Publications

seasonal incidence and hemoparasite infection rates of ixodid ticks (acari: ixodidae) detached from cattle in costa rica.	to determine the tick species hindering the cattle industry in costa rica and to assess infection rates of ticks with three important hemoparasite species, cattle were monitored during a period of six months (october 1992-march 1993). four farms were located in the dry pacific region of the canton of tilarán and a fifth farm on the slopes of the poás volcano in a cool tropical cloud-forest ecosystem. on each farm 3 to 5 animals of 6 to 24 months of age were selected at random. all ticks were rem ...	1994	7501871
functional and phenotypic characterization of wc1+ gamma/delta t cells isolated from babesia bovis-stimulated t cell lines.	functional studies with wc1+ gamma/delta t cell lines were performed to clarify the role of this subpopulation of gamma/delta t cells in the in vitro immune response to babesia bovis. as cd4+ t cells decreased and gamma/delta t cells increased in b. bovis-stimulated t cell lines, antigen-specific proliferation declined to background levels. one irradiated gamma/delta t cell line inhibited proliferation of autologous th1 cells, although unirradiated gamma/delta t cells either synergized with or h ...	1994	7507005
cd4+ t-cell clones obtained from cattle chronically infected with fasciola hepatica and specific for adult worm antigen express both unrestricted and th2 cytokine profiles.	the well-established importance of helper t (th)-cell subsets in immunity and immunoregulation of many experimental helminth infections prompted a detailed study of the cellular immune response against fasciola hepatica in the natural bovine host. t-cell lines established from two cattle infected with f. hepatica were characterized for the expression of t-cell surface markers and proliferative responses against f. hepatica adult worm antigen. parasite-specific t-cell lines contained a mixture of ...	1994	7509319
isolation of babesia bigemina and babesia bovis merozoites by ammonium chloride lysis of infected erythrocytes.	1. we describe the isolation of viable merozoites from erythrocytes infected with babesia bovis or babesia bigemina organisms by ammonium chloride lysis. 2. parasite morphology was examined by both light and transmission electron microscopy. erythrocyte-free parasites maintain their viability and infectivity, retain their antigenicity and are suitable for use in the indirect fluorescent antibody assay.	1994	7549981
seroepidemiological studies of bovine babesiosis caused by babesia ovata, b. bigemina and b. bovis in peninsular malaysia.	cattle in peninsular malaysia were examined for evidence of infection with babesia ovata, b. bigemina and b. bovis by an enzyme-linked immunosorbent assay for detection of antibody to the three babesia species. all of the test samples when assayed with b. ovata antigen, resulted in low value indicating low probability of cattle infected with b. bigemina, 74.4% were positive for b. bovis and 72.6% were positive for both babesia species. in addition, a serological survey with regard to age differe ...	1994	7865596
a review on vaccination against protozoa and arthropods of veterinary importance.	the recent advances in immunology and biotechnology have stimulated much research on the control of parasitic diseases through vaccination. this is a review of the state of the art regarding important protozoan and arthropod veterinary parasites. a live oocyst vaccine for avian coccidiosis is still in use but much work has been done on the identification, cloning, and assay of protective antigens. the sporozoites of eimeria tenella have been the preferred subject and at least four recombinant an ...	1994	7886919
detection of antibodies to babesia bovis using an elisa test.	an enzyme-linked immunoassay (elisa) is described for the detection of antibodies to babesia bovis using a partially purified antigen. the optimum conditions required to perform the test were determined and 210 serum samples were comparatively tested using elisa and indirect immunofluorescence (ifa) tests, finding a diagnostic coincidence of 96.1%, a relative sensitivity of 96%, and a relative specificity of 96.4%.	1994	7919817
development of a babesia bovis live attenuated vaccine.	babesia bovis is the blood parasite causing the highest morbidity and mortality of cattle in cuba. thus a control program based on immunization with a vaccine using an attenuated strain of the parasite was developed. for this purpose, a virulent b. bovis strain was isolated and then attenuated by the traditional method in which biological characteristics, proteolytic activity and vector transmissibility were studied. the protection conferred by the vaccine was measured by vaccinating cattle whic ...	1994	7919825
interleukin-10 is expressed by bovine type 1 helper, type 2 helper, and unrestricted parasite-specific t-cell clones and inhibits proliferation of all three subsets in an accessory-cell-dependent manner.	murine interleukin-10 (il-10) is produced by type 2 helper (th2) cells and selectively inhibits cytokine synthesis by type 1 helper (th1) cells, whereas human il-10 is produced by and inhibits proliferation and cytokine synthesis by both th1 and th2 subsets. this study reports that bovine il-10 mrna is expressed by th0, th1, and th2 clones of bovine t cells specific for either babesia bovis or fasciola hepatica but not by two cd8+ t-cell clones. the antigen-induced proliferative responses of all ...	1994	7927745
cross-protective immunity induced by babesia bovis clones with antigenically unrelated variable merozoite surface antigens.	babesia bovis merozoite surface antigen 1 (msa-1) induces antibodies capable of neutralizing merozoites in vitro. both msa-1 and the co-expressed msa-2 are encoded by a polymorphic multigene family and are antigenically variant among strains isolated from widely separated geographic regions. in this study, cross-protective immunity between two b. bovis clones, mexico mo-7 and israel-c, that have antigenically unrelated msa-1 and msa-2 surface proteins was assessed. cattle immunized by infection ...	1994	7941314
antigenic profile of a pure isolate of anaplasma marginale of brazilian origin, using a western blot technique.	anaplasma marginale initial bodies of the brazilian isolate aufv1 were purified from infected erythrocytes using a combination of lysis, ultrasonic disruption and differential centrifugation. initial bodies were solubilised with a buffer containing protease inhibitors and non-ionic detergents. immunochemical analysis by the western blot technique revealed at least five proteins with apparent molecular weights (mw) of 105, 100, 97, 87 and 38 kda when homologous sera were used as primary antibodie ...	1994	8030178
