| attempts to transmit anaplasma marginale with hippobosca rufipes and stomoxys calcitrans. | three attempts to transmit anaplasmosis with field collections of hippobosca rufipes were unsuccessful, despite the fact that the flies had been fed initially on splenectomized cattle acutely infected with anaplasma marginale. however, 1 out of the 3 attempts, made concurrently with the others, to transmit this organism with stomoxys calcitrans was successful. the prepatent period was 27 days. | 1981 | 7312304 |
| effect of anaplasma marginale infection upon blood gases and electrolytes in splenectomized calves. | | 1981 | 7328469 |
| freeze-drying of anaplasma marginale. | heparinized whole blood, heavily parasitized with anaplasma marginale, was collected from 3 splenectomized oxen. buffered lactose peptone (blp) was added to equal volumes as a stabilizer and the mixture lyophilized in 2 ml aliquots after rapid freezing. the dried material was reconstituted with 2 ml sterile water and inoculated without delay. the product remained infective for at least 6 months when stored in an ordinary household deep-freeze unit. | 1981 | 7335334 |
| chemoprophylaxis of vector-borne anaplasmosis with sustained-release boluses. | sustained-release oxytetracycline boluses (20%) delivering 145 to 150 mg/bolus/day were administered to complement-fixation test-negative cattle at dosages of 2.0, 2.5, and 3.0 mg/kg of body weight. subsequent challenge exposure of cattle with dermacentor andersoni stiles infected with anaplasma marginale theiler indicated that treatment with the dosage of 2.5 mg/kg prevented clinical anaplasmosis and that treatment with the dosage of 3.0 mg/kg prevented disease infection. | 1981 | 7340579 |
| infection of splenectomized calves with anaplasma ovis. | an anaplasma was not recovered from 2 splenectomized calves at 17 days after a ovis inoculation, but was recovered from 1 of the calves at 177 days after inoculation. in a 3rd calf exposed to a ovis, an anaplasma was recovered at 177 and 262 days after inoculation. the anaplasma recovered from these calves was determined to be a ovis on the basis of cross-infectivity trials, using anaplasma marginale. | 1981 | 7340580 |
| antibody formation to babesia bovis and anaplasma marginale in calves in bolivia. | | 1981 | 7344191 |
| prevalence of antibodies to babesia bovis and anaplasma marginale in dairy cattle in bolivia. | | 1980 | 7368318 |
| characterization of immune responses of cattle to erythrocyte stroma, anaplasma antigen, and dodecanoic acid-conjugated anaplasma antigen: cell-mediated immunity. | sonically disrupted normal erythrocyte stroma (ses) and two anaplasma antigens (sonically disrupted anaplasma antigen; saa, and french pressure cell disrupted anaplasma antigen; faa) were prepared from normal and anaplasma marginale-infected blood. the saa and faa antigens were chemically modified by conjugation with dodecanoic acid (saada and faada). significant (p less than or equal to 0.05) anti-anaplasma lymphocyte-transformation responses were obtained from all cattle given saa, saada, or f ... | 1980 | 7369609 |
| susceptibility of bos indicus crossbred and bos taurus cattle to anaplasma marginale infection. | the effects of infection with anaplasma marginale in groups of bos indicus-brahman crossbred and bos taurus cattle aged 27 and 48 months were studied using the parameters of body weight change, packed cell volume, parasitaemia and humoral antibody. twenty-six animals (8 bos taurus and 18 bos indicus crosses) of each age group were infected. no significant differences between any of the groups were observed. | 1980 | 7414703 |
| a comparative study of experimental anaplasmosis in bos indicus and bos taurus cattle. | comparative studies were carried out on the susceptibility of 8 bos taurus and 10 predominantly bos indicus cross cows aged 48 months to anaplasma marginale infection. measurements were carried out on bodyweight, parasitaemia, haematological factors, humoral antibody response and serum transaminase levels. except for minor differences in reaction bos indicus and bos taurus animals were equally susceptible to infecton with the strain of a. marginale employed. such differences observed were not si ... | 1980 | 7425986 |
| epidemiology of bovine anaplasmosis in beef calves in northern queensland. | natural infection of calves with anaplasma marginale was studied in two endemic areas of tropical north queensland. infection, assessed by a micro-complement fixation test, occurred throughout the year but was most frequent just after the summer wet season. infection was clinically inapparent. calves vaccinated with a. centrale did not show improved growth rate when compared with non-vaccinated calves. the complement fixation test was shown to be most effective in the detection of recent infecti ... | 1980 | 7425987 |
| comparison of three methods of immunization against bovine anaplasmosis: an examination of postvaccinal effects. | normandy calves ranging in age from 7 to 11 months were immunized against bovine anaplasmosis, using a diluted virulent anaplasma marginale stabilate of colombian origin, diluted bovine blood containing an apparently mild strain of a marginale isolated in colombia, or an attenuated a marginale vaccine of ovine origin from the united states. calves given the stabilate generally showed a moderate degree of parasitemia and reduction in packed cell volume (pcv). calves given the apparently mild colo ... | 1980 | 7436099 |
