| characterisation of the 33kda piroplasm surface antigen of theileria orientalis/sergenti/buffeli isolates from west java, indonesia. | the immunodominant 33/35kda antigen of a theileria isolate from west java, indonesia, was characterised and immuno-affinity purified by use of a monoclonal antibody, kul-a4, and was shown to be representative of the t. orientalis/sergenti/buffeli group. the aminoterminal sequence of the purified 35kda peptide (20 residues) was determined by automated edman degradation and found to correspond to the predicted amino acid sequence of a prospective p33 gene previously sequenced from the same isolate ... | 2002 | 11809330 |
| conservation of major surface protein 1 genes of anaplasma marginale during cyclic transmission between ticks and cattle. | bovine anaplasmosis is a rickettsial disease of world-wide economic importance caused by anaplasma marginale. several major surface proteins with conserved gene sequences have been examined as potential candidates for vaccines and/or diagnostic assays. major surface protein 1 (msp1) is composed of polypeptides msp1a and msp1b. msp1a is expressed from the single copy gene msp1 alpha and msp1b is expressed by members of the msp1 beta multigene family. in order to determine if the msp1 genes are co ... | 2002 | 11814681 |
| evolution and function of tandem repeats in the major surface protein 1a of the ehrlichial pathogen anaplasma marginale. | the major surface protein (msp) 1a of the ehrlichial cattle pathogen anaplasma marginale, encoded by the single-copy gene msp1alpha, has been shown to have a neutralization-sensitive epitope and to be an adhesin for bovine erythrocytes and tick cells. msp1alpha has been found to be a stable genetic marker for the identification of geographic isolates of a. marginale throughout development in acutely and persistently infected cattle and in ticks. the molecular weight of msp1a varies among geograp ... | 2001 | 11831437 |
| immunity following use of australian tick fever vaccine: a review of the evidence. | to review the evidence available on the degree and duration of immunity provided by australian tick fever vaccines against babesia bovis, b. bigemina and anaplasma marginale infections in australia and overseas. | 2001 | 11837905 |
| merozoite surface protein 3 and protection against malaria in aotus nancymai monkeys. | a blood-stage vaccine based on plasmodium falciparum merozoite surface protein 3 (msp3) was tested for efficacy in a primate model. aotus nancymai monkeys were vaccinated with yeast-expressed msp3 before a lethal challenge with plasmodium falciparum parasites. five of 7 control monkeys had acute infections and required treatment to control parasitemia. only 1 of 7 monkeys vaccinated with msp3 required this treatment. the efficacy of the msp3 vaccination appeared to be comparable to that of msp1( ... | 2002 | 11865423 |
| selective in vivo depletion of cd4(+) t lymphocytes with anti-cd4 monoclonal antibody during acute infection of calves with anaplasma marginale. | to investigate the in vivo role of cd4(+) t lymphocytes during acute anaplasmosis, thymectomized calves were selectively depleted of cd4(+) t lymphocytes by treatment with anti-cd4 monoclonal antibody (mab) and were then infected with the florida strain of anaplasma marginale in two sequential experiments (experiments 1 and 2). treatment of thymectomized calves with a total of 5.0 mg of anti-cd4 mab/kg of body weight during the 1st week followed by 0.3-mg/kg doses administered twice weekly for 7 ... | 2002 | 11874888 |
| antigenic variation of anaplasma marginale msp2 occurs by combinatorial gene conversion. | the rickettsial pathogen anaplasma marginale establishes lifelong persistent infection in the mammalian reservoir host, during which time immune escape variants continually arise in part because of variation in the expressed copy of the immunodominant outer membrane protein msp2. a key question is how the small 1.2 mb a. marginale genome generates sufficient variants to allow long-term persistence in an immunocompetent reservoir host. the recombination of whole pseudogenes into the single msp2 e ... | 2002 | 11918803 |
| a msp1alpha polymerase chain reaction assay for specific detection and differentiation of anaplasma marginale isolates. | anaplasma marginale is the causative agent of bovine anaplasmosis, a disease which can be protected by vaccination with the less pathogenic anaplasma species, a. centrale. currently, there is no polymerase chain reaction (pcr) assay available which differentiates between different species of anaplasma or which can differentiate isolates of a. marginale within outbreaks and between different countries. a molecular test specific for a. marginale would be ideal for the identification of anaplasma s ... | 2002 | 11955782 |
| infection of tick cells and bovine erythrocytes with one genotype of the intracellular ehrlichia anaplasma marginale excludes infection with other genotypes. | anaplasma marginale, a tick-borne rickettsial pathogen of cattle, is endemic in several areas of the united states. many geographic isolates of a. marginale that occur in the united states are characterized by the major surface protein 1a, which varies in sequence and molecular weight due to different numbers of tandem repeats of 28 or 29 amino acids. recent studies (g. h. palmer, f. r. rurangirwa, and t. f. mcelwain, j. clin. microbiol. 39:631-635, 2001) of an a. marginale-infected herd of catt ... | 2002 | 11986275 |
| molecular epidemiology of plasmodium falciparum infections among asymptomatic inhabitants of a holoendemic malarious area in northern ghana. | age dependence of malaria infection was assessed in an age-stratified cluster sample of 308 individuals from kassena-nankana district of northern ghana during june and july 2000. overall prevalence of plasmodium falciparum by microscopy was 70%, with the maximum among 5-9 year olds. parasite density was highest (geometric mean 1922/microl blood) in 1-2 year olds. eighty-two per cent of samples were positive by polymerase chain reaction (pcr), and restriction fragment length polymorphism typing o ... | 2002 | 12000651 |
