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babesial antibody dynamics after cattle immunisation with live vaccines, measured with an indirect immunofluorescence test.the efficacy of vaccination of argentinean cattle against babesiosis and anaplasmosis using live immunogens was tested to detect specific antibodies in samples obtained about 60 days after vaccination. under these conditions a higher than expected proportion of cattle failed to show antibodies against babesia bigemina. therefore, a study was designed to evaluate if this failure was due to insensitivity of the routine test to detect antibodies to b. bigemina or to lack of infectivity of the live ...19979195707
effect of breed of cattle on innate resistance to infection with babesia bovis, b bigemina and anaplasma marginale.to assess the innate resistance of naive bos taurus, bos taurus cross bos indicus and bos indicus cattle to virulent babesia bovis, b bigemina and anaplasma marginale parasites.19979196820
immunisation of smallholder dairy cattle against anaplasmosis and babesiosis in malawi.a field study was conducted in the southern region of malawi to evaluate the possible benefits of immunisation of improved dairy cattle against anaplasma marginale, babesia bigemina and babesia bovis. friesian crossbred heifers were immunised when they were being reared on government farms. they were then issued to smallholder farmers, together with unvaccinated controls, where many of them were exposed to heavy tick infestation. vaccination was shown to provide a significant degree of protectio ...19979203307
ultrastructure of anaplasma marginale with an inclusion appendage, isolated in minas gerais state, brazil.this is the first report on the occurrence and isolation of a strain of anaplasma marginale with an inclusion appendage in brazil. the inclusion appendage presented longitudinal electron-dense striations and did not originate directly from the body of the rickettsia but from an electron-dense complex located at the junction of the inclusion membrane and inclusion appendage. the inclusion appendage remained in the host cell after the anaplasma inclusion appeared to be leaving the red blood cell. ...19979211652
different seasonal occurrence of anaplasmosis outbreaks in beef and diary cattle in an area of argentina free of boophilus microplus ticks.the seasonal occurrence of anaplasmosis (anaplasma marginale) outbreaks in dairy and beef cattle was analysed for a region of argentina (29 degrees to 31 degrees s and 58 degrees to 62 degrees w) that is free of boophilus microplus ticks, using data collected from december 1978 to november 1995. the outbreaks were confirmed by inspection of blood smears obtained from sick or dead cattle. a total of 94 outbreaks were confirmed by inspection of blood smears obtained from sick or dead cattle. a tot ...19979225428
the prevalence of serum antibodies to tick-borne infections in cattle in smallholder dairy farms in murang'a district, kenya; a cross-sectional study.the most important tick-borne disease of cattle in eastern, central and southern africa is east coast fever (ecf) caused by theileria parva and transmitted by the tick rhipicephalus appendiculatus. other less-important tick-borne diseases in cattle are benign theileriosis caused by theileria mutans, babesiosis caused by babesia bigemina, anaplasmosis caused by anaplasma marginale and cowdriosis caused by cowdria ruminatum. in murang's district, central province of kenya, five agroecological zone ...19979234414
[clinical and hematological changes in calves infected with anaplasma marginale].clinical and hematological changes of six anaplasma marginale (isolated zulia) inoculated calves (experimental group) and four healthy calves (control group) were studied during twenty and eighty days before and after infection, respectively. the behavior of the four calves used as control group was stable and no significant changes in the parameters analyzed was observed. the experimental group developed the three typical phases of illness. during the prepatent phase, which lasted a mean of 21. ...19969334450
anaplasma marginale: effect of the treatment of cattle with an interferon gamma-neutralizing monoclonal antibody or the nitric oxide synthetase inhibitor aminoguanidine on the course of infection.cattle undergoing initial infection with the rickettsia anaplasma marginale were treated with either a monoclonal antibody (moab) with neutralizing activity for bovine interferon gamma (ifn-gamma) or aminoguanidine (ag), a specific inhibitor of the inducible form of nitric oxide synthetase (inos). plasma levels of moab and ag were measured over the time of administration. the course of a. marginale infection was not altered in the moab-treated cattle relative to untreated controls. in cattle tre ...19979347517
carbohydrate moiety of plasmodium falciparum glycoproteins: the nature of the carbohydrate-peptide linkage in the msp-2 glycoprotein.metabolic labelling of plasmodium falciparum parasites with [3h]glcn, [3h]man, [3h]gal and [3h]ethanolamine, and subsequent purification by sds-page of the labelled material provided effective labelling of the msp-1, 195 kda, and msp-2, 42-53 kda, glycoproteins. reductive beta-elimination of the msp-2 released from the gel consisted of glycopeptides containing labelled sugars. processing of the eliminated components and identification of the sugar residues demonstrated the presence of n-acetylgl ...19979352084
immunodominant major outer membrane proteins of ehrlichia chaffeensis are encoded by a polymorphic multigene family.several immunodominant major proteins ranging from 23 to 30 kda were identified in the outer membrane fractions of ehrlichia chaffeensis and ehrlichia canis. the n-terminal amino acid sequence of a 28-kda protein of e. chaffeensis (one of the major proteins) was determined. the gene (p28), almost full length, encoding the 28-kda protein was cloned by pcr with primers designed based on the n-terminal sequence of the e. chaffeensis 28-kda protein and the consensus sequence between the c termini of ...19989423849
seasonal prevalence of ticks and tick-transmitted haemoparasites in traditionally managed n'dama cattle with reference to strategic tick control in the gambia.a survey of tick spatial and seasonal distribution in traditional managed n'dama cattle over 1 year old was carried out in the gambia over 16 months. presence of anaplasma marginale and babesia spp. in the blood smears and their antibodies in the serum of same animals were also examined. tick species, in decreasing order of abundance, were: boophilus geigy, rhipicephalus senegalensis, b.decoloratus, hyalaomma truncatum, h.marginatum rufipes and amblyomma variegatum. all tick species peaked durin ...19979430113
bovine anaplasmosis prevalence in northern veracruz state, mexico.in order to learn more about the presence of bovine anaplasmosis in northern veracruz state, méxico, paired blood and serum samples from 368 cattle were subjected to polymerase chain reaction (pcr) and complement-fixation test (cft). the overall prevalence of anaplasma marginale by pcr was 69.2% and seroprevalence by cft 54.6%. age-specific prevalence was calculated for each test. sixty-eight percent of animals from 0 to 3 months of age already were infected (pcr-positive), compared to only 42.4 ...19979443325