| comparison of three methods of immunization against bovine anaplasmosis: evaluation of protection afforded against field challenge exposure. | the efficacy of three immunization methods for bovine anaplasmosis was tested on 88 yearling normandy cattle which were challenge-exposed under field conditions in an enzootic zone in colombia, south american. a total of 30 cattle were immunized (premunized) with a presumed mild colombian isolate of anaplasma marginale; 29 calves were vaccinated with an attenuated a marginale of ovine origin; and 29 were exposed to a virulent a marginale stabilate of colombian origin. twenty-nine nonvaccinated c ... | 1980 | 7436100 |
| seasonal incidence and hemoparasite infection rates of ixodid ticks (acari: ixodidae) detached from cattle in costa rica. | to determine the tick species hindering the cattle industry in costa rica and to assess infection rates of ticks with three important hemoparasite species, cattle were monitored during a period of six months (october 1992-march 1993). four farms were located in the dry pacific region of the canton of tilarán and a fifth farm on the slopes of the poás volcano in a cool tropical cloud-forest ecosystem. on each farm 3 to 5 animals of 6 to 24 months of age were selected at random. all ticks were rem ... | 1994 | 7501871 |
| effects of tick infestation and tick-borne disease infections (heartwater, anaplasmosis and babesiosis) on the lactation and weight gain of mashona cattle in south-eastern zimbabwe. | the effects of ticks and tick-borne disease infections on the lactation and weight gain of mashona cattle were studied at mbizi quarantine station in the south-eastern lowveld of zimbabwe. twenty-nine mashona cows were allocated to 2 balanced groups and kept in separate paddocks at a stocking rate of one animal per 8 ha. one group received regular acaricide treatment to control bont (amblyomma hebraeum) and other ticks. the other group was left untreated. the cows were artificially inseminated. ... | 1995 | 7502343 |
| antigen recognition on anaplasma marginale and bovine erythrocytes: an electron microscopy study. | the reactivity of sera from anaplasma marginale-infected bovine with red blood cells and with purified anaplasma bodies was analyzed by electron immunomicroscopy. red blood cells from non-infected and from anaplasma-infected cows and a. marginale bodies separated from parasitized erythrocytes, were incubated with control, pre-immune and immune sera followed by anti-bovine igg-peroxidase. immune sera from cows infected with the venezuelan and florida isolate reacted with red blood cell membranes ... | 1993 | 7504852 |
| 16s rrna gene sequence of neorickettsia helminthoeca and its phylogenetic alignment with members of the genus ehrlichia. | neorickettsia helminthoeca (tribe ehrlichieae, family rickettsiaceae) is the agent of salmon poisoning disease, which affects members of the family canidae. this bacterium is unusual in that it is the only known obligately intracellular bacterium that is transmitted via a helminth vector. the nucleotide sequence of the n. helminthoeca 16s rrna gene was determined and compared with the sequences of intracellular bacteria belonging to the alpha subgroup of the proteobacteria. the n. helminthoeca s ... | 1995 | 7537055 |
| detection of anaplasma ovis infection in goats by major surface protein 5 competitive inhibition enzyme-linked immunosorbent assay. | a competitive inhibition enzyme-linked immunosorbent assay (elisa) based on a major surface protein 5 (msp5) b-cell epitope conserved among anaplasma species was used to detect goats infected with anaplasma ovis. we examined strains of a. ovis isolated from goats in kenya and demonstrated that msp5 and the target b-cell epitope, bound by monoclonal antibody anaf16c1, were conserved. sera from 149 goats in four regions of kenya and from 302 goats in six u.s. states were tested for the presence of ... | 1995 | 7538510 |
| epidemiology of babesiosis and anaplasmosis in south and central america. | babesiosis (babesia bovis and babesia bigemina) and anaplasmosis (anaplasma marginale) affect native cattle from uruguay and northern argentina to guatemala. the distribution of babesia follows the dissemination of the tick vector. seroepidemiological studies showed that enzootic instability exist in herds in several areas of the region. however, clinical cases occurred less frequently than expected. the babesial tick infection rate is related to the vector abundance which in turn is regulated b ... | 1995 | 7597777 |
| targeting ticks for control of selected hemoparasitic diseases of cattle. | development in and transmission of hemoparasites by tick vectors are phenomena closely synchronized with the tick feeding cycle. in all known life cycles, initial infection of tick tissues occurs in midgut epithelial cells and transmission is effected as ticks feed after parasites have developed and multiplied in salivary glands. many factors reviewed affect development and transmission of hemoparasites by ticks including age of ticks, artificial temperature, climate and/or season, tick stage or ... | 1995 | 7597779 |