bovine babesiosis: a review of recent advances.	bovine babesiosis, caused by parasites of the genus babesia, is one of the world's most severe tick-borne problems of cattle in temperate to tropical areas. in the americas babesia bovis and b. bigemina are the causative agents, with the former considered to produce the greatest economic impact. the great complexity of the relationships causal agent-vector-host has severely hindered the efforts towards the production of a safe, long-lasting, solid-protection inducing vaccine. recent important co ...	1994	7919821
bovine anaplasmosis and babesiosis in the lesser antilles: risk assessment of an unstable epidemiologic situation.	a seroepidemiological survey on tick-borne diseases of ruminants was carried out on 11 islands of the lesser antilles from grenada to st martin. a total of 1,795 cattle were randomly sampled and sera tested for antibodies to anaplasmosis (anaplasma marginale) and babesiosis (babesia bovis and b bigemina) using a dot-elisa test. except for anaplasmosis, which was virtually absent from guadeloupe, the seroprevalence of the 3 tick-borne diseases ranged from 18 to 71%. the epidemiologic situation wa ...	1994	8038806
adenosine analogues as antimetabolites against plasmodium falciparum malaria.	analogues of purine nucleosides and deoxynucleosides were tested for toxicity against the intraerythrocytic parasite plasmodium falciparum in vitro culture. sangivamycin (7-deaza-7-amido-adenosine) (ic37 of 0.3 microm), tubercidin (7-deaza-adenosine) (ic37 of 0.7 microm), 6-methylamino-deoxyadenosine (ic37 of 10 microm), 8-aza-2-amino-deoxy-adenosine (ic37 of 11 microm) and 2-chloro-adenosine (ic37 of 11 microm) were found to be the most toxic towards the parasite. structure-activity analysis su ...	1994	8070953
use of random amplified polymorphic dna analysis to compare babesia bovis and b. bigemina isolates.	random amplified polymorphic dna analysis provides characteristic fingerprints for babesia bovis and b. bigemina. this genetic profile reflects similarities and minor differences between closely related regional isolates and the greater diversity representative of species from distant geographic locations.	1994	8073018
interstrain conservation of babesial rap-1 surface-exposed b-cell epitopes despite rap-1 genomic polymorphism.	members of the babesial rhoptry-associated protein 1 (rap-1) family express surface-exposed b-cell epitopes and are candidate antigens for vaccine development. the relationship between rap-1 genomic polymorphism and surface-exposed b-cell epitope expression was analyzed by comparison of biological clones of mexico strain babesia bigemina and babesia bovis with strains isolated in argentina. despite genomic polymorphism between strains, including sequences located within the open reading frame, d ...	1994	7518810
babesia bovis: infectivity of an attenuated strain of brazilian origin for the tick vector, boophilus microplus.	in order to verify the infectivity and transovarian transmission of one strain of babesia bovis of brazilian origin, attenuated by repeated passages in splenectomized calves to the biological tick vector, boophilus microplus, an inoculation of that strain was performed in hemoparasite-free calves infested with hemoparasite-free ticks. subsequently, engorged female ticks were collected to examine hemolymph and progeny for presence of developing stages of babesia bovis. using an optical microscope ...	1994	8030179
polymerase chain reaction-based diagnostic assay to detect cattle chronically infected with babesia bovis.	from a b. bovis gene sequence coding for a 60 kda merozoite surface protein previously published, two sets of primers were designed for the polymerase chain reaction (pcr) assay. primer set bof/bor was used to prime taq polymerase dna amplification of a 350 bp fragment of the target b. bovis dna. primer set bofn/born was used to prepare a pcr-synthesized, digoxigenin-dutp-labeled probe (291 bp) which would hybridize to a sequence within the pcr-amplified parasite target dna. pcr amplification of ...	1994	7938942
a study of autoantibodies to phosphatidyl-serine in babesia bovis and babesia bigemina infections in cattle.	sera from cattle infected with babesia bovis were found to contain antibodies to phosphatidyl-serine (ps), a negatively charged phospholipid normally found on the internal membrane of erythrocytes. in contrast, no autoantibodies were detected following babesia bigemina infection indicating that the autoimmunity is not genus specific. during infection with babesia bovis, ps translocates to the external membrane and it is suggested that this may result in ps behaving as an autoantigen owing to a t ...	1994	8160363
antigenic variation of parasite-derived antigens on the surface of babesia bovis-infected erythrocytes.	the hemoparasite babesia bovis antigenically alters the bovine erythrocyte membrane surface by expression of isolate-specific, parasite-derived polypeptides. to determine whether antigenic variation also occurred on the infected erythrocyte surface, a calf was infected once with parasitized erythrocytes carrying the c9.1 clonal line of b. bovis. in vitro cultures then were established periodically from the peripheral blood and analyzed with sequentially collected sera from the same animal. the s ...	1994	8262654
use of helper t cells to identify potential vaccine antigens of babesia bovis.	babesia bovis is an economically important hemoprotozoon parasite o f cattle that is prevalent in many, tropical and subtropical regions o f the world. effective vaccines against this tick-transmitted parasite consist o f live organisms attenuated by passage through splenectomized calves. however, the nature o f acquired resistance to challenge infection with heterologous isolates of this parasite has not been clearly defined. unsuccessful attempts to select protective antigens have relied upon ...	1994	15275482
vaccines against babesiosis using soluble parasite antigens.	babesiosis in cattle and dogs causes severe economical and emotional loss. although effective chemotherapeutic treatment of infected animals is available, the prevention of babesiosis by vaccination would be preferable. attenuated parasite lines of babesia bovis have been used successfully to control tropical babesiosis in cattle. however, among other drawbacks associated with live vaccines, such vaccines bear the risk of variable infectivity and morbidity requiring veterinary surveillance. solu ...	1995	15275383
immune evasion by babesia bovis and plasmodium falciparum: cliff-dwellers of the parasite world.	erythrocyte-dwelling parasites, such as babesia bovis and plasmodium falciparum, are not accessible to the host immune system during most of their asexual reproductive cycle because they are intracellular. while intracellular, the host immune response must be directed toward the surface of the infected erythrocyte. immune individuals mount protective antibody and cell-mediated responses which eliminate most of the parasites, yet some survive to establish chronic infections. in this review, david ...	1995	15275361