in vitro cultivation of anaplasma marginale in bovine erythrocytes co-cultured with endothelial cells.primary cultures of anaplasma marginale infected erythrocytes were used to determine conditions for in vitro cultivation of the rickettsia. the infected erythrocytes that were maintained by regular addition of glasgow's mem with fetal calf serum and uninfected erythrocytes showed a 1-5% increase in percent infected erythrocytes on the evaluation of giemsa stained smears. this increase in parasitemia resulted in up to 70% change in the number of infected erythrocytes. co-culture of the infected e ...19979477491
expression of anaplasma marginale major surface protein 2 variants during persistent cyclic rickettsemia.anaplasma marginale is an intraerythrocytic rickettsial pathogen of cattle in which infection persists for the life of the animal. persistent a. marginale infection is characterized by repetitive rickettsemic cycles which we hypothesize reflect emergence of a. marginale antigenic variants. in this study, we determined whether variants of major surface protein 2 (msp-2), a target of protective immunity encoded by a polymorphic multigene family, arise during persistent rickettsemia. by using a qua ...19989488414
detection of cattle naturally infected with anaplasma marginale in a region of endemicity by nested pcr and a competitive enzyme-linked immunosorbent assay using recombinant major surface protein 5.a competitive enzyme-linked immunosorbent assay using recombinant major surface protein 5 (rmsp5-celisa) of anaplasma marginale was validated in a naturally infected cattle herd in an area of eastern oregon where a. marginale is endemic. the true positive and negative a. marginale infection status of 235 randomly selected cattle was determined by using a nested pcr (npcr) coupled with msp5 sequence analysis and hybridization. judgment of the reliability of the npcr and hybridization for detectio ...19989508311
ultrastructural differentiation of the genogroups in the genus ehrlichia.ultrastructural characteristics of 15 strains and isolates of ehrlichiae belonging to three genogroups, or clades of genetically related organisms united in the genera ehrlichia, cowdria, anaplasma, neorickettsia and a strain of wolbachia pipientis which represents a fourth genogroup in this cluster of species, were studied in continuous cell culture or in vivo: e. canis (oklahoma strain and vhe isolate), e. muris (as 145), e. chaffeensis (arkansas, 91he17 and sapulpa), human granulocytic ehrlic ...19989511829
observations on the treatment of natural haemosporidia infections by total alkaloid of peganum harmala l. in cattle.eighty two cattle naturally infected with haemosporidians were treated with total alkaloid hydrochloride of peganum harmale l. (0.5 mg/kg/day). fifty eight cases with theileria sergenti showed a cure rate of 86%; thirteen cases with theileria annulata showed a cure rate of 85%; eight cattle infected with babesia bigemina showed a cure rate of 88% and three cases of anaplasma marginale were completely cured. the results suggested that the curative effect of total alkaloid of p. harmale was better ...19979512749
vaccines against hemoparasitic diseases in israel with special reference to quality assurance.four vaccines against hemoparasitic diseases (anaplasmosis, babesiosis and theileriosis) and a vaccine against besnoitiosis are currently used in israel. these vaccines contain live attenuated parasites derived from cell culture (theileria annulata and besnoitia besnoiti) or from blood of infected, splenectomized calves (babesia bigemina, b. bovis and anaplasma centrale). cryopreserved master seed is used to initiate production of the vaccines. quality control performed during the preproduction ...19979512751
evaluation of an enzyme-linked immunosorbent assay using recombinant major surface protein 5 for serological diagnosis of bovine anaplasmosis in venezuela.an indirect enzyme-linked immunosorbent assay (elisa) was developed for the serological diagnosis of bovine anaplasmosis with purified recombinant major surface protein 5 (msp5) of anaplasma marginale produced in escherichia coli. serum antibody responses against msp5 were detected in calves experimentally infected with a. marginale as early as 21 days postinfection and reached maximum titers at 28 days postinfection. the msp5 elisa performed with serum samples taken from field cattle from diffe ...19989521155
tick-borne diseases of sheep and goats caused by babesia, theileria or anaplasma spp.a review is given on the babesia, theileria, and anaplasma species infecting sheep and goats. b. ovis is the most important disease agent. it is transmitted by rhipicephalus bursa, r. turanicus, hyalomma anatolicum excavatum, and probably by r. evertsi evertsi b. ovis is widely spread in southern europe, the middle east, and central asia. its geographical distribution in south and east asia and in africa is widely unknown. b. motasi obviously represents several nosodemes in separate regions. it ...19979530692
tick-borne diseases of sheep and goats and their related vectors in iran.haemoparasitic diseases have long been considered as a major problem to efficient sheep and goats production in iran. theileriosis due to theileria hirci and babesiosis due to babesia ovis and b. motasi are the most pathogenic protozoa. b. crassa, anaplasma ovis and eperythrozoon ovis are usually non-pathogenic and do not cause any apparent problem. the major tick genera found on sheep and goats are hyalomma, rhipicephalus, haemaphysalis, ixodes and rarely dermacentor distributed in all part of ...19979530694
subunit vaccines for the control of tick-borne diseases: implications for the future.tick-borne parasites are a major constraint to the improvement of livestock productivity in the developing world. these parasites include theileria parva, t. annulata, babesia bigemina, b. bovis, anaplasma marginale and cowdria ruminantium. the impact of these diseases is currently limited by the use of acaricides to decrease transmission by the tick vectors and immunization of the host animals using live vaccines. the use of acaricide is hampered by the development of acaricide resistance and l ...19979530697
status of the tick-borne diseases in sheep and goats in turkey.a serological survey using indirect fluorescent antibody test (ifat) for babesia ovis infection of sheep has been carried out in different geographical regions of turkey. the results indicated that 71.6% of 141 sheep in black sea region, 70.9% of 93 sheep in central anatolia, 80.2% of 96 sheep in aegean region and 55.7% of 122 sheep in eastern anatolia were seropositive. this means that b. ovis infection is endemic throughout turkey. in addition, occurrence of b. ovis, b. motasi, theileria hirci ...19979530701
conformational dependence of anaplasma marginale major surface protein 5 surface-exposed b-cell epitopes.the anaplasma marginale outer membrane is composed of immunogenic major surface proteins (msps) linked both covalently and noncovalently in multimeric complexes (m. c. vidotto, t. c. mcguire, t. f. mcelwain, g. h. palmer, and d. p. knowles, infect. immun. 62:2940-2946). consequently, effective induction of antibody against surface-exposed msp epitopes has been postulated to require maintenance of msp secondary through quatenary structures. using msp5 as a model and the approach of epitope mappin ...19989596725
