| characterization of allelic variation in the babesia bovis merozoite surface antigen 1 (msa-1) locus and identification of a cross-reactive inhibition-sensitive msa-1 epitope. | the babesia bovis merozoite surface antigen 1 (msa-1), a member of the variable merozoite surface antigen (vmsa) family, is an immunodominant glycoprotein which elicits antibodies that inhibit erythrocyte invasion. while antigenic polymorphism is a general feature of vmsa genes, the molecular basis and extent of msa-1 sequence polymorphism have not been well characterized. in this study we defined the msa-1 locus in the biologically cloned mexico mo7 strain of b. bovis and identified the sequenc ... | 2000 | 11083806 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| persistence of antibodies against epitopes encoded by a single gene copy of the babesia bovis merozoite surface antigen 1 (msa-1). | the babesia bovis merozoite surface antigen-1 (msa-1) is an immunodominant, neutralization-sensitive merozoite surface antigen encoded by a polymorphic gene family. msa-1 antigenic polymorphism results in a complete lack of immunologic cross-reactivity among strains. it is unknown how rapidly this antigenic shift occurs, or whether it evolves in the mammalian host. to determine whether the dominant epitopes encoded by a single msa-1 gene copy vary during the course of a single infection, the ant ... | 1998 | 9576525 |
| babesiosis (babesia bovis) stability in unstable environments. | enzootic stability (herd immunity) in bovine babesiosis occurs when the rate of transmission (inoculation rate) of babesia spp by the tick vector is sufficient to immunize a majority of susceptible calves before the loss of calfhood resistance. the effect of three tick (boophilus microplus) control strategies (none, threshold, and strategic) on enzootic stability and the likelihood of babesiosis (babesia bovis) outbreaks was studied using a spreadsheet age-class computer simulation model. the mo ... | 2000 | 11193666 |
| 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, ... | 1986 | 15462818 |
| 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 |
| a novel 20-kilodalton protein conserved in babesia bovis and b. bigemina stimulates memory cd4(+) t lymphocyte responses in b. bovis-immune cattle. | acquired immunity against the hemoprotozoan parasite babesia bovis is believed to depend on activation of antigen-specific cd4(+) t lymphocytes and ifn-gamma production. a strategy was employed to identify potentially protective antigens from b. bovis based on memory cd4(+) t lymphocyte recognition of fractionated merozoite proteins. fractions of merozoites separated by continuous flow electrophoresis (cfe) that contained proteins of approximately 20 kda were shown previously to stimulate memory ... | 2001 | 11704278 |
| identification of babesia bovis l-lactate dehydrogenase as a potential chemotherapeutical target against bovine babesiosis. | in this study, we characterized a novel babesia bovis cdna clone obtained by immunoscreening the cdna expression phage library with b. bovis-infected bovine serum. the genetic analyses showed that it contained an open reading frame of 993 bp, which was considered to encode b. bovis l-lactate dehydrogenase (bbldh: e.c. 1.1.1.27) because of the strikingly high amino acid identities of its gene product to the ldhs of plasmodium falciparum and toxoplasma gondii. immunological analyses with the anti- ... | 2004 | 15478796 |
| molecular approaches to elucidating innate and acquired immune responses to babesia bovis, a protozoan parasite that causes persistent infection. | for many vector-transmitted protozoal parasites, immunological control of acute infection leads to a state of persistent infection during which parasitemias may cycle unnoticed in infected but otherwise clinically healthy animals. achieving persistent infection is a strategy that favors parasitism, since both host and, therefore, parasite survive, and endemically infected animal populations provide a reservoir of parasites continually available for subsequent transmission. examples of the major ... | 2001 | 11707299 |
| identification of a coronin-like protein in babesia species. | the present study was designed to immunochemically identify a coronin-like protein in babesia bovis, b. bigemina, b. divergens, and b. canis. a 2-kbp cdna insert of b. bovis carried by plasmid bvn9 was sequenced by the dideoxichain-termination method on both strands. the cdna insert contained a 1719-bp long open reading frame coding for a deduced protein sequence of 61.7 kda. sequence analysis using the psi-blast program revealed about 30% protein sequence identity with a coronin-like protein of ... | 2004 | 15604480 |
| use of a monoclonal antibody against babesia bovis merozoite surface antigen-2c for the development of a competitive elisa test. | bovine babesiosis caused by babesia bovis is a disease that hampers the production of beef and dairy cattle in tropical and subtropical regions of the world. new diagnostic methods based on recombinant antigens constitute valuable biotechnological tools for the strategic control of this disease. we have developed a competitive enzyme-linked immunosorbent assay that includes a recombinant form of the merozoite surface antigen-2c and a novel monoclonal antibody against it. preliminary results show ... | 2004 | 15604488 |
| clotrimazole, ketoconazole, and clodinafop-propargyl inhibit the in vitro growth of babesia bigemina and babesia bovis (phylum apicomplexa). | we evaluated the growth inhibitory efficacy of the imidazole derivatives, clotrimazole (clt) and ketoconazole (kc), and the herbicide clodinafop-propargyl (cp), in in vitro cultures of babesia bovis and b. bigemina. clotrimazole was effective in a dose range of 15 to 60 microm (ic50: 11 and 23.5 microm), followed by kc (50 to 100 microm; ic50: 50 and 32 microm) and cp (500 microm; ic50: 265 and 390 microm). in transmission electron microscopy, extensive damage was observed in the cytoplasm of dr ... | 2003 | 14636017 |
| molecular technology and antigenic variation among intraerythrocytic hemoparasites: do we see reality? | antigenic variation is one mechanism of immune evasion utilized by many microorganisms--encompassing such broad evolutionary groups as viruses, bacteria, and protozoa--to survive the onslaught of a specifically activated host immune system. because of its importance to the survival of many infectious agents there is considerable interest in understanding this phenomenon. with knowledge of the molecular mechanisms by which these microbes deliberately manipulate their genomes, it may be possible t ... | 2001 | 11707301 |
| first report of babesia bovis in spain. | | 2001 | 11787787 |
| hsp20, a novel alpha-crystallin, prevents abeta fibril formation and toxicity. | beta-amyloid (abeta) is a major protein component of senile plaques in alzheimer's disease, and is neurotoxic when aggregated. the size of aggregated abeta responsible for the observed neurotoxicity and the mechanism of aggregation are still under investigation; however, prevention of abeta aggregation still holds promise as a means to reduce abeta neurotoxicity. in research presented here, we show that hsp20, a novel alpha-crystallin isolated from the bovine erythrocyte parasite babesia bovis, ... | 2005 | 15722443 |