| antigenic characterization of anaplasma marginale isolates from different regions of brazil. | antigenic characterization of a. marginale isolates has contributed to identifying the presence of common and restricts epitopes of major surface proteins (msps). the data may improve vaccine development to protect against a. marginale isolates from different regions. brazilian a. marginale isolates were characterized antigenically by western blot with monoclonal antibodies (mabs) against msps and rabbit anti-msp-4 from florida strain. six a. marginale isolates from ms, mg (aufv1), sp, pr-l1, pr ... | 2002 | 12034541 |
| effect of tetracycline on development of anaplasma marginale in cultured ixodes scapularis cells. | infections of the tick-borne ehrlichial pathogen, anaplasma marginale, in cattle have been controlled, in part, by administration of low doses of tetracycline. recently, a cell culture system was developed for a. marginale using a tick cell line derived from embryonic ixodes scapularis. this study was designed to determine the effect of tetracycline on a. marginale propagated in a tick cell culture assay. various concentrations of tetracycline (0, 0.01, 0.10, 1.0, 5, 10, 20 or 100 microg/ml) wer ... | 2002 | 12072219 |
| antigenic characterization of morphologically distinct anaplasma marginale isolates using a panel of monoclonal antibodies. | the present study, describes the antigenic characterization of a brazilian isolate of anaplasma marginale with appendage (tail). a panel of monoclonal antibodies (mcabs) was produced and tested by the indirect fluorescent antibody test (ifat), elisa and western blotting, and used to characterize two isolates of a. marginale (one with appendage and another without appendage). among the clones produced, eight recognized antigenic proteins, with molecular weights varying from 18.4 to 66kda. in west ... | 2002 | 12072223 |
| detection of the anaplasma centralevaccine strain and specific differentiation from anaplasma marginale in vaccinated and infected cattle. | bovine anaplasmosis caused by the intraerythrocytic rickettsia anaplasma marginale is the most prevalent tick-borne disease of cattle worldwide. the most efficient method to control anaplasmosis is by vaccination using live anaplasma centrale, a closely related species or subspecies of low pathogenicity that is capable of inducing significant protection against the more virulent a. marginale. in the present study, we applied pcr assays to detect and discriminate field infection with a. marginale ... | 2002 | 12107477 |
| identification and characterization of a site-specific tyrosine recombinase within the variable loci of mycoplasma bovis, mycoplasma pulmonis and mycoplasma agalactiae. | three highly mutable loci of the wall-less pathogens mycoplasma bovis, mycoplasma pulmonis and mycoplasma agalactiae undergo high-frequency genomic rearrangements and generate extensive antigenic variation of major surface lipoproteins. adjacent to each locus, an open reading frame exists as a single chromosomal copy and is predicted to encode a site-specific dna recombinase exhibiting high homology to the recombinases xerd of escherichia coli and codv of bacillus subtilis. each of the mycoplasm ... | 2002 | 12119115 |
| pcr-elisa for diagnosis of trypanosoma evansi in animals and vector. | a highly sensitive and specific polymerase chain reaction (pcr) based assay for the detection of trypanosoma evansi present in the blood of different animals and vector was developed. a simple lysis method was used to remove of the red blood cells to facilitate direct input of samples into the pcr reactions. the primer set was designed and synthesized to amplify a single band of 257 bp pcr product that was subsequently examined by enzyme-linked immunosorbent assay (elisa). the sensitivity limit ... | 2002 | 12144767 |
| conservation of the unique rickettsial rrna gene arrangement in anaplasma. | the organization of the rrna genes of anaplasma marginale, the type species of the genus anaplasma, was identified to determine if the atypical rrna gene arrangement identified in rickettsiae preceded divergence of the order rickettsiales into the families anaplasmataceae and rickettsiaceae. the rrna genes are encoded by two unlinked units, each present in a single copy per a. marginale genome. the 16s rrna gene is separated from the linked 23s and 5s rrna genes by a minimum of 100 kb. similar t ... | 2002 | 12148657 |
| phylogeography of new world isolates of anaplasma marginale based on major surface protein sequences. | gene and protein sequences of major surface proteins (msp) 1a and 4 of anaplasma marginale (rickettsiales: anaplasmataceae) were used to infer phylogenetic relationships between new world isolates from argentina, brazil, mexico and the united states. seventeen isolates of a. marginale plus two outgroup taxa (a. centrale and a. ovis) were used for maximum-parsimony analysis of msp4, while 20 isolates were used for phylogenetic analysis of msp1a. msp4 analysis provided strong bootstrap support for ... | 2002 | 12151201 |
| epidemiology of bovine tick-borne diseases in southern italy. | this investigation was carried out in an area covering part of three southern italian regions: campania, basilicata and apulia. eighty-one farms were involved using the formula suggested by thrusfield; they were equally distributed over the area which was subdivided into 81 geo-referenced sub-areas. in may and june 1999 from a total of 506 cattle, older than 18 months, blood-samples were taken and ticks were collected and identified. serum samples were tested for antibodies of bahesia bigemina, ... | 2002 | 12199369 |
| simultaneous detection of anaplasma marginale and a new ehrlichia species closely related to ehrlichia chaffeensis by sequence analyses of 16s ribosomal dna in boophilus microplus ticks from tibet. | to identify ehrlichial agents in boophilus microplus ticks, dna samples of b. microplus collected from the tibet autonomous region and sichuan province of china were screened by a nested pcr. sixteen of 43 (37%) dna samples of b. microplus from tibet were positive in nested pcr analysis. all 27 samples from sichuan were negative. the screen identified two ehrlichial agents based on different 16s rrna genes that were found after amplifying and sequencing the 5'-end fragments of the 16s rrna genes ... | 2002 | 12202567 |
| evaluation of sensitivity and specificity of a mycoplasma haemomuris-specific polymerase chain reaction test. | mycoplasma haemomuris, a small pleomorphic bacterium parasitic of red blood cells, often causes chronic and subclinical infection of rodents. mycoplasma haemomuris is uncultivable, and a serologic testing method is not readily available. the purpose of the study reported here was to develop a sensitive and specific polymerase chain reaction (pcr) test for detection of m. haemomuris in blood samples. | 2002 | 12211273 |