| strategies for the control of one-host ticks and relationship with tick-borne diseases in south america. | a variety of hemoparasites occurs in ruminants of south america (12 degrees 00'n-56 degrees 00's), but there is consensus on the significant economic impact of babesiosis (babesia bovis and babesia bigemina) and anaplasmosis (anaplasma marginale). the tick vector for the babesia spp. for the whole region is boophilus microplus which has been the most important target in control/eradication programs. boophilus microplus and many different hematophagous diptera species are considered vectors of a. ... | 1995 | 7597780 |
| live vaccines against hemoparasitic diseases in livestock. | live vaccines against hemoparasitic diseases in livestock are based on parasites derived from culture (theileria annulata), from blood of infected animals (babesia bovis, babesia bigemina, anaplasma centrale, (attenuated) anaplasma marginale and cowdria ruminantium), and from ticks (theileria parva). the t. annulata attenuated cultured schizont vaccine is safe for all varieties of cattle. blood derived vaccines are recommended mainly for young cattle, the age limit varying with the different vac ... | 1995 | 7597786 |
| molecular basis for vaccine development against anaplasmosis and babesiosis. | immunization of livestock against the erythroparasitic pathogens anaplasma marginale, babesia bigemina, and babesia bovis with safe and effective killed vaccines is not yet feasible on a practical basis. however, the immune protection afforded by recovery from natural infection and premunition indicates that microbial epitopes capable of inducing immunity exist and that the bovine immune system can be primed appropriately. induction of protection by immunization with killed parasite fractions, e ... | 1995 | 7597787 |
| vaccine development from a commercial point of view. | the development of a commercial vaccine comprises distinct stages. initiation of a research project is triggered by demands from the market. if commercial and technical requirements are met, a feasibility study is carried out. research is started, and aimed at formulating the product profile (what the product looks like). the product profile is subject to requirements set by the market (e.g. whether the product will fit into existing vaccination schedules) and very often technical aspects affect ... | 1995 | 7597789 |
| recent developments in the molecular biology of anaplasmosis. | recent applications of dna analysis, cloning, sequencing and expression technology have resulted in significant advances in our understanding of the hemoparasite anaplasma marginale. analysis of 16s ribosomal rna has confirmed a phylogenetic position close to ehrlichia sp. and cowdria ruminantium. intact genomic dna of a. marginale digested with sfii separates into bands from 14 to 170 kbp on pulse-field gels, with a total genome size of 1200-1260 kbp and g + c content of 56 mol%. major surface ... | 1995 | 7597790 |
| conserved recombinant antigens of anaplasma marginale and babesia equi for serologic diagnosis. | the competitive inhibition elisa (ci-elisa) format overcomes problems associated with antigen purity since the specificity of the ci-elisa depends solely on the monoclonal antibody (mab) used. therefore, the ci-elisa format is well suited for use with recombinant antigens. molecular clones expressing a conserved 19 kda protein of anaplasma marginale and a 34 kda protein of babesia equi were derived and characterized. the 19 kda a. marginale protein, conserved in all recognized anaplasma species, ... | 1995 | 7597796 |
| recent developments in elucidating tick vector relationships for anaplasmosis and equine piroplasmosis. | this brief review focuses first on several epidemiologically relevant aspects of anaplasmosis, including: (1) the role of male ticks as intrastadial, biological vectors of anaplasma through interhost transfer; (2) the application of molecular diagnostic assays in assessing tick vector competence and evaluating the role of chronically infected carrier cattle as sources of anaplasma marginale infection in vector ticks; (3) opportunities provided by a recently developed in vitro tick feeding system ... | 1995 | 7597797 |
| susceptibility to different tick genera in gambian n'dama and gobra zebu cattle exposed to naturally occurring tick infestations. | tick collection on one side of the body and whole tail was performed weekly over one year on 11 gambian n'dama (bos taurus) and 11 gobra zebu (bos indicus) cattle to assess breed susceptibility to naturally occurring ticks. enzyme-linked immunosorbant assay was also performed to assess the serological prevalence of anaplasma marginale antigen and babesia bigemina antibody. packed red cell volume was measured and liveweight gain was recorded. significantly higher numbers of amblyomma variegatum ( ... | 1995 | 7652946 |
| expression and immune recognition of the conserved msp4 outer membrane protein of anaplasma marginale. | defining conserved, protective epitopes is essential to the design of an effective vaccine against bovine anaplasmosis. msp4, one of six initial body proteins recognized by a neutralizing serum, is conserved among anaplasma marginale isolates at both the protein and the dna levels. sera from cattle immunized with an outer membrane fraction of a. marginale and protected from a virulent challenge bind msp4. the gene for msp4 has been cloned, and the recombinant protein has been expressed, isolated ... | 1993 | 7693596 |