| progression towards endemic stability to bovine babesiosis in cattle introduced onto a game ranch. | an opportunity to study progression toward endemic stability to babesia bigemina arose when cattle were reintroduced onto a game ranch in 1999 after an absence of three years. the study was conducted between august 2000 and june 2001. the unvaccinated breeding cows were sampled only once. calves born during october 1999 were initially vaccinated against b. bigemina and babesia bovis at the age of 4 months and were then bled at 10, 17 and 20 months of age. calves born during 2000 were bled at 7 a ... | 2004 | 15732461 |
| serological survey of babesia bovis and anaplasma marginale in cattle in tete province, mozambique. | a serological survey of bovine babesiosis and anaplasmosis in communal cattle was conducted in the northwestern province of tete, mozambique. blood was collected from cattle ranging from 4 to 15 months old from randomly selected farms from six districts. thirty-nine per cent of all 478 calves tested in tete province were seropositive to the elisa for babesia bovis antibodies and 63% of all calves were seropositive in the card agglutination test for anaplasma marginale. seroprevalence of b. bovis ... | 2005 | 15742867 |
| structural implications of novel diversity in eucaryal rnase p rna. | previous eucaryotic rnase p rna secondary structural models have been based on limited diversity, representing only two of the approximately 30 phylogenetic kingdoms of the domain eucarya. to elucidate a more generally applicable structure, we used biochemical, bioinformatic, and molecular approaches to obtain rnase p rna sequences from diverse organisms including representatives of six additional kingdoms of eucaryotes. novel sequences were from acanthamoeba (acathamoeba castellanii, balamuthia ... | 2005 | 15811915 |
| vaccination of older bos taurus bulls against bovine babesiosis. | two separate groups of bos taurus bulls, one of 106 and the second of 27 animals, imported to israel from areas free of babesia bovis and babesia bigemina, were vaccinated against babesiosis with a bivalent live attenuated vaccine. in light of the fact that routine vaccination is recommended at the weaning age, these bulls--of highly susceptible breeds--were kept under close surveillance to prevent losses that might be caused by severe clinical reactions to their vaccination at the age of 16-18 ... | 2005 | 15845278 |
| conservation of babesia bovis small heat shock protein (hsp20) among strains and definition of t helper cell epitopes recognized by cattle with diverse major histocompatibility complex class ii haplotypes. | babesia bovis small heat shock protein (hsp20) is recognized by cd4+ t lymphocytes from cattle that have recovered from infection and are immune to challenge. this candidate vaccine antigen is related to a protective antigen of toxoplasma gondii, hsp30/bag1, and both are members of the alpha-crystallin family of proteins that can serve as molecular chaperones. in the present study, immunofluorescence microscopy determined that hsp20 is expressed intracellularly in all merozoites. importantly, hs ... | 2004 | 14742557 |
| babesia spp. infection in boophilus microplus engorged females and eggs in sao paulo state, brazil. | babesia spp. infections were investigated in bos taurus x bos indicus dairy cows and calves and in boophilus microplus engorged female ticks and eggs. blood samples and engorged female ticks were collected from 25 cows and 27 calves. babesia spp. was detected in ticks by microscopic examination of hemolymph of engorged female and by squashes of egg samples. cattle infection was investigated in blood thin smears and by dna amplification methods (pcr and nested pcr), using specific primers for bab ... | 2005 | 15893070 |
| a longitudinal study of sero-conversion to tick-borne pathogens in smallholder dairy youngstock in tanzania. | a longitudinal study of sero-conversion of youngstock to the tick-borne pathogens theileria parva, t. mutans, anaplasma marginale, babesia bigemina and b. bovis was conducted over two years on smallholder dairy farms in tanga region, tanzania. there was evidence of maternal antibodies to all tick-borne pathogens in animals less than 18 weeks of age. seroprevalence increased as expected with age in animals older than this but seroprevalence profiles underestimated the force of infection due to wa ... | 2005 | 15936149 |
| babesiosis of cattle. | tick fever or cattle fever (babesiosis) is economically the most important arthropod-borne disease of cattle worldwide with vast areas of australia, africa, south and central america and the united states continuously under threat. tick fever was the first disease for which transmission by an arthropod to a mammal was implicated at the turn of the twentieth century and is the first disease to be eradicated from a continent (north america). this review describes the biology of babesia spp. in the ... | 2004 | 15938514 |
| improved enzyme-linked immunosorbent assay using c-terminal truncated recombinant antigens of babesia bovis rhoptry-associated protein-1 for detection of specific antibodies. | an enzyme-linked immunosorbent assay (elisa) based on a recombinant rhoptry-associated protein-1 (rap-1) of babesia bovis has been previously developed, but it was imperfect because some cross-reactions were still present in babesia bigemina-infected bovine sera. to improve its accuracy for the specific detection of the antibodies to b. bovis, we constructed three c-terminal truncated recombinant antigens of the rap-1-rct1 (amino acids [aa] 301 to 408), rct2 (aa 388 to 490), and rct3 (aa 466 to ... | 2004 | 15071011 |
| host serum modifies the drug susceptibility of babesia bovis in vitro. | babesia parasites generally require a defined percentage of serum in the culture medium for their in vitro growth. in this study, we attempted to culture babesia bovis in a serum-free condition. the growth pattern and morphology of b. bovis in serum-free (plain) git medium were unaltered as compared to those of the standard growth condition containing 40% bovine serum in m199. when exposed to the test drugs, the parasite in plain git medium showed clearly lower ic50 values than those in 40% seru ... | 2005 | 15991491 |
| spatial and management factors associated with exposure of smallholder dairy cattle in tanzania to tick-borne pathogens. | a cross-sectional study of serum antibody responses of cattle to tick-borne pathogens (theileria parva, theileria mutans,anaplasma marginale, babesia bigemina and babesia bovis) was conducted on smallholder dairy farms in tanga and iringa regions of tanzania. seroprevalence was highest for t. parva (48% in iringa and 23% in tanga) and b. bigemina (43% in iringa and 27% in tanga) and lowest for b. bovis (12% in iringa and 6% in tanga). we use spatial and non-spatial models, fitted using classical ... | 2005 | 16023121 |
