlichia risticii, the agent of potomac horse fever, in freshwater stream snails (pleuroceridae: juga spp.) from northern california. | ehrlichia dna was identified by nested pcr in operculate snails (pleuroceridae: juga spp.) collected from stream water in a northern california pasture in which potomac horse fever (phf) is enzootic. sequencing of pcr-amplified dna from a suite of genes (the 16s rrna, groesl heat shock operon, 51-kda major antigen genes) indicated that the source organism closely resembled ehrlichia risticii, the causative agent of phf. the minimum percentage of juga spp. harboring the organism in the population ... | 1998 | 9687446 |
| 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 |
| detection of ehrlichia phagocytophila dna in ixodes ricinus ticks from areas in switzerland where tick-borne fever is endemic. | a total of 1,523 adult ixodes ricinus ticks were collected from regions where bovine ehrlichiosis is endemic and were examined for ehrlichia phagocytophila via pcr. of the ticks from cattle with ehrlichiosis, the ticks from healthy cattle, and the free-living ticks, 26.5% (18 of 68), 4.4% (35 of 802), and 0.8% (5 of 653), respectively, were positive. | 1998 | 9705425 |
| immune response in rabbits against rhipicephalus sanguineus. | rabbits immunised with homogenates of unfed larvae and nymphs of the tick r. sanguineus developed significant level of protective immunity to infestation with all the stages of the species. the acquisition of resistance was based on feeding and developmental performance parameters (rejection, moulting percentages and feeding period) of larvae and nymphs. the acquisition of resistance against adults was also measured by feeding and reproductive performance of female ticks viz., rejection percent, ... | 1998 | 9717464 |
| saliva of rhipicephalus sanguineus tick impairs t cell proliferation and ifn-gamma-induced macrophage microbicidal activity. | in this study, we investigated tick saliva effects on t cell proliferation, antigen presentation and ifn-gamma-induced macrophage activation, events which are associated with host immune defense mechanisms. mice repeatedly infested with rhipicephalus sanguineus ticks, similarly to dogs, did not develop resistance to further infestations. we determined that r. sanguineus tick saliva inhibited, in a dose-dependent manner, both con-a and specific antigen-induced splenic t cell proliferation. tick s ... | 1998 | 9730222 |
| 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 |
| effects of infestation by rhipicephalus sanguineus on lymphocyte blastogenic responses to mitogens in dogs. | mitogen blastogenic responses of lymphocytes from dogs infested with adult rhipicephalus sanguineus and the effects of salivary gland extracts (sge) of the tick on the blastogenic responses of lymphocytes from normal dogs were studied. infestation by r. sanguineus significantly suppressed concanavalin a, phyto-hemagglutinin and pokeweed mitogen responses of lymphocytes from dogs. the inhibition of lymphocyte responses of dogs in the first infestation was greater than that in the second infestati ... | 1998 | 9795902 |
| seroprevalence of ehrlichia canis and of canine granulocytic ehrlichia infection in dogs in switzerland. | serum samples from 996 dogs in switzerland were examined for antibodies to ehrlichia canis and to the agent causing canine granulocytic ehrlichiosis (cge). ehrlichiosis, borreliosis, and systemic illness not associated with ticks were suspected in 75, 122, and 157 of these dogs, respectively. the remainder of the serum samples were obtained from clinically healthy dogs which resided north (n = 235) or south (n = 407) of the alps. the serum samples were tested by an indirect immunofluorescence te ... | 1998 | 9817854 |
| 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 |
| [ehrlichia canis infections of dogs in germany. epidemiology, diagnosis, therapy and prophylaxis]. | between january and december 1997 infections with ehrlichia canis were detected in 211 dogs in germany. of the 53 epidemiologically evaluable dogs, 19 animals born and raised in germany had travelled with their owners abroad in endemic areas, 30 dogs originated from there and four dogs had never left germany. as regards to the possible location of infection it has been registered that most dogs had been taken to countries of the mediterranean sea (spain, france, italy, greece) or had been import ... | 1998 | 9857421 |
| mitochondrial gene order is not conserved in arthropods: prostriate and metastriate tick mitochondrial genomes. | the entire mitochondrial genome was sequenced in a prostriate tick, ixodes hexagonus, and a metastriate tick, rhipicephalus sanguineus. both genomes encode 22 trnas, 13 proteins, and two ribosomal rnas. prostriate ticks are basal members of ixodidae and have the same gene order as limulus polyphemus. in contrast, in r. sanguineus, a block of genes encoding nadh dehydrogenase subunit 1 (nd1), trna(leu)(uur), trna(leu)(cun), 16s rdna, trna(val), 12s rdna, the control region, and the trna(ile) and ... | 1998 | 9866211 |
| 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 |
| rickettsia helvetica in ixodes ricinus ticks in sweden. | in the present study further characterization of the amplified sequence of the citrate synthase gene of the spotted fever group rickettsia isolated from ixodes ricinus ticks in sweden showed that it has 100% homology with the deposited sequence of the citrate synthase gene of rickettsia helvetica. the restriction fragment length polymorphism (rflp) pattern of an amplified 382-bp product of the citrate synthase sequence, defined by primers rpcs877 and rpcs1258, yielded fragments for our isolate t ... | 1999 | 9889227 |
| [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 |
| comparison of ehrlichia muris strains isolated from wild mice and ticks and serologic survey of humans and animals with e. muris as antigen. | in metropolitan tokyo, the ehrlichia muris seropositivity rate of 24 wild mice was 63% in hinohara village, but in the surrounding areas, it was 0 to 5%. this finding suggests that the reservoir of e. muris is focal. among the 15 seropositive mice, ehrlichiae were isolated from 9 apodemus speciosus mice and 1 a. argenteus mouse, respectively. five ehrlichial isolates were obtained from 10 ticks (haemaphysalis flava) collected in asuke town, aichi prefecture, where the e. muris type strain had be ... | 1999 | 10074536 |
