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babesia bovis: attachment of infected erythrocytes to heparin-sepharose columns. 19836827443
the detection of babesiosis in bovines by the indirect immunofluorescent antibody test compared to the prevalence of babesia bovis in cerebral smears. 19836344958
babesia bovis: isolation of a protective antigen by using monoclonal antibodies.three distinct monoclonal antibody-producing hybridomas have been produced against a partly purified protective fraction of babesia bovis. all three stain the parasite or infected erythrocytes or both in precise and different manners when fluorescent-antibody techniques are used. the relevant antigens for each monoclonal antibody were isolated by immunoadsorption, their native molecular weights being 1.3 x 10(6), 180 x 10(3), and 44 x 10(3). each antigen reacted in serological assays with homolo ...19836345394
babesia bovis: comparison of culture-derived parasites, non-living antigen and conventional vaccine in the protection of cattle against heterologous challenge.twenty bos taurus cattle were vaccinated with either live commercial babesia bovis vaccine, live parasites from in vitro culture or non-living supernatant antigen (nlsa) derived from in vitro culture and combined with the adjuvant saponin. heterologous strain challenge 10 weeks later indicated that cattle vaccinated with live parasites from either source were strongly protected, those given 2 doses of nlsa 2 weeks apart were partially protected, and those given one dose of nlsa were poorly prote ...19836347164
babesia bovis: computer simulation of the relationship between the tick vector, parasite, and bovine host.components contributing to the survival of babesia bovis in its tick vector (boophilus microplus) and bovine host were identified and their relationship simulated with an interactive basic computer program. estimates for major independent variables (host-finding success, feeding success, filial infection rate, recovery rate) were derived from published laboratory and field data. values for dependent variables (tick burden, inoculation rate, tick and bovine infection rates) were calculated during ...19836873224
cell culture-derived babesia bovis vaccine: sequential challenge exposure of protective immunity during a 6-month postvaccination period.cell culture-derived soluble babesia bovis vaccine admixed with a saponin adjuvant was administered in 2 doses, 3 weeks between doses, to 18 yearling heifers. an additional 9 heifers served as nonvaccinated controls. comparable groups of these animals were challenge exposed at 131 and 178 days after vaccination, using 1 x 10(8) b bovis organisms contained in freshly collected blood from a splenectomized calf with ascending parasitemia. challenge exposure led to no deaths of vaccinated animals, w ...19836354014
babesial antigens in a saline eluate of sucrose washed bovine erythrocytes infected with babesia bovis.a saline eluate from sucrose washed bovine erythrocytes infected with babesia bovis contains at least 4 babesial antigens. the antigens are located not only in the parasite but also in the internal matrix of the infected erythrocyte.19836360707
babesia bovis: proteins of virulent and avirulent parasites passaged through ticks and splenectomized or intact calves.passage of the avirulent vaccine (k) strain of babesia bovis (ka) through either boophilus microplus ticks, intact calves, or intact calves and then ticks, resulted in two distinct protein and protein antigen profiles as analyzed by two-dimensional gel electrophoresis of biosynthetically labeled proteins and immunoprecipitates. different degrees of expression of two major acidic antigens of ka designated ka1 (mr 47,500) and ka2 (mr 43,000) were observed. ka1 was apparently lost following passage ...19836617805
localization of culture-derived soluble babesia bovis antigens in the infected erythrocyte.immunoprecipitates derived from crossed immunoelectrophoresis of babesia bovis culture supernatant fluid against a polyspecific anti-b. bovis serum were used to produce monospecific rabbit antibodies to individual b. bovis antigens. these antibodies were utilized in an immunofluorescence test to identify the location of the respective antigens within the infected erythrocyte. two antigens were found on or near the erythrocyte membrane, while a third antigen was directly associated with the paras ...19836362173
hypocholesterolemia and hypocortisolemia in acute and terminal babesia bovis infections.sera from babesia bovis-infected cross-bred cows and purebred steers were evaluated throughout the course of acute babesia bovis infection for cholesterol and cortisol concentrations. cholesterol and cortisol values of surviving cattle became markedly reduced (less than 50% of normal values) during the acute phase of the disease, days 10-15 postinoculation, and returned to essentially normal values by the end of the 35 day experimental period. the combined control group values were approximately ...19836683035
the lysate from bovine erythrocytes infected with babesia bovis. analysis of antigens and a report on their immunogenicity when polymerized with glutaraldehyde.a group of babesia bovis antigens obtained by a lengthy biochemical procedure involving disruption of infected erythrocytes has previously been shown to be highly protective. this study shows that these antigens can be found in a simple lysate of infected erythrocytes. the antigens have been characterized by gel filtration and nitrocellulose transfer and consist of a wide spectrum of molecular sizes. some of the antigens exist in complex form and are easily dissociated. the lysate was polymerize ...19836414195
serological response of cattle to infection with babesia bigemina and babesia bovis in southern africa.the indirect fluorescent antibody test was used to measure the antibody response of cattle for 8 weeks after infection with either babesia bigemina or babesia bovis, or a combination of both species. serological cross-reactions were observed between the 2 species, but these were most marked when b. bigemina antigen was used. in animals infected with both babesia spp., the b. bigemina reaction appeared to suppress the b. bovis reaction.19836634084