studies on failure of t strain live babesia bovis vaccine.	field investigations of the protection afforded by the australian live babesia bovis vaccine used in the early 1990s (t strain) revealed inadequate vaccine-induced protection in certain herds. vaccination/challenge trials using 207 experimental cattle were conducted to evaluate the protection afforded by t strain b bovis against field isolates from these herds. the trials investigated whether isolates that could 'break-through' t strain immunity were present in the field, the ability or inabilit ...	1995	8579560
phylogeny of the large extrachromosomal dna of organisms in the phylum apicomplexa.	organisms in the phylum apicomplexa appear to have a large extrachromosomal dna which is unrelated to the mitochondrial dna. based on the apparent gene content of the large (35 kb) extrachromosomal dna of plasmodium falciparum, it has been suggested that it is a plastid-like dna, which may be related to the plastid dna of rhodophytes. however, phylogenetic analyses have been inconclusive. it has been suggested that this is due to the unusually high a+t content of the plasmodium falciparum large ...	1995	8520581
exoantigens of an attenuated strain of babesia bovis used as a vaccine against bovine babesiosis.	bovine babesiosis caused by babesia bovis remains a significant constraint to beef and milk cattle production throughout the world. exoantigens released by the parasites in culture supernatants are a potential source of antigen to induce protective immunity. an attenuated strain of b. bovis from brazil, catalogued as bbufv1, was maintained in vitro by the masp method, and exoantigen-containing supernatant fluids were collected daily to form a pool representing a 72-h culture cycle for preparatio ...	1995	8533277
identification of an immunodominant 40 kda merozoite antigen common to the australian t and dixie vaccine strains of babesia bovis and the development of diagnostic tests specific for these strains.	antigenic differences among australian vaccine and field strains of babesia bovis were investigated in an attempt to identify strain specific antigens. immunoblots revealed substantial differences between the current vaccine strains, designated t and dixie, and previous vaccine strains and field isolates collected on properties where vaccination with the t or dixie strains had failed to provide complete protection against tick-borne challenge. a major difference was an immunodominant 40 kda anti ...	1995	8747906
babesia bigemina: identification of b cell epitopes associated with parasitized erythrocytes.	rhoptries are involved in host cell invasion and rhoptry polypeptides, including the babesia bigemina rhoptry-associated protein-1 (rap-1), are targets for protective immune responses. polyclonal antisera produced against isolated rhoptries is directed predominantly against rap-1 and reacts with both the merozoite and the membrane of parasitized erythrocytes. to determine whether these b cell epitopes associated with the parasitized erythrocyte are derived from rap-1 or, alternatively, from prev ...	1995	8542990
an organelle-like small subunit ribosomal rna gene from babesia bovis: nucleotide sequence, secondary structure of the transcript and preliminary phylogenetic analysis.	investigations aimed at identifying the mitochondrial genome of babesia bovis using the polymerase chain reaction (pcr) have established the existence of an organelle-like small subunit ribosomal rna (ssu rrna) gene in the parasite. the sequence, compiled from three main pcr products, was 1448 bp in length (including the primer regions), had a 73% a+t content and showed significant similarity (68% sequence identity) to the "organellar" ssu rrna gene from plasmodium falciparum. the proposed secon ...	1995	8550293
identification of babesia bovis merozoite antigens separated by continuous-flow electrophoresis that stimulate proliferation of helper t-cell clones derived from b. bovis-immune cattle.	to characterize babesia bovis merozoite antigens that stimulate anamnestic t helper (th)-cell responses from b. bovis-immune cattle, b. bovis-specific th-cell lines and clones, previously assigned to different antigenic groups (w. c. brown, s. zhao, a. c. rice-ficht, k. s. logan, and v. m. woods, infect. immun. 60:4364-4372, 1992), were tested in proliferation assays against fractionated merozoite antigens. the antigenic groups were determined by the patterns of response of th clones to differen ...	1995	7622238
interleukin-10 downregulates proliferation and expression of interleukin-2 receptor p55 chain and interferon-gamma, but not interleukin-2 or interleukin-4, by parasite-specific helper t cell clones obtained from cattle chronically infected with babesia bovis or fasciola hepatica.	human recombinant interleukin-10 (il-10) was previously shown to inhibit accessory cell (ac)-dependent proliferation of bovine parasite-specific t helper 1 (th1), th2, and th0 cells in an il-2-reversible manner (brown, w.c., woods, v.m., chitko-mckown, c.g., hash, s.m., and rice-ficht, a.c., 1994. infect. immun. 62, 4697-4708). the present study was therefore designed to determine whether the effect of il-10 on t cell proliferation corresponded with downregulated expression of cytokines, or thei ...	1995	8564714
detection of theileria annulata in blood samples of carrier cattle by pcr.	we report the detection of theileria annulata, the causative agent of tropical theileriosis, by pcr in blood samples obtained from carrier cattle. the assay employs primers specific for the gene encoding the 30-kda major merozoite surface antigen of t. annulata. a 721-bp fragment was amplified from blood samples taken monthly from calves experimentally infected with one of four different stocks of t. annulata originating in either mauritania, portugal, spain, or turkey. at the end of the experim ...	1995	8567902
detection of anaplasma marginale dna in bovine erythrocytes by slot-blot and in situ hybridization with a pcr-mediated digoxigenin-labeled dna probe.	a 409-base pair (bp) dna fragment derived from the msp-1 beta gene of anaplasma marginale was amplified and simultaneously labeled with digoxigenin-11-dutp by a polymerase chain reaction (pcr) assay. the resulting digoxigenin-labeled 409-bp pcr product was used as a probe for slot-blot and in situ hybridization to detect a. marginale dna from experimentally infected bovine erythrocytes. the hybrid formation was detected with alkaline phosphatase-conjugated anti-digoxigenin antibody and substrate ...	1995	8580166
the structural gene for carbamoyl phosphate synthetase from the protozoan parasite babesia bovis.		1995	8719167