| serological evidence of infection with ehrlichia spp. in red foxes (vulpes vulpes) in switzerland. | serum samples from 1,550 red foxes in switzerland were tested for antibodies to the agents of canine granulocytic and monocytic ehrlichiosis by an indirect immunofluorescent technique. forty-four (2.8%) of the samples were positive for ehrlichia phagocytophila, which is an antigen marker for granulocytic ehrlichiosis. in contrast, none of the samples had antibodies specific to ehrlichia canis, the agent of monocytic ehrlichiosis. | 1999 | 10074544 |
| duration of antibodies against 24 kd protein of rhipicephalus sanguineus extract in dogs infested with the adult ticks. | a 24 kd protein from rhipicephalus sanguineus (rs24p) which was common to larvae, nymphs, male and female whole body and salivary gland extract of males and female was detected specifically in the serum from dogs after repeated infestation with adult r. sanguineus. the duration of antibodies against rs24p in dogs infested with adults was examined by western blotting analysis. anti-rs24p antibody was detected in two of 4 dogs during the period of 40 days in the first infestation. in the second in ... | 1999 | 10081760 |
| activity of a deltamethrin shampoo against ctenocephalides felis and rhipicephalus sanguineus in dogs. | a controlled clinical trial was undertaken to assess the efficacy of an application of a 0.07% deltamethrin shampoo against fleas and ticks in dogs. twenty beagles, housed in separate cages, were randomly allocated into two groups of 10. the dogs were infested with 50 ctenocephalides felis and 50 rhipicephalus sanguineus each, and parasites were counted 24 h (fleas) and 72 h (ticks) later (day 0). dogs, when state, were then treated with 25 ml of a shampoo containing 0.07% deltamethrin (group 1) ... | 1999 | 10206106 |
| molecular cloning of the gene for a conserved major immunoreactive 28-kilodalton protein of ehrlichia canis: a potential serodiagnostic antigen. | a gene encoding a 28-kda protein of ehrlichia canis was cloned, sequenced, and expressed, and a comparative molecular analysis with homologous genes of e. canis, cowdria ruminantium, and ehrlichia chaffeensis was performed. the complete gene has an 834-bp open reading frame encoding a protein of 278 amino acids with a predicted molecular mass of 30.5 kda. an n-terminal signal sequence was identified, suggesting that the protein undergoes posttranslational modification to a mature 27.7-kda protei ... | 1999 | 10225842 |
| successive tick infestations selectively promote a t-helper 2 cytokine profile in mice. | several studies have revealed that t lymphocytes and cytokines play a crucial role in determining the outcome of parasitic infections in terms of protective immunity. in this study we found that rhipicephalus sanguineus tick saliva stimulates transforming growth factor-beta (tgf-beta), and reduces interleukin-12 (il-12) secretion by cells from normal c3h/hej mice. moreover, murine lymph node cells harvested 6 days after the fourth infestation with ticks presented an 82.4% decrease in their proli ... | 1999 | 10233725 |
| seasonal distribution of rhipicephalus sanguineus ticks (acari: ixodidae) on dogs in an urban area of morelos, mexico. | between 1993 and 1995, we examined 1742 dogs at two veterinary clinics in cuernavaca city in mexico for the presence of rhipicephalus sanguineus ticks. the overall tick infestation prevalence was 20% and there were no significant differences (p > 0.05) between different years. the prevalence was somewhat higher in spring, summer and autumn (20% or more) than in winter (13.7%). a positive correlation (p < 0.01) was found between prevalence of ticks and rainfall in spring, summer and autumn, where ... | 1999 | 10356770 |
| comparison of an amitraz-impregnated collar with topical administration of fipronil for prevention of experimental and natural infestations by the brown dog tick (rhipicephalus sanguineus). | to compare the efficacies of amitraz and fipronil for prevention of experimental and natural infestations of rhipicephalus sanguineus. | 1999 | 10382021 |
| invasion and intracellular development of the human granulocytic ehrlichiosis agent in tick cell culture. | human granulocytotropic ehrlichias are tick-borne bacterial pathogens that cause an acute, life-threatening illness, human granulocytic ehrlichiosis (hge). ehrlichias within neutrophil granulocytes that invade tick bite sites are likely ingested by the vector, to be transmitted to another mammalian host during the tick's next blood meal. thus, the cycle of replication and development in the vector is prerequisite to mammalian infection, and yet these events have not been described. we report tic ... | 1999 | 10405394 |
| coinfection with multiple tick-borne pathogens in a walker hound kennel in north carolina. | both dogs and humans can be coinfected with various ehrlichia, bartonella, rickettsia, and babesia species. we investigated a kennel of sick walker hounds and their owners in southeastern north carolina for evidence of tick-borne infections and associated risk factors. a high degree of coinfection was documented in the dog population. of the 27 dogs, 26 were seroreactive to an ehrlichia sp., 16 to babesia canis, and 25 to bartonella vinsonii, and 22 seroconverted to rickettsia rickettsii antigen ... | 1999 | 10405413 |
| development of babesia gibsoni in the midgut of larval tick, rhipicephalus sanguineus. | studies were made on the development of babesia gibsoni in the midgut of the larval tick, rhipicephalus sanguineus. six hr after repletion, merozoites of b. gibsoni, freed from erythrocytes, were observed in the midgut contents of the tick. after that, within 24 hr, those merozoites were transformed into the ring-forms which were relatively large, 2-3 microns in diameter. later, the ring forms developed into the spherical forms which were subelliptical in shape and 4-6 microns in diameter. withi ... | 1999 | 10423693 |