the characterisation of an esterase derived from babesia bovis and its use as a vaccine.an esterase was isolated from a crude extract of babesia bovis by affinity chromatography, using soy bean trypsin inhibitor as a ligand. in native form this enzyme had a molecular weight greater than 200 000, but on denaturing gels major bands were observed with molecular weights of 20 000, 10 000 and 7 000. western transfer analysis revealed a major band with a molecular weight of 19 000-20 000. both bovine and rabbit antisera avidly stained infected red cells, using indirect immunofluorescence ...19836419487
babesia bovis: vaccination of cattle against heterologous challenge with fractions of lysate from infected erythrocytes.the distilled water lysate of erythrocytes infected with babesia bovis was separated by gel filtration on sephadex g200. the void volume fraction or a pool of retained fractions which had immunodiffusion activity were injected into two groups of five cattle. these were challenged 2 weeks after the final vaccination with a heterologous strain of b. bovis. a control group of five cattle was similarly challenged. two of the five control animals died from the challenge, whereas none of the vaccinate ...19846429962
protein phosphorylation by intact babesia bovis.babesia bovis rapidly incorporated [32p]orthophosphate into more than 30 polypeptide chains, the majority of which appeared to be membrane or particle bound. phosphorylation occurred more rapidly in free parasites than in parasitized erythrocytes, suggesting the acceptor polypeptides were either babesial in origin or erythrocyte proteins were intimately associated with the parasite. some characteristics of the phosphorylation system are described. the phosphorylation was little affected by dibut ...19846482904
dna polymorphisms and subpopulations in babesia bovis.independent isolates of babesia bovis differ by only a limited number of polypeptides, some of which may be important as host protective antigens. avirulent derivatives of these parasites also differ from their virulent counterparts in only a few polypeptides. to identify genes encoding such polypeptides we have isolated cdna clones corresponding to poly(a)+ rnas that are expressed only in certain isolates. for this purpose a cdna clone library was constructed from poly(a)+ rna of the k-avirulen ...19846205269
accurate transcription of a cloned gene from babesia bovis in saccharomyces cerevisiae.two cloned chromosomal segments of the hemoprotozoan babesa bovis bearing genes from the polymorphic locus designated babr were inserted into plasmid vector ycp19, cloned in escherichia coli and then introduced into saccharomyces cerevisiae. both genes were transcribed producing poly(a+) rnas. in at least one case, the transcript was very similar if not identical to that produced in b. bovis. it is therefore possible that s. cerevisiae can recognize at least some hemoprotozoan promoter and poly( ...19846205270
immune responses of cattle following vaccination with living and non-living babesia bovis antigens.twenty-four yearling hereford (bos taurus) cattle were vaccinated against babesia bovis using either live parasites or non-living antigens obtained from the supernatant of in vitro cultures. a single dose of live parasites was given subcutaneously, while the non-living supernatant antigen (nlsa) was combined with saponin and 2 doses given, 2 weeks apart. following vaccination with live parasites, serum antibodies remained at high levels for 6 months, but the lymphocyte transformation response wa ...19846542722
the role of specific immunoglobulins in antibody-dependent cell-mediated cytotoxicity assays during babesia bovis infection.a stabilate prepared from babesia bovis-infected boophilus microplus ticks was used to infect intact adult cattle. whole sera and immunoglobulin fractions from representative sera were tested by complement fixation (cf), indirect fluorescent antibody (ifa), and antibody-dependent cell-mediated cytotoxicity (adcc) assays. the last test utilized 51cr-labeled chicken erythrocytes coated with babesia bovis antigen as targets. mononuclear cell preparations, obtained from peripheral blood of normal do ...19846369760
comparison of blood smear and indirect fluorescent antibody techniques in detection of haemoparasite infections in trade cattle in nigeria.the incidence of blood parasites in trade cattle was surveyed with emphasis on tick-borne parasites, using blood smears and immunofluorescent antibody (ifa) techniques. with the blood smear method, about 9 and 8.9% of cattle examined were found positive for babesia bigemina and anaplasma marginale, respectively. percentage infections with other parasites were 3.33, 1.92, 0.75, 0.75 and 0.58, respectively, for babesia bovis, trypanosoma brucei, anaplasma centrale, eperythrozoon and theileria spec ...19846369761
an update of the isolation and characterization of culture-derived soluble antigens of babesia bovis.in this paper recent progress concerning the identification of soluble antigens from cultures of babesia bovis parasites is reviewed. soluble antigens present in the supernatant of b. bovis cultures have been shown to be efficient immunogens for induction of protective immunity against bovine babesiosis. immunochemical analysis of culture supernatants has demonstrated that at least 3 parasite antigens are released in vitro. sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that at ...19846382780
serological prevalence of bovine babesiosis in mali.a serological survey of cattle in mali was carried out to determine the prevalence of antibody activity to babesia bovis and b. bigemina. it was found that the level of b. bovis infection as indicated by antibody activities was too low to be of immediate concern. however, the serological prevalence of b. bigemina was high and this may indicate a potential disease problem. it was also found that when zebu and n'dama cattle grazed together the n'dama were twice as likely to have positive titres to ...19846385427
increased activity of bovine adcc effector cells during acute babesia bovis infection.mononuclear effector cells from the peripheral blood of babesia bovis-infected cattle responded during initial infection and destroyed fc-bearing target cells. the activity of these cells was measured in an antibody-dependent, cell-mediated cytotoxicity (adcc) assay utilizing chicken erythrocytes coated with bovine anti-chicken erythrocyte antibody as targets. the activity of these effector cells was enhanced during the parasitemic crisis and returned to normal levels of activity following the r ...19846395478