| major histocompatibility complex class ii dr-restricted memory cd4(+) t lymphocytes recognize conserved immunodominant epitopes of anaplasma marginale major surface protein 1a. | native major surface protein 1 (msp1) of anaplasma marginale, composed of covalently associated msp1a and msp1b proteins, stimulates protective immunity in cattle against homologous and heterologous strain challenge. protective immunity against pathogens in the family anaplasmataceae involves both cd4(+) t cells and neutralizing immunoglobulin g. thus, an effective vaccine should contain both cd4(+) t- and b-lymphocyte epitopes that will elicit strong memory responses upon infection with homolog ... | 2002 | 12228278 |
| occurrence of concurrent trypanosomosis, theileriosis, anaplasmosis and helminthosis in friesian, zebu and sahiwal cattle in uganda. | an epidemiological investigation was conducted on farms in tororo and soroti districts of uganda from january to february 2000 to determine the cause of reported persistent mortality of cattle. blood and faecal material of 98 cattle comprising of 33 friesians, 58 zebu and 7 sahiwal were examined. results revealed that seven (7.1 %) cattle had trypanosome infection, mainly due to trypanosoma vivax and t. brucei, 17 (17.3%) fasciola infection, 28 (28.6%) gastrointestinal nematode infection, 33 (33 ... | 2002 | 12233999 |
| vaccination of cattle with anaplasma marginale derived from tick cell culture and bovine erythrocytes followed by challenge-exposure with infected ticks. | anaplasmosis, a hemolytic disease of cattle caused by the tick-borne pathogen anaplasma marginale (rickettsiales: anaplasmataceae) has been controlled using killed vaccines made with antigen harvested from infected bovine erythrocytes. we recently developed a cell culture system for propagation of a. marginale in a continuous tick cell line. in this study, we performed a cattle trial to compare the bovine response to vaccination with a. marginale harvested from tick cell culture or bovine erythr ... | 2002 | 12243900 |
| dna-encoded fetal liver tyrosine kinase 3 ligand and granulocyte macrophage-colony-stimulating factor increase dendritic cell recruitment to the inoculation site and enhance antigen-specific cd4+ t cell responses induced by dna vaccination of outbred animals. | dna-based immunization is a contemporary strategy for developing vaccines to prevent infectious diseases in animals and humans. translating the efficacy of dna immunization demonstrated in murine models to the animal species that represent the actual populations to be protected remains a significant challenge. we tested two hypotheses directed at enhancing dna vaccine efficacy in outbred animals. the first hypothesis, that dna-encoding fetal liver tyrosine kinase 3 ligand (flt3l) and gm-csf incr ... | 2002 | 12244180 |
| expression of anaplasma marginale major surface protein 2 operon-associated proteins during mammalian and arthropod infection. | the antigenically variant major surface protein 2 (msp2) of anaplasma marginale is expressed from a 3.5-kb operon that contains, in a 5'-to-3' direction, four open reading frames, opag3, opag2, opag1, and msp2. this operon structure was shown to be conserved among genotypically and phenotypically distinct a. marginale, a. ovis, and a. centrale strains. the individual opag amino acid sequences are highly conserved among a. marginale strains, with identities ranging from 95 to 99%. opag2 and opag3 ... | 2002 | 12379676 |
| tick-borne diseases (tbds) of dairy cows in a mediterranean environment: a clinical, serological, and hematological study. | a longitudinal study of tick-borne diseases (tbds) in southern italy was carried out by monitoring two dairy farms (a and b) located in the apulia region. on each farm ten calves and ten heifers were observed monthly from may 1999 to february 2001 for clinical signs and blood parameters; antibodies against babesia bigemina and anaplasma marginale using an elisa test were also monitored for the first eight months of the study. totals of 28 and 14 cases of tbds were observed in the complete herds ... | 2002 | 12381611 |
| characterization of the functional domain of major surface protein 1a involved in adhesion of the rickettsia anaplasma marginale to host cells. | the major surface protein (msp) 1a of the genus type species anaplasma marginale (rickettsiales: anaplasmataceae) has been shown to mediate adhesion, infection and transmission of the organism, as well as to contribute to protective immunity in cattle. msp1a contains a variable number of tandemly repeated peptides in the amino-terminal region, while the remainder of the protein is highly conserved among isolates. the number of repeats varies among geographic isolates of a. marginale but is const ... | 2003 | 12458174 |
| phylogenetic analysis of the erythrocytic anaplasma species based on 16s rdna and groel (hsp60) sequences of a. marginale, a. centrale, and a. ovis and the specific detection of a. centrale vaccine strain. | phenotypic criteria for the identification of erythrocytic ruminant anaplasma species has relied on subjective identification methods such as host pathogenicity (virulence for cattle or sheep) and/or the location of anaplasma inclusion bodies within the host's red cells. sequence comparisons of new and available genbank accessions were investigated to elucidate the relationships among these closely related anaplasma species. twenty-one 16s rdna and groel (hsp60) sequences from 13 anaplasma margi ... | 2003 | 12488078 |
| infection exclusion of the rickettsial pathogen anaplasma marginale in the tick vector dermacentor variabilis. | anaplasma marginale is a tick-borne, rickettsial cattle pathogen that is endemic in several areas of the united states. recent studies (j. de la fuente, j. c. garcia-garcia, e. f. blouin, j. t. saliki, and k. m. kocan, clin. diagn. lab. immunol. 9:658-668, 2002) demonstrated that infection of cultured tick cells and bovine erythrocytes with one genotype of a. marginale excluded infection with other genotypes, a phenomenon referred to as infection exclusion. the present study was undertaken to co ... | 2003 | 12522060 |