| development of babesia gibsoni in the midgut of the nymphal stage of the tick, rhipicephalus sanguineus. | studies were made on the development of babesia gibsoni in the midgut of the nymphal stage of the tick, rhipicephalus sanguineus. six hr after repletion, merozoites of b. gibsoni, free of erythrocytes, were observed in the midgut contents of the ticks. after that, within 24 hr, those merozoites were transformed into ring-forms which were relatively large ring 1-2 microns in diameter. later, the ring forms developed into spherical forms which were somewhat elliptical in shape and 3-4 microns in d ... | 1999 | 10423695 |
| recent advances in determining the pathogenesis of canine monocytic ehrlichiosis. | | 1999 | 10449445 |
| 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 |
| characterization of mutations in the rpob gene in naturally rifampin-resistant rickettsia species. | rickettsiae are gram-negative, obligately intracellular bacteria responsible for arthropod-borne spotted fevers and typhus. experimental studies have delineated a cluster of naturally rifampin-resistant spotted fever group species. we sequenced the 4, 122- to 4,125-bp rna polymerase beta-subunit-encoding gene (rpob) from typhus and spotted fever group representatives and obtained partial sequences for all naturally rifampin-resistant species. a single point mutation resulting in a phenylalanine- ... | 1999 | 10508014 |
| q fever. | q fever is a zoonosis with a worldwide distribution with the exception of new zealand. the disease is caused by coxiella burnetii, a strictly intracellular, gram-negative bacterium. many species of mammals, birds, and ticks are reservoirs of c. burnetii in nature. c. burnetii infection is most often latent in animals, with persistent shedding of bacteria into the environment. however, in females intermittent high-level shedding occurs at the time of parturition, with millions of bacteria being r ... | 1999 | 10515901 |
| molecular typing of borrelia burgdorferi sensu lato: taxonomic, epidemiological, and clinical implications. | borrelia burgdorferi sensu lato, the spirochete that causes human lyme borreliosis (lb), is a genetically and phenotypically divergent species. in the past several years, various molecular approaches have been developed and used to determine the phenotypic and genetic heterogeneity within the lb-related spirochetes and their potential association with distinct clinical syndromes. these methods include serotyping, multilocus enzyme electrophoresis, dna-dna reassociation analysis, rrna gene restri ... | 1999 | 10515907 |
| new rickettsiae in ticks collected in territories of the former soviet union. | dermacentor nuttallii from siberia, rhipicephalus sanguineus from crimea, and rh. pumilio from the astrakhan region were infected with rickettsia sibirica (12%), r. conorii (8%), and the astrakhan fever agent (3%), respectively. three new rickettsiae of the r. massiliae genogroup were identified in ticks by 16s rdna, glta, and ompa sequencing. | 1999 | 10603217 |
| molecular cloning and characterization of the 120-kilodalton protein gene of ehrlichia canis and application of the recombinant 120-kilodalton protein for serodiagnosis of canine ehrlichiosis. | the 120-kda outer membrane protein (p120) is a potential adhesin of ehrlichia chaffeensis, and recombinant p120 is very useful for serodiagnosis of human monocytotropic ehrlichiosis. the analogous gene of p120 in ehrlichia canis was cloned, sequenced, and expressed. like the e. chaffeensis p120, the e. canis p120 contains tandem repeat units. however, neither the repeat number nor the amino acid sequences in the repeats are identical in the two ehrlichia species. the repeat units are hydrophilic ... | 2000 | 10618118 |
| sequential histopathology at the rhipicephalus sanguineus tick feeding site on dogs and guinea pigs. | the tick rhipicephalus sanguineus is a very common parasite of dogs worldwide. dogs seem unable to acquire resistance against this tick species, whereas guinea pigs demonstrate a very strong resistance following primary infestation. we studied the inflammatory reaction at the r. sanguineus tick feeding site on dogs and guinea pigs during primary and tertiary infestations at different time intervals after attachment. biopsies were collected after 4, 24, 48 and 96 hours. changes that were found in ... | 1999 | 10668866 |
| 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 |
| helminthic transmission and isolation of ehrlichia risticii, the causative agent of potomac horse fever, by using trematode stages from freshwater stream snails. | we report successful helminthic transmission of ehrlichia risticii, the causative agent of potomac horse fever, using trematode stages collected from juga yrekaensis snails. the ehrlichial agent was isolated from the blood of experimentally infected horses by culture in murine monocytic cells and identified as e. risticii ultrastructurally and by characterization of three different genes. | 2000 | 10699046 |
| 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%. | 2000 | 10699047 |
| short report: isolation and identification of two spotted fever group rickettsial strains from patients in catalonia, spain. | two rickettsial strains, 16b (previously isolated) and fb1, were isolated from blood from patients with mediterranean spotted fever in catalonia, spain. these are the only 2 human rickettsial isolates of the spotted fever group obtained so far in spain. these strains were identified by the polymerase chain reaction and sequence analysis of a fragment of the outer membrane protein a (ompa) gene. the partial ompa sequence was found to be 100% identical with that of rickettsia conorii (malish 7 str ... | 2000 | 10761740 |
| the complete mitochondrial dna sequence of the horseshoe crab limulus polyphemus. | we determined the complete 14,985-nt sequence of the mitochondrial dna of the horseshoe crab limulus polyphemus (arthropoda: xiphosura). this mtdna encodes the 13 protein, 2 rrna, and 22 trna genes typical for metazoans. the arrangement of these genes and about half of the sequence was reported previously; however, the sequence contained a large number of errors, which are corrected here. the two strands of limulus mtdna have significantly different nucleotide compositions. the strand encoding m ... | 2000 | 10779542 |