genes of the protozoan parasite babesia bovis that rearrange to produce rna species with different sequences.we describe a highly polymorphic gene family from the protozoan parasite babesia bovis that encodes a complex pattern of transcripts. gene rearrangements at this locus (designated babr ) have generated rna species that differ in sequence. the naturally occurring virulent field isolate kv expresses two different sized transcripts that are identical in sequence at their 5' ends but different at the 3' ends. an avirulent derivative of this isolate, ka, expresses not only these two transcripts but a ...19846327081
common and isolate-restricted antigens of anaplasma marginale detected with monoclonal antibodies.anaplasma marginale-infected erythrocytes were examined for the presence of maturation, isolate-restricted, and isolate-common antigens by indirect immunofluorescence with monoclonal antibodies. a panel of 18 monoclonal antibodies was used; none of the antibodies reacted with anaplasma ovis, babesia bigemina, babesia bovis, trypanosoma brucei, trypanosoma congolense, or uninfected bovine erythrocytes. antigens common to all six a. marginale isolates were detected by nine antibodies. single isola ...19846205996
oxytetracycline-induced resistance to babesia bovis infection in splenectomised calves. 19854060237
a field strain of babesia bovis apparently resistant to amicarbalide isethionate. 19853992668
structural alteration of the membrane of erythrocytes infected with babesia bovis.babesia bovis, causative agent of cattle babesiosis, induces characteristic alterations on the membrane of infected erythrocytes. elliptical protrusions measuring about 320 nm in long axis and about 160 nm in short axis appear on the membrane of infected erythrocytes, both in vitro and in vivo. freeze-fracture demonstrated alignment of intramembrane particles (imp) along the long axis of both the p and e faces of the protrusions. the number of imp on the endoplasmic face increases, but the numbe ...19853882012
mitigation of the response of friesian calves to live babesia bovis vaccine by treatment with long acting oxytetracycline.forty 11- to 13-month-old friesian calves were inoculated with live babesia bovis vaccine. twenty of the calves were treated with long acting oxytetracycline seven and 15 days after receiving the vaccine. parasites were detected in nine of the treated calves compared with all 20 of the untreated control group. treated calves were less febrile and had higher packed cell volumes than control animals. all calves from both groups developed a considerable antibody titre to b bovis. it appears that lo ...19854071930
heterologous strain immunity in bovine babesiosis using a culture-derived soluble babesia bovis immunogen.the cross-protective capacity of culture-derived soluble immunogens against heterologous babesia bovis strains from different geographical locations of latin america was examined. susceptible yearling cattle were either immunized with immunogens derived from venezuelan or mexican strains, or were administered a multi-component immunogen containing antigens of the australian, mexican and venezuelan strains. cattle were challenged with virulent b. bovis organisms of the argentinian, colombian, ecu ...19854090242
growth inhibition of babesia bovis in culture by secretions from bovine mononuclear phagocytes.bovine blood mononuclear phagocytes from babesia-free cattle were cultured in vitro. cell monolayers were treated with culture-derived soluble babesia bovis exoantigens, immune complexes, and bovine anti-b. bovis immune serum. subsequently, the monolayers were washed free of the reagents and allowed to develop further in the presence of standard culture medium. transfer of supernatant media from these cultures to those of b. bovis revealed the presence of growth-inhibiting factors. these factors ...19854055032
proteinases in the lysate of bovine erythrocytes infected with babesia bovis: initial vaccination studies. 19853905658
babesia bovis: the effect of acute inflammation and isoantibody production in the detection of babesial antigens.immunoblots of babesia bovis antigen contain dominant antigens which react not only with antisera to b. bovis but with sera from naive calves recovering from an acute inflammatory reaction. it seems likely these antigens are from the host rather than the parasite.19854076403
protective vaccination against virulent babesia bovis with a low-molecular-weight antigen.a babesia bovis low-molecular-weight antigen was purified from crude material by using affinity adsorption techniques first with a mouse monoclonal antibody and then by adsorption with normal bovine sera. the antigen was then further purified by gradient gel electrophoresis. analysis by western transfer revealed only one antigen band, with an apparent molecular mass of 29 kilodaltons. a band (12 by 0.3 by 0.6 cm) corresponding to this antigen was excised from the acrylamide gel and injected twic ...19853980077
babesia bovis: successful vaccination against homologous challenge in splenectomised calves using a fraction of haemagglutinating antigen. 19853997349
detection of babesia bovis using dna hybridization.plasmids containing inserts of babesia bovis dna were prepared and clones suitable for use in the diagnosis of b. bovis infections were isolated. dot blot hybridization with dna from these plasmids, which probably contain repetitive sequences, can detect after an overnight exposure 100 pg of b. bovis dna, which corresponds to the amount of dna present in 50 microliters of 0.01% parasitemic erythrocytes. no detectable cross-hybridization was observed with babesia microti, plasmodium falciparum, p ...19863007751
babesia bovis: vaccination trial with a dominant immunodiffusion antigen in splenectomised calves.the dominant immunodiffusion antigen of babesia bovis was prepared from the lysate of infected erythrocytes by cation exchange chromatography, gel filtration and preparative native acrylamide electrophoresis. it was seemingly free of other babesial antigens and tested as a vaccine. in vaccinated calves, compared to controls, there was a delay in parasitaemia and at times a statistically significant difference in parasite numbers. however, the vaccinates showed little difference in pathophysiolog ...19863099492
experimental babesia bovis infection in holstein calves.one intact and two splenectomized holstein calves were infected intravenously with a mexican strain of babesia bovis and killed following the onset of severe clinical disease. a light and electron microscopic study was conducted on selected tissues to examine the relationship between parasitized erythrocytes and microvascular endothelial cells. the pattern and degree of specific organ sequestration of parasitized erythrocytes was assessed and correlated to lesions. red blood cells infected with ...19863776013