cloning of the gene encoding the 44-kilodalton antigen of the agent of human granulocytic ehrlichiosis and characterization of the humoral response.antibodies in the sera of patients with human granulocytic ehrlichiosis (hge) commonly recognize a 44-kda antigen. we cloned the gene encoding the 44-kda protein of the agent of hge (aohge) by probing an aohge lambda zap ii genomic dna expression library with sera from aohge-infected mice. the gene, hge-44, is part of a multigene family, with sequence similarity to the anaplasma marginale msp-2 genes. rna-pcr studies confirmed that hge-44 is expressed by aohge cultured in hl-60 cells and by aohg ...19989632594
the safety and efficacy of australian tick-borne disease vaccine strains in cattle in paraguay.glycerol preserved, frozen tick-borne disease vaccine strains developed in australia were imported into paraguay to test their safety in pregnant holando heifers and their efficacy against challenge from inoculated local field strains of babesia bigemina, b. bovis and anaplasma marginale in hereford x criolla heifers. the two babesia strains proved to be safe and the b. bovis k strain was very effective in providing immunity to a local field strain of b. bovis. the b. bigemina efficacy trial was ...19989653988
bovine babesiosis and anaplasmosis follow-up on cattle relocated in an endemic area for hemoparasitic diseases.a multiplex pcr/dna probe assay was used to monitor babesia bovis, b. bigemina and anaplasma marginale infection in cattle introduced to a boophilus microplus-infested area in veracruz, mexico. eight intact, 18-month-old, cross-bred beef cattle (four naive, group a; four babesia species--premunized, group b) were immediately exposed to ticks after arrival and were clinically monitored from day 6 to day 98 post-exposure (pe) to ticks. blood sample analysis for dna detection by the mpcr/dna probe ...19989668444
evaluation of anaplasma marginale from tick cell culture as an immunogen for cattle.anaplasma marginale has been propagated and continuously passaged in an ixodes scapularis cell line. anaplasma development was characterized and cultures with a high density of rickettsiae were harvested at a predictable rate. culture-derived a. marginale (cam) remained infective for cattle and was used effectively as antigen in diagnostic tests with the sensitivity to identify bovine carriers of a. marginale. this study presents results of an initial trial using the cam as an immunogen for catt ...19989668472
use of tick cell culture-derived anaplasma marginale antigen in a competitive elisa for serodiagnosis of anaplasmosis.anaplasma marginale was propagated in a continuous tick cell line and detergent-solubilized infected cells were used as antigen in a competitive elisa (c-elisa) for detection of anaplasma-specific antibody in bovine sera. positive control sera competed well (> or = 35% inhibition) with an a. marginale-specific monoclonal antibody for binding to this antigen, while negative sera failed to compete (< 35% inhibition). the c-elisa was compared to the standard complement-fixation test (cft) using 2,2 ...19989668475
the development of a semi-automated latex agglutination test for the detection of antibodies to anaplasma marginale using a cell culture-derived antigen.serologic diagnosis of anaplasmosis is currently done by the complement-fixation, elisa, and card agglutination tests. these tests have utilized a. marginale harvested from bovine erythrocytes as antigen which is often contaminated with erythrocyte stroma. we are currently testing a. marginale propagated in a ixodes scapularis cell line as antigen for serologic tests. in this study, we report the use of the cell culture-derived a. marginale as antigen for development of a rapid, semi-automated l ...19989668476
characterization of an immunogen of anaplasma marginale. 19989668501
seroprevalence of anaplasma marginale in cattle in parana state, brazil, by msp-5 competitive elisa. 19989668503
major antigenic proteins of the agent of human granulocytic ehrlichiosis are encoded by members of a multigene family.western blot analysis of proteins from a cell culture isolate (usg3) of the human granulocytic ehrlichiosis (hge) agent has identified a number of immunoreactive proteins, including major antigenic proteins of 43 and 45 kda. peptides derived from the 43- and 45-kda proteins were sequenced, and degenerate pcr primers based on these sequences were used to amplify dna from usg3. sequencing of a 550-bp pcr product revealed that it encodes a protein homologous to the msp-2 proteins of anaplasma margi ...19989673253
cloning and characterization of multigenes encoding the immunodominant 30-kilodalton major outer membrane proteins of ehrlichia canis and application of the recombinant protein for serodiagnosis.a 30-kda major outer membrane protein of ehrlichia canis, the agent of canine ehrlichiosis, is the major antigen recognized by both naturally and experimentally infected dog sera. the protein cross-reacts with a serum against a recombinant 28-kda protein (rp28), one of the outer membrane proteins of a gene (omp-1) family of ehrlichia chaffeensis. two dna fragments of e. canis were amplified by pcr with two primer pairs based on the sequences of e. chaffeensis omp-1 genes, cloned, and sequenced. ...19989705412
observations on the use of anaplasma centrale for immunization of cattle against anaplasmosis in zimbabwe.a total of 93 bos taurus cattle was used in pen trials to compare vaccine stocks of anaplasma centrale from south africa and australia (which stock came from south africa in 1934) in protecting against three virulent field isolates from clinical anaplasma marginale infections. in addition, field observations were made on the use of a vaccine, prepared from the australian stock, in over 9553 cattle of mixed age and breeds on 16 co-operator farms and at one communal dip. the results of the pen tri ...19989741051
development of an enzyme-linked immunosorbent assay for detection of antibodies to babesia bigemina in cattle.monoclonal antibodies, directed against a 58-kda babesia bigemina merozoite antigen that reacted strongly with immune sera from experimentally and naturally infected cattle in western blots, were used to develop a competitive-inhibition enzyme-linked immunosorbent assay (elisa). as based on the testing of 70 antibody-positive sera from experimentally infected cattle and 166 antibody-negative sera collected in non-endemic areas of australia, the sensitivity and specificity of the elisa were 95.7% ...19989747938
morphology and development of anaplasma marginale (rickettsiales: anaplasmataceae) in cultured ixodes scapularis (acari: ixodidae) cells.anaplasma marginale theiler, a tick-borne rickettsial pathogen of cattle, was recently propagated in a continuous tick cell line, ide8, derived from embryonic ixodes scapularis say. cell monolayers were infected briefly with a high multiplicity of infection to synchronize rickettsial development and allow for description of the invasion, development, and release of a. marginale from the cultured cells. sequential samples were collected, fixed, and processed for examination with light and electro ...19989775610