| effect of ivermectin on the brown dog tick, rhipicephalus sanguineus. | ivermectin (ivomec) proved to be effective in controlling r. sanguineus. all brown dog ticks infesting the treated dogs (subcutaneous injections) with 1.5 ml or 2 ml/50 kg dropped off within 4 or 3 days respectively. the dropped off ticks were completely inactive and died within one day or two. ticks exposed to filter papers impregnated with 100 micrograms/ml (66.67%) died within four days. a dose of 1.5-2 microliters/50 kg eradicated toxocara canis infection in four dogs, and caused shrinkage o ... | 2000 | 10786024 |
| is the detection of anti-rhipicephalus sanguineus (rs24p) antibodies a valuable epidemiological tool of tick infestation in dogs? | antibodies against the 24 kda rhipicephalus sanguineus (rs24p) protein were detected by elisa to evaluate the relationship between antibodies and tick infestation. the mean titer of 3 dogs that underwent 2 experimental infestations with adult ticks was transiently increased after the second infestation. there was a significant difference in mean titers between positive control dogs naturally infested with ticks and tick-naive dogs. these results suggested that anti-rs24p antibodies detected by e ... | 2000 | 10863953 |
| tick species parasitizing people in an area endemic for tick-borne diseases in north-western italy. | in 1995 and 1996, 318 ticks were recovered from 240 people in liguria (province of savona, italy). most of the ticks (284; 89.3%) were sheep ticks, ixodes ricinus. rhipicephalus sanguineus (31; 9.8%) and dermacentor marginatus (3; 0.9%) were also recorded. all three life stages of i. ricinus were found on humans while only nymphs and adults of r. sanguineus and adults of d. marginatus were collected. human tickbites were most frequent in the municipalities of the province where roe deer density ... | 1999 | 10870560 |
| 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 |
| babesiosis. | babesiosis is an emerging, tick-transmitted, zoonotic disease caused by hematotropic parasites of the genus babesia. babesial parasites (and those of the closely related genus theileria) are some of the most ubiquitous and widespread blood parasites in the world, second only to the trypanosomes, and consequently have considerable worldwide economic, medical, and veterinary impact. the parasites are intraerythrocytic and are commonly called piroplasms due to the pear-shaped forms found within inf ... | 2000 | 10885987 |
| a review of the ticks (acari, ixodida) of brazil, their hosts and geographic distribution - 1. the state of rio grande do sul, southern brazil. | a review of the ticks (acari, ixodida) of the state of rio grande do sul, southern brazil, was completed as a step towards a definitive list (currently indicated as 12) of such species, their hosts and distribution. the ticks: argas miniatus (poultry), ixodes loricatus (opossums), amblyomma aureolatum (dogs), a. calcaratum (anteaters), a. cooperi (capybaras), a. nodosum (anteaters), a. tigrinum (dogs) (neotropical) and rhipicephalus sanguineus (dogs) (introduced, cosmopolitan, afrotropical) were ... | 2000 | 10904399 |
| performance of female rhipicephalus sanguineus (acari: ixodidae) fed on dogs exposed to multiple infestations or immunization with tick salivary gland or midgut tissues. | this investigation compared the effects of repeated infestations to immunization of dogs with tick salivary gland or midgut extracts on the feeding and fecundity performances of female rhipicephalus sanguineus (latrielle). in each immunized group, three tick-naive dogs were immunized three times with tick salivary gland or midgut extracts, and twice challenged at 21-d intervals by allowing 80 female and 40 male adult ticks to feed on each host. the repeated infestation group of three naive dogs ... | 2000 | 10916303 |
| efficacy of selamectin against experimentally induced tick (rhipicephalus sanguineus and dermacentor variabilis) infestations on dogs. | seven controlled studies were conducted to investigate the efficacy of selamectin against weekly infestations of dogs with rhipicephalus sanguineus and dermacentor variabilis. treatments (selamectin or vehicle alone) were applied topically at weekly, 2-week, or monthly intervals or in a "monthly plus" regimen (monthly treatment with an additional treatment at 14 days after the first treatment). selamectin was supplied in unit dose tubes designed to deliver a minimum dosage of 6mgkg(-1). the stud ... | 2000 | 10940535 |
| mortality rate of adult ticks due to infection by entomopathogenic nematodes. | the mortality of boophilus annulatus, hyalomma excavatum, rhipicephalus bursa, and rhipicephalus sanguineus adult ticks was recorded after their exposure in petri dishes to 5 entomopathogenic nematode strains. the strains used were dt and mexican of steinernema carpocapsae, hb hp88 of heterorhabditis bacteriophora, and is-3 and is-5 of heterorhabditis sp. the most rapid killing rates (lt50 and lt90) were observed for b. annulatus ticks (0.8-5.0 days). most unfed males died 0.3-2.8 days after the ... | 2000 | 10958439 |
| the ixodid tick species attaching to domestic dogs and cats in great britain and ireland. | the species of ixodid ticks, attached to dogs and cats presented to veterinary practices in great britain and ireland were identified. most host animals carried only one tick species with ixodes ricinus linné (acari: ixodidae) being the most common, identified on 52% of animals, ixodes hexagonus leach (acari: ixodidae) the second most common (on 39%) and ixodes canisuga johnston (acari: ixodidae) the third most common (on 11%). a significantly higher proportion of dogs than cats carried i. ricin ... | 2000 | 11016442 |
| detection of ehrlichia platys dna in brown dog ticks (rhipicephalus sanguineus) in okinawa island, japan. | thirty-two rhipicephalus sanguineus females collected from eight free-roaming dogs in okinawa island, japan, were examined for ehrlichial dna by 16s rrna-based pcr and subsequent sequencing. partial sequences of ehrlichia platys 16s rrna (678 to 679 bp) were detected in three ticks (9.4%) from two dogs. this is the first report of detection of e. platys in japan, and also the first report of detection in ticks. | 2000 | 11060094 |