| heterologous strain challenge of cattle immunized with anaplasma marginale outer membranes. | in this study, we tested the hypothesis that outer membrane immunization would induce protection against an antigenically variant strain. outer membranes were isolated from the virginia strain of anaplasma marginale using density gradient centrifugation, combined with saponin adjuvant, and used to immunize friesian cattle in zimbabwe. immunized cattle developed high antibody titers (80,000-160,000) against outer membrane polypeptides including msp-2 and msp-5 in both the homologous virginia and ... | 1994 | 7810060 |
| molecular and biological characterization of a newly isolated anaplasma marginale strain. | anaplasma marginale, a rickettsial hemoparasite of cattle and other ruminants, results in significant economic losses worldwide. distinct strains of a. marginale have been identified based on differences in tick transmissibility, molecular size of surface proteins and dna restriction fragments, and reactivity to a panel of monoclonal antibodies. these different strains vary considerably in their virulence, antigenic composition, and ability to protect against heterologous challenge. in this pape ... | 1994 | 7858023 |
| protein analysis of anaplasma marginale and anaplasma centrale by two-dimensional polyacrylamide gel electrophoresis. | protein compositions of anaplasma marginale and a. centrale were analyzed by two-dimensional gel electrophoresis. both species had a major protein which was composed of 3-4 spots. the molecular weights of these two proteins were approximately 39 kda. however, the position of these proteins in the gels were slightly different when 2 gel maps were superimposed. five other protein spots were shared by a. marginale and a. centrale, whereas all the other protein spots were appeared to be unique to ea ... | 1994 | 7865577 |
| analysis of the anaplasma marginale genome by pulsed-field electrophoresis. | anaplasma marginale is a rickettsial parasite of bovine erythrocytes causing world-wide economic losses in livestock production. despite its importance, little is known about this rickettsia at a molecular level because it has not been cultured in vitro, and there is no small-animal model. although several genes have been cloned and sequenced, the gross genome structure of the organism has not yet been well characterized. we separated intact bovine erythrocytes from leucocytes, and determined th ... | 1993 | 7902862 |
| molecular epidemiology of bovine anaplasmosis. | bovine anaplasmosis presents a worldwide distribution. however, specific models for studying the epidemiology of the disease are not available. epidemiological modeling encounters some difficulties due to a lack of culturing techniques for anaplasma marginale, the causative agent, as well as for the lack of typing techniques to characterize strains. the chronic carrier state and the population dynamics of mechanical and biological vectors also create difficulties. in addition, conventional serol ... | 1994 | 7919822 |
| characterization of hemagglutinating components on the anaplasma marginale initial body surface and identification of possible adhesins. | interaction of anaplasma marginale initial bodies with the bovine erythrocyte surface was examined by a direct hemagglutination assay. purified initial bodies were shown to specifically hemagglutinate bovine erythrocytes but not erythrocytes from nonhost animal species. hemagglutination was inhibited by treatment of purified initial bodies with trypsin, alpha-chymotrypsin, or proteinase k but not by treatment with neuraminidase or sodium periodate. treatment of bovine erythrocytes with alpha-chy ... | 1994 | 7927725 |
| putative adhesins of anaplasma marginale: major surface polypeptides 1a and 1b. | genes for the msp1a and msp1b subunits of the anaplasma marginale surface antigen complex msp1 were previously cloned and expressed in escherichia coli. we report here the localization of msp1a and msp1b polypeptides on the surface of recombinant e. coli by using a live cell indirect immunofluorescent antibody assay. recombinant e. coli cells expressing the msp1 alpha gene or the msp1 beta gene encoding the msp1a and msp1b polypeptide subunits, respectively, were shown by a culture recovery adhe ... | 1994 | 7927726 |
| polymerase chain reaction-based diagnostic assay to detect cattle chronically infected with babesia bovis. | from a b. bovis gene sequence coding for a 60 kda merozoite surface protein previously published, two sets of primers were designed for the polymerase chain reaction (pcr) assay. primer set bof/bor was used to prime taq polymerase dna amplification of a 350 bp fragment of the target b. bovis dna. primer set bofn/born was used to prepare a pcr-synthesized, digoxigenin-dutp-labeled probe (291 bp) which would hybridize to a sequence within the pcr-amplified parasite target dna. pcr amplification of ... | 1994 | 7938942 |
| [ticks and hemoparasitoses of livestock in senegal. vi. the soudano-sahelian zone]. | the authors report the results of a study on ticks and hemoparasitoses among cattle, sheep and goats in the sudano-sahelian zone. during a period of 15 months, ticks were systematically removed from 40 cattle, 40 sheep and 40 goats in order to assess the population dynamics and determine more accurately the preferential sites of settlement of the different species. the following species were collected in ruminants: hyalomma truncatum, h. marginatum rufipes, rhipicephalus evertsi evertsi, rh. gui ... | 1994 | 7991897 |