| cellular adhesive phenomena in apicomplexan parasites of red blood cells. | the apicomplexan parasites babesia and plasmodium are related, yet phylogenetically distinct haemoprotozoa that infect red blood cells and cause severe diseases of major human and veterinary importance. a variety of cellular and molecular interactions are pivotal in many aspects of the pathogenicity of these two parasites. comparison of the cellular and molecular mechanisms that culminate in accumulation of parasitised red blood cells in the microvasculature of cattle infected with babesia bovis ... | 2005 | 16087297 |
| babesia bovis merozoite surface antigen 1 and rhoptry-associated protein 1 are expressed in sporozoites, and specific antibodies inhibit sporozoite attachment to erythrocytes. | we examined babesia bovis sporozoites for the expression of two molecules, merozoite surface antigen 1 (msa-1) and rhoptry-associated protein 1 (rap-1), that are postulated to be involved in the invasion of host erythrocytes. both msa-1 and rap-1 were transcribed and expressed in infectious sporozoites. importantly, monospecific msa-1 and rap-1 antisera each inhibited sporozoite invasion of erythrocytes in vitro. this is the first identification of antigens expressed in babesia sp. sporozoites a ... | 2002 | 11854249 |
| intrahaplotype and interhaplotype pairing of bovine leukocyte antigen dqa and dqb molecules generate functional dq molecules important for priming cd4(+) t-lymphocyte responses. | antigen-specific cd4(+) t-lymphocyte responses are restricted by major histocompatibility complex class ii molecules, which influence t-cell priming during infection. human leukocyte antigen (hla) and bovine leukocyte antigen (bola) drb3 and dq genes are polymorphic, but unlike hla, many bola haplotypes have duplicated dq genes, and antibody-blocking studies indicated that bola-dq molecules present various pathogen epitopes. limited experimentation also suggested that bola-dq molecules formed by ... | 2005 | 16220347 |
| the babesia bovis merozoite surface antigen 2 locus contains four tandemly arranged and expressed genes encoding immunologically distinct proteins. | members of the variable merozoite surface antigen (vmsa) gene family of babesia bovis encode membrane proteins involved in erythrocyte invasion. in this study, we have identified and sequenced the complete 8.3-kb genomic locus containing msa-2, a member of the vmsa family, in the biologically cloned mexico mo7 strain. four tandemly arranged copies of msa-2-related genes were found in the locus. the four genes, designated msa-2a(1) (which corresponds to the originally described msa-2 gene), msa-2 ... | 2002 | 12065497 |
| potential for recombinant babesia bovis antigens to protect against a highly virulent isolate. | two antigens from babesia bovis,12d3 and 11c5, were expressed and purified as recombinant proteins in escherichia coli and used to vaccinate groups of six babesia-susceptible cattle. these were subsequently challenged with a highly virulent strain of b. bovis. all cattle showed symptoms of disease and most required treatment. cattle vaccination groups receiving either 12d3 or 11c5 or a combination of both, reduced parasitaemia by approximately fourfold and a number of individual animals appeared ... | 2005 | 16255742 |
| serological survey of babesia bovis, babesia bigemina, and anaplasma marginale antibodies in cattle from the semi-arid region of the state of bahia, brazil, by enzyme-linked immunosorbent assays. | the objectives of this work were to determine the prevalence of babesia bovis, babesia bigemina, and anaplasma marginale detecting antibodies in cattle raised in the semi-arid region of the state of bahia, brazil, through indirect enzyme linked immunosorbent assays (elisa) and to compare the performances of indirect enzyme-linked immunosorbent assays with crude (i-elisa-cranaag) and recombinant major surface protein-5 (i-elisa-msp-5ag), as antigens to detect antibodies against a. marginale. an s ... | 2005 | 16302060 |
| a babesia bovis merozoite protein with a domain architecture highly similar to the thrombospondin-related anonymous protein (trap) present in plasmodium sporozoites. | recognition and invasion of host cells is a key step in the life-cycle of all apicomplexan parasites. the thrombospondin-related anonymous protein (trap) of plasmodium sporozoites is directly involved in both processes and shares conserved adhesive domains with micronemal transmembrane proteins of other apicomplexans. here, we report the cloning and characterization of a babesia bovis trap homologue (bbtrap). it was predicted to be a type 1 transmembrane protein containing a von willebrand facto ... | 2004 | 15138064 |
| antigenic variation in babesia bovis occurs through segmental gene conversion of the ves multigene family, within a bidirectional locus of active transcription. | antigenic variation in babesia bovis is one aspect of a multifunctional virulence/survival mechanism mediated by the heterodimeric variant erythrocyte surface antigen 1 (vesa1) protein that also involves endothelial cytoadhesion with sequestration of mature parasitized erythrocytes. the ves1alpha gene encoding the vesa1a subunit was previously identified. in this study, we present the unique organization of the genomic locus from which ves1alpha is transcribed, and identify a novel branch of the ... | 2006 | 16390438 |
| myosins of babesia bovis: molecular characterisation, erythrocyte invasion, and phylogeny. | using degenerate primers, three putative myosin sequences were amplified from australian isolates of babesa bovis and confirmed as myosins (termed bbmyo-a, bbmyo-b, and bbmyo-c) from in vitro cultures of the w strain of b. bovis. comprehensive analysis of 15 apicomplexan myosins suggests that members of class xiv be defined as those with greater than 35% myosin head sequence identity and that these be further subclassed into groups bearing above 50-60% identity. bbmyo-a protein bears a strong si ... | 2002 | 12112135 |
| a novel 78-kda fatty acyl-coa synthetase (acs1) of babesia bovis stimulates memory cd4+ t lymphocyte responses in b. bovis-immune cattle. | antigen-specific cd4+ t lymphocyte responses contribute to protective immunity against babesia bovis, however the antigens that induce these responses remain largely unknown. a proteomic approach was used to identify novel b. bovis antigens recognized by memory cd4+ t cells from immune cattle. fractions obtained from merozoites separated by continuous-flow electrophoresis (cfe) that contained proteins ranging from 20 to 83 kda were previously shown to stimulate memory cd4+ lymphocyte responses i ... | 2006 | 16469396 |
| age-related innate immune response in calves to babesia bovis involves il-12 induction and il-10 modulation. | there is a strong innate immunity in calves to infection with babesia bovis. interleukin (il)-12 and il-10 have been shown in vitro to be important immunoregulatory cytokines. here we demonstrate in vivo that the protective innate response in young calves to infection with virulent b. bovis involves the early appearance of il-12 and interferon-gamma (ifn-gamma) transcripts in the spleen. in contrast, il-12 and ifn-gamma mrna expression in the spleens of adult cattle that succumbed to the infecti ... | 2002 | 12381584 |