cd4(+) t-lymphocyte and immunoglobulin g2 responses in calves immunized with anaplasma marginale outer membranes and protected against homologous challenge.protective immunity against the ehrlichial pathogen anaplasma marginale has been hypothesized to require induction of immunoglobulin g2 (igg2) antibody against outer membrane protein epitopes and coordinated activation of macrophages for phagocytosis and killing. in the present study, cell-mediated immune responses, including induction of igg isotype switching, were characterized in calves immunized with purified outer membranes of the florida strain of a. marginale. importantly, these calves we ...19989784551
the absence of clinical disease in cattle in communal grazing areas where farmers are changing from an intensive dipping programme to one of endemic stability to tick-borne diseases.a two-year field study was conducted in four communal grazing areas in south africa. sera were collected from young cattle (6-18 months old) in these areas during the winters of 1991 to 1993. the sera were tested for antibodies to babesia bovis, babesia bigemina, anaplasma marginale and cowdria ruminantium. in two of the four areas, treatment with acaricide was erratic and dependent on the discretion of individual owners. in these areas the drought of 1992 had a major impact on tick burdens and ...19989809321
persistence of anaplasma ovis infection and conservation of the msp-2 and msp-3 multigene families within the genus anaplasma.goats which have recovered from acute anaplasma ovis infection remain seropositive, although infected erythrocytes cannot be detected by microscopic examination. persistence of a. ovis 17 to 21 months following experimental infection was demonstrated by pcr detection of the msp-5 gene. quantitative analysis of persistent rickettsemia over time showed that all levels were below the limit of microscopic detection and ranged from a low of 10(2) organisms/ml to peaks of 10(6) organisms/ml. two patte ...19989826393
protozoal parasites in tick species infesting camels in sinai peninsula.a faunistic survey of ticks infesting camels was carried out in 7 localities of sinai; el-arish, beer el abd, nakhel, ain mousa, st. catherine, wadi hadra, and dahab. the protozoal organisms present in the gut and haemolymph of the collected tick species were investigated. results revealed the presence of six species of tick infesting camels, hyalomma dromedarii, h. impeltatum, h. an. excavatum, h. an. anatolicum, h. marginatum and h. schulzei. the first 3 species were most common, whereas the l ...19989914699
restriction of major surface protein 2 (msp2) variants during tick transmission of the ehrlichia anaplasma marginale.anaplasma marginale is an ehrlichial pathogen of cattle that establishes lifelong persistent infection. persistence is characterized by rickettsemic cycles in which new a. marginale variant types, defined by the sequence of the expressed msp2 transcripts, emerge. the polymorphic msp2 transcripts encode structurally distinct msp2 proteins and result in an antigenically diverse and continually changing a. marginale population within the blood. in this manuscript, we used sequence analysis of msp2 ...199910077656
upregulation of interleukin-4 and ifn-gamma expression by ifn-tau, a member of the type i ifn family.trophoblast interferon-tau (ifn-tau) is a new member of the type i ifn family that is produced in large quantities by the ruminant conceptus. like other type i ifn, ifn-tau inhibits viral replication and activates natural killer (nk)-mediated cytotoxicity. in mice and humans, type i ifn enhances type 1 t helper (th) cell responses, but the effects of type i ifn, including ifn-tau, on cytokine expression by bovine th cells have not been described. the present study determined the effects of ifn-t ...199910090403
the efficacy of used engine oil against ticks on cattle.the study was conducted in a peri-urban agricultural system at botshabelo, a city in the south-eastern free state. a questionnaire survey revealed that 88.5% of cattle farmers in the area experienced problems related to ticks and tick-borne diseases. because of the cost of commercial acaricides the botshabelo farmers use alternative, cheaper methods of tick control, including the application of used engine oil. the specific aim of the study was to determine whether used engine oil can effectivel ...199810192839
epidemiology of tick-borne diseases of cattle in botshabelo and thaba nchu in the free state province.a seroepidemiological study was conducted on 151 cattle from the botshabelo and thaba nchu areas in the central free state province of south africa, two areas where small scale, peri-urban cattle farming is practised. an indirect fluorescent antibody test was used to test for babesia bigemina and b. bovis antibodies. to test for anaplasma marginale antibodies a competitive inhibition enzyme-linked immunosorbent assay method was used. there were no significant differences in serological test resu ...199810192841
infections of granulocytic ehrlichiae and borrelia burgdorferi in white-tailed deer in connecticut.serum or whole blood samples, obtained from 141 white-tailed deer (odocoileus virginianus) in connecticut (usa) during 1980, 1991, and 1996, were analyzed to detect past or current infections of ehrlichia phagocytophila genogroup organisms and borrelia burgdorferi. when the bds or nch-1 strains of granulocytic ehrlichiae were used separately in indirect fluorescent antibody (ifa) staining methods, antibody positivity rates varied from 25 to 64% in 1991 and 1996, respectively. all 50 sera tested ...199910231753
simultaneous detection of bovine theileria and babesia species by reverse line blot hybridization.a reverse line blot (rlb) assay was developed for the identification of cattle carrying different species of theileria and babesia simultaneously. we included theileria annulata, t. parva, t. mutans, t. taurotragi, and t. velifera in the assay, as well as parasites belonging to the t. sergenti-t. buffeli-t. orientalis group. the babesia species included were babesia bovis, b. bigemina, and b. divergens. the assay employs one set of primers for specific amplification of the rrna gene v4 hypervari ...199910325324
comparison of a competitive inhibition elisa and the card agglutination test for detection of antibodies to anaplasma marginale and anaplasma centrale in cattle.to compare a recently developed recombinant msp-5 competitive inhibition elisa with a card agglutination test for detection of antibodies to anaplasma marginale and anaplasma centrale in australian cattle.199910330556
dermacentor hunteri (acari: ixodidae): an experimental vector of anaplasma marginale and a. ovis (rickettsiales: anaplasmataceae) to calves and sheep.the experimental vector competence of laboratory-reared dermacentor hunteri bishopp for anaplasma marginale theiler and anaplasma ovis lestoquard was evaluated by delayed transfer of male ticks from infected to susceptible holstein calves and from infected to susceptible domestic sheep, respectively. after feeding for 4 or 5 d on rickettsemic acquisition hosts, the ticks were held off the host at 26 degrees c, approximately 93% rh, and a photoperiod of 14:10 (l:d) h for 7 or 8 d, then test fed f ...199910337102