| intermolecular relationships of major surface proteins of anaplasma marginale. | immunization with anaplasma marginale membranes containing major surface proteins (msps) induces protective immunity against clinical disease (n. tebele, t. c. mcguire, and g. h. palmer, infect. immun. 59:3199-3204, 1991). for use in design of a recombinant antigen subunit vaccine for a. marginale, intermolecular relationships of known a. marginale msps were analyzed. under nonreducing conditions, msp-2 and msp-5 occur as multimers. a large (> 300-kda-molecular-mass), nonreduced protein complex ... | 1994 | 8005681 |
| recombinant vaccinia virus expression of anaplasma marginale surface protein msp-1a: effect of promoters, leader sequences and gpi anchor sequence on antibody response. | anaplasma marginale surface protein msp-1a was expressed by recombinant vaccinia viruses with different promoters and as hybrid proteins. transcription of msp1 alpha with p11 late promoter resulted in more msp-1a than with p7.5 early-late promoter; however, mice immunized with the recombinants had similar antibody titres. recombinants expressing hybrid msp-1a with either a murine leukaemia virus or a trypanosomal glycoprotein signal sequence did not enhance antibody responses and resulted in a d ... | 1994 | 8023555 |
| antigenic profile of a pure isolate of anaplasma marginale of brazilian origin, using a western blot technique. | anaplasma marginale initial bodies of the brazilian isolate aufv1 were purified from infected erythrocytes using a combination of lysis, ultrasonic disruption and differential centrifugation. initial bodies were solubilised with a buffer containing protease inhibitors and non-ionic detergents. immunochemical analysis by the western blot technique revealed at least five proteins with apparent molecular weights (mw) of 105, 100, 97, 87 and 38 kda when homologous sera were used as primary antibodie ... | 1994 | 8030178 |
| bovine anaplasmosis and babesiosis in the lesser antilles: risk assessment of an unstable epidemiologic situation. | a seroepidemiological survey on tick-borne diseases of ruminants was carried out on 11 islands of the lesser antilles from grenada to st martin. a total of 1,795 cattle were randomly sampled and sera tested for antibodies to anaplasmosis (anaplasma marginale) and babesiosis (babesia bovis and b bigemina) using a dot-elisa test. except for anaplasmosis, which was virtually absent from guadeloupe, the seroprevalence of the 3 tick-borne diseases ranged from 18 to 71%. the epidemiologic situation wa ... | 1994 | 8038806 |
| an attempt to transmit anaplasma marginale by buffalo flies (haematobia irritans exigua). | | 1994 | 8048908 |
| the immunoprotective anaplasma marginale major surface protein 2 is encoded by a polymorphic multigene family. | an anaplasma marginale florida msp-2 gene was cloned and expressed in escherichia coli. pulsed-field gel electrophoresis and southern blot analysis revealed the presence of multiple msp-2 gene copies that were widely distributed throughout the chromosomes of all three strains examined. genomic polymorphism among copies was greatest in the 5' end of msp-2 but also occurred in 3' regions. the presence of gene-copy-specific epitopes was indicated by the reactivity of the cloned msp-2 copy with some ... | 1994 | 8063397 |
| seroprevalence of bovine anaplasmosis in oklahoma from 1977 to 1991. | the prevalence of anaplasmosis in oklahoma cattle was determined on the basis of the standardized anaplasma marginale complement fixation test on 20,155 sera submitted to the oklahoma animal disease diagnostic laboratory during a 15-year period. rates of seropositivity ranged from 4.7% to 17.6% on samples submitted for anaplasmosis testing of adult cows. the geographic distribution of recorded cases of anaplasmosis was 35 oklahoma counties in 1977 and 48 oklahoma counties in 1991. | 1994 | 8068752 |
| [ticks and hemoparasitoses in livestock in senegal. v. the northern guinea area]. | the authors report the results of a study on ticks and hemoparasitoses among cattle, sheep and goats in the north-guinean zone. during a period of 15 months, ticks were systematically removed from 40 cattle, 40 sheep and 40 goats in order to assess the population dynamics and to determine more accurately the preferential sites of settlement of the following different species collected from these animals: amblyomma variegatum, boophilus geigyi, hyalomma truncatum, h. marginatum rufipes, rhipiceph ... | 1993 | 8073170 |
| taxonomic position of the rickettsiae: current knowledge. | the term rickettsiae initially encompassed all intracellular bacteria. early rickettsial taxonomy was based on a comparison of a few phenotypic characteristics and recently, molecular studies brought new bases for rickettsial taxonomy. all rickettsial species studied so far belong to the alpha and gamma groups of the proteobacteria. ehrlichiae complex groups cowdria ruminantium, anaplasma marginale and wolbachia pipientis and the related parthenogenesis and cytoplasmic incompatibility bacteria, ... | 1994 | 8117465 |