| distribution and ecology of ticks (acari: ixodidae) infesting livestock in tunisia: an overview of eighth years field collections. | ticks (ixodidae) play a significant role as vectors of pathogens of domestic animals in tunisia. the major losses caused by ticks are related to transmission of protozoan parasites. these include agents of tropical theileriosis and babesiosis in ruminants. since 1991, we conducted research studies on tick population of livestock in tunisia. this overview reports a synthesis on tick distribution, their biology and their role as vectors of pathogens in domestic animals, particularly cattle. during ... | 1999 | 11071534 |
| general review of tick species present in portugal. | at present, 24 species are known to occur in portugal: argas vespertilionis, ornithodoros maritimus and ornithodoros erraticus in argasidae; ixodes acuminatus, ixodes bivari, ixodes canisuga, ixodes frontalis, ixodes hexagonus, ixodes ricinus, ixodes simplex simplex, ixodes ventalloi, ixodes vespertilionis, dermacentor marginatus, dermacentor pictus', haemaphysalis hispanica, haemaphysalis inermis, haemaphysalis punctata, rhipicephalus bursa, rhipicephalus pusillus, rhipicephalus sanguineus, rhi ... | 1999 | 11071535 |
| epidemiology of mediterranean theileriosis in extremadura region, spain. | extremadura is an extensive region (41,000 km2) located in the southwest of spain, where animal husbandry is a very important economical resource. livestock parasitism of ticks is common in the region and it is favoured by the environmental conditions and management systems. mediterranean theileriosis (mt) is perhaps the most important tick-borne disease of cattle. although theileria annulata has been identified in extremadura since 1933, little epidemiological information is available. during t ... | 1999 | 11071543 |
| interleukin-10 modulates proinflammatory cytokines in the human monocytic cell line thp-1 stimulated with borrelia burgdorferi lipoproteins. | we determined previously that lipoproteins of borrelia burgdorferi stimulate inflammatory and anti-inflammatory cytokines (interleukin-10 [il-10]) in monocytes. il-10 could have an effect on innate and acquired immune responses to b. burgdorferi and influence the magnitude of the infectious inoculum and disease outcome. to understand the mechanism(s) of il-10 action during early infection, when innate immunity expressed chiefly by skin macrophages is key, we investigated the effect of exogenous ... | 2000 | 11083779 |
| hepatozoon canis infection associated with dog ticks of rural areas of rio de janeiro state, brazil. | hepatozoon canis is a tick-borne protozoan that infects dogs and has been reported throughout the world. manifestation of h. canis infection varies from being sub-clinical in apparently healthy dogs to severe illness. the main vector of the infection is the dog tick, rhipicephalus sanguineus although other species may also transmit this agent. h. canis has been reported previously in brazil, but mostly as an occasional finding during laboratory exams and always associated with other diseases. th ... | 2001 | 11113545 |
| tick salivary gland extract inhibits killing of borrelia afzelii spirochetes by mouse macrophages. | salivary gland extract (sge) from ixodes ricinus ticks inhibited the killing of borrelia afzelii spirochetes by murine macrophages. sge also reduced the production of two major defense molecules of phagocytes, superoxide and nitric oxide. it is likely that the suppression of macrophage microbicidal mechanisms contributes to the inhibitory effect of tick saliva on the killing of b. afzelii spirochetes, thus facilitating the transmission of this important pathogen. | 2001 | 11119556 |
| humoral immune response of dogs immunized with salivary gland, midgut, or repeated infestations with rhipicephalus sanguineus. | the antibody (ab) responses of dogs immunized with adult tick salivary gland (tsg), midgut (tmg), or repeated infestations of rhipicephalus sanguineus were monitored to determine if there is an association between ab production and r. sanguineus performance. tick-naïve dogs were immunized with tsg or tmg and subjected to two challenge infestations. the control group was infested five times at 21-day intervals. the elisa technique was used to measure ab levels in sera from these dogs, which expre ... | 2000 | 11193634 |
| biocontrol of ticks by entomopathogenic nematodes. research update. | entomopathogenic nematodes (epns) are lethal to ticks even though they do not use their normal propagation cycle within tick cadavers. the tick boophilus annulatus was found to be far more susceptible to epns than hyalomma excavatum, rhipicephalus bursa, or rhipicephalus sanguineus. ticks seem to be less susceptible to nematodes when feeding on a host. preimaginal tick stages were less susceptible to nematodes than adult ticks. the mortality rate of unfed females was highest, followed by unfed m ... | 2000 | 11193678 |
| cross reactivity between instars of the rhipicephalus sanguineus (latreille, 1806) tick. | | 2000 | 11193682 |
| 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 ... | 2000 | 11193705 |
| the effect of male ticks on the feeding performance of immature stages of rhipicephalus sanguineus and amblyomma americanum (acari: ixodidae). | a unique group of immunoglobulin-binding proteins (igbps), produced by ixodid male ticks during the latter half of their prolonged feeding period, improves the feeding performance of co-feeding females. as a follow-up to this observation, we investigated whether male tick feeding also affects the feeding of other developmental stages. immature stages of rhipicephalus sanguineus (latreeille) and amblyomma americanum (l.) were fed on rabbits in the presence or absence of conspecific males. the mea ... | 2000 | 11201360 |
| ectoparasites of dogs belonging to people in resource-poor communities in north west province, south africa. | a total of 344 dogs belonging to people in resource-poor communities in north west province, south africa, was examined for ectoparasites, and all visible arthropods were collected from the left side of each dog. by doubling these numbers it was estimated that the dogs harboured 14,724 ixodid ticks, belonging to 6 species, 1,028 fleas, belonging to 2 species, and 26 lice. haemaphysalis leachi accounted for 420 and rhipicephalus sanguineus for 14,226 of the ticks. pure infestations of h. leachi w ... | 2000 | 11205167 |