| antibodies to anaplasma marginale major surface proteins 1a and 1b inhibit infectivity for cultured tick cells. | major surface protein 1 (msp1) of the cattle pathogen anaplasma marginale (rickettsiales: anaplasmataceae) is a complex of two proteins, msp1a and msp1b. previous studies demonstrated that msp1a and msp1b are adhesins for bovine erythrocytes, while only msp1a proved to be an adhesin for tick cells. in this study, a tick cell culture system for propagation of a. marginale was used to develop an infection inhibition assay for testing the ability of antisera to block infection of a. marginale for c ... | 2003 | 12531299 |
| conservation of a gene conversion mechanism in two distantly related paralogues of anaplasma marginale. | anaplasmataceae, the causative agents of anaplasmosis and ehrlichiosis, persist in the bloodstream of their mammalian hosts, allowing acquisition and transmission by tick vectors. anaplasma marginale establishes persistent infection characterized by sequential cycles of rickettsaemia in which new antigenic variants emerge. the two most immunodominant outer membrane proteins, msp2 and msp3, are paralogues, each encoded by a distinct family of related genes. this study demonstrates that, although ... | 2003 | 12535066 |
| comparison of pcr assays for detection of the agent of human granulocytic ehrlichiosis, anaplasma phagocytophilum. | human granulocytic ehrlichiosis is an emerging infectious disease in the united states and europe, and pcr methods have been shown to be effective for the diagnosis of acute infections. numerous pcr assays and primer sets have been reported in the literature. the analytical sensitivities (limits of detection) of 13 published pcr primer sets were compared using dna extracted from serial dilutions of anaplasma phagocytophilum-infected hl-60 cells. the specificity of the assays that were able to de ... | 2003 | 12574272 |
| co-feeding studies of ticks infected with anaplasma marginale. | ticks often cluster at preferred feeding sites on hosts, and the co-feeding of ticks at the same site has been shown to increase feeding success and the transmission of some pathogens. while the major route of infection of ticks with pathogens is via the bloodmeal during feeding on a parasitemic host, non-systemic transmission of viruses and spirochetes has been shown to occur from infected to uninfected ticks at common feeding sites on uninfected hosts. in this research, two separate studies we ... | 2003 | 12623209 |
| the hypervariable region of anaplasma marginale major surface protein 2 (msp2) contains multiple immunodominant cd4+ t lymphocyte epitopes that elicit variant-specific proliferative and ifn-gamma responses in msp2 vaccinates. | major surface protein 2 (msp2) is an immunodominant outer membrane protein of anaplasma marginale and anaplasma phagocytophilum pathogens that cause bovine anaplasmosis and human granulocytic ehrlichiosis, respectively. msp2 has a central hypervariable region (hvr) flanked by highly conserved amino and carboxyl termini. during a. marginale infection, dynamic and extensive amino acid sequence variation in msp2 occurs through recombination of msp2 pseudogenes into the msp2 expression site, followe ... | 2003 | 12646645 |
| expression of multiple outer membrane protein sequence variants from a single genomic locus of anaplasma phagocytophilum. | anaplasma phagocytophilum is the causative agent of an emerging tick-borne zoonosis in the united states and europe. the organism causes a febrile illness accompanied by other nonspecific symptoms and can be fatal, especially if treatment is delayed. persistence of a. phagocytophilum within mammalian reservoir hosts is important for ensuring continued disease transmission. in the related organism anaplasma marginale, persistence is associated with antigenic variation of the immunoprotective oute ... | 2003 | 12654783 |
| applications of a cell culture system for studying the interaction of anaplasma marginale with tick cells. | a cell culture system for the tick-borne rickettsia anaplasma marginale offers new opportunities for research on this economically important pathogen of cattle. a. marginale multiplies in membrane-bound inclusions in host cells. whereas erythrocytes appear to be the only site of infection in cattle, a. marginale undergoes a complex developmental cycle in ticks and transmission occurs via the salivary glands during feeding. we recently developed a cell culture system for a. marginale using a cell ... | 2002 | 12665106 |
| anaplasma marginale msp1alpha genotypes evolved under positive selection pressure but are not markers for geographic isolates. | anaplasma marginale (order rickettsiales, family anaplasmataceae), a tick-borne pathogen of cattle, is endemic in tropical and subtropical regions of the world. many geographic isolates of a. marginale occur in the united states and have been identified by major surface protein 1a (msp1a), which varies in sequence and molecular weight due to different numbers of tandem 28- to 29-amino-acid repeats. the present study was undertaken to examine the genetic variations among isolates of a. marginale ... | 2003 | 12682152 |
| multiple infection in bovines from the tropics: observation of blood parasites by scanning and transmission electron microscope. | blood samples from a splenectomized bovine, experimentally inoculated with blood from a field cow living in southwestern venezuela, were processed for transmission and scanning electron microscopy. the blood sample showed multiple infection with hemoparasites of the genera anaplasma marginale, eperythrozoon wenyonii and trypanosoma vivax. scanning electron microscope showed that the blood from bovines with multiple infection had profound deformation in knob-like protruding structures with reduce ... | 2002 | 12701380 |
| identification of novel protective antigens from anaplasma marginale. | a successful recombinant vaccine against anaplasma marginale remains elusive, despite intensive study of the protective, though variable major surface antigens. as an alternative approach to the discovery of additional antigens, crude parasite material was subjected to conventional protein fractionation, coupled with vaccination and parasite challenge trials, without making assumptions as to the nature or location of these antigens. this has lead to the identification of four novel antigens that ... | 2003 | 12706672 |