evaluation of a cloned babesia bovis organism as a live immunogen.a babesia bovis isolate was cloned by in vitro cultivation and compared to the original cultured isolate for pathogenicity by animal inoculation. four yearling heifers were inoculated with cloned material and 4 with the original culture. the four animals which received the cloned babesia showed comparatively minor hematologic changes and no clinical signs. one animal died in the group that received uncloned babesia and the mean temperature increase and mean reduction in packed cell volume (pcv) ...19863564326
bovine babesiosis (babesia bovis infection) in zambia.two cases of babesia bovis, a parasite associated with the tick boophilus microplus, are reported for the first time from the central part of zambia. it is concluded that infected b. microplus ticks are occasionally introduced into central zambia by tick-infested cattle from the north-eastern part of the country where b. bovis is endemic. the spread of b. microplus in southern africa in a westward direction is discussed and related to the epidemiology of bovine babesiosis in zambia.19863727339
a microplate enzyme-linked immunosorbent assay for measuring antibody to anaplasma marginale in cattle serum.an enzyme-linked immunosorbent assay (elisa) method is described for measuring antibody against anaplasma marginale in cattle serum. this method was more sensitive and objective than a previously described elisa method for a. marginale and possible reasons for this are discussed. all 83 cattle experimentally infected with a. marginale (81) or a. centrale (2) developed demonstrable specific antibody but the serums of 98.8% of 839 cattle from cattle tick-free areas did not react by elisa; 378 seru ...19863729834
babesia bovis: increased percentage parasitized erythrocytes in cultures and assessment of growth by incorporation of [3h]hypoxanthine.babesia bovis was established in continuous in vitro erythrocyte cultures using a modification of techniques developed previously. using optimal conditions for maintaining continuous exponential growth, a threshold number of infected erythrocytes was obtained after which exponential growth ceased. however, at this level, individual parasite development continued resulting in a higher proportion of mature merozoite infected erythrocytes. additionally, the percentage parasitized erythrocytes could ...19863743714
the inability of a south african babesia bovis vaccine strain to infect boophilus microplus.a strain of babesia bovis that had been attenuated by rapid syringe passage through a series of 23 splenectomized calves was unable to infect its vector boophilus microplus. an attempt to transmit the attenuated australian babesia bigemina g strain with a south african strain of b. microplus was likewise unsuccessful. the epidemiological implication of these observations in terms of babesiosis control is discussed.19863763166
effect of imidocarb dipropionate prophylaxis on the infectivity and immunogenicity of a babesia bovis vaccine in cattle.imidocarb dipropionate (idp), a potent prophylactic drug against babesia bovis infections in cattle, was tested for its effect on the infectivity and immunogenicity of a live b. bovis vaccine marketed in australia. at the recommended prophylactic dose rate of 3 mg/kg, idp suppressed infectivity of the vaccine for at least 6 weeks. the vaccine infected all cattle inoculated either 8 weeks after treatment with 3 mg/kg, or 4 weeks after treatment with the recommended therapeutic dose of 1.2 mg/kg. ...19863767795
babesia bovis infection of secretory cells in the gut of the vector tick boophilus microplus. 19863721701
enzymatic characterization of babesia bovis.agarose gel electrophoresis was used to identify metabolic enzymes in babesia bovis and b. bigemina. glutamate dehydrogenase, lactate dehydrogenase, glucose phosphate isomerase, and hexokinase were identified in b. bovis- and b. bigemina-infected erythrocytes and b. bovis merozoite preparations. a specific electrophoretic mobility was observed for each enzyme. malate dehydrogenase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and adenylate kinase were only detected in nor ...19863795141
complement does not facilitate in vitro invasion of bovine erythrocytes by babesia bovis. 19863643020
studies on the role of complement in the in vitro invasion of bovine erythrocytes by babesia bovis. 19863659482
babesia bovis: purification and concentration of merozoites and infected bovine erythrocytes.babesia bovis merozoites, externalized by removal of infected erythrocytes from ordinary culture conditions, were completely separated from red blood cells and stroma by centrifugation in a percoll gradient. a merozoite band formed at a point corresponding to about 1.087 g/ml specific density. infected red blood cells were concentrated approximately fourfold to obtain greater than 49.0% parasitemia after centrifugation in percoll. most highly enriched fractions positioned between 1.121 and 1.123 ...19863007196
chemoprophylactic activity of imidocarb, diminazene and oxytetracycline against babesia bovis and b. bigemina.splenectomized calves treated with imidocarb, diminazene, and oxytetracycline were exposed to babesia bigemina and b. bovis stabilates at various time intervals following treatment to evaluate prophylactic efficacy. diminazene showed no residual activity against a b. bigemina challenge given 54 days after treatment. oxytetracycline appeared responsible for an increased incubation time when given 2 days prior to b. bigemina exposure. imidocarb showed marked prophylactic efficacy against both b. b ...19863739203
uptake of tritiated nucleic acid precursors by babesia bovis in vitro. 19863744669
molecular vaccines against parasites.prophylactic vaccines can be expected to be one of the major practical outputs of parasitology research. various groups within australia have pursued the vaccine objective for several years, with particular emphasis on blood-stage falciparum malaria in man, intestinal helminths of sheep and cattle, cutaneous myiasis (blowfly strike) in sheep, cysticercosis in sheep and cattle, bovine babesiosis, and cattle ticks. other vaccine programmes are concerned with giardiasis, filariasis, toxoplasmosis, ...198615462818