| molecular cloning, sequence analysis, and expression of the gene encoding the immunodominant 32-kilodalton protein of cowdria ruminantium. | cowdria ruminatium, the causative agent of heartwater disease, expresses an immunodominant and conserved 32-kilodalton protein (map1; formerly called cr32), which is currently in use for serodiagnosis of the disease. the gene encoding this protein, designated map1, was detected, cloned, and characterized. the gene is conserved between four different stocks of c. ruminantium originating from senegal, sudan, south africa, and zimbabwe. homology searches revealed map1 to be homologous to the anapla ... | 1994 | 8132352 |
| persistence of tick-derived anaplasma marginale in cultured bovine turbinate and endothelial cells. | anaplasma marginale from salivary glands of dermacentor andersoni was used to inoculate monolayers of bovine turbinate and endothelial cells. monolayers were passaged at 2 or 4 week intervals and monitored with light and electron microscopy and with an a. marginale-specific dna probe. intracellular inclusions were observed in turbinate cells after 2-4 weeks. the number of inclusion-bearing cells increased over 1-2 weeks and gradually disappeared. a radiolabeled fragment from within the msp1 beta ... | 1993 | 8134656 |
| use of multiplex polymerase chain reaction-based assay to conduct epidemiological studies on bovine hemoparasites in mexico. | a study was conducted to test the applicability of a polymerase chain reaction (pcr)-based approach for the simultaneous detection of the bovine hemoparasites babesia bigemina, b. bovis and anaplasma marginale. bovine blood samples from cattle ranches of a previously determined enzootic zone in the yucatan peninsula of mexico, were collected from peripheral blood and processed for pcr analysis. blood samples were subjected to dna amplification by placing an aliquot in a reaction tube containing ... | 1993 | 8134659 |
| antibody prevalence of eight ruminant infectious diseases in california mule and black-tailed deer (odocoileus hemionus). | we tested 276 sera from 18 free-ranging black-tailed and mule deer (odocoileus hemionus) herds in california (usa) collected from 1987 to 1991 in five biogeographical habitat types, for antibodies against eight infectious disease agents. overall antibody prevalence was 56% for anaplasma marginale, 31% for borrelia burgdorferi, 16% for bluetongue virus serotype 17, 15% for epizootic hemorrhagic disease virus, 7% for coxiella burnetii and toxoplasma gondii, respectively, and 0% for bovine leukosis ... | 1994 | 8151824 |
| demonstration of the oral path of infection with anaplasma marginale in calves. | when four calves were experimentally infected orally with blood infected with anaplasma marginale they developed anaplasmosis after an average incubation period of 30 days, as demonstrated by the presence of the organism in blood films and positive titres in a complement fixation test. | 1993 | 8212485 |
| application of enzyme-linked immunosorbent assay for epidemiological studies of diseases of livestock in the tropics of mexico. | this study was conducted at the centre for research, teaching and extension in tropical livestock (centro de investigación, enseñanza y extensión en ganadería tropical) of the faculty of veterinary medicine of the national autonomous university of mexico. during the latter part of 1986 and throughout 1988 and 1989, the herd of holstein x zebu cattle at the university was tested for igg antibodies to twenty-one viral, bacterial, rickettsial and parasitic agents. antigens prepared from twenty infe ... | 1993 | 8219327 |
| opsonization of anaplasma marginale mediated by bovine antibody against surface protein msp-1. | antibody from cattle immunized with purified major surface protein-1 (msp-1) was demonstrated to significantly enhance phagocytosis of florida strain anaplasma marginale by bovine macrophages in vitro. serum immunoglobulin from individual msp-1 immunized, protected cattle varied in ability to promote phagocytosis, however all sera were significantly opsonic as compared with sera from sham immunized control cattle. | 1993 | 8236809 |
| multiplex polymerase chain reaction based assay for the detection of babesia bigemina, babesia bovis and anaplasma marginale dna in bovine blood. | a highly sensitive polymerase chain reaction (pcr) based method was developed to detect, in the same blood sample, dna of hemoparasites frequently found together infecting cattle in tropical and subtropical areas. bovine blood containing equal parasitemias of babesia bigemina, b. bovis and anaplasma marginale infected erythrocytes was mixed to standardize the test. twenty microliters of 10-fold dilutions from the pooled blood sample were resuspended in pcr mixture buffer containing each of the s ... | 1993 | 8291198 |
| derivation of the complete msp4 gene sequence of anaplasma marginale without cloning. | the gene encoding msp4, a 31-kda surface protein of the rickettsia anaplasma marginale, was completely sequenced without prior cloning of the gene. degenerate oligodeoxyribonucleotides (oligos) corresponding to the n-terminal amino-acid sequence of msp4 were used as primers in the polymerase chain reaction (pcr) to amplify a 65-bp fragment of which the central 32 bp was nondegenerate. the 32-bp probe was hybridized to restriction enzyme-digested, genomic a. marginale dna in southern blots, and t ... | 1993 | 8294020 |