| rna polymerase beta-subunit-based phylogeny of ehrlichia spp., anaplasma spp., neorickettsia spp. and wolbachia pipientis. | sequence analysis of rpob, the gene encoding the beta-subunit of rna polymerase, was used in a phylogenetic investigation of nine species from the genera ehrlichia, neorickettsia, wolbachia and anaplasma. the complete nucleotide sequences obtained for anaplasma phagocytophilum (hge agent), ehrlichia chaffeensis, neorickettsia sennetsu, neorickettsia risticii, anaplasma marginale and wolbachia pipientis were amongst the longest rpob sequences in genbank and ranged from 4074 bp for n. sennetsu to ... | 2003 | 12710612 |
| cpg odn 2006 and il-12 are comparable for priming th1 lymphocyte and igg responses in cattle immunized with a rickettsial outer membrane protein in alum. | immunostimulatory oligodeoxynucleotides containing unmethylated cpg dinucleotides (cpg odn) stimulate il-12-dependent th1 dominated cytokine and enhanced igg responses when co-delivered with antigen to mice. however, the cpg odn sequences that are optimal for each mammalian species may differ. previously, we demonstrated that a cpg odn containing the gtcgtt motif was optimal for stimulating bovine b cell proliferation, and induced il-6, il-12 and ifn-gamma production by peripheral blood mononucl ... | 2003 | 12804862 |
| major surface protein 2 of anaplasma phagocytophilum facilitates adherence to granulocytes. | anaplasma phagocytophilum is an obligate intracellular bacterium that infects myeloid cells in the mammalian host. msp2 (p44) is the major immunodominant outer-membrane protein of these bacteria. we hypothesized that msp2 acts as an adhesin for a. phagocytophilum entry into granulocytes. this potential role was investigated by blocking binding with msp2 monoclonal antibodies and by antagonizing binding and propagation with recombinant msp2 (rmsp2) in vitro. with hl-60 cells, fresh human peripher ... | 2003 | 12819090 |
| ehrlichiae and ehrlichial diseases in china. | the various ticks collected from different areas of china were examined for the existence of ehrlichial agents by polymerase chain reaction (pcr) with genus- or species-specific primers designed on the basis of ehrlichial 16s rrna genes and sequence analyses. in southern china, e. chaffeensis was detected in amblyomma testudinarium ticks from infested cattle, haemaphysalis yeni ticks from hare, and ixodes ovatus ticks from muntiacus reevesi. e. canis was identified in rhipicephalus sanguineus ti ... | 2003 | 12860598 |
| antigenic characterization of brazilian isolates of anaplasma marginale. | antigenic characterization of anaplasma marginale isolates, by identifying conserved and variable epitopes of major surface proteins (msp), is an important tool for vaccine development against this rickettsia. the b cell epitopes of a. marginale isolates from three microregions of the state of pernambuco and one from the state of mato grosso do sul, brazil, were characterized by indirect fluorescent antibody technique (ifat) and western blot (wb) with 15 monoclonal antibodies (mabs). the epitope ... | 2003 | 12886423 |
| characterization of anaplasma marginale isolated from north american bison. | anaplasma marginale (rickettsiales: anaplasmataceae), a tick-borne pathogen of cattle, is endemic in tropical and subtropical regions of the world. although serologic tests have identified american bison, bison bison, as being infected with a. marginale, the present study was undertaken to confirm a. marginale infection and to characterize isolates obtained from naturally infected bison in the united states and canada. major surface protein (msp1a and msp4) sequences of bison isolates were chara ... | 2003 | 12902301 |
| transmission of anaplasma marginale by boophilus microplus: retention of vector competence in the absence of vector-pathogen interaction. | whether arthropod vectors retain competence for transmission of infectious agents in the long-term absence of vector-pathogen interaction is unknown. we addressed this question by quantifying the vector competence of two tick vectors, with mutually exclusive tropical- versus temperate-region distributions, for genetically distinct tropical- and temperate-region strains of the cattle pathogen anaplasma marginale. the tropical cattle tick boophilus microplus, which has been eradicated from the con ... | 2003 | 12904396 |
| a report of the screening of aralen dihydrochloride for activity against anaplasma marginale. | | 1953 | 13092384 |
| [experiments on the culture of a bovine strain of anaplasma marginale]. | | 1953 | 13094451 |
| the histochemical nature of anaplasma marginale. | | 1955 | 13238738 |
| detection of anaplasma marginale by means of fluorescein-labeled antibody. | | 1957 | 13470250 |
| observations on the morphology of anaplasma marginale with reference to projections or tails. | | 1958 | 13498276 |
| infection and antibody response in deer experimentally infected with anaplasma marginale from bovine carriers. | | 1958 | 13513488 |
| latent anaplasma marginale infection in wild deer demonstrated by calf inoculation. | | 1959 | 13619297 |
| demonstration of anaplasma marginale with the fluorescent dye, acridine orange; comparisons with the complement-fixation test and wright's stain. | | 1961 | 13702950 |
| studies on the morphology and respiration of anaplasma marginale. | | 1961 | 13735717 |
| studies in anaplasmosis. ii. electron microscopy of anaplasma marginale in deer. | | 1961 | 13741873 |
| electron microscopy of anaplasma marginale in the bovine erythrocyte. | | 1961 | 13749410 |
| persistence of latent anaplasma marginale infection in deer. | | 1960 | 13810091 |
| anaplasma marginale. i. studies with phase contrast and electron microscopy. | | 1959 | 13820793 |
| biologic properties and characteristics of anaplasma marginale. i. effects of temperature on infectivity of whole blood preparations. | | 1962 | 13866454 |
| biologic properties and characteristics of anaplasma marginale. ii. the effects of sonic energy on the infectivity of whole blood preparations. | | 1963 | 13970197 |
| properties of anaplasma marginale antigen used in a capillary tube-agglutination test. | | 1962 | 14006080 |
| immunology and serology of anaplasma marginale. i. fractionation of the complement-fixing antigen. | rogers, thomas e. (louisiana state university, baton rouge), richard j. hidalgo, and george t. dimopoullos. immunology and serology of anaplasma marginale. i. fractionation of the complement-fixing antigen. j. bacteriol. 88:81-86. 1964.-studies were conducted to fractionate and purify the complement-fixation (cf) antigen of anaplasma marginale in infected erythrocytes of cattle. initial attempts were made to resolve the antigen from crude stromatal preparations by various chemical and physical m ... | 1964 | 14197909 |