| analysis of the systematic relationships among ticks of the genera rhipicephalus and boophilus (acari: ixodidae) based on mitochondrial 12s ribosomal dna gene sequences and morphological characters. | a portion of mitochondrial 12s rdna sequences (337-355 base pairs) and 63 morphological characters of 36 hard-tick species belonging to 7 genera were analyzed to determine the phylogenetic relationships among groups and species of rhipicephalus and between the genera rhipicephalus and boophilus. molecular and morphological data sets were first examined separately. the molecular data were analyzed by maximum parsimony (mp), maximum likelihood, and neighbor-joining distance methods; the morphologi ... | 2001 | 11227901 |
| analysis of transcriptionally active gene clusters of major outer membrane protein multigene family in ehrlichia canis and e. chaffeensis. | ehrlichia canis and e. chaffeensis are tick-borne obligatory intramonocytic ehrlichiae that cause febrile systemic illness in humans and dogs, respectively. the current study analyzed the pleomorphic multigene family encoding approximately 30-kda major outer membrane proteins (omps) of e. canis and e. chaffeensis. upstream from seca and downstream of hypothetical transcriptional regulator, 22 paralogs of the omp gene family were found to be tandemly arranged except for one or two genes with oppo ... | 2001 | 11254561 |
| characterization of acaricide resistance in rhipicephalus sanguineus (latreille) (acari: ixodidae) collected from the corozal army veterinary quarantine center, panama. | rhipicephalus sanguineus (latreille) were collected from the corozal army veterinary quarantine center in panama and characterized for resistance to five classes of acaricides. these ticks were highly resistant to permethrin, ddt, and coumaphos; moderately resistant to amitraz; and not resistant to fipronil when compared with susceptible strains. resistance to both permethrin and ddt may result from a mutation of the sodium channel. however, synergist studies indicate that enzyme activity is inv ... | 2001 | 11296838 |
| effects of salivary gland extract from rhipicephalus sanguineus on immunoglobulin class productivity of canine peripheral blood lymphocytes. | effects of salivary gland extract (sge) from rhipicephalus sanguineus on immunoglobulin class productivity of canine peripheral blood lymphocytes (pbl) in vitro were studied. the detectable limit of the elisa for canine total immunoglobulin, igm and a was at least 1, 1 and 15 ng/ml, respectively, and it seems to be useful for the evaluation of non-specific immunoglobulin class productivity in vitro. sge from r. sanguineus suppressed pokeweed mitogen- or lipopolysaccharide-induced total immunoglo ... | 2001 | 11307936 |
| prevalence of vectors of the spotted fever group rickettsiae and murine typhus in a bedouin town in israel. | a survey of the vectors of spotted fever group rickettsiae and of murine typhus was carried out in rahat, a bedouin town in the negev desert, where the diseases are endemic. houses with known cases of spotted fever group rickettsiae or murine typhus were compared with those without reported clinical cases. a neighboring jewish community, lehavim, where no cases of spotted fever group rickettsiae and murine typhus were reported in recent years, was used as a control. in the houses of patients wit ... | 2001 | 11372975 |
| [toxic effects and in vitro inefficacy of deltamethrin on larvae of rhipicephalus sanguineus from goiânia, goiás, brazil]. | it has been observed that formulations of deltamethrin developed for disinsectization of infested places and control of parasitic arthropods of bovines and equines have frequently been used by breeders of dogs to control ticks in their animals and kennels, but without due consideration of the correct dosage or means of application. with the purpose of evaluating the efficacy of this product on rhipicephalus sanguineus, bioassays were realized with larvae at 27+/-1 degrees c, ur>80% and light per ... | 2001 | 11391437 |
| transmission of hepatozoon canis to dogs by naturally-fed or percutaneously-injected rhipicephalus sanguineus ticks. | hepatozoon canis is an apicomplexan protozoan parasite of dogs, prevalent in asia, africa, and southern europe. experimental transmission of h. canis to dogs was performed with laboratory-reared rhipicephalus sanguineus nymphs that fed on a naturally infected dog or were percutaneously injected with canine blood containing h. canis gamonts. dogs were inoculated by oral ingestion of adult ticks containing h. canis oocysts. transstadial transmission of h. canis was recorded, whereas transovarial t ... | 2001 | 11426725 |
| quantitative analyses of variations in the injury of endothelial cells elicited by 11 isolates of rickettsia rickettsii. | eleven isolates of spotted fever group rickettsiae from the blood of patients or ixodid ticks from north and south america were characterized. all isolates were identified as rickettsia rickettsii using restriction fragment length polymorphism analysis of a 532-bp rompa gene fragment obtained by pcr. the ability of the r. rickettsii isolates to elicit cytopathic effects and parameters of oxidative injury were examined in cultured human ea.hy 926 endothelial cells. cytopathic effects were determi ... | 2001 | 11427428 |
| recombinant major antigenic protein 2 of ehrlichia canis: a potential diagnostic tool. | the major antigenic protein 2 (map2) of ehrlichia canis was cloned and expressed. the recombinant protein was characterized and tested in an enzyme-linked immunosorbent assay (elisa) format for potential application in the serodiagnosis of canine monocytic ehrlichiosis. the recombinant protein, which contained a c-terminal polyhistidine tag, had a molecular mass of approximately 26 kda. the antigen was clearly identified by western immunoblotting using antihistidine antibody and immune serum fro ... | 2001 | 11427559 |