expression and biological activities of bovine interleukin 4: effects of recombinant bovine interleukin 4 on t cell proliferation and b cell differentiation and proliferation in vitro.	interleukin 4 (il-4) is a pleotropic cytokine affecting a wide range of cell types in both the mouse and the human. these activities include regulation of the growth and differentiation of both t and b lymphocytes. the activities of il-4 in nonprimate, nonmurine systems are not well established. herein, we demonstrate in the bovine system that il-4 upregulates production of igm, igg1, and ige in the presence of a variety of costimulators including anti-igm, staphylococcus aureus cowan strain i, ...	1995	7606798
a plasmodium falciparum gene encoding a high mobility group protein box.		1995	7477107
identification of candidate vaccine antigens of bovine hemoparasites theileria parva and babesia bovis by use of helper t cell clones.	current vaccines for bovine hemoparasites utilize live attenuated organisms or virulent organisms administered concurrently with antiparasitic drugs. although such vaccines can be effective, for most hemoparasites the mechanisms of acquired resistance to challenge infection with heterologous parasite isolates have not been clearly defined. selection of potentially protective antigens has traditionally made use of antibodies to identify immunodominant proteins. however, numerous studies have indi ...	1995	7597783
small extrachromosomal nucleic acid segments in protozoan parasites.	viruses have been described in the following protozoa: babesia spp., trichomonas vaginalis, giardia lamblia, leishmania braziliensis and eimeria spp. in order to study the babesia bovis virus, merozoites have been prepared from the blood of infected cattle. agarose gel electrophoresis of nucleic extracts from the bovine protozoa b. bovis and babesia bigemina were separated into genomic dna and at least two additional nucleic acids. one molecule with a relative mobility of 5.5 kilobase pairs (kbp ...	1995	7597793
epidemiology of babesiosis and anaplasmosis in south and central america.	babesiosis (babesia bovis and babesia bigemina) and anaplasmosis (anaplasma marginale) affect native cattle from uruguay and northern argentina to guatemala. the distribution of babesia follows the dissemination of the tick vector. seroepidemiological studies showed that enzootic instability exist in herds in several areas of the region. however, clinical cases occurred less frequently than expected. the babesial tick infection rate is related to the vector abundance which in turn is regulated b ...	1995	7597777
experimental studies of the rate of infection of boophilus microplus eggs with babesia bovis.	babasia bovis infection in the eggs of boophilus microplus was investigated by examining the total output of eggs by 10 engorged female ticks with a level of haemolymph infection with b bovis ranging from 0.2 to 20.6 kinetics per microscope field. the ticks were fed on infected calves, with a parasitaemia ranging from 0.01 per cent to 0.02 per cent, inoculated with a stabilate of b microplus larvae containing the protozoa. infected eggs, 9.5 per cent of the total eggs laid, were detected from th ...	1995	7659857
genetic and antigenic characterization of babesia bovis merozoite spherical body protein bb-1.	a babesia bovis merozoite protein, bb-1, was localized by immunoelectron microscopy to an apical organelle known as the spherical body. this unique structure appears to be analogous to dense granules of other apicomplexan protozoa. similar to previously described dense granule proteins of plasmodium spp., bb-1 is secreted during or just after invasion of host erythrocytes and becomes associated with the cytoplasmic face of the infected cell. the amino terminal sequence of bb-1 contains a predict ...	1995	7770080
use of monoclonal antibodies in immunoelectron microscopy.		1995	7550674
targeting ticks for control of selected hemoparasitic diseases of cattle.	development in and transmission of hemoparasites by tick vectors are phenomena closely synchronized with the tick feeding cycle. in all known life cycles, initial infection of tick tissues occurs in midgut epithelial cells and transmission is effected as ticks feed after parasites have developed and multiplied in salivary glands. many factors reviewed affect development and transmission of hemoparasites by ticks including age of ticks, artificial temperature, climate and/or season, tick stage or ...	1995	7597779
strategies for the control of one-host ticks and relationship with tick-borne diseases in south america.	a variety of hemoparasites occurs in ruminants of south america (12 degrees 00'n-56 degrees 00's), but there is consensus on the significant economic impact of babesiosis (babesia bovis and babesia bigemina) and anaplasmosis (anaplasma marginale). the tick vector for the babesia spp. for the whole region is boophilus microplus which has been the most important target in control/eradication programs. boophilus microplus and many different hematophagous diptera species are considered vectors of a. ...	1995	7597780
live vaccines against hemoparasitic diseases in livestock.	live vaccines against hemoparasitic diseases in livestock are based on parasites derived from culture (theileria annulata), from blood of infected animals (babesia bovis, babesia bigemina, anaplasma centrale, (attenuated) anaplasma marginale and cowdria ruminantium), and from ticks (theileria parva). the t. annulata attenuated cultured schizont vaccine is safe for all varieties of cattle. blood derived vaccines are recommended mainly for young cattle, the age limit varying with the different vac ...	1995	7597786
molecular basis for vaccine development against anaplasmosis and babesiosis.	immunization of livestock against the erythroparasitic pathogens anaplasma marginale, babesia bigemina, and babesia bovis with safe and effective killed vaccines is not yet feasible on a practical basis. however, the immune protection afforded by recovery from natural infection and premunition indicates that microbial epitopes capable of inducing immunity exist and that the bovine immune system can be primed appropriately. induction of protection by immunization with killed parasite fractions, e ...	1995	7597787
current state and future trends in the diagnosis of babesiosis.	an overview is given of the currently available methods to diagnose babesiosis in livestock. microscopic techniques are still the only appropriate techniques to diagnose acute disease. thin or thick blood films stained with giemsa's stain are sufficient. the sensitivity ranges from 10(-5) to 10(-6), i.e. one parasite per 10(5)-10(6) erythrocytes can be detected. thick films stained with acridine orange (sensitivity approximately 10(-7)) and the quantitative buffy coat (qbc) analysis tube system ...	1995	7597794