| anaplasmosis. xii. the growth and survival in deer and sheep of the parasites present in the blood of calves infected with the oregon strain of anaplasma marginale. | | 1963 | 14035670 |
| anaplasmosis. xi. immunoserologic characteristics of the parasites present in the blood of calves infected with the oregon strain of anaplasma marginale. | | 1963 | 14035669 |
| gamma irradiation of anaplasma marginale. | | 1964 | 14227186 |
| anaplasmosis. x. morphologic characteristics of the parasites present in the blood of calves infected with the oregon strain of anaplasma marginale. | | 1963 | 14035668 |
| catalase activity in anaplasma marginale. | wallace, w. r. (louisiana state university, baton rouge), and g. t. dimopoullos. catalase activity in anaplasma marginale. j. bacteriol. 91:309-311. 1965.-extracts of erythrocytes infected with anaplasma marginale were found to contain more catalase activity than normal erythrocytic preparations. the increase in catalase activity appeared concurrently with increases in the number of erythrocytes containing anaplasma bodies. antisera against normal bovine erythrocytes and anaplasma-infected eryth ... | 1965 | 14329440 |
| structural characterization of anaplasma marginale in acute and carrier infections. | | 1960 | 14437588 |
| anaplasma marginale theiler observed in the gut and excreta of dermacentor andersoni stiles (dermacentor venustus marx). | | 1964 | 14204828 |
| an exo-antigen of anaplasma marginale in serum and erythrocytes of cattle with acute anaplasmosis. | | 1964 | 14227163 |
| antigens and alternatives for control of anaplasma marginale infection in cattle. | anaplasmosis, a tick-borne cattle disease caused by the rickettsia anaplasma marginale, is endemic in tropical and subtropical areas of the world. the disease causes considerable economic loss to both the dairy and beef industries worldwide. analyses of 16s rrna, groesl, and surface proteins have resulted in the recent reclassification of the order rickettsiales. the genus anaplasma, of which a. marginale is the type species, now also includes a. bovis, a. platys, and a. phagocytophilum, which w ... | 2003 | 14557295 |
| adaptations of the tick-borne pathogen, anaplasma marginale, for survival in cattle and ticks. | the tick-borne cattle pathogen anaplasma marginale (rickettsiales: anaplasmataceae) multiplies within membrane-bound inclusions in host cell cytoplasm. many geographic isolates of a. marginale occur that vary in genotype, antigenic composition, morphology and infectivity for ticks. a tick cell culture system for propagation of a. marginale proved to be a good model for study of tick-pathogen interactions. six major surface proteins (msps) identified on a. marginale from bovine erythrocytes were ... | 2002 | 14570114 |
| simultaneous variation of the immunodominant outer membrane proteins, msp2 and msp3, during anaplasma marginale persistence in vivo. | vector-borne bacterial pathogens persist in the mammalian host by varying surface antigens to evade the existing immune response. to test whether the model of surface coat switching and immune evasion can be extended to a vector-borne bacterial pathogen with multiple immunodominant surface proteins, we examined anaplasma marginale, a rickettsia with two highly immunogenic outer membrane proteins, major surface protein 2 (msp2) and msp3. the simultaneous clearance of variants of the two most immu ... | 2003 | 14573687 |
| assessment of a low virulence australian isolate of anaplasma marginale for pathogenicity, immunogenicity and transmissibility by boophilus microplus. | a 14-year-old cow (dawn) born and kept in a boophilus microplus-free region gave birth to a calf, which showed the presence of an anaplasma marginale infection after splenectomy. the calf's grand dam was from a b. microplus infected area and we assume the infection originated via the transplacental route over two generations. an isolate, prepared from the calf, had similar or lower pathogenicity as anaplasma centrale, and previously exposed steers were resistant to challenge by four a. marginale ... | 2003 | 14651881 |
| sensitive and specific detection of proviral bovine leukemia virus by 5' taq nuclease pcr using a 3' minor groove binder fluorogenic probe. | sensitive assays are required to detect proviral bovine leukemia virus (blv) in donor cattle used for the in vivo preparation of australian tick fever vaccines. 5' taq nuclease assays using 3' minor groove binder dna probes (taqmanmgb) were developed and compared to conventional pcr assays for sensitive detection of australian blv. seven beef and dairy herds were screened using dna prepared by a variety of protocols to evaluate these tests. comparative sensitivities of pcr tests were determined ... | 2004 | 14667532 |
| a novel antigen from anaplasma marginale: characterization, expression and preliminary evaluation of the recombinant protein. | through a process of protein fractionation and vaccination we previously identified four native antigens that confer a degree of protection against challenge with anaplasma marginale. one of these, ana 29 has been successfully cloned and sequenced using degenerate primers designed to n-terminal and internal peptide sequences. the full-length gene codes for a protein with a theoretical molecular weight of 27 kda and pi 8.6. the sequence is highly conserved, showing 99% identity between two austra ... | 2004 | 14670322 |
| characterization of the anaplasma marginale msp2 locus and its synteny with the omp1/p30 loci of ehrlichia chaffeensis and e. canis. | major surface protein 2 (msp2) is an immunodominant and antigenically variant protein in the outer membrane of the rickettsia anaplasma marginale. msp2 variation is generated by recombination into a single operon-linked genomic expression site. the complete 5.6-kb msp2 locus was identified by sequencing a 90-kb region of the st. maries strain of a. marginale. the locus encoded, in a 5' to 3' direction, a transcriptional regulator followed by five outer membrane proteins, omp1, opag3, opag2, opag ... | 2004 | 14697516 |