| ixodid ticks on white-tailed deer and feral swine in florida. | a state-wide survey was conducted in florida during the 1997-99 hunting seasons to examine white-tailed deer (odocoileus virginianus) and feral swine (sus scrofa) for potential indigenous vectors of the rickettsial agent of heartwater, cowdria ruminantium. a total of 504 white-tailed deer and 166 feral swine was examined from 30 wildlife management areas across the state. amblyomma maculatum, an experimental vector of c. ruminantium, was common on both deer and feral swine throughout the state. ... | 2001 | 11469190 |
| molecular and antigenic comparison of ehrlichia canis isolates from dogs, ticks, and a human in venezuela. | we previously culture isolated a strain of ehrlichia canis, the causative agent of canine ehrlichiosis, from a human in venezuela. in the present study, we examined whether dogs and ticks are infected with e. canis in venezuela and, if so, whether this is the same strain as the human isolate. pcr analysis using e. canis-specific primers revealed that 17 of the 55 dog blood samples (31%) and all three pools of four rhipicephalus sanguineus ticks each were positive. an ehrlichial agent (venezuelan ... | 2001 | 11473993 |
| investigation of blood parasites in livestock infested with argasid and ixodid ticks in egypt. | nineteen species and subspecies of ixodid and argasid ticks, hyalomma dromedarii, h. impeltatum, h. anatolicum excavatum, h. a. anatolicum, h. truncatum, h. m. marginatum, h. m. rufipes, h. m. turanicum, boophilus annulatus, rhipicephalus sanguineus, r. turanicus, r. guilhoni, r. camicasi, amblyomma lipidum, a. marmoreum, a. vareigatum, argas persicus, a. hermanii and a. arboreus were collected from different localities in five governorates, giza, sharkia, ismailia, el beheira and sinai. hyalomm ... | 2001 | 11478436 |
| detection of haemoparasites in cattle by reverse line blot hybridisation with a note on the distribution of ticks in sicily. | a reverse line blot hybridisation (rlb) of 21 oligonucleotides with polymerase chain reaction (pcr) amplified regions of 16s rrna (ehrlichia/anaplasma group) or 18s rrna (babesia/theileria group) genes of haemoparasites detected theileria annulata, t. buffeli/orientalis, babesia bovis, b. bigemina, b. divergens, ehrlichia bovis, anaplasma marginale, a. centrale and unknown species within the rickettsia tribe.a very high prevalence of mixed infections was detected, which indicated that animals in ... | 2001 | 11511414 |
| transcriptional analysis of p30 major outer membrane multigene family of ehrlichia canis in dogs, ticks, and cell culture at different temperatures. | ehrlichia canis, an obligatory intracellular bacterium of monocytes and macrophages, causes canine monocytic ehrlichiosis. e. canis immunodominant 30-kda major outer membrane proteins are encoded by a polymorphic multigene family consisting of more than 20 paralogs. in the present study, we analyzed the mrna expression of 14 paralogs in experimentally infected dogs and rhipicephalus sanguineus ticks by reverse transcription-pcr using gene-specific primers followed by southern blotting. eleven ou ... | 2001 | 11553557 |
| analysis of the use of fenthion via epicutaneous in dogs for rhipicephalus sanguineus control. | the action of fenthion was studied in a 15% epicutaneous formulation upon rhipicephalus sanguineus, which may transmit pathogens to men and other animals, such as ehrlichia, babesia and ricketsia. dogs were artificially infected for the trial. the fenthion bioassays were begun four months after artificial infestation. the test group, having a mean of 186 ticks per dog, received the formulation dosage according to body weight on the neck region. tick counts were performed, considering diameters > ... | 2001 | 11562726 |
| aortic valve endocarditis in a dog due to bartonella clarridgeiae. | we report the first documented case of endocarditis associated with bartonella clarridgeiae in any species. b. clarridgeiae was identified as a possible etiological agent of human cat scratch disease. infective vegetative valvular aortic endocarditis was diagnosed in a 2.5-year-old male neutered boxer. historically, the dog had been diagnosed with a systolic murmur at 16 months of age and underwent balloon valvuloplasty for severe valvular aortic stenosis. six months later, the dog was brought t ... | 2001 | 11574571 |
| survey of tick infestation and tick-borne ehrlichial infection of dogs in ishigaki island, japan. | twelve (54.5%) of 22 free-roaming dogs in ishigaki island had tick infestation identified as rhipicephalus sanguineus. there were 121 ticks recovered and consisted of 28 females, 58 males, 22 nymphs and 3 larvae. infection of dogs possibly with canine ehrlichial pathogens was examined by both indirect immunofluorescence assay and polymerase chain reaction (pcr). two dogs of the 13 examined were sero-positive for the human granulocytic ehrlichia agent, and one of two dogs was pcr positive for ehr ... | 2001 | 11767058 |
| pathogenicity of entomopathogenic fungi to different developmental stages of rhipicephalus sanguineus (acari: ixodidae). | the pathogenicity of 4 species of entomopathogenic fungi (hyphomycetes species: beauveria bassiana, metarhizium anisopliae, metarhizium flavoviride, and paecilomyces fumosoroseus) to various developmental stages of rhipicephalus sanguineus (acari: ixodidae) ticks was compared under laboratory conditions. the most virulent isolate, m. anisopliae-108, caused 92-96% mortality to unfed larvae and nymphs on day 7 postinfection (pi) and 100% mortality to unfed adults and engorged females on day 21 pi. ... | 2001 | 11780821 |
| detection of ehrlichia canis in canine carrier blood and in individual experimentally infected ticks with a p30-based pcr assay. | detection of vector-borne pathogens is necessary for investigation of their association with vertebrate and invertebrate hosts. the ability to detect ehrlichia spp. within individual experimentally infected ticks would be valuable for studies to evaluate the relative competence of different vector species and transmission scenarios. the purpose of this study was to develop a sensitive pcr assay based on oligonucleotide sequences from the unique ehrlichia canis gene, p30, to facilitate studies th ... | 2002 | 11825969 |