biased immunoglobulin g1 isotype responses induced in cattle with dna expressing msp1a of anaplasma marginale.immunization with the native major surface protein 1 (msp1) (a heterodimer containing disulfide and noncovalently bonded polypeptides designated msp1a and msp1b) of the erythrocytic stage of anaplasma marginale conferred protection against homologous challenge (g. h. palmer, a. f. barbet, w. c. davis, and t. c. mcguire, science 231:1299-1302, 1986). the msp1a polypeptide possesses a conserved neutralization-sensitive epitope. in the present study, the immune response to dna-mediated immunization ...199910377129
molecular basis for vaccine development against the ehrlichial pathogen anaplasma marginale.anaplasma marginale is a tick-transmitted ehrlichial pathogen causing severe morbidity and mortality in livestock on six continents. development of safe effective vaccines would be greatly facilitated by identification of the protective immune mechanisms and by understanding how the pathogen evades immune effectors to establish persistent infection. in this article, guy palmer and colleagues review recent progress in identifying how defined epitopes induce protective immunity and the role of ant ...199910377531
vaccine strategies for cowdria ruminantium infections and their application to other ehrlichial infections.suman mahan and co-authors review the strategies applied to develop improved vaccines for cowdria ruminantium infections (heartwater). inactivated vaccines using cell-cultured c. ruminantium organisms combined with an adjuvant are capable of protecting goats, sheep and cattle against lethal c. ruminantium challenge. immune responses induced with this vaccine, or after recovery from infection, target outer membrane proteins of c. ruminantium, in particular the major antigenic protein 1 (map-1). g ...199910377533
pyruvate metabolism by anaplasma marginale in cell-free culture.partially purified anaplasma marginale initial bodies were cultivated in a cell-free system in the presence of [3-14c]pyruvate for 24 or 48 h. experiments showed that a significant portion of the pyruvate supplied to the cultures was incorporated into initial body components. label incorporation was reduced by 72% in the presence of oxytetracycline. fractionation and chromatography of the organisms revealed radioactive incorporation as alanine. this is the first report of de novo amino acid synt ...199910380651
emergence of anaplasma marginale antigenic variants during persistent rickettsemia.anaplasma marginale is an ehrlichial pathogen of cattle, in the order rickettsiales, that establishes persistent cyclic rickettsemia in the infected host. within each rickettsemic cycle, a. marginale expressing antigenically variant major surface protein 2 (msp2) emerge. by cloning 17 full-length msp2 transcripts expressed during cyclic rickettsemia, we determined that emergent variants have a single, central hypervariable region encoding variant b-cell epitopes. the n- and c-terminal regions ar ...199910531237
serosurvey for selected disease agents in white-tailed deer from mexico.serum samples from 350 white-tailed deer (odocoileus virginianus texanus) collected in march 1994 from northeastern mexico were tested for the prevalence of antibody activity against five infectious diseases of ruminants. the prevalence rate was 81% for bluetongue virus (btv) of all serotypes, 72% for epizootic hemorrhagic disease virus (ehdv), 3% for borrelia burgdorferi, 69% for anaplasma marginale, and 0% for brucella abortus, b. melitensis, and b. ovis. these are diseases that affect domesti ...199910574545
interleukin-12 as an adjuvant promotes immunoglobulin g and type 1 cytokine recall responses to major surface protein 2 of the ehrlichial pathogen anaplasma marginale.anaplasma marginale is a tick-transmitted pathogen of cattle closely related to the human ehrlichiae, ehrlichia chaffeensis and the agent of human granulocytic ehrlichiosis (hge). these pathogens have in common a structurally conserved outer membrane protein (omp) designated the major surface protein 2 (msp-2) in a. marginale and hge and omp-1 in e. chaffeensis. protective immunity against ehrlichial pathogens is believed to require induction of gamma interferon (ifn-gamma) and opsonizing immuno ...200010603398
prevalence of blood parasites among cattle at the central area of saudi arabia.the present study aimed to investigate the parasites infecting cattle blood at al-qassim region. examination of 307 blood samples revealed that 235 (76.5%) and 3 (0.98%) of cattle were infected with theileria annulata and anaplasma marginale, respectively. t. annulata was the prevalent blood parasite among cattle while a. marginale was scarcely encountered. the monthly incidence of t. annulata ranged from 38.5% in march to 94.7% in october. also, the infection rate reached a maximum (84.3%) in b ...200010622615
effect of breed of cattle on innate resistance to infection with anaplasma marginale transmitted by boophilus microplus.to assess the innate resistance of and transmission in naive bos taurus cross bos indicus and purebred bos indicus cattle when placed in a paddock with cattle infected with anaplasma marginale and carrying boophilus microplus ticks.199910685172
expression of polymorphic msp1beta genes during acute anaplasma marginale rickettsemia.immunization of cattle with native msp1 induces protection against anaplasma marginale. the native immunogen is composed of a single msp1a protein and multiple, undefined msp1b polypeptides. in addition to the originally sequenced gene, designated msp1beta(f1), we identified three complete msp1beta genes in the florida strain: msp1beta(f2), msp1beta(f3), and msp1beta(f4). each of these polymorphic genes encodes a structurally unique msp1b protein, and unique transcripts can be identified during ...200010722587
molecular detection of pathogen dna in ticks (acari: ixodidae): a review.ticks play an important role in human and veterinary medicine, in particular due to their ability to transmit a wide spectrum of pathogenic micro-organisms of protozoal, rickettsial, bacterial and viral origin. pathogens in ticks can be identified by conventional methods such as indirect immunofluorescence, isolation in cell culture or by using histological staining techniques. however, the advent of the polymerase chain reaction (pcr) has resulted in tremendous improvements in the specific and ...199910737729
antigenic variation in the persistence and transmission of the ehrlichia anaplasma marginale.tick-borne transmission of ehrlichial pathogens requires rickettsemic reservoir hosts to maintain a population of infected vectors. persistence in their respective mammalian hosts appears to be a common feature of the tick-transmitted ehrlichiae. how infection persists in immunocompetent hosts is unknown. in this review, we describe studies on anaplasma marginale, an ehrlichial pathogen of cattle, that support antigenic variation as a primary mechanism of persistence.200010742689