antigenic relationship between plasmodium falciparum and babesia bovis: reactivity with antibodies to culture-derived soluble exoantigens.antigenic similarities between plasmodium and babesia parasites of the phylum apicomplexa have been previously demonstrated primarily by the serological cross reactivity observed in the indirect fluorescent antibody (ifa) test. we have now studied the antigenic relationship between the human malaria parasite, plasmodium falciparum, and the hemoparasitic agent of cattle, babesia bovis, using rabbit monospecific antibodies produced against individual culture-derived p. falciparum polypeptides and ...19873309271
bovine babesiosis: induction of protective immunity with culture-derived babesia bovis and babesia bigemina immunogens.the comparative protective efficacy of culture-derived babesia bovis and b. bigemina immunogens against challenge exposure of susceptible crossbred cattle to heterologous strains was examined and correlated with the antigenic threshold requirements for induction of protective immunity. strong protection was observed in animals vaccinated with 10 ml-equivalent doses of soluble, b. bovis exoantigen-containing supernatant fluids. similar protective responses to b. bigemina exoantigens were evident ...19873325981
cdna clone encoding a high molecular weight antigen of babesia bovis.an expression library was constructed by inserting cdna copied from mrna of the blood stages of babesia bovis isolate ka into bacteriophage lambda gt11-amp3. an antigen-positive cdna clone detected by screening the library with antibodies from cattle vaccinated with the ka isolate was shown to encode part of a high-molecular weight polypeptide antigen of b. bovis. this molecule was a dominant immunogen and was found by immunofluorescence to be within the parasite in infected erythrocytes.19873033495
comparison of genomic, plasmid, synthetic, and combined dna probes for detecting plasmodium falciparum dna.total genomic plasmodium falciparum dna, the plasmid clone prephind, and a 21-base-long synthetic dna probe (pfr1), the sequence of which was derived from prephind, were hybridized with dna from various species of the phylum apicomplexa. the genomic probe hybridized with p. reichenowi and p. falciparum dna and significantly cross-hybridized with dna of all the other plasmodium species tested. the synthetic and plasmid probes hybridized to p. falciparum dna and at reduced levels to p. reichenowi ...19873034963
procoagulant activity of babesia bovis-infected erythrocytes. 19873656001
chronic splenitis as a possible complicating factor in calves inoculated with an attenuated redwater vaccine.in two consecutive years a total of 3810 calves were inoculated with the onderstepoort redwater live-blood vaccine, containing attenuated strains of babesia bigemina and babesia bovis. twenty calves died 8-13 days later due to b. bigemina-infection. necropsies were performed on 19 of these animals. in 11 calves the spleen was distinctly smaller than normal and its morphology was distorted, and showed changes of chronic splenitis. histological lesions in the spleens of 6 of the 11 calves are desc ...19873508205
successful homologous vaccination against babesia bovis using a heparin-binding fraction of infected erythrocytes. 19873583543
detection of culture-derived babesia bovis exoantigen using a two-site enzyme immunoassay.soluble exoantigens in the supernatants of babesia bovis cultures have been shown to be efficient immunogens against bovine babesiosis. we used a two-site enzyme immunoassay to monitor the release of these antigens during in vitro cultivation. bovine immunoglobulin g was isolated from serum of an adult cow previously immunized with culture-derived b. bovis exoantigens and challenged via needle with virulent parasites. the specific immunoglobulin g was used as a capture antibody and as an enzyme- ...19873308949
babesia bovis--analysis and vaccination trial with the cryoprecipitable immune complex.plasma samples from cattle recovering from acute babesia bovis infection contain cryoprecipitable immune complexes (ic). production of bovine and rabbit antisera to ic and subsequent serological assays indicated ic contained antigens of both babesial and erythrocytic origin. vaccination of naive cattle with ic produced low titred antibody to b. bovis but the vaccinates did not survive challenge with a heterologous strain of b. bovis.19873103316
babesia bovis: vaccination studies with three groups of high molecular weight antigens from lysate of infected erythrocytes.a void volume fraction and fractions of mean sizes 800 kdalton and 300 kdalton were isolated by gel filtration from lysate of bovine erythrocytes infected with babesia bovis. all fractions had good serological activity, as assayed by elisa and ifa. groups of four splenectomized calves were vaccinated with each fraction and then challenged, together with groups of four control calves, with a homologous strain of b. bovis. the group vaccinated with the 300 kdalton fraction showed some protection, ...19873303020
attenuation of babesia bovis by in vitro cultivation.a virulent strain of babesia bovis was adapted to grow in erythrocyte culture in the presence of equine serum and in lieu of bovine serum. four splenectomized calves inoculated with the adapted strain, 429, developed hematologic signs of infection and a low grade fever, but remained free of central nervous system (cns) signs and recovered. all of six control animals inoculated with a virulent strain reacted severely and five showed cns signs and died. the calves injected with the attenuated stra ...19873590611
bovine abortion due to prenatal babesia bovis infection. 19873606511
use of long-acting oxytetracycline in the immunisation of cattle against babesia bovis and b bigemina.forty friesian one-year-old calves were vaccinated simultaneously with live babesia bovis and b bigemina vaccines. three groups of 10 calves each were treated with two, three or four doses of 20 mg kg-1 long-acting oxytetracycline (otc/la) at six- to seven-day intervals starting from day 6 after vaccination. ten animals remained untreated. the treated calves showed considerably fewer days of patency and higher packed cell volumes than the vaccinated untreated calves. all calves developed serum a ...19873628985
babesia bovis: molecular and biological characteristics of cloned parasite lines.an in vivo limiting dilution technique was used to produce several babesia bovis cloned lines with which to study the basis of virulence and immunogenicity in this parasite. dna hybridization using a cloned dna fragment from the babr locus demonstrated that the cloned lines were a more restricted genetic population than the parent strain. biosynthetic labeling and immunoprecipitation studies indicated that the cloned lines differed from each other and from the parentals in the expression of a sm ...19873032666