| residual effect of antibabesial drugs on the live redwater blood vaccines. | it has been demonstrated that the attenuated organisms used in the unfrozen south african babesia bovis and b. bigemina (redwater) vaccines are susceptible for longer periods to the residual effect of the anti-babesial drugs diminazene and imidocarb dipropionate than the virulent field strains. reports of vaccine failures in some animals vaccinated with the frozen south african redwater vaccines after prophylactic treatment with imidocarb dipropionate have led us to reinvestigate the validity of ... | 2002 | 12381585 |
| a serological survey of bovine babesiosis in northern and eastern zimbabwe. | the geographical distribution of babesia bovis and babesia bigemina antibodies in communal herds in northern and eastern zimbabwe was determined using the elisa technique. the animals in different herds in the study region had different levels of natural exposure to b. bovis (mean 32%, range 0-79%) and b. bigemina (mean 52%, range 5-92%) infections. the majority of herds (90%) were endemically unstable for b. bigemina and 62% were unstable for b. bovis. natural region 5 and manicaland province h ... | 1999 | 10689698 |
| sequencing a new target genome: the boophilus microplus (acari: ixodidae) genome project. | the southern cattle tick, boophilus microplus (canestrini), causes annual economic losses in the hundreds of millions of dollars to cattle producers throughout the world, and ranks as the most economically important tick from a global perspective. control failures attributable to the development of pesticide resistance have become commonplace, and novel control technologies are needed. the availability of the genome sequence will facilitate the development of these new technologies, and we are p ... | 2006 | 16506442 |
| competitive enzyme-linked immunosorbent assay based on a rhoptry-associated protein 1 epitope specifically identifies babesia bovis-infected cattle. | the competitive enzyme-linked immunosorbent assay (celisa) format has proven to be an accurate, reliable, easily standardized, and high-throughput method for detecting hemoparasite infections. in the present study, a species-specific, broadly conserved, and tandemly repeated b-cell epitope within the c terminus of the rhoptry-associated protein 1 of the hemoparasite babesia bovis was cloned and expressed as a histidine-tagged thioredoxin fusion peptide and used as antigen in a celisa. the assay ... | 2003 | 12522037 |
| antigenic variation as an exploitable weakness of babesial parasites. | babesia bovis and its bovine host interact in many ways, resulting in a range of disease and infection phenotypes. host responses to the parasite elicit or select for a variety of responses on the part of the parasite, the full range of which is not yet known. one well-established phenomenon, thought to aid parasite survival by evasion of host adaptive immune responses, is the sequential expansion of antigenically variant populations during an infection, a phenomenon referred to as "antigenic va ... | 2006 | 16517078 |
| identity of the causal agents of human babesiosis in europe. | most cases of human babesiosis are caused either by babesia divergens in europe or babesia microti in america. b. microti, once regarded as a single species, occurs as a world-wide species complex and although both phenotypic and genotypic features lend support to suggestions that zoonotic b. microti may occur in europe, convincing medical evidence is lacking. several b. divergens-like parasites have emerged in the last few years, but 18s rrna gene analysis suggests that b. divergens 'sensu stri ... | 2006 | 16524772 |
| expressed sequence tag (est) analysis of the erythrocytic stages of babesia bovis. | expressed sequence tags (ests) provide an efficient way to identify large numbers of genes expressed in a specific stage of the life cycle of an organism. here we analysed approximately 13,000 ests derived from the erythrocytic stage of the apicomplexan parasite babesia bovis. the ests were clustered in order to obtain information on the expression level of a gene and to increase sequence length and reliability. a total of 3522 clusters were obtained and annotated using blast algorithms. the clu ... | 2006 | 16530971 |
| genetic basis for gpi-anchor merozoite surface antigen polymorphism of babesia and resulting antigenic diversity. | glycosyl-phosphatidylinositol anchor merozoite surface antigens (gpi-anchor msa) are proposed to act in the invasion process of infective merozoites of babesia into host erythrocytes. because of their essential function in the survival of babesia parasites, they constitute good candidates for the development of vaccines against babesiosis and they have been extensively analyzed. these include babesia bovis variable msa (vmsa) and babesia bigemina gp45/gp55 proteins of the agents of bovine babesi ... | 2006 | 16551492 |
| comparison of different direct diagnostic methods to identify babesia bovis and babesia bigemina in animals vaccinated with live attenuated parasites. | blood smear examination, flow cytometry, duplex polymerase chain reaction (pcr), and duplex nested pcr (npcr) were evaluated for detection of babesia bigemina and babesia bovis infections in cattle vaccinated with live attenuated strains. two groups of four cattle were immunized with either b. bigemina (bi) or b. bovis (bo). on day 23 post inoculation (pi), bi cattle were vaccinated with b. bovis (bibo) and bo cattle were vaccinated with b. bigemina (bobi). babesia bigemina was first detected by ... | 2006 | 16580136 |
| bovine splenic nk cells synthesize ifn-gamma in response to il-12-containing supernatants from babesia bovis-exposed monocyte cultures. | the spleen is a critical effector organ functioning, in haemoparasitic diseases like babesiosis, to destroy the pathogen and clear the host of infected erythrocytes. it has an important role in both innate responses and adaptive immune responses. young calves demonstrate a strong spleen-dependent innate response to an initial infection with babesia bovis involving the type-1 regulating cytokines il-12 and ifn-gamma. however, the specific splenic cell types that produce ifn-gamma in response to i ... | 2006 | 16629708 |
| the impact of 2 dipping systems on endemic stability to bovine babesiosis and anaplasmosis in cattle in 4 communally grazed areas in limpopo province, south africa. | a 12-month study was conducted in 4 communal grazing areas in the bushbuckridge region, limpopo province, south africa. the main objective was to investigate the impact of reduced acaricide application on endemic stability to bovine babesiosis (babesia bigemina and babesia bovis) and anaplasmosis (anaplasma marginale) in the local cattle population. to this end 60 cattle in each communal grazing area were bled at the beginning and the conclusion of the experimental period and their sera were ass ... | 2005 | 16642719 |
| characterization and gene expression of babesia bovis elongation factor-1alpha. | elongation factor 1 alpha (ef-1alpha) is a constitutively expressed, abundant protein that is a key element in eukaryotic protein translation. because of its high level of transcription, the ef-1alpha promoter has been utilised to drive exogenous gene expression in transfected cells. in this study, we identified and characterised the ef-1alpha locus of babesia bovis, a causative agent of bovine babesiosis, and examined the transcriptional activity of the ef-1alpha promoter. the ef-1alpha locus i ... | 2006 | 16677650 |