| [prevalence of anaplasma marginale and specific antibodies in new born calves]. | anaplasma marginale is an intraerythrocytic rickettsia that affects the cattle and constitute a constraint for its production. the transplacental transmission of a. marginale could be of importance under field conditions, but until now no data is available to interpret its relevance in venezuela. the goal of this work was to evaluate both the presence of a. marginale and the antibody response against the rickettsia in new born calves. fourteen calves, one week old, were simultaneously bled for p ... | 2003 | 14976783 |
| the effect of management factors on the seroprevalence of anaplasma marginale in bos indicus cattle in the mexican tropics. | a cross-sectional study with a two-stage design and proportional distribution was carried out to determine the effect of management factors on the seroprevalence of anaplasma marginale in bos indicus cattle in the mexican tropics. serum was obtained from 384 cattle aged 1-2 years on 92 farms. the number of samples was proportionally distributed according to the number of farms in eastern yucatan. antibody activity against a. marginale was assessed using the card agglutination test. a primary scr ... | 2004 | 14998312 |
| mapping of b-cell epitopes in the n-terminal repeated peptides of anaplasma marginale major surface protein 1a and characterization of the humoral immune response of cattle immunized with recombinant and whole organism antigens. | major surface protein (msp) 1a of the genus type species anaplasma marginale (rickettsiales: anaplasmataceae) together with msp1b forms the msp1 complex. msp1a has been shown to be involved in adhesion, infection and tick transmission of a. marginale, as well as to contribute to protective immunity in cattle. a differential antibody response to msp1a and msp1b was observed in cattle immunized with a. marginale derived from bovine erythrocytes (anti-msp1a response) or cultured tick cells (anti-ms ... | 2004 | 15010223 |
| differential expression of the msp1alpha gene of anaplasma marginale occurs in bovine erythrocytes and tick cells. | major surface proteins (msp) 1a and 1b of the tick-borne pathogen anaplasma marginale (rickettsiales: anaplasmataceae) are conserved on a. marginale derived from bovine erythrocytes and tick cells. msp1a and msp1b form the msp1 complex and are adhesins involved in infection of host cells. while both msp1a and msp1b are adhesins for bovine erythrocytes, only msp1a is an adhesin for cultured and native tick cells. these studies were initiated because antibody responses to msp1a and msp1b differed ... | 2004 | 15036535 |
| adhesion of outer membrane proteins containing tandem repeats of anaplasma and ehrlichia species (rickettsiales: anaplasmataceae) to tick cells. | infection of cells by tick-borne rickettsiae appears to be mediated by outer membrane proteins that allow pathogens to adhere to host cells. major surface protein (msp) 1a of anaplasma marginale, the type species for the genus anaplasma, was shown previously to be an adhesin for tick cells. the a. marginale msp1a has a variable number of tandem 28 or 29 amino acid repeats located in the amino terminal region of the protein that contains an adhesion domain that is necessary and sufficient for inf ... | 2004 | 15036540 |
| application of a reverse line blot assay to the study of haemoparasites in cattle in uganda. | recent advances in genomic technology have focused many veterinary researchers on the possibility of producing one multivalent recombinant vaccine against all the haemoparasites that infect cattle in the tropics. before such a vaccine is developed it is essential to define target cattle populations as well as the range of anti-pathogen vaccines required in order to control disease. to further this objective, we have evaluated a reverse line blot (rlb) assay, which simultaneously detects the prin ... | 2004 | 15064125 |
| serological evidence of exposure to tick fever organisms in young cattle on queensland dairy farms. | to compare the features of farms on which the exposure of young cattle to tick fever organisms is sufficient to ensure that immunity is high and the risk of clinical disease is low (endemic stability) with those of farms on which exposure is insufficient to induce widespread immunity (hence without endemic stability); to examine the relationships between the management of ticks and tick fever, and endemic stability to babesia bovis, b. bigemina and anaplasma marginale. | 2003 | 15080428 |
| glycosylation of anaplasma marginale major surface protein 1a and its putative role in adhesion to tick cells. | anaplasma marginale, the causative agent of bovine anaplasmosis, is a tick-borne rickettsial pathogen of cattle that multiplies in erythrocytes and tick cells. major surface protein 1a (msp1a) and msp1b form the msp1 complex of a. marginale, which is involved in adhesion of the pathogen to host cells. in this study we tested the hypothesis that msp1a and msp1b were glycosylated, because the observed molecular weights of both proteins were greater than the deduced molecular masses. we further hyp ... | 2004 | 15102815 |
| molecular conservation of msp4 and msp5 in anaplasma marginale and a. centrale vaccine strain. | anaplasma centrale msp4 and msp5 genes were cloned and sequenced, and the recombinant proteins were expressed. the identity between anaplasma marginale and a. centrale msp4 was 83% in the nucleotide sequences and 91.7% in the encoded protein sequences. a. centrale msp5 nucleotide sequences shared 86.8% identity with a. marginale msp5, and there was 92.9% homology between a. centrale and a. marginale encoded amino acids of the msp5 protein. southern blots hybridized with probes derived from the m ... | 2004 | 15135513 |
| genetic diversity and molecular phylogeny of anaplasma marginale isolates from minas gerais, brazil. | anaplasma marginale (rickettsiales: anaplasmataceae), a tick-borne pathogen of cattle, is endemic in tropical and subtropical regions of the world, and many isolates of a. marginale may occur in a given geographic area. phylogenetic relationships have been reported for a. marginale isolates from the us using gene and protein sequences of msp1a and msp4. these studies demonstrated that msp4 sequences, but not msp1a dna or protein sequences, provide phylogeographic information and also that msp1a ... | 2004 | 15135871 |
| simplified specimen preparation for electron microscopic studies of an intra-erythrocytic parasite, anaplasma marginale. | | 1962 | 14492493 |