sequence and expression analysis of a surface antigen gene family of the rickettsia anaplasma marginale.the tick-borne rickettsial organism, anaplasma marginale, causes a disease in cattle of world-wide economic significance. this disease, anaplasmosis, is characterized by severe hemolytic anemia, high levels of rickettsemia and, often, death in animals over 3years of age. animals that survive acute infection remain carriers, with continuous sub-microscopic cycles of rickettsemia that can persist for the lifetime of the animal. in the search for potential recombinant immunogens, it was discovered ...200010925201
antigenic variation in vector-borne pathogens.several pathogens of humans and domestic animals depend on hematophagous arthropods to transmit them from one vertebrate reservoir host to another and maintain them in an environment. these pathogens use antigenic variation to prolong their circulation in the blood and thus increase the likelihood of transmission. by convergent evolution, bacterial and protozoal vector-borne pathogens have acquired similar genetic mechanisms for successful antigenic variation. borrelia spp. and anaplasma margina ...200010998374
risk of babesiosis and anaplasmosis in different ecological zones of santa cruz department, bolivia.a cross-sectional study was done of seroprevalence of babesia bigemina, b.bovis, and anaplasma marginale in cattle from eastern bolivia, to characterise the risk of tick-borne disease in three ecological zones. nineteen farms were sampled in the subtropical humid zone, 13 in the dry subtropical zone and nine in the lower western valleys of the andean massif. the enzyme-linked immunosorbent assay was used. all three pathogens were widespread. for b. bovis, seroprevalences were high (75-78%) in th ...200011027858
evaluation of a commercially available elisa kit for detection of antibodies to anaplasma marginale and anaplasma centrale in cattle in australia and zimbabwe.a newly available competitive inhibition elisa kit for the serological diagnosis of anaplasmosis was evaluated in australia and zimbabwe. in australia the performance of the test was compared with the card agglutination test (cat). the assay was evaluated using negative sera collected from anaplasma-free herds, positive sera from experimentally infected cattle and sera from anaplasma marginale-endemic herds. the sensitivity and specificity of the elisa in australia were 100 % and 83,3 %, respect ...200011028743
antigenic variation of anaplasma marginale by expression of msp2 mosaics.anaplasma marginale is a tick-borne pathogen, one of several closely related ehrlichial organisms that cause disease in animals and humans. these ehrlichia species have complex life cycles that require, in addition to replication and development within the tick vector, evasion of the immune system in order to persist in the mammalian reservoir host. this complexity requires efficient use of the small ehrlichial genome. a. marginale and related ehrlichiae express immunoprotective, variable outer ...200011035716
anaplasma marginale inactivated vaccine: dose titration against a homologous challenge.the present study was performed to dose-titrate an anaplasma marginale experimental immunogen derived from partially purified initial bodies from three geographically different mexican strains. three five-bovine groups were inoculated twice on days zero and 21 with a. marginale initial bodies equivalent to 1.5 x 10(10) (group i), 3 x 10(10) (group ii) or 6 x 10(10) (group iii) infected erythrocytes mixed with stdcm adjuvant. a similar group served as non-vaccinated controls. all four groups were ...200011038126
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 ...199911071535
livestock production and animal health in sicily, italy.in sicily, as in other mediterranean areas, livestock represents one of the most important resources for the island economy. this sector involves more than 16,000 farms of cattle and 10,000 farms of sheep and goats (respectively 6% and 15% of national production) which are actually increasing their number. most livestock in sicily is owned by small holders and pastoralists. regional production of milk feeds some industries, which involve a large and increasing occupational area. due to its pecul ...199911071536
tick-borne diseases of livestock in italy: general review and results of recent studies carried out in the apulia region.this paper reviews basic information on the knowledge of tick-borne diseases, babesiosis, anaplasmosis and theileriosis, in horses, cattle, sheep and goats in italy with particular reference to the southern part of the country. it is stressed that there is limited knowledge about the parasite species present, their vectors, distribution, prevalence and impact on livestock production and there is the need to assess their epidemiology. a study carried out in the apulia region to assess the prevale ...199911071537
identification of theileria buffeli/orientalis and babesia bigemina in apulian cattle using molecular techniques and study of changes in blood parameters.recently several cases of theileriosis due to the haemoprotozoan theileria buffeli/orientalis have been recorded in the apulian region, italy. in this area other tick-borne pathogens were usually identified such as anaplasma marginale and babesia bigemina. outbreaks were recorded showing that these pathogens can be observed separately or in mixed infections. sub-clinical cases and carrier animals were also previously identified. a lack of specific techniques could not rule out the presence of ot ...199911071538
development of sero-diagnostic and molecular tools for the control of important tick-borne pathogens of cattle in africa.tick-borne diseases (tbds) are a major economic constraint to livestock production in sub-saharan africa. ilri is focussing on developing a range of products, such as vaccines, diagnostics and decision support services to underpin improved control programmes against these diseases. we have developed three highly sensitive and specific enzyme linked immuno-assays (elisas), which allow precise diagnosis of theileria parva, babesia bigemina and anaplasma marginale. these tests have been standardise ...199911071549
cattle and small ruminant piroplasmosis in macedonia, greece.macedonia is an endemic region of cattle as well as of sheep and goat piroplasmosis in cattle, theileria orientalis (=t. buffeli?), the agent of eurasian benign theileriosis, is the most common and widespread piroplasm species. t. annulata, the agent of tropical theileriosis, seems to be rare and limited to few foci, but causes very severe clinical cases, especially in imported pure-bred or cross-bred animals. babesia bovis and b. bigemina are present in several localities, and often coexist. ca ...199911071550
antigenic analysis of anaplasma marginale grown in bovine erythrocytes co-cultured with bovine endothelial cells.two monoclonal antibodies (mabs) for a. marginale were used to test the antigenic integrity of a. marginale grown in vitro in bovine erythrocytes co-cultured with endothelial cells. both the mabs reacted in the indirect immunofluorescent antibody test with a. marginale grown in vitro and also detected the antigens in western immunoblots of sds-page separated antigens made from a. marginale infected erythrocytes from the cultures. furthermore, active replication was evident as [35s]-methionine is ...200011078951