| molecular diagnosis of theileria and babesia species infecting cattle in northern spain using reverse line blot macroarrays. | piroplasmosis in cattle is caused by tick-borne haemoprotozoan parasites of the genera theileria and babesia. molecular detection techniques offer higher sensitivity and specificity than microscopy examination methods and serological tests. a reverse line blot (rlb) macroarray that included generic and species-specific probes for theileria annulata, theileria buffeli, babesia bovis, babesia bigemina, babesia divergens and babesia major was used to study the presence and identity of the piroplasm ... | 2006 | 16684356 |
| the babesia bovis merozoite surface antigen 1 hypervariable region induces surface-reactive antibodies that block merozoite invasion. | a hypervariable region (hvr) previously identified in the carboxy-terminal one-third of the babesia bovis variable merozoite surface antigen family was more extensively analyzed in merozoite surface antigen 1 (msa-1) from 16 strains and isolates. the msa-1 hvr is proline rich and contains three semiconserved motifs nearly identical to those described for the related family member msa-2. two msa-1-specific monoclonal antibodies previously shown to be reactive with the merozoite surface bound to a ... | 2006 | 16714599 |
| elevated anti-parasitic activity in peripheral blood monocytes and neutrophils of cattle infected with babesia bovis. | the innate immune response to bovine babesia bovis infection in vivo has not previously been established. we used assays measuring phagocytosis and oxidative burst to investigate the immune response because they are indicative of the innate antimicrobial capacity of monocytes and neutrophils. monocyte and neutrophil phagocytosis is thought to be non-specific in nature and so the phagocytosis of either opsonised zymosan or escherichia coli was used to indicate the non-specific phagocytic capacity ... | 2001 | 11165268 |
| small heat shock proteins differentially affect abeta aggregation and toxicity. | beta-amyloid (abeta) is the primary protein component of senile plaques in alzheimer's disease (ad) and has been implicated in neurotoxicity associated with the disease. abeta aggregates readily in vitro and in vivo, and its toxicity has been linked to its aggregation state. prevention of abeta aggregation has been investigated as a means to prevent abeta toxicity associated with ad. recently we found that hsp20 from babesia bovis prevented both abeta aggregation and toxicity [s. lee, k. carson, ... | 2006 | 16828710 |
| a secreted cystatin from the tick haemaphysalis longicornis and its distinct expression patterns in relation to innate immunity. | proteins capable of selective and specific inhibition of cysteine protease have been identified as cystatins and are isolated from a variety of microbes and tissues of animals and plants. the physiological function of these proteins has been proposed to be the regulation of protein turnover and defense against pathogens as well as the balance of the host-parasite immune relationship. genes encoding cystatins have been found in several species of ticks, but the function of cystatin in ticks is no ... | 2006 | 16835018 |
| babesia bovis merozoite surface protein-2c (msa-2c) contains highly immunogenic, conserved b-cell epitopes that elicit neutralization-sensitive antibodies in cattle. | the search for vaccine candidates against bovine babesiosis caused by babesia bovis is greatly focused on the identification of merozoite surface-exposed antigens that are widely conserved, functionally relevant and immunodominant in cattle protected against b. bovis infections. we have recently identified msa-2c, a member of the b. bovis variable merozoite surface antigen (vmsa) gene family, which in contrast to other members, appears to be highly conserved among geographically distant b. bovis ... | 2003 | 12672522 |
| intra-uterine infection with babesia bovis in a 2-day-old calf. | infection with babesia bovis was diagnosed in a 2-day-old female calf apparently transmitted in utero. the calf was born as the second calving to a cross-bred beef cow permanently on pasture. diagnosis was based upon identification of b. bovis in peripheral blood smears and clinical signs which included fever, jaundice, pale mucous membranes and convulsions. anaemia, leucocytosis, thrombocytopenia and lymphocytosis were noted at the febrile acute stage of the disease. the blood smears revealed e ... | 2003 | 12675895 |
| prevalence of blood parasites in cattle from wilayates of annaba and el tarf east algeria. | between june and september 2002, a preliminary study was conducted to assess the prevalence of blood parasites of cattle in eastern algeria. fifty-four bovines of different genotypes were submitted to clinical examination. from each animal, blood smears were made and stained by giemsa. four species of parasites, namely theileria annulata, t. orientalis, babesia bovis and anaplasma marginale were encountered. fifty animals carried single or multiple infections with blood parasites and four were f ... | 2004 | 16929762 |
| reverse line blotting: a new technique for the sensitive detection of tick borne pathogens. | recently, a new molecular diagnostic technique for tick borne pathogens has been developed and is called reverse line blotting. this paper outlines the basis of this method and then illustrates its use for the analysis of blood samples obtained from ugandan cattle and buffalo. the sensitivity and the specificity are discussed in relation to the use of this technique in the maghreb | 2004 | 16929766 |
| bovine piroplasms in minorca (balearic islands, spain): a comparison of pcr-based and light microscopy detection. | the present study provides the first epidemiological data regarding infection by theileria and babesia piroplasms in cattle in minorca. more than 94% of the studied animals were positive for the presence of theileria sp., and of those, 41.3% were positive for the presence of theileria annulata. these results indicate that the prevalence of mediterranean theileriosis caused by t. annulata is very high in minorcan dairy farms and that other theileria sp. are also present in the area. the prevalenc ... | 2001 | 11502372 |
| overcoming constraints to meeting increased demand for babesia bigemina vaccine in australia. | demand for live trivalent tick fever vaccine containing babesia bovis, babesia bigemina and anaplasma centrale produced by the department of primary industries, queensland, has increased from less than 10,000 doses in 1988 to 500,000 doses in 2001. this paper describes a series of trials aimed at overcoming certain constraints to obtain b. bigemina parasitised erythrocytes (pes) on a large enough scale from infected splenectomised calves to meet the demand. passage through a series of splenectom ... | 2003 | 12935736 |