immunization of cattle with recombinant babesia bovis merozoite surface antigen-1.	cattle immunized with a recombinant merozoite surface antigen-1 molecule (msa-1) produced high-titered antibody that reacted with the surface of the parasite and neutralized merozoite infectivity in vitro. however, recombinant msa-1 immunization did not confer protection against challenge with virulent babesia bovis. these results indicate that antibody-mediated neutralization of merozoite infectivity in vitro, at least for msa-1-specific antibody, does not reflect in vivo protective immunity to ...	1995	7806376
cloning and characterization of a ribosomal p protein from taenia solium, the aetiological agent of human cysticercosis.	a cdna encoding the complete open reading frame of the taenia solium acidic ribosomal phosphoprotein p2 has been cloned. the 417 bp cdna (arpp2) was isolated from a t. solium cdna expression library by pcr using p protein specific pimers. the orf encodes a protein of 121 amino acids exhibiting 40-55% identity to mammalian, fungal, insect, and parasite p2 proteins. the inferred molecular mass of the protein is 12,592 daltons, similar to that reported for other ribosomal p2 proteins. after subclon ...	1996	8619813
human interleukin-12 upregulates proliferation and interferon-gamma production by parasite antigen-stimulated th cell clones and gamma/delta t cells of cattle.		1996	8958944
monitoring babesia bovis infections in cattle by using pcr-based tests.	the sensitivity and specificity of pcr tests based on the small-subunit rrna gene sequence of babesia bovis were compared in a blind study of experimentally infected cattle with the corresponding parameters of the complement fixation (cf) test currently used in the united states to screen for bovine babesiosis. cattle were experimentally infected with a single inoculum of a cloned laboratory strain of b. bovis. blood samples were collected and tested over a period covering from the day of infect ...	1996	8897177
effect of passage of babesia ovis in the gerbil (acomys cahirinus) on the course of infection in splenectomized lambs.	splenectomized gerbils (acomys cahirinus) have been found to be susceptible to babesia ovis applied via blood inoculation, whereas intact gerbils were not infected. blood from splenectomized latently infected gerbils caused infection in a splenectomized lamb. intact acomys cahirinus gerbils did not become infected by b. ovis, and all captured rodents in an enzootic area, intact and splenectomized, were found to be negative for b. ovis. it can thus be concluded that acomys cahirinus does not serv ...	1996	8916410
subunit vaccines for complex tick-borne pathogens: dream or reality?		1996	8979420
prospects for subunit vaccines against tick-borne diseases.	tick-borne parasites are a serious impediment to the improvement of live-stock production in the developing world. the major parasites affecting cattle include theileria parva, t. annulata, babesia bigemina, b. bovis, anaplasma marginale and cowdria ruminantium. the control of these infections is dependent on the use of acaricides to decrease transmission by the tick vectors, and immunization of susceptible animals with live vaccines. the use of acaricide is hampered by the development of resist ...	1996	8979421
characterization of helper t cell responses against rhoptry-associated protein 1 (rap-1) of babesial parasites.		1996	8784494
effect of management and inherent factors on birth seropositivity and seroconversion to babesia bovis in calves in costa rica.	the relationship between calf characteristics, farm management, seropositivity, and age at seroconversion to babesia bovis was assessed. a total of 3624 samples obtained from 494 animals on 11 farms was analyzed by an indirect elisa assay, and individual results classified as positive or negative. the animals were sampled from birth to weaning, beginning in april 1990 and ending in april 1992. we found 59.1% (n = 467) of seropositive neonatal calves (mean age 4.4 days). using a logistic binomial ...	1996	8784491
use of polymerase chain reaction in bovine babesiosis research.	the polymerase chain reaction (pcr) in babesiosis research was originally developed to detect babesia bovis or babesia bigemina in blood samples containing infected erythrocytes. these preliminary studies led to development of a sensitive pcr/dna probe assay to detect the following hemoparasites: b. bigemina and b. bovis in a single sample. this modified procedure, referred to as a duplex pcr/ nonradioactive probe assay, has an analytic sensitivity of 0.00001% for b. bigemina, and 0.00001% infec ...	1996	8784529
light microscopy diagnosis of babesia bovis and b. bigemina kinetes in the hemolymph of artificially infected boophilus microplus engorged female ticks.		1996	8784530
epizootiologic instability of bovine populations against babesia bovis (piroplasmida:babesiidae) in the region of poas, costa rica.	in poás (costa rica), more than 78% of the cattle population is susceptible to babesia bovis (babes, 1888) which indicates that care should be taken during animal movement to avoid tick exposure. seroprevalence is less than 22%; the frequency distribution of antibody titers is presented. significant differences (p < 0.05) were observed in the distribution of seropositive animals between ecological zones. lower mountain rain forest and lower mountain wet forest presented higher risk for seroposit ...	1996	8784492
comparative sensitivity of two tests for the diagnosis of multiple hemoparasite infection of cattle.	the purpose of this study was to evaluate the efficacy of light microscopy (lm) examination of blood smears and a multiplex polymerase chain reaction (mpcr) assay, in terms of their ability to detect cattle experimentally infected with babesia bovis, babesia bigemina, and anaplasma marginale. blood samples were collected from 32 intact, 1-2 year old, holstein bulls, previous to and after simultaneous inoculation of culture-derived or field isolates of b. bovis- and b. bigemina-infected erythrocy ...	1996	8784493
molecular cloning of a putative rhoptry associated protein homologue from babesia divergens.		1996	8784776
piroplasms of domestic animals in the macedonia region of greece. 1. serological cross-reactions.	during a serological survey on haemoparasites in macedonia, serum samples were collected from cattle, sheep and goats. all sera were tested by the indirect immunofluorescence test (ifat); the cattle sera against theileria orientalis, t. annulata, babesia bigemina, b. bovis, b. divergens and b. major antigens; the sheep and goat sera against t. ovis, b. ovis, b. motasi and b. crassa antigens. parallel tests of negative and positive control sera against all the antigens showed the existence of cro ...	1996	8792579