highly conserved regions of the immunodominant major surface protein 2 of the genogroup ii ehrlichial pathogen anaplasma marginale are rich in naturally derived cd4+ t lymphocyte epitopes that elicit strong recall responses.genogroup ii ehrlichia, including the agent of human granulocytic ehrlichiosis, ehrlichia phagocytophila, and the bovine pathogen anaplasma marginale, express a markedly immunodominant outer membrane protein designated major surface protein 2 (msp2). msp2 is encoded by a multigene family, resulting in the expression of variant b cell epitopes. msp2 variants are sequentially expressed in the repeated cycles of rickettsemia that characterize persistent a. marginale infection and control of each ri ...200111145692
strain composition of the ehrlichia anaplasma marginale within persistently infected cattle, a mammalian reservoir for tick transmission.tick-borne ehrlichial pathogens of animals and humans require a mammalian reservoir of infection from which ticks acquire the organism for subsequent transmission. in the present study, we examined the strain structure of anaplasma marginale, a genogroup ii ehrlichial pathogen, in both an acute outbreak and in persistently infected cattle that serve as a reservoir for tick transmission. using the msp1alpha genotype as a stable strain marker, only a single genotype was detected in a disease outbr ...200111158120
culture-derived parasites in vaccination of cattle against tick-borne diseases.the major economically important tick-borne diseases of cattle are theileriosis, babesiosis, anaplasmosis, and cowdriosis. culture-derived attenuated schizonts of theileria annulata have proved to be safe for all types of cattle and they protect against tick-borne theileriosis. t. parva was also successfully grown in vitro; however, inoculation of cattle with allogeneic schizont-infected cells resulted in rejection and destruction of the parasites together with the host cells. the number of schi ...200011193616
anaplasmosis control and diagnosis in south africa.anaplasmosis is widespread in south africa with more than 99% of the total cattle population at risk. five tick species have been experimentally shown to be capable of transmitting anaplasma in south africa. mechanical transmission through blood contaminated instruments and biting flies also occurs. vaccination against anaplasma marginale by administration of an anaplasma centrale live-blood vaccine has been practiced in this country since 1912. although generally a mild pathogen, anaplasma cent ...200011193662
integrated molecular diagnosis of theileria and babesia species of cattle in italy.a reverse line blot hybridization (rlb) test was developed to specifically identify six theileria spp. (t. annulata, t. parva, t. mutans, t. velifera, t. taurotragi, and t. buffeli/orientalis) and three babesia spp. (b. bovis, b. bigemina, and b. divergens). no cross reaction was observed with other livestock pathogens (such as anaplasma marginale, a. centrale, a. ovis, cowdria ruminantium, trypanosoma brucei, t. congolense, and t. vivax). this method was used to test bovine blood samples collec ...200011193668
attenuated trivalent vaccine against babesiosis and anaplasmosis in colombia. 200011193685
homologous and heterologous immune reactions between venezuelan geographic isolates of anaplasma marginale. 200011193694
analysis of the 16s rrna gene sequence of anaplasma centrale and its phylogenetic relatedness to other ehrlichiae.the nucleotide sequence of the anaplasma centrale 16s rrna gene was determined and compared with the sequences of ehrlichial bacteria. the sequence of a. centrale was closely related to anaplasma marginale by both level-of-similarity (98.08% identical) and distance analysis. a species-specific pcr was developed based upon the alignment data. the pcr can detect a. centrale dna extracted from 10 infected bovine red blood cells in a reaction mixture. a. centrale dna was amplified in the reaction, b ...200111238202
identification of antigenic differences that discriminate between cattle vaccinated with anaplasma centrale and cattle naturally infected with anaplasma marginale.monoclonal antibodies were raised against the vaccine strain of anaplasma centrale used in australia. a monoclonal antibody that reacted with an 80 kda antigen was used to develop an a. centrale-specific fluorescent antibody test that will be useful for confirming species identity in patent infections. another monoclonal antibody that reacted with a 116 kda antigen was used to develop an a. centrale-specific competitive inhibition enzyme-linked immunosorbent assay (elisa) for the serological ide ...200111239938
efficient use of a small genome to generate antigenic diversity in tick-borne ehrlichial pathogens.ehrlichiae are responsible for important tick-transmitted diseases, including anaplasmosis, the most prevalent tick-borne infection of livestock worldwide, and the emerging human diseases monocytic and granulocytic ehrlichiosis. antigenic variation of major surface proteins is a key feature of these pathogens that allows persistence in the mammalian host, a requisite for subsequent tick transmission. in anaplasma marginale pseudogenes for two antigenically variable gene families, msp2 and msp3, ...200111274438
[molecular tools in the epidemiology of tick-borne bacterial diseases].molecular tools have been used to detect rickettsiae in ticks. in ixodes ricinus ticks collected in france, we detected for the first time there an emerging pathogen, rickettsia helvetica, and an ehrlichia sp, closely related to the agent of human granulocytic ehrlichiosis. in guadeloupe (french west indies), we described the occurrence of african tick-bite fever due to rickettsia africae, which had been previously reported in sub-saharan africa only. in africa, we completed our knowledge about ...200111282521
antigenic variation of anaplasma marginale: major surface protein 2 diversity during cyclic transmission between ticks and cattle.the rickettsial pathogen anaplasma marginale expresses a variable immunodominant outer membrane protein, major surface protein 2 (msp2), involved in antigenic variation and long-term persistence of the organism in carrier animals. msp2 contains a central hypervariable region of about 100 amino acids that encodes immunogenic b-cell epitopes that induce variant-specific antibodies during infection. previously, we have shown that msp2 is encoded on a polycistronic mrna transcript in erythrocyte sta ...200111292724
use of repetitive dna elements to define genetic relationships among anaplasma marginale isolates.anaplasma marginale genomic dna was tested for the presence of repetitive extragenic palindromic (rep) and enterobacterial repetitive intergenic consensus (eric)-like sequences in order to evaluate the genetic diversity of multiple a. marginale isolates. a. marginale isolates were obtained from cattle of six different states of brazil, from the us and an anaplasma centrale strain was obtained from uruguay. patterns obtained from a. marginale isolates varied from 14 to 17 fragments by rep-polymer ...200111313126