| seroprevalence of babesia bovis and babesia bigemina in cattle in the soutpansberg region, limpopo province, south africa, associated with changes in vector-tick populations. | a survey was conducted at 30 communal dip tanks and on 5 commercial farms in limpopo province, south africa, during 1999 and 2000 to determine the seroprevalence of antibodies to babesia bovis and babesia bigemina. cattle seropositive for b. bovis were found in 97% of the herds on communal land; the overall seroprevalence changed little between 1999 (63.3%) and 2000 (62.4%). all herds surveyed were infected with b. bigemina, and overall seroprevalence decreased significantly from 56.1% in 1999 t ... | 2006 | 17120620 |
| identification of common antigens in babesia bovis, b. bigemina, and b. divergens. | bovine babesiosis, caused by babesia bovis, b. bigemina, and b. divergens, is a significant impediment to livestock production in countries with tropical/subtropical and temperate climates. previous studies conducted on the immunoprophylaxis against the disease and diagnosis of these parasites has demonstrated the presence of similar antigens. the objective of this article was to identify and partially characterize antigens conserved among these three species. immunochemical analysis using sera ... | 2006 | 17135542 |
| cross-sectional estimation of babesia bovis antibody prevalence in cattle in two contrasting dairying areas in tanzania. | the crude prevalence of antibodies to babesia bovis infection in cattle was estimated by serology using indirect elisa during the period january to april, 1999. sera were obtained from 1,395 dairy cattle (of all ages, sexes and breeds) on smallholder farms, the majority being kept under a zero grazing regime. the crude prevalence of antibodies to babesia bovis was 6 % for tanga and 12 % for iringa. the forces of infection based on the age sero-prevalence profile, were estimated at six for iringa ... | 2004 | 15580770 |
| field challenge of cattle vaccinated with a combined babesia bovis and babesia bigemina frozen immunogen. | to determine the optimal dose of a combined, frozen immunogen containing in vitro culture-derived strains of babesia bovis and babesia bigemina, twenty-four 14-month-old bos taurus steers from a boophilus microplus-free area in northern mexico were used in this experiment. cattle were randomly allocated into six groups with four animals each, and were intramuscularly inoculated as follows: group 1 (control animals) were administered with normal bovine erythrocytes; group 2 received 1 x 10(7) b. ... | 2004 | 15604506 |
| amount of cholesterol in host membrane affects erythrocyte invasion and replication by babesia bovis. | cholesterol is a major component of the erythrocyte membrane. in the present study, we investigated the effects of cholesterol reduction in host bovine erythrocytes (rbc) on the growth of babesia bovis, a major bovine haemoprotozoon. an in vitro growth assay with bovine rbc that had been prepared by pre-treatment with a cholesterol depletion agent (methyl-beta-cyclodextrin, mcd) showed that the culture with 5 mm mcd-treated rbc inhibited the growth of b. bovis significantly as compared with that ... | 2007 | 17147838 |
| the development of an enzyme-linked immunosorbent assay for trypanosoma vivax antibodies and its use in epidemiological surveys. | there are data indicating that the distribution of trypanosoma vivax in the brazilian territory is expanding with potential to reach other areas, where the vectors are present. the detection of anti-trypanosomal antibodies in serum provides important information of the trypanosomal status in cattle herds. for this reason, an enzyme-linked immunosorbent assay (tv-elisa-ab) with crude antigen from one brazilian isolate of t. vivax was developed and evaluated. the sensitivity and specificity were r ... | 2006 | 17160291 |
| immune response to babesia bigemina infection in pregnant cows. | babesiosis is a tick-borne disease of cattle caused by babesia bigemina and babesia bovis and is transmitted by the tick vector boophilus microplus. in this study, we investigate b. bigemina infection regarding the clinical infection, t cell distribution, and cytokine profile during the acute phase of an experimental infection in pregnant cows. | 2004 | 15604509 |
| pcr-based detection of babesia bovis and babesia bigemina in their natural host boophilus microplus and cattle. | pcr and nested-pcr methods were used to assess the frequency of babesia bovis and babesia bigemina infection in boophilus microplus engorged females and eggs and in cattle reared in an area with endemic babesiosis. blood and the engorged female ticks were from 27 naturally infested calves and 25 crossbred cows. the frequency of both babesia species was similar in calves and cows (p>0.05). babesia bovis was detected in 23 (85.2%) calves and in 25 (100%) cows and b. bigemina was detected in 25 (92 ... | 2005 | 15619521 |
| detection of babesia bigemina infection in strains of rhipicephalus (boophilus) microplus collected from outbreaks in south texas. | the sudden death of several cattle infested experimentally with rhipicephalus (boophilus) microplus led to a clinical investigation into the reasons for the unexpected mortality. microscopic evidence for babesia bigemina infection was found in blood smears from the affected animals and a pcr assay was designed to detect the presence of b. bigemina and babesia bovis in all r. microplus strains received and propagated at the laboratory. the assay utilizes a nested pcr approach with the first pcr a ... | 2007 | 17178440 |
| bmigi: a database of cdnas expressed in boophilus microplus, the tropical/southern cattle tick. | we used an expressed sequence tag approach to initiate a study of the genome of the southern cattle tick, boophilus microplus. a normalized cdna library was synthesized from pooled rna purified from tick larvae which had been subjected to different treatments, including acaricide exposure, heat shock, cold shock, host odor, and infection with babesia bovis. for the acaricide exposure experiments, we used several strains of ticks, which varied in their levels of susceptibility to pyrethroid, orga ... | 2005 | 15857764 |
| development of detection methods for ruminant interleukin (il)-4. | recombinant bovine il-4 (rbo il-4) was transiently expressed in cos-7 cells. mice were immunised with a plasmid encoding rbo il-4 and boosted with rbo il-4. a number of monoclonal antibodies (mab) were generated that reacted with rbo il-4 in an elisa and these cloned hybridomas were termed cc311, cc312, cc313 and cc314. a pair of mab (cc313 and cc314) was identified that together could be used to detect both recombinant and native bovine il-4 by elisa and a luminometric detection method was appl ... | 2005 | 15979636 |
| sequence variation and immunologic cross-reactivity among babesia bovis merozoite surface antigen 1 proteins from vaccine strains and vaccine breakthrough isolates. | the babesia bovis merozoite surface antigen 1 (msa-1) is an immunodominant membrane glycoprotein that is the target of invasion-blocking antibodies. while antigenic variation has been demonstrated in msa-1 among strains from distinct geographical areas, the extent of sequence variation within a region where it is endemic and the effect of variation on immunologic cross-reactivity have not been assessed. in this study, sequencing of msa-1 from two australian b. bovis vaccine strains and 14 breakt ... | 2005 | 16113254 |