ovine babesiosis: induction of a protective immune response with crude extracts of either babesia bovis or b ovis.adult sheep were vaccinated twice with crude extracts of either babesia bovis or b ovis parasites in freund's complete adjuvant, four weeks apart. three weeks later these two groups and a third susceptible group were challenged with b ovis organisms. both vaccinated groups had significantly lower parasitaemias than control animals.19873444987
protection of babesia bigemina-immune animals against subsequent challenge with virulent babesia bovis.two groups of cattle, one previously exposed to babesia bigemina and one not, were challenged with babesia bovis. the group previously infected with babesia bigemina was only mildly affected upon challenge with b. bovis, whereas four of five of the other group were severely affected. immunoblotting studies performed in both homologous and heterologous systems showed that there were polypeptides of similar molecular weight in both species, but species-specific polypeptides were demonstrated only ...19873542832
an enzyme linked immunosorbent assay to diagnose babesia bovis infection in cattle.the optimum gel filtration fraction from lysate of babesia bovis infected erythrocytes was determined for use as an antigen in an elisa to diagnose b. bovis infection in cattle. of four enzyme labels tested, horseradish peroxidase was the most suitable. the assay is both sensitive and specific in detecting antibody for 2-4 years after a single infection. false positive reactions were obtained only with some sera from some anaplasma marginale infected cattle.19873106957
the pathogenicity and immunologic relationship of a virulent and a tissue-culture-adapted babesia bovis.babesia bovis grown in tissue culture was used to inoculate 12, 2-year-old holstein steers. all 12 developed serological evidence of infection but only six had a febrile response of greater than or equal to 40 degrees c, and only one had a demonstrable b. bovis parasitemia. an average modest drop of 19% was observed in packed cell volume (pcv) during the period of reaction. all 12 steers were subsequently challenged with virulent b. bovis: seven on day 78 post inoculation (p.i.), two on day 106 ...19883285573
babesia bovis: studies of parameters influencing microvascular stasis of infected erythrocytes.bovine erythrocytes infected with babesia bovis were analysed for parameter changes known to influence rigidity and deformability of erythrocytes. marked increases in malonyldialdehyde were detected indicating that lipid peroxidation occurs during infection. consequently, increases in membrane lipid, methaemoglobin and membrane-bound haemoglobin were detected. conversely, decreases in the antioxidant vitamin e and decreases in sialic acid were also detected. the cumulative effect of these change ...19883387676
identification of babesia bovis merozoite surface antigens by using immune bovine sera and monoclonal antibodies.three babesia bovis merozoite surface proteins with relative molecular weights of 37,000, 42,000, and 60,000 were identified by indirect immunofluorescence of live merozoites and by immunoprecipitation of 125i-surface-labeled merozoite proteins with immune bovine sera and monoclonal antibodies. these proteins were clearly of parasite origin, as evidenced by immunoprecipitation of metabolically labeled [( 35s]methionine) merozoites from cultures with specific antimerozoite monoclonal antibodies. ...19883410541
prevalence of anaplasmosis and babesiosis in n'dama cattle of the gambia.sera from 184 n'dama cattle randomly selected and averaging 2-7 years of age were tested for the presence of specific antibodies to anaplasma marginale, babesia bovis and b. bigemina, using one or more serological tests including complement fixation, rapid card agglutination and indirect fluorescent antibody (ifa). tests for a. marginale and b. bovis were essentially negative. utilising the ifa test 65% of the sera tested were positive for b. bigemina. three randomly selected two-year-old n'dama ...19883281338
effects of ph, buffers and medium-storage on the growth of babesia bovis in vitro. 19883192349
radioimmunoassay for anaplasma marginale antibodies in cattle.a radioimmunoassay is described for use in the detection of anaplasma marginale antibodies in cattle sera. optimal sensitivity and specificity were obtained by using 2 antigens, an a marginale antigen and a rbc antigen (obtained before infection was established) from the same calf. in addition, sera were preabsorbed with rbc from healthy cattle and with sonicated babesia bovis. of 86 sera obtained from cattle with a marginale infection (as determined by blood smear examination or by results of s ...19883377309
identification of babesia bigemina and babesia bovis merozoite proteins with isolate- and species-common epitopes recognized by antibodies in bovine immune sera.immunoprecipitation of radiolabeled antigens with bovine antisera indicated that many babesia bigemina and babesia bovis merozoite proteins contain isolate-common epitopes, while at least 16 b. bigemina and 8 b. bovis proteins contain species-cross-reactive epitopes. one immunogenic, isolate-common, and species-specific candidate diagnostic protein from each species was identified.19882453470
failure of a recombinant babesia bovis antigen to protect cattle against heterologous strain challenge.groups of cattle were inoculated subcutaneously with (i) a recombinant dna-derived babesia bovis protein (kabbl-gz) fused to beta-galactosidase and combined with adjuvants, or (ii) native beta-galactosidase (gz) plus adjuvant, or (iii) adjuvant only or (iv) a live, attenuated b bovis vaccine. kabbl-gz was produced in the lambda gt11-amp3 system as a 5-10 kd babesial polypeptide linked to gz. kabbl has previously been shown to be an immunodominant antigen of b bovis, localised at the apex of the ...19883194602
immunopathophysiology of babesia bovis and plasmodium falciparum infections.babesia bovis and plasmodium falciparum are both vector-borne parasites primarily infecting the erythrocytes of their respective hosts. they have obvious differences, yet the diseases caused by these parasites share many common features. both have generated a considerable body of research but, perhaps because of the classical distinction between veterinary and medical parasitology, many of the similarities between the two have been neglected. as this review shows however, many of the pathophysio ...198815463101