piroplasms of domestic animals in the macedonia region of greece. 2. piroplasms of cattle.	a study was carried out on piroplasms of cattle in the macedonia region of greece. during 1984-1986, 602 serum samples were collected from cattle in 33 localities. blood smears were also prepared from 50 of the animals in 13 localities. the indirect fluorescent antibody (ifa) test revealed that 41.4% of cattle sera were positive to theileria orientalis, 2.0% to theileria annulata, 21.6% to babesia bovis, 15.2% to babesia bigemina, 5.1% to babesia major and 2.7% to babesia divergens. some of the ...	1996	8792580
field observations on the duration of immunity in cattle after vaccination against anaplasma and babesia species.	in an outbreak of babesia bovis in a large herd of friesian x malawi zebu cattle, which occurred after an interruption of intensive dipping, clinical or fatal babesiosis occurred in 54/299 (18.1%) animals which had never been vaccinated, as compared to 9/153 (5.9%) vaccinated animals. eight of the nine affected vaccinates had been vaccinated more than 27 months previously. sera were collected every 3-4 months from 33 friesian x malawi zebu heifers maintained with intensive dipping and vaccinated ...	1996	8848296
anaplasma marginale: detection of carrier cattle by pcr-elisa.	a highly sensitive and specific polymerase chain reaction (pcr) based assay for the detection of the minute levels of anaplasma marginale present in the blood of long-term carrier cattle was developed. a simple lysis method was used to remove most of the haemoglobin from the blood to facilitate direct input of samples into the pcr reactions without prior purification of the dna. pcr product was detected by enzyme-linked immunosorbent assay (elisa) to simplify the processing of large numbers of s ...	1996	8982791
integrated tick and tick-borne disease control trials in crossbred dairy cattle in malawi.	crossbred dairy heifers on a farm in an east coast fever (ecf) endemic area in malawi were immunised against theileria parva, anaplasma spp., babesia bigemina, babesia bovis and cowdria ruminantium. they were treated at infrequent intervals with chlorfenvinphos to limit infestation with adult ticks, without providing complete tick control. in one trial, which tested a threshold dipping regimen, 20 heifers were dipped only once in 6 months to control a flush of boophilus microplus. unimmunised co ...	1996	8983132
the growing importance of the plastid-like dnas of the apicomplexa.	organisms in the phylum apicomplexa possess, in addition to their mitochondrial genome, an extrachromosomal dna that possesses significant similarities with the extrachromosomal genomes of plastids. to date, the majority of data on these plastid-like dnas have been obtained from the human malarial organism, plasmodium falciparum. in common with plastid dnas, the plastid-like dna of p. falciparum possesses genes for dna-dependent rna polymerase subunits beta and beta 1 and for organellar-like lar ...	1996	9024859
a babesia bovis 225-kilodalton spherical-body protein: localization to the cytoplasmic face of infected erythrocytes after merozoite invasion.	a 225-kda babesia bovis protein occurs on the cytoplasmic side of infected-erythrocyte membranes. here it is demonstrated that the 225-kda protein localizes to spherical-body organelles of merozoites. organelles consistent in size and shape with spherical bodies were isolated between 1.17 and 1.21 g/cm(3) in a sucrose density gradient. organelles consistent with rhoptries and micronemes were also present in fractions from 1.17 to 1.19 g/cm(3). antisera generated by immunizing mice with the fract ...	1996	8698487
babesia bovis: biosynthesis and localisation of 12d3 antigen in bovine erythrocytes.	the 12d3 antigen of babesia bovis was found to be synthesised rapidly in cultured parasites, and localised to both the apical complex of the merozoite and the cytoplasm of the parasitised erythrocyte. amino-terminal sequencing suggested that the nascent protein had been processed and differences between the predicted and measured molecular weights suggested post-translational modification. the major proportion of 12d3 appeared in the soluble compartment of the parasitised erythrocytes with a mol ...	1996	9024870
characterisation of genes encoding a nucleoside monophosphate kinase and a l35 ribosomal protein from babesia bovis.	we have sequenced a region of the babesia bovis nuclear genome that encodes a l35 ribosomal protein homologue (bl35) and a putative nucleoside monophosphate kinase (bnmk) that is most similar to the adenylate kinase of gram-positive bacteria and the mitochondrial form of adenylate kinase in eukaryotes. bnmk appears to be unique in that it is the first eukaryotic family member to feature a putative zinc-binding domain. bnmk and bl35 are closely linked and transcribed from opposite dna strands. ex ...	1996	8920009
babesia bovis rhoptry-associated protein 1 is immunodominant for t helper cells of immune cattle and contains t-cell epitopes conserved among geographically distant b. bovis strains.	the ability of rhoptry-associated protein 1 (rap-1) of babesia bovis and babesia bigemina to confer partial protective immunity in cattle has stimulated interest in characterizing both b-cell and t-cell epitopes of these proteins. it was previously shown that b. bovis rap-1 associates with the merozoite surface as well as rhoptries and expresses b-cell epitopes conserved among otherwise antigenically different b. bovis strains. an amino-terminal 307-amino-acid domain of the molecule that is high ...	1996	8757873
cd4+ t-helper lymphocyte responses against babesia bigemina rhoptry-associated protein i.	a multigene family of 58- to 60-kda proteins, which are designated rhoptry-associated protein 1 (rap-1) and which come from the parasites babesia bigemina and babesia bovis, is a target for vaccine development. the presence of multiple gene copies and conserved sequences and epitopes of rap-1 implies that these proteins are functionally important for the survival of these parasites. furthermore, it was previously shown that b. bigemina rap-1 induced partial protection against challenge infection ...	1996	8675310
viability after thawing and dilution of simultaneously cryopreserved vaccinal babesia bovis and babesia bigemina strains cultured in vitro.	a live, frozen experimental vaccine containing babesia bovis and babesia bigemina multiplied in vitro was stored in liquid nitrogen after simultaneous cryopreservation using glycerol as cryoprotectant. the viability of the vaccine was tested by inoculating (subcutaneously) three groups of seven steers each, 2, 12 and 24 h after thawing at 40 degrees c and dilution to obtain a dose of 2 x 10(7) of each organism. all vaccinated cattle developed detectable parasitaemia in thin and/or thick blood sm ...	1996	8720572