| isolation, initial characterization and serological studies of glycolipid antigens from babesia bovis-infected erythrocytes. | serological analysis of babesia bovis-derived glycolipids by elisa and the indirect fluorescent antibody technique demonstrated the existence of their antigenic and immunogenic activities not only in b. bovis but also in b. bigemina infections. this indicates that serological cross-reactivity of b. bovis and b. bigemina relates to glycolipids. the negative elisa reaction obtained with anaplasma marginale antisera suggested the specificity of the reaction to the genus babesia. fractionation of th ... | 1993 | 8300296 |
| sheep-adapted anaplasma marginale maintains virulence for cattle. | | 1993 | 8343094 |
| detection of anaplasma marginale (rickettsiales: anaplasmataceae) in hemolymph of dermacentor andersoni (acari: ixodidae) with the polymerase chain reaction. | the polymerase chain reaction (pcr) was used to detect anaplasma marginale in hemolymph collected from live dermacentor andersoni stiles ticks. hemolymph was collected from severed legs of male and female ticks exposed to a. marginale as either nymphs or adults. heat treatment was found to be the optimum method of hemolymph preparation for pcr. hemolymph samples were collected and pooled from adult ticks exposed as nymphs on days 0-10 of feeding on a susceptible calf. for male and female ticks e ... | 1993 | 8360902 |
| detection of anaplasma marginale (rickettsiales: anaplasmataceae) in secretagogue-induced oral secretions of dermacentor andersoni (acari: ixodidae) with the polymerase chain reaction. | the polymerase chain reaction (pcr) was used to detect anaplasma marginale in secretagogue-induced oral secretions of male and female dermacentor andersoni stiles exposed as nymphs or adults by feeding on infected calves. a 409-bp dna fragment derived from the a. marginale (florida isolate) msp1 beta gene was amplified with oligonucleotide primers bap-2 (5'-gtatggcacgtagtcttgggatca-3') and al34s (5'-cagcagcagcaagaccttca-3'). the target dna was amplified in oral secretions of female ticks exposed ... | 1993 | 8360903 |
| impact of persistent anaplasma marginale rickettsemia on tick infection and transmission. | anaplasma marginale, an intraerythrocytic rickettsia of cattle, is transmitted biologically by ticks. because of the brevity of acute a. marginale infection, transmission may rely on the tick's ability to acquire the organism from persistently infected cattle with low rickettsemia levels. by using a nucleic acid probe to quantitate low-level infection, we found that rickettsemia levels in persistently infected cattle fluctuated at approximately 5-week intervals during a 24-week period, from < 10 ... | 1993 | 8370734 |
| effect of 4-bromo-calcium ionophore a23187 on release of anaplasma marginale from bovine erythrocytes in vitro. | the ionophore a23187 was used to facilitate release and continued development of anaplasma marginale in short-term erythrocyte cultures. addition of 10 microm a23187 to the cultures resulted in significant decrease in percentage of parasitized erythrocytes (ppe) by 24 hours after treatment; further development and increase in ppe was not observed. in contrast, the ppe of untreated cultures, those treated with dimethyl sulfoxide (dmso) only and with 1 microm a23187 increased slightly during that ... | 1993 | 8381627 |
| advances in the diagnosis of some parasitic diseases by monoclonal antibody-based enzyme-linked immunosorbent assays. | advances in diagnostic assays for parasitic diseases include the use of monoclonal antibodies (mabs) in antigen capture and competitive inhibition enzyme-linked immunosorbent assays (c-elisa). antigen capture elisas for anaplasma marginale and cryptosporidium parvum provide direct detection of these parasites during clinical disease, and the c-elisa format has been adapted for detection of anti-babesia equi, anti-a. marginale and anti-bluetongue virus antibodies. false-positive results may occur ... | 1993 | 8400383 |
| development of anaplasma marginale in salivary glands of male dermacentor andersoni. | development of the rickettsia, anaplasma marginale, in salivary glands of male dermacentor andersoni exposed as nymphs or adult ticks, was studied indirectly by inoculation of susceptible calves with homogenates and directly by examination, using light microscopy and a dna probe; some unfed ticks were incubated before tissues were collected. salivary gland homogenates made from ticks in every treatment group caused anaplasmosis when injected into susceptible calves; prepatent periods decreased a ... | 1993 | 8427453 |
| a comparison of field tick infestation on n'dama, zebu and n'dama x zebu crossbred cattle. | tick burdens, estimated from cumulative tick counts, were determined on n'dama, zebu and f1 n'dama x zebu crossbred cattle. n'dama showed significantly fewer ticks than the zebu and f1 cattle (p < 0.001). a previous trypanosomosis infection did not affect tick burdens on the three genotypes. amblyomma variegatum had a prevalence of 84.8% and hyalomma spp. 15.2%, with the ratio similar on all cattle breeds. trypanosomosis infection increased the serological prevalence of anaplasma marginale in ze ... | 1993 | 8493760 |
| human interferon alpha fails to inhibit the development of babesia bigemina and anaplasma marginale infections in cattle. | studies were undertaken to determine whether human interferon alpha (huifn-alpha) administered orally could inhibit the development of clinical disease caused by the intraerythrocytic protozoan babesia bigemina and the intraerythrocytic rickettsia anaplasma marginale in cattle. huifn-alpha did not inhibit intraerythrocytic multiplication of either of the two parasites, suggesting that there is no role for huifn-alpha administered orally in the control of these pathogens. | 1993 | 8493761 |