phylogenetic relationships of anaplasma marginale and 'ehrlichia platys' to other ehrlichia species determined by groel amino acid sequences.the heat-shock protein (groel) genes of anaplasma marginale, ehrlichia muris and 'ehrlichia platys' were sequenced and compared with the groel of other species of ehrlichia. the groel amino acid sequences of a. marginale and 'e. platys' were most similar to the groel sequence of ehrlichia phagocytophila, with which they formed one group with 6-10% divergence. the e. muris groel was most closely related to the groel of two unclassified strains (hf-565 and anan), then to ehrlichia chaffeensis, ehr ...200111414267
health protocol for translocation of free-ranging elk.when considering an elk (cervus elaphus) restoration program, wildlife managers must evaluate the positive and negative elements of translocation. we prepared this protocol to give an overview of health considerations associated with translocation of elk, with an emphasis on movement of free-ranging elk from western north america to the southeastern usa. we evaluated infectious agents and ectoparasites reported in elk from two perspectives. first, we made a qualitative estimate of the ability of ...200111504216
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 ...200111511414
expression and immune recognition of the conserved msp4 outer membrane protein of anaplasma marginale.defining conserved, protective epitopes is essential to the design of an effective vaccine against bovine anaplasmosis. msp4, one of six initial body proteins recognized by a neutralizing serum, is conserved among anaplasma marginale isolates at both the protein and the dna levels. sera from cattle immunized with an outer membrane fraction of a. marginale and protected from a virulent challenge bind msp4. the gene for msp4 has been cloned, and the recombinant protein has been expressed, isolated ...19937693596
[toxinology of bovine paraplegic syndrome].a clinical entity named "bovine paraplegic syndrome" ("síndrome parapléjico de los bovinos") has spread alarmingly, in the cattle growing areas of the central and eastern plains of venezuela. approximately four million cattle are bread in the area were the disease occurs. the mortality index due to the disease ranges 5 to 25% of the animals at risk, mostly cows, pregnant or lactating. the principal characteristic of the bovine paraplegic syndrome is decubitus, ventral or sternal, in animals that ...19938085407
antigen profiles of anaplasma ovis and a. mesaeterum and cross infection trials with them and a. marginale.antigen profiles of anaplasma ovis and a. mesaeterum were analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting, and cross infection trials were performed by a. ovis challenge to a. mesaeterum- or a. marginale-inoculated goats and a. marginale challenge to an a. ovis-inoculated calf. antigen analysis showed unique and common proteins of a. ovis and a. mesaeterum and identified a major 38 kda protein to be a dominant immunogen bearing two epitopes common to anap ...19938296449
detection of anaplasma marginale (rickettsiales: anaplasmataceae) in hemolymph of dermacentor andersoni (acari: ixodidae) with the polymerase chain reaction.the polymerase chain reaction (pcr) was used to detect anaplasma marginale in hemolymph collected from live dermacentor andersoni stiles ticks. hemolymph was collected from severed legs of male and female ticks exposed to a. marginale as either nymphs or adults. heat treatment was found to be the optimum method of hemolymph preparation for pcr. hemolymph samples were collected and pooled from adult ticks exposed as nymphs on days 0-10 of feeding on a susceptible calf. for male and female ticks e ...19938360902
detection of anaplasma marginale (rickettsiales: anaplasmataceae) in secretagogue-induced oral secretions of dermacentor andersoni (acari: ixodidae) with the polymerase chain reaction.the polymerase chain reaction (pcr) was used to detect anaplasma marginale in secretagogue-induced oral secretions of male and female dermacentor andersoni stiles exposed as nymphs or adults by feeding on infected calves. a 409-bp dna fragment derived from the a. marginale (florida isolate) msp1 beta gene was amplified with oligonucleotide primers bap-2 (5'-gtatggcacgtagtcttgggatca-3') and al34s (5'-cagcagcagcaagaccttca-3'). the target dna was amplified in oral secretions of female ticks exposed ...19938360903
advances in the diagnosis of some parasitic diseases by monoclonal antibody-based enzyme-linked immunosorbent assays.advances in diagnostic assays for parasitic diseases include the use of monoclonal antibodies (mabs) in antigen capture and competitive inhibition enzyme-linked immunosorbent assays (c-elisa). antigen capture elisas for anaplasma marginale and cryptosporidium parvum provide direct detection of these parasites during clinical disease, and the c-elisa format has been adapted for detection of anti-babesia equi, anti-a. marginale and anti-bluetongue virus antibodies. false-positive results may occur ...19938400383
cross-reactive, stage-specific antigens in the oestridae family.the larval stages of different economically important oestridae species were studied for their antigenicity and cross reactivity, using elisa and immunoblotting. the immune sera of cattle from algeria, belgium, france and switzerland were compared for their capacity to recognize the stage-specific antigens of their specific parasites hypoderma bovis and h lineatum, originating from different populations. this comparison was extended to other hypoderminae species responsible for economic losses i ...19968822621
variations in seroprevalence and host factors for bovine anaplasmosis in illinois.the modified card agglutination test (mcat) was used to detect antibodies to anaplasma marginale in 4994 samples collected from market cattle through the brucellosis eradication program in illinois. the mcat reactor rate in the sample was 6.4%. the statewide prevalence estimate increased to between 7.1% and 10.7% when corrected for sampling distribution and test sensitivity and specificity. while the sample reactor rate measures the proportion of infected cattle moving through the market system ...19979060138
increased resistance to anaplasma marginale infection in cattle chronically infected with theileria buffeli (syn. t. orientalis).calves chronically infected with the benign haemoprotozoan parasite theileria buffeli (syn. t. orientalis) and t. buffeli-free calves were experimentally infected with virulent anaplasma marginale. the daily mean maximum parasitaemia in the t. buffeli-carrier calves was lower and delayed relative to that of the theileria-free calves. anaemia was less marked in the theileria infected calves, although this difference was not statistically significant. the susceptibility of theileria-carrier and th ...19979195728
an unidentified species of theileria infective for cattle discovered in china.infection experiments, morphological observations and transmission experiments were conducted with an unidentified theileria sp. isolated from a naturally infected ox. the results showed that the protozoa could multiply extensively in a splenectomized ox and the parasitaemia could reach 52.69%. the theileria sp. was polymorphic: being pear-shaped, circular, elliptical, rod-like, comma-shaped, three-leafed- or cross-shaped and having many other irregular-shapes which were seldom detected. in eryt ...19979512745
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