| modification of host erythrocyte membranes by trypsin and chymotrypsin treatments and effects on the in vitro growth of bovine and equine babesia parasites. | in the present study, we investigated the effects of protease pretreatments of host erythrocytes (rbc) on the in vitro growth of bovine babesia parasites (babesia bovis and b. bigemina) and equine babesia parasites (b. equi and b. caballi). the selected proteases, trypsin and chymotrypsin, clearly modified several membrane proteins of both bovine and equine rbc, as demonstrated by sds-page analysis; however, the protease treatments also modified the sialic acid content exclusively in bovine rbc, ... | 2007 | 17436968 |
| merozoite surface antigen 2 proteins of babesia bovis vaccine breakthrough isolates contain a unique hypervariable region composed of degenerate repeats. | the merozoite surface antigen 2 (msa-2) proteins of babesia bovis are members of the variable merozoite surface antigen (vmsa) family that have been implicated in erythrocyte invasion and are important targets for antibody-mediated blocking of invasion. extensive sequence variation in another vmsa member, msa-1, has been shown in all vaccine breakthrough isolates. to test the hypothesis that the msa-2 genes of vaccine breakthrough isolates would also encode a diverse set of proteins, the complet ... | 2005 | 16239512 |
| label-free detection of babesia bovis infected red blood cells using impedance spectroscopy on a microfabricated flow cytometer. | impedance spectroscopy is a powerful tool for label-free analysis and characterisation of living cells. in this work, we achieved the detection of babesia bovis infected red blood cells using impedance spectroscopy on a microfabricated flow cytometer. the cellular modifications caused by the intracellular parasite result in a shift in impedance which can be measured dielectrically. thus, a rapid cell-by-cell detection with microliter amounts of reagents is possible. unlike other diagnostic tests ... | 2007 | 17451631 |
| antigenic variation by protozoan parasites: insights from babesia bovis. | antigenic variation of surface membrane proteins by protozoan parasites enables these pathogenic organisms to avoid host immune responses and thus perpetuate long-term infections. babesia bovis, the causative agent of severe babesiosis in cattle, was previously shown to undergo antigenic variation through modifications to its primary surface antigen, a protein called vesa1. in this issue, al-khedery and allred provide a detailed description of the genes that encode vesa1 and present convincing e ... | 2006 | 16390434 |
| a quantitative pcr assay for the detection and quantification of babesia bovis and b. bigemina. | the haemoparasites babesia bovis and babesia bigemina affect cattle over vast areas of the tropics and temperate parts of the world. microscopic examination of blood smears allows the detection of clinical cases of babesiosis, but this procedure lacks sensitivity when parasitaemia levels are low. in addition, differentiating between similar haemoparasites can be very difficult. molecular diagnostic procedures can, however, overcome these problems. this paper reports a quantitative pcr (qpcr) ass ... | 2007 | 17466458 |
| detection and quantification of anaplasma marginale dna in blood samples of cattle by real-time pcr. | a taqman-based real-time pcr assay was developed for the diagnosis of anaplasma marginale infection of cattle. the established assay was proven to be highly specific, since no cross-reactions were observed with other anaplasma species of ruminants, including the closely related anaplasma centrale, or other haemoparasites of ruminants (anaplasma bovis, anaplasma ovis, anaplasma phagocytophilum, babesia bovis, babesia bigemina, theileria annulata and theileria buffeli). the detection limit was equ ... | 2007 | 17466470 |
| epidemiological studies on tick-borne diseases of cattle in central equatoria state, southern sudan. | a herd-based study was carried out in central equatoria state, southern sudan, to study epidemiological aspects of tick-borne diseases. six herds of cattle situated in three different locations were selected and investigated every 3 months during the year 2005. blood smears for giemsa staining and blood spots on filter paper for deoxyribonucleic acid extraction were collected from 600 apparently healthy indigenous cattle. a total of 69 (11.5%) samples showed the presence of piroplasms in giemsa- ... | 2007 | 17530477 |
| expression of c-terminal truncated and full-length babesia bigemina rhoptry-associated protein 1 and their potential use in enzyme-linked immunosorbent assay. | recombinant antigen-based enzyme-linked immunosorbent assay (elisa) was developed for the serological diagnosis of babesia bigemina infection by using a full-length b. bigemina rhoptry-associated protein 1 (rrap-1) and the truncated c-terminal rap-1 (rrap-1/ct). while the rrap-1 showed cross reactivity between b. bigemina- and babesia bovis-infected bovine sera, the rrap-1/ct was highly specific to b. bigemina-infected bovine sera and proved useful in the detection of sequential sera collected f ... | 2006 | 16442735 |
| development of two immunochromatographic tests for the serodiagnosis of bovine babesiosis. | in this study, we developed two immunochromatographic tests (icts), which are nitrocellulose membrane-based immunoassays for the convenient and rapid serodiagnosis of bovine babesiosis caused by babesia bovis (boict) and babesia bigemina (biict). the efficacy of two icts was evaluated using 13 positive sera from experimentally infected cattle with b. bovis or b. bigemina. clear results showed that the boict and elisa detected antibodies in sera collected from 14 to 93 days post-infection, while ... | 2007 | 17590275 |
| cyclin-dependent kinase inhibitors block erythrocyte invasion and intraerythrocytic development of babesia bovis in vitro. | summarycyclin-dependent kinases (cdks) are essential for the regulation of the eukaryotic cell cycle. a number of chemicals, which selectively inhibit the cdk activities, have been synthesized for the development of anti-cancer drugs. this report describes the inhibitory effect of purine derivatives known to be cdk inhibitors on the asexual growth of babesia bovis. the 4 compounds, roscovitine, purvalanol a, cgp74514a, and cdk2 inhibitor ii, showed significantly suppressive effects on the in vit ... | 2007 | 17634158 |
| effects of protein kinase inhibitors on the in vitro growth of babesia bovis. | staurosporine, ro-31-7549, and kn-93, which are inhibitors of serine/threonine protein kinase, protein kinase c, and calcium-modulin kinase, respectively, were tested for their effects on the in vitro growth of babesia bovis. staurosporine was the most effective inhibitor, completely clearing the parasitaemia as early as the first day of exposure at a concentration of 100 microm. moreover, staurosporine caused a significant increase in the percentage of extracellular merozoites, most likely due ... | 2006 | 16497251 |