| transcript heterogeneity of the p44 multigene family in a human granulocytic ehrlichiosis agent transmitted by ticks. | human granulocytic ehrlichiosis (hge) is an emerging tick-borne zoonosis caused by a strain of anaplasma phagocytophila called the hge agent, an obligatory intracellular bacterium. the agent expresses immunodominant 44-kda outer membrane proteins (p44s) encoded by a multigene family. the present study established an experimental process for transmission of the hge agent from infected mice (a reservoir model) to nymphal ixodes scapularis ticks (a biological vector) and subsequently to horses (a p ... | 2002 | 11854198 |
| importation of the brown dog or kennel tick (rhipicephalus sanguineus) into the uk. | | 2002 | 11878449 |
| ticks parasitizing dogs in northwestern georgia. | from january 1998 through september 1999, 324 dogs in three northwestern georgia counties were examined for ticks. six species of ticks were recovered. the three most commonly collected ticks were the american dog tick, dermacentor variabilis (say) (310 male male, 352 female female; prevalence, 97%; mean intensity 2.1); the brown dog tick, rhipicephalus sanguineus (latreille) (118 male male, 119 female female, 38 nymphs; prevalence, 22%; mean intensity, 3.8); and the lone star tick, amblyomma am ... | 2002 | 11931241 |
| diversity, seasonality and sites of attachment of adult ixodid ticks on dogs in the central region of the free state province, south africa. | several surveys of ticks infesting dogs belonging to owners in resource-limited and more affluent communities have been conducted in south africa, but no such investigation has been carried out in the free state province of this country. the present study was initiated to meet this shortcoming. ticks were collected from dogs at six localities in, and to the east of the city of bloemfontein in the central region of the province. three of these localities could be classed as resource-limited and t ... | 2001 | 12026063 |
| genetic identification of rickettsiae isolated from ticks in japan. | following the description in japan of japanese spotted fever, caused by rickettsia japonica, a search for the vector of this disease led to the isolation of several rickettsiae from various tick species. sixty-three rickettsial isolates were obtained from six different tick species, and six type strains were described by pcr and monoclonal antibody testing. we identified these six strains by amplification and sequencing of the genes encoding 16s rrna and citrate synthase. we confirmed that the i ... | 2002 | 12037083 |
| study on immunobiology in ectoparasites of public health interest: rhipicephalus sanguineus. | the recently defined range of mediterranean spotted fever (msf) in sardinia coincides with that of the widely studied rickettsia conorii vector, the brown dog tick rhipicephalus sanguineus. this tick is major vector of disease in humans, domestic and wild animals. characteristic features of the vector with respect to their seasonal activity, abundance as well as incidence of human-tick contact and how these factors influence the incidence of msf were studied. this paper also looks at host, patho ... | 2001 | 12078475 |
| [complications of mediterranean spotted fever]. | mediterranean spotted fever is an infectious disease due to rickettsia conori transmitted to man by the dog tick rhipicephalus sanguineus. the review of a consecutive series of 525 cases, admitted to caltagirone hospital in the last 20 years, permits the classic clinical picture to be identified by fever, maculopapular eruption and tache noire, and any complications to be visualized. usually the course of the disease is good, but 12.7% of our cases reported complications such as renal failure, m ... | 2001 | 12087217 |
| ehrlichia ewingii infection in white-tailed deer (odocoileus virginianus). | two closely related zoonotic ehrlichiae, ehrlichia chaffeensis and e. ewingii, are transmitted by amblyomma americanum, the lone star tick. because white-tailed deer (odocoileus virginianus) are critical hosts for all mobile stages of a. americanum and are important vertebrate reservoirs of e. chaffeensis, we investigated whether deer may be infected with e. ewingii, a cause of granulocytotropic ehrlichiosis in humans and dogs. to test for e. ewingii infection, we used polymerase chain reaction ... | 2002 | 12095432 |
| the omp-1 major outer membrane multigene family of ehrlichia chaffeensis is differentially expressed in canine and tick hosts. | sixteen of 22 omp-1 paralogs encoding 28-kda-range immunodominant outer membrane proteins of ehrlichia chaffeensis were transcribed in blood monocytes of dogs throughout a 56-day infection period. only one paralog was transcribed by e. chaffeensis in three developmental stages of amblyomma americanum ticks before or after e. chaffeensis transmission to naïve dogs. | 2002 | 12117987 |
| isolation of coxiella burnetii by a centrifugation shell-vial assay from ticks collected in cyprus: detection by nested polymerase chain reaction (pcr) and by pcr-restriction fragment length polymorphism analyses. | ticks are the principal vectors and reservoirs of coxiella burnetii. the identification of isolates is necessary for understanding the clinical diversity of q fever in different geographic areas. this is the first report of isolation of c. burnetii from ticks by the shell-vial assay and by nested polymerase chain reaction (pcr) assay for the detection of this pathogen in ticks. of 141 ticks collected in cyprus (rhipicephalus sanguineus and hyalloma spp.), 10% were found to be infected with c. bu ... | 2002 | 12135275 |
| the dog factor in brown dog tick rhipicephalus sanguineus (acari: ixodidae) infestations in and near human dwellings. | three cases of the tick rhipicephalus sanguineus infiltration in or near human dwellings caused by dogs, and their influence on epidemiological features of human habitats have been investigated. (a) the observation of dogs kept indoors proved that single tick females could engorge and oviposit inside apartments followed by the development of subadults. (b) abundant micropopulations of ticks were formed in small yards or gardens near the dwellings where dogs lived in kennels. (c) a huge field pop ... | 2002 | 12141741 |