light microscopy diagnosis of babesia bovis and babesia bigemina kinetes in the haemolymph of artificially infected boophilus microplus engorged female ticks.	the length, width and position of the nucleus of babesia bovis and babesia bigemina kinetes from the haemolymph of boophilus microplus engorged female ticks were recorded. additionally, the shape of babesia bovis kinetes were registered as curved, semi-curved or straight. to this aim boophilus microplus tick larvae from a colony free of babesia were fed on splenectomised calves artificially infected with either babesia bovis or babesia bigemina pathogenic strains. six engorged female ticks showi ...	1996	8750679
conservation of merozoite membrane and apical complex b cell epitopes among babesia bigemina and babesia bovis strains isolated in brazil.	babesia merozoite polypeptides bear surface exposed and neutralization-sensitive b cell epitopes and have been shown to induce partial protection against experimental challenge. variation in these epitopes has been examined in a limited number of strains. in this study, utilizing strains of babesia bovis and babesia begemina from matto grosso do sul in brazil, we examined the conservation of epitopes bound by monoclonal antibodies developed against mexico strains of b. bovis and b. bigemina. api ...	1996	8750680
reactive oxygen and nitrogen intermediates and products from polyamine degradation are babesiacidal in vitro.	products released from activated macrophages have been demonstrated to have microbicidal activity against a variety of microorganisms. reactive oxygen intermediates (roi) and reactive nitrogen intermediates (rni) have been shown to affect the induction of degenerate (crisis) forms of plasmodium spp. polyamines are degraded into acrolein which has also been shown to be toxic to plasmodium spp. we have investigated the possibility that these products act similarly with babesia bovis. crisis forms ...	1996	8784495
sequences upstream and downstream from the glutamine-dependent carbamoyl phosphate synthetase-encoding gene from the protozoan babesia bovis.	in the protozoan parasite, babesia bovis, the glutamine-dependent carbamoyl phosphate synthetase-encoding gene (cpsii) contains contiguous amidotransferase- and synthetase-encoding sequences. unlike the organisation in most eukaryotes, the gene is not fused with other genes encoding enzymes of pyrimidine biosynthesis de novo. the nucleotide sequences immediately upstream and downstream from the gene contain motifs which may be involved in regulating its expression.	1996	8654985
non-histone protein 1 (nhp1) is a member of the ku protein family which is upregulated in differentiating mouse myoblasts and human promyelocytes.	we have previously purified and characterized a ubiquitous non-histone protein (nhp1) which has a high affinity (kd 10(-11) m) for different avian vitellogenin gene sequences containing cpgs (hughes et al. (1989) biochemistry 28, 9137-9142; hughes and jost (1989) nucleic acids res. 17, 8511-8520). here we show by microsequencing that the peptides derived from the purified p75 and p85 subunits of nhp1 from hela cells have between 64 and 100% identity with the human ku autoantigen. during the diff ...	1996	8605992
in vitro responsiveness of babesia bovis to imidocarb dipropionate and the selection of a drug-adapted line.	a south african stock of babesia bovis was successfully resuscitated from liquid nitrogen, and cultured in microaerophilous stationary phase. the in vitro susceptibility of the b. bovis stock to titrated concentrations of imidocarb dipropionate was observed and the 50% inhibitory concentration (ic) was determined (8.7 x 10(7) g ml-1). a drug-adapted line was developed by culture in the presence of sub-inhibitory concentrations of imidocarb dipropionate and it had an ic50 eight times higher than ...	1996	8638391
a mouse model for cerebral babesiosis.	clinical symptoms and pathology observed in the cattle infected with babesia bovis are quite similar to those of human cerebral malaria. mechanisms involved in the pathogenesis of cerebral babesiosis, however, are still poorly understood because of the lack of a suitable experimental animal model. in this report, masayoshi tsuji and his colleagues describe b. bovis infection in severe combined immunodeficiency (scid) mice, whose circulating red blood cells (rbcs) have been substituted with bovin ...	1996	15275216
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.	1997	9196820
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 ...	1997	9203307
comparison of the infectivity of babesia bovis, babesia bigemina and anaplasma centrale for cattle after cryopreservation in either dimethylsulphoxide (dmso) or polyvinylpyrrolidone (pvp).		1997	9034504
immunization with babesia bigemina rhoptry-associated protein 1 induces a type 1 cytokine response.	rhoptry-associated protein-1 (rap-1) homologues of babesia bigemina and babesia bovis are promising candidates for inclusion in subunit vaccines against these hemoprotozoan parasites. partial protection against challenge infection has been achieved with native forms of these antigens, but the mechanism of immunity has not been thoroughly defined. we previously demonstrated that a panel of antigen-specific t helper cell clones derived from b. bigemina rap-1-immunized cattle expressed relatively h ...	1997	9041471
[investigation of babesia in farm workers and blood donors in the province of ciego de avila].	a descriptive study of cases was conducted in which 781 sera were investigated using the indirect immunofluorescent technique with antigens of babesia bovis and babesia bigemina at the national center for agricultural health. of them, 371 came from agricultural workers and 410 from donors in the province of ciego de avila. it was started from dilutions of 1/64. an epidemiological survey was done to each seropositive so as to know the risk factors. the test of difference of proportions was used t ...	1997	9685976
immunochemical methods for identification of babesia bovis antigens expressed on the erythrocyte surface.	intraerythrocytic parasites, such as babesia bovis, modify the erythrocyte plasma membrane structurally, antigenically, and functionally. for such parasites the infected erythrocyte surface also is thought to be a primary site for interaction with the host immune system. these properties demand characterization of the various alterations to understand the overall host-parasite interaction, immunity to disease or infection, and bases for parasite persistence. a paucity of adequate methods exists ...	1997	9405201
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 ...	1997	9430113