| attenuated vaccines for tropical theileriosis, babesiosis and heartwater: the continuing necessity. | overwhelming evidence has accumulated of the effectiveness of immunization with live attenuated vaccines to control tick-borne diseases of livestock. despite several disadvantages, vaccination with live attenuated organisms against tropical theileriosis, babesiosis and possibly heartwater constitutes one of the most cost-effective intervention strategies. although great advances have been made through genomics and proteomics research, this has not yet translated into effective non-living vaccine ... | 2007 | 17656155 |
| erythrocyte invasion by babesia parasites: current advances in the elucidation of the molecular interactions between the protozoan ligands and host receptors in the invasion stage. | during an asexual growth cycle of babesia parasites in a natural host, the extracellular merozoites invade (i.e., attach to, penetrate, and internalize) the host erythrocytes (rbc) via multiple adhesive interactions of several protozoan ligands with the target receptors on the host cell surface. after internalizing the host rbc, they asexually multiply, egress from the rbc by rupturing the host cells, and then invade the new rbc again. in the invasion stage, several surface-coating molecules of ... | 2006 | 16504403 |
| live vaccines against bovine babesiosis. | bovine babesiosis is an important tick-borne disease caused by babesia bovis, b. bigemina and b. divergens. the first steps taken in the development of an effective vaccination strategy against bovine babesiosis followed the observations that animals, recovered from natural infection with babesia were strongly protected against subsequent challenge. further investigation indicated that the use of donor blood from recovered animals to infect recipient animals did not produce the severe form of th ... | 2006 | 16504404 |
| advances in the development of molecular tools for the control of bovine babesiosis in mexico. | the severe negative impact that bovine babesiosis has in the mexican cattle industry has not been ameliorated basically due to the lack of safe and effective commercially available vaccines and sensitive and reliable diagnostic tests. in recent years, the bovine babesiosis laboratory at the national center for disciplinary research in veterinary parasitology-inifap in morelos state, mexico has been directing efforts towards three main research areas: (1) the development of in vitro culture-deriv ... | 2007 | 17691602 |
| immune control of babesia bovis infection. | babesia bovis causes an acute and often fatal infection in adult cattle, which if resolved, leads to a state of persistent infection in otherwise clinically healthy cattle. persistently infected cattle are generally resistant to reinfection with related parasite strains, and this resistance in the face of infection is termed concomitant immunity. young animals are generally more resistant than adults to b. bovis infection, which is dependent on the spleen. despite the discovery of b. bovis over ... | 2006 | 16510249 |
| babesia divergens (phylum apicomplexa) in vitro growth in the presence of calf serum. | resistance to severe babesiosis in young calves has frequently been ascribed to an unknown serum factor(s) which inhibits growth of babesia bovis in vitro. our experiments show that young calf sera are as suitable as adult bovine sera for the in vitro culture of babesia divergens, indicating that in this species at least inverse age resistance is due to alternative mechanisms. the suitability of commercial foetal calf sera for b. divergens cultures seems highly variable. | 2004 | 15177717 |
| optimization of babesia bovis transfection methods. | the tick borne babesia parasites remain an important limitation for development of cattle industries worldwide. a stable transfection of babesia bovis will be useful for functional analysis of the recently sequenced b. bovis genome and to design improved methods to control babesia infections. in this study, we describe a novel system for nucleofection of b. bovis infected erythrocytes and we optimize methods to introduce plasmids encoding the luciferase reporter gene into babesia infected erythr ... | 2007 | 17691610 |
| immunologic and molecular identification of babesia bovis and babesia bigemina in free-ranging white-tailed deer in northern mexico. | the suitability of white-tailed deer (odocoileus virginianus) as hosts for the cattle ticks rhipicephalus (boophilus) microplus and rhipicephalus (boophilus) annulatus, has been well documented. these ticks have a wide host range, and both transmit babesia bovis and babesia bigemina, the agents responsible for bovine babesiosis. although this disease and its vectors have been eradicated from the united states and some states in northern mexico, it still is a problem in other mexican states. it i ... | 2007 | 17699089 |
| a shared antigen among babesia species: ribosomal phosphoprotein p0 as a universal babesial vaccine candidate. | babesia gibsoni ribosomal phosphoprotein p0 (bgp0) was previously identified as a cross-protective antigen against babesia microti infection in mice. interestingly, the same protein showed considerable antigenicity when tested with serum samples collected from babesia-infected animals. moreover, the polyclonal antibody raised against the recombinant bgp0 (rbgp0) recognized the p0 homologues from other babesia species either by immunoblotting or by immunoscreening. the p0 genes from babesia cabal ... | 2007 | 17823817 |
| influence of dipping practices on the seroprevalence of babesiosis and anaplasmosis in the foot-and-mouth disease buffer zone adjoining the kruger national park in south africa. | a serological survey of bovine babesiosis and anaplasmosis was conducted in the foot-and-mouth disease buffer zone surrounding the kruger national park in south africa between 2001 and 2003 to determine whether the withdrawal of government-subsidized dipping in certain regions had affected the seroprevalence of these tick-borne diseases. seroprevalence of anaplasma marginale and babesia bovis increased during the study period. this increase was greater in limpopo province where farmers had to su ... | 2007 | 17883196 |
| effect of diminazene block treatment on live redwater vaccine reactions. | one third of the manufacturer's prescribed dose of diminazene has long been used to block treat the south african unfrozen babesia bigemina and babesia bovis (redwater) vaccine reactions, with no known adverse effects. it is known that the inhibitory effect of antibabesial drugs is more pronounced in animals inoculated with the frozen vaccine than those with the unfrozen vaccine. reports of vaccine failures in some animals in which diminazene was used for block treatment of the reactions followi ... | 2004 | 15373333 |
| intergenic regions in the rhoptry associated protein-1 (rap-1) locus promote exogenous gene expression in babesia bovis. | members of the babesiarap-1 gene family are expressed during multiple parasite stages, and are regulated by both transcriptional and post-transcriptional mechanisms. in all babesia species, tandemly arranged rap-1 gene copies are separated by an intergenic (ig) region that is hypothesized to regulate gene expression. in this study, we tested that hypothesis by determining whether the babesia bovisrap-1 ig region could promote extra-chromosomal expression of exogenous genes introduced into merozo ... | 2004 | 15380689 |
| 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 ... | 1988 | 15463101 |