| anaplasma infection in free-ranging iberian red deer in the region of castilla-la mancha, spain. | organisms in the genus anaplasma are obligate intracellular pathogens that multiply in both vertebrate and invertebrate hosts. the type species, anaplasma marginale, causes bovine anaplasmosis and infects erythrocytes of the vertebrate host and undergoes a complex developmental cycle in ticks which serve as biological vectors. infected cattle, wild ruminants and ticks can all serve as reservoirs of a. marginale. in this study, hunter killed iberian red deer (cervus elaphus hispanicus) from the r ... | 2004 | 15145495 |
| cd4+ t lymphocytes from anaplasma marginale major surface protein 2 (msp2) vaccinees recognize naturally processed epitopes conserved in msp3. | major surface protein 2 (msp2) and msp3 of the persistent bovine ehrlichial pathogen anaplasma marginale are immunodominant proteins that undergo antigenic variation. the recently completed sequence of msp3 revealed blocks of amino acids in the n and c termini that are conserved with msp2. this study tested the hypothesis that cd4+ t cells specific for msp2 recognize naturally processed epitopes conserved in msp3. at least one epitope in the n terminus and two in the c terminus of msp2 were also ... | 2004 | 15155686 |
| infection of endothelial cells with anaplasma marginale and a. phagocytophilum. | anaplasma marginale and a. phagocytophilum are obligate intracellular, tick-borne pathogens that target erythrocytes and neutrophil granulocytes, respectively. because ticks do not directly tap blood vessels, an intermediate tissue may mediate infection of blood cells. we considered that vascular endothelium interacts with circulating blood cells in vivo, and could be involved in pathogenesis and dissemination of the organisms. we used light and electron microscopy and immune labeling to show th ... | 2004 | 15201033 |
| anaplasma phagocytophilum has a functional msp2 gene that is distinct from p44. | the msp2 and p44 genes encode polymorphic major outer membrane proteins that are considered unique to the intraerythrocytic agent of anaplasma marginale and the intragranulocytic agent of anaplasma phagocytophilum, respectively. in the present study, however, we found an msp2 gene in a. phagocytophilum that was remarkably conserved among a. phagocytophilum strains from human granulocytic anaplasmosis (hga) patients, ticks, and a horse from various regions in the united states, but the gene was d ... | 2004 | 15213131 |
| artificial feeding of ixodid ticks. | ixodid ticks are economically important as they cause direct damage to livestock and are vectors of several pathogens that cause diseases in humans and animals. some of the important tick-borne pathogens of livestock are theileria parva, t. annulata, babesia bigemina, b. bovis, anaplasma marginale and cowdria ruminantium. these pathogens are responsible for causing enormous losses in livestock. identification of factors that influence transmission and development of these pathogens in ticks will ... | 1996 | 15275192 |
| prevalence of antibodies to bluetongue virus and anaplasma marginale in montana yearling cattle entering alberta feedlots: fall 2001. | a serologic survey was conducted in yearling cattle imported into alberta feedlots from montana during october 2001 to estimate the prevalence of antibodies to bluetongue virus (btv) and anaplasma marginale in montana yearling cattle. the apparent prevalence of antibodies to btv when the competitive enzyme-linked immunosorbent assay (celisa) was used was 0.37% (21/5608). test positive celisa samples were also all positive when tested by virus neutralization (vn) and they reacted to 1 or more btv ... | 2004 | 15283518 |
| concurrent infections with vector-borne pathogens associated with fatal hemolytic anemia in a cattle herd in switzerland. | bovine anaplasmosis is a vector-borne disease that results in substantial economic losses in other parts of the world but so far not in northern europe. in august 2002, a fatal disease outbreak was reported in a large dairy herd in the swiss canton of grisons. diseased animals experienced fever, anorexia, agalactia, and depression. anemia, ectoparasite infestation, and, occasionally, hemoglobinuria were observed. to determine the roles of vector-borne pathogens and to characterize the disease, b ... | 2004 | 15297529 |
| a comparison of serologic tests for the detection of serum antibodies to whole-cell and recombinant borrelia burgdorferi antigens in cattle. | serum samples from healthy dairy and beef cattle, living in tick-infested areas of connecticut, usa, were analyzed by polyvalent enzyme-linked immunosorbent assays (elisa), indirect fluorescent antibody (ifa) staining methods, or western blot procedures to detect antibodies to tick-borne agents. of the 80 sera tested by elisa with whole-cell or 10 separate recombinant antigens (fusion proteins) of borrelia burgdorferi sensu stricto, 57 (71%) were positive to 1 or more antigens, while 36 (45%) re ... | 2004 | 15368740 |
| the cd4+ t cell immunodominant anaplasma marginale major surface protein 2 stimulates gammadelta t cell clones that express unique t cell receptors. | major surface protein 2 (msp2) of the bovine rickettsial pathogen anaplasma marginale is an abundant, serologically immunodominant outer membrane protein. immunodominance partially results from numerous cd4+ t cell epitopes in highly conserved amino and carboxy regions and the central hypervariable region of msp2. however, in long-term cultures of lymphocytes stimulated with a. marginale, workshop cluster 1 (wc1)+ gammadelta t cells and cd4+ alphabeta t cells proliferated, leading to a predomina ... | 2005 | 15522917 |
| stochastic transmission of multiple genotypically distinct anaplasma marginale strains in a herd with high prevalence of anaplasma infection. | multiple genotypically unique strains of the tick-borne pathogen anaplasma marginale occur and are transmitted within regions where the organism is endemic. in this study, we tested the hypothesis that specific a. marginale strains are preferentially transmitted. the study herd of cattle (n = 261) had an infection prevalence of 29% as determined by competitive inhibition enzyme-linked immunosorbent assay and pcr, with complete concordance between results of the two assays. genotyping revealed th ... | 2004 | 15528749 |