a recombinant surface protein of babesia bovis elicits bovine antibodies that react with live merozoites.ten monoclonal antibodies (moabs) were generated against five surface-exposed proteins (16 kda, 42 kda, 44 kda, 60 kda, 225 kda) on merozoites of babesia bovis. a genomic library constructed in the lambda gt11 expression vector was screened with moabs in a plaque immunoassay for identification of clones expressing recombinant surface proteins. two recombinant clones were identified (lambda bo44-15 and lambda bo44-16) that encoded a protein recognized by a moab specific for an epitope on the nati ...19892473398
recently developed methods for the detection of babesial infections.during the acute phase of babesiosis the direct identification of the causative agent is possible by examination of stained blood smears. an improved identification procedure for the diagnosis of babesia bovis using dna hybridization has been reported recently. for the diagnosis of both acute and chronic babesiosis, various serodiagnostic techniques have been developed. recent advances in serodiagnosis designed for the detection of anti-babesia antibodies were partly achieved by improving and st ...19892696156
babesia bovis on the island of pemba, tanzania. 19892750034
cloned dna probes identify anaplasma ovis in goats and reveal a high prevalence of infection.anaplasma organisms are observed in erythrocytes from goats with anemia and weight loss in kenya. three anaplasmas have been isolated in nature, anaplasma ovis, anaplasma marginale, and anaplasma centrale. the two recognized species, a. ovis and a. marginale, are known to infect goats. since only a. ovis causes clinical disease in goats, the anaplasma species in goats in kenya were identified. to detect a. ovis, a 9.6-kilobase-pair section of genomic dna was cloned into pbr322 (pao12a) and was u ...19892592538
immunopathophysiology of babesial infections.humans infected with plasmodium falciparum and bovines infected with babesia bovis display severe haemolysis, alterations in red cell deformability and rigidity, and endothelial cell damage leading to pulmonary oedema and cerebral dysfunction. much of the pathology associated with these infections is not easily attributable to the relatively small numbers of parasites present. this paper considers the possible roles of soluble mediators released from macrophages, and chemical and physical change ...19892696155
repetitive dna probes for the detection of babesia equi.this report describes dna probes for the identification of babesia equi. a genomic library of b. equi was constructed in puc13. several clones were identified that hybridized strongly to b. equi dna. clone pbe33 hybridized specifically to b. equi dna and did not hybridize to horse dna nor to dna from babesia caballi, babesia bovis or babesia bigemina. two subclones of pbe33 (psb20 and peh21) containing b. equi repetitive sequences, could detect 0.49 ng and 0.97 ng b. equi dna, respectively.19892710167
molecular characterization of babesia bovis merozoite surface proteins bearing epitopes immunodominant in protected cattle.eight surface-radioiodinated merozoite proteins from a cloned, pathogenic isolate of babesia bovis can be immunoprecipitated by antibody from cattle that are completely protected against clinical babesiosis. among these eight surface proteins, the 55- and 42-kda molecules are biosynthetically labeled with [3h]glucosamine. the 42-kda glycoprotein can also be labeled with [3h]myristic acid and partitions exclusively into the detergent phase in triton x-114 extracts, indicating that it is an integr ...19892482443
in vitro adherence of bovine erythrocytes infected with babesia bovis to thrombospondin and laminin.this study was undertaken to examine how eight putative adhesive agents bound to plastic surfaces affected the capacity of bovine erythrocytes, infected with either virulent or avirulent strains of babesia bovis, to adhere in vitro. thrombospondin (tsp) induced b. bovis-infected bovine erythrocytes to adhere and adherence was augmented when the infected blood was cultured for 24 h before the assay. moreover, tsp also caused erythrocytes infected with avirulent strains of b. bovis to adhere to pl ...19892777473
babesia bovis: gene isolation and characterization using a mung bean nuclease-derived expression library.genomic dna prepared from erythrocyte cultures of babesia bovis merozoites was digested with mung bean nuclease and used to construct a lambda gt11 expression library of b. bovis recombinants. immunoscreening with two polyclonal antibody probes detected multiple recombinants from which two, designated bb-1 and bb-3, were chosen for further analysis. monospecific immunoglobulins isolated from the screening sera using nitrocellulose-bound fusion proteins were employed to determine the native molec ...19892676576
in vitro killing of babesia bovis by the ornithine analog alpha-monofluoromethyldehydroornithine methyl ester.the effects of the 2 ornithine decarboxylase inhibitors alpha-difluoromethylornithine (dfmo) and alpha-monofluoromethyldehydroornithine methyl ester (delta mfmo-me) on growth of babesia bovis blood stages in vitro were tested. the dfmo had no apparent effects on in vitro growth of b. bovis nor on the morphology of the parasite at concentrations up to 20 mm. in contrast, delta mfmo-me had cytotoxic effects on b. bovis at 0.5 mm which were more pronounced at 5 mm. delta mfmo-me caused both a decre ...19892509686
induction of nucleoside transport sites into the host cell membrane of babesia bovis infected erythrocytes.normal bovine erythrocytes have negligible ability to transport adenosine and related nucleosides across their cell membrane. however, infection with the intraerythrocytic parasite babesia bovis was found to induce a nucleoside permeation site into the host cell membrane. transport experiments over periods of up to 30 s determined that the transport rate of 1 microm adenosine into the infected cell was 1.72 +/- 1.2 pmol incorporated (microliter cell water)-1s-1, a rate three times higher than fo ...19892747745