babesia bovis: identification of immunodominant merozoite surface proteins in soluble culture-derived exoantigen.	babesia bovis merozoite proteins presenting as exoantigens in in vitro culture supernatants have been characterized. bovine antisera to b. bovis exoantigens were used to immunoprecipitate [35s]-methionine metabolically labeled or lactoperoxidase-catalyzed radioiodinated b. bovis merozoite proteins. a total of 24 metabolically labeled proteins ranging in molecular weight from 24,000 to 225,000 da and 9 radioiodinated proteins with molecular weights varying between 24,000 and 225,000 da were ident ...	1997	9342742
vaccination against babesia bovis: t cells from protected and unprotected animals show different cytokine profiles.	vaccination of cattle against the haemoprotozoan parasite, babesia bovis, with the recombinant antigen 11c5 resulted in 9 of 15 cattle being protected against challenge infection. the cellular immune responses of protected and unprotected cattle were compared in order to identify differences in response. no differences were observed in the pattern of change in various blood leukocyte populations throughout challenge infection. facscan analysis revealed an increase in the proportion of cells bear ...	1997	9467739
genetic variation in the dimorphic regions of rap-1 genes and rap-1 loci of babesia bigemina.	the rhoptry-associated protein-1 (rap-1) of babesia bigemina induces protective immune responses in cattle. rap-1 has two regions of sequence dimorphism at the carboxy and amino terminal ends, respectively. neutralization-sensitive, surface-exposed b-cell epitopes are present in the amino terminal variant type 1 (nt-1), and cd4+ t-cell epitopes in the carboxy terminal variant type 1 (ct-1). importantly, antibodies recognizing nt-1 epitopes do not cross react with nt-2 and cd4+ t-cells recognizin ...	1997	9476795
cross-sectional estimation of babesia bovis antibody prevalence in an area of argentina used for extensive cattle breeding as an aid to control babesiosis.	the prevalence of babesia bovis antibodies was estimated by using an elisa (98% sensitivity and 95% specificity). sera were obtained from 165 calves (mean age and standard deviation: 9.7 +/- 2.7 months) from an area in argentina known to be unfavourable for the development of the vector tick, boophilus microplus. the area comprised about 300,000 ha used for cattle breeding. the cattle population of 55,000 included 12,000 cattle under 1 year of age. cattle were maintained mainly on natural grasse ...	1997	9234418
development of effective living vaccines against bovine babesiosis--the longest field trial?	between 1959 and 1996, research was performed to change a vaccine against babesiosis in australia and to improve it as actual or threatened untoward field responses became apparent. the most significant change occurred in 1964 with the traditionally used carriers of babesia being replaced as vaccine donors by acutely infected splenectomised calves. this ensured the infectivity of the vaccine and was fortuitously associated with a reduction in the virulence of babesia bovis in vaccine. since then ...	1997	9279577
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 ...	1997	9195707
genotypic diversity in field isolates of babesia bovis from cattle with babesiosis after vaccination.	to determine whether particular genotypes of babesia bovis were common to field isolates obtained from cattle properties in queensland where the b bovis vaccine had apparently failed.	1997	9293339
pcr methods for the discrimination of babesia bovis isolates.	three different polymerase chain reaction assays for the typing of isolates of babesia bovis have been developed and compared with a hybridisation based method. primers were designed within conserved regions flanking the variable length tandem repeats of the bv80 and bvva1 genes. for the long array of repeats in bvva1, up to 7.5 kb, a modified long template pcr method was developed. the assays were compared using ten independent isolates of babesia bovis. using the bvva1 and bv80 pcr assays, 13 ...	1997	9299692
babesia bovis: genome size, number of chromosomes and telomeric probe hybridisation.	pulsed field gel electrophoresis of intact chromosomes of babesia bovis revealed four chromosomes in the haploid genome. a telomere probe, derived from plasmodium berghei, hybridised to eight sfii restriction fragments of genomic b. bovis dna digests indicating the presence of four chromosomes. a small subunit (18s) ribosomal rna gene probe hybridised to the third chromosome only. the genome size of b. bovis is estimated to be 9.4 million base pairs. the sizes of chromosomes 1, 2, 3 and 4 are es ...	1997	9467743
an enzyme-linked immunosorbent assay (elisa) for the detection of antibodies against babesia bovis in cattle.	a method for the isolation of babesia bovis merozoites from infected erythrocytes (machado et al., 1994) and an enzyme-linked immunosorbent assay (elisa) for the detection of anti-b. bovis antibodies were developed. this elisa utilizes a soluble, alkali-digested b. bovis antigen. sera from calves experimentally infected with b. bovis were screened by this technique from day 9 to day 233 postinfection (pi). maximum titers were reached between days 29 and 149 pi. sera from calves (n = 62), heifers ...	1997	9231985
characterization of a variant erythrocyte surface antigen (vesa1) expressed by babesia bovis during antigenic variation.	babesia bovis, an intraerythrocytic, protozoal parasite of cattle, undergoes clonal antigenic variation (allred dr, cinque rm, lane tj, ahrens kp. infect immun 1994;62:91-98). this ability could provide a mechanism by which the parasite escapes host immune defenses to establish chronic infection. previous work identified two parasite-derived antigens of mr 128,000 and 113,000 that were present on the surface of the infected erythrocyte and appeared to be associated with clonal antigenic variatio ...	1997	9364970
studies on the pathogenicity of babesia bovis in water buffaloes after cryopreservation and resuscitation.	packed erythrocytes infected with babesia bovis were mixed with an equal volume of 16% dimethyl sulphoxide (dmso) in alsever's solution and dispensed into 1.5 or 5 ml cryotubes. the vials were kept in liquid nitrogen (-196 degrees c) for 26, 78, 142 or 149 days. the samples were removed from the liquid nitrogen container and rapidly thawed in a 40 degrees c water bath. the thawed blood successfully infected splenectomised buffalo calves by injection via subcutaneous or intravenous or via intrave ...	1997	9512744
detection of babesia bovis using a dig-labeled dna probe.	a plasmid dna containing the inserted babesia bovis cdna clone designated c51a was used to prepare a dna probe for b. bovis. the purified 0.6 kb specific dna fragment was labeled by dig dna labeling. after denaturation, the probe was hybridised with the blotted target dna extracted from bovine red blood cells infected with b. bovis or other protozoa or bovine red blood cells plus extra white blood cells. it was found that the probe produced from purified 0.6 kb dna fragment could detect sample o ...	1997	9512746