growth of babesia bovis parasites in stationary and suspension cultures and their use in experimental vaccination of cattle.a combination of stationary culture and suspension culture was used to produce litre quantities of babesia bovis parasites suitable for use as live vaccine. the australian vaccine strain of b bovis, ka, was maintained continuously in microaerophilus stationary phase (masp) cultures, and for a short period in batch and flow-through spinner flask cultures. although continuous culturing was not achieved in spinner flasks, the production of litre quantities of heavily parasitised erythrocytes was ac ...19892595088
comparison between sri lankan and australian strains of babesia bovis in the vaccination of imported cattle in sri lanka.a sri lankan strain of babesia bovis (designated a strain) was isolated from larval ticks and prepared for use as vaccine by syringe-passage in 20 splenectomised calves followed by irradiation. the a strain and a vaccine strain of babesia bovis (designated k strain) brought in frozen form from australia were used to vaccinate 37 susceptible bulls imported from southern australia. rectal temperatures, packed cell volumes, parasitaemias and overt clinical signs were monitored for three weeks follo ...19892665254
detection of babesia bigemina in cattle by a radioimmunoassay incorporating specifically depleted antigen.it was observed that mild acidification (ph less than 4.0) together with solvent extraction of the soluble sonicate of a crude preparation of babesia bigemina infected cattle erythrocytes caused a quantitative loss of b. bigemina-specific antigen. cross-reacting antigen activities with babesia bovis remained intact. these properties were utilized in an assay system wherein antibody response to the specifically depleted antigen preparation was subtracted from the response to the initial crude pre ...19892763443
infectivity of cryopreserved babesia bovis, babesia bigemina and anaplasma centrale for cattle after thawing, dilution and incubation at 30 degrees c.blood containing either babesia bovis, babesia bigemina or anaplasma centrale was mixed with an equal volume of 3 m glycerol in phosphate-buffered saline with or without glucose and then stored in liquid nitrogen for 2-30 days. after being thawed, the parasitized blood was subjected to various procedures, including dilution up to 1000-fold followed by incubation at 30 or 4 degrees c for 8 h, before infectivity of the parasites was tested in a total of 70 cattle. the results showed that the blood ...19892763444
development of a recombinant anaplasma marginale dna probe.an anaplasma marginale dna probe has been developed by using an improved method for the isolation of genomic dna. purified genomic a. marginale dna from the st. croix isolate was partially digested with sau 3a1 into fragments (greater than or equal to 5.0 kb). the restriction fragments were cloned using standard techniques in the pbr322 vector and used to transform e. coli (dh5) host cells. the recombinant a. marginale dna library was screened by the colony lifting procedure. colonies containing ...19902260276
concurrent infection with theileria buffeli caused depression of parasitaemia in babesia bovis and anaplasma centrale infections in splenectomised calves but not in b bigemina infections.in five experiments undertaken in splenectomised calves it was found that theileria buffeli infections depressed the parasitaemias of superimposed babesia bovis and anaplasma centrale infections, but not b bigemina infections. the course of a centrale infections did not appear to be affected by a concurrent eperythrozoon teganodes infection.19902267426
cloning and characterization of the rrna genes and flanking regions from babesia bovis: use of the genes as strain discriminating probes.three sets of rrna genes (units 1s-3s) have been identified in babesia bovis (samford isolate). all three units are present in the same, probably single, copy number. the rrna genes and flanking regions have been analysed by cloning, restriction mapping and dna hybridization. the units are approximately 7 kb in length and have essentially identical restriction maps. in contrast the flanking regions exhibit significant restriction site differences. however, the regions upstream of all three units ...19902290441
an improved elisa for the detection of antibodies against babesia bovis using either a native or a recombinant b. bovis antigen.two new enzyme-linked immunosorbent assays (elisa) for the diagnosis of babesia bovis in cattle are described. the elisa using a native antigen is more sensitive and less laborious than the assays described previously, because it does not require adsorption of sera with bovine erythrocytes. the second elisa, using a recombinant b. bovis antigen expressed in escherichia coli, was both sensitive and specific. it is suitable to replace the native antigen, thus avoiding large batch-to-batch variatio ...19902251239
dna probes distinguish geographical isolates and identify a novel dna molecule of babesia bovis.a genomic dna library of babesia bovis was screened to identify dna probe candidates for direct detection of the parasite. two sequences, bo6 and bo25, had the highest sensitivity and further analysis revealed unique characteristics of each of these. neither sequence hybridized detectably to bovine dna. bo6 detected 100 pg of both a mexican and an australian isolate of b. bovis, but bo6 also detected 1.0 ng of babesia bigemina dna under identical conditions. a unique characteristic of bo6 is tha ...19902254817
study of virulence and vector transmission of babesia bovis by use of cloned parasite lines.cloned lines of babesia bovis were prepared from the avirulent vaccine strain, ka, by an in vivo limiting dilution procedure. the virulence of these clones for adult bos taurus cattle varied from completely avirulent to highly virulent. this suggests that the parent strain, ka, is composed of a mixture of subpopulations of varied virulence. passage of the avirulent clone k-19-47 in intact (nonsplenectomized) cattle resulted in its full reversion to virulence. this suggests that two mechanisms ar ...19902365457
calcium-dependent protein phosphorylation in babesia bovis and its role in growth regulation.intracellular growth of protozoan parasite babesia bovis has been followed to study the effect of some chemical agents on growth regulation. using an in vitro parasite culture system we present evidence that the normal growth of the parasite is dependent upon available calcium and a ca2(+)-binding protein, calmodulin, because sequestration of either of these 2 components from the culture medium causes inhibition of parasitic growth. further studies demonstrate that the parasite contains a protei ...19902108234
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