| intrastadial and interstadial transmission of anaplasma marginale by boophilus annulatus ticks in cattle. | the 1-host tick boophilus annulatus was found to transmit anaplasmosis in cattle transstadially. anaplasma marginale was invariably transmitted when ticks that had been pulled off anaplasma-infected calves either after 7 days (as fully engorged larvae) or after 14 to 15 days (as fully engorged nymphs) were transferred within 4 days to susceptible calves. three morphologically different a marginale isolates, 1 round (tailless) and 2 with different types of appendages (tailed) were transmitted by ... | 1993 | 8498744 |
| theileria sergenti and t. buffeli: polymerase chain reaction-based marker system for differentiating the parasite species from infected cattle blood and infected tick salivary gland. | benign theileria species in cattle. theileria sergenti and t. buffeli, are morphologically indistinguishable. the polymerase chain reaction (pcr) was used to amplify the genes encoding the 33- and 34-kda major piroplasm antigens (p33/34) of t. sergenti and t. buffeli from cattle blood infected with these parasites and tick salivary gland infected with t. sergenti. following amplification, the p33 gene from t. sergenti and the p34 gene from t. buffeli were clearly differentiated using the restric ... | 1995 | 8542983 |
| detection of theileria annulata in blood samples of carrier cattle by pcr. | we report the detection of theileria annulata, the causative agent of tropical theileriosis, by pcr in blood samples obtained from carrier cattle. the assay employs primers specific for the gene encoding the 30-kda major merozoite surface antigen of t. annulata. a 721-bp fragment was amplified from blood samples taken monthly from calves experimentally infected with one of four different stocks of t. annulata originating in either mauritania, portugal, spain, or turkey. at the end of the experim ... | 1995 | 8567902 |
| detection of anaplasma marginale dna in bovine erythrocytes by slot-blot and in situ hybridization with a pcr-mediated digoxigenin-labeled dna probe. | a 409-base pair (bp) dna fragment derived from the msp-1 beta gene of anaplasma marginale was amplified and simultaneously labeled with digoxigenin-11-dutp by a polymerase chain reaction (pcr) assay. the resulting digoxigenin-labeled 409-bp pcr product was used as a probe for slot-blot and in situ hybridization to detect a. marginale dna from experimentally infected bovine erythrocytes. the hybrid formation was detected with alkaline phosphatase-conjugated anti-digoxigenin antibody and substrate ... | 1995 | 8580166 |
| an assessment of the role of white-tailed deer in the epizootiology of anaplasmosis in the southeastern united states. | the role of white-tailed deer (odocoileus virginianus) in the epizootiology of anaplasmosis in the southeastern united states was examined through retrospective and prospective serosurveys and by experimental infection studies. no serum antibody reactive to anaplasma marginale was detected with an indirect fluorescent antibody (ifa) assay from any of 1,376 free-ranging deer sampled from 1968 through 1990 from 13 states and puerto rico. thirty-one additional deer from three bovine anaplasmosis en ... | 1995 | 8592360 |
| susceptibility of elk (cervus elaphus) to experimental infection with anaplasma marginale and a. ovis. | anaplasma ovis was experimentally transmitted from domestic sheep to elk (cervus elaphus) and back to splenectomized sheep. no rickettsemias were detected but serum from three of seven experimentally inoculated elk developed anaplasma spp.-reactive antibody as measured by indirect immunofluorescence (iif) or by the rapid card agglutination and complement fixation assays. three elk were experimentally infected with a. marginale. the rickettsiae were detected in blood of these elk and caused disea ... | 1996 | 8627938 |
| expression of major surface protein 2 antigenic variants during acute anaplasma marginale rickettsemia. | antigenic variants of anaplasma marginale major surface protein 2 (msp-2), a target of protective immune responses, have been detected by use of copy-specific monoclonal antibodies reactive with some, but not all, organisms during acute rickettsemia. the presence of polymorphic msp-2 genes was confirmed by cloning and sequencing two gene copies, 11.2 and df5, each of which encodes a full-length msp-2 with a unique amino acid sequence. transcription of msp-2 genes during acute rickettsemia was an ... | 1996 | 8641789 |
| ixodes (ixodes) scapularis (acari:ixodidae): redescription of all active stages, distribution, hosts, geographical variation, and medical and veterinary importance. | the blacklegged tick, ixodes (ixodes) scapularis say, 1821, is redescribed, based on laboratory reared specimens originating in bulloch county, georgia. information on distribution, host associations, morphological variation, and medical/veterinary importance is also presented. a great deal of recent work has focused on this species because it is the principal vector of the agent of lyme disease (borrelia burgdorferi johnson, schmidt, hyde, steigerwaldt & brenner) in eastern north america. its d ... | 1996 | 8667375 |
| preliminary studies on the effect of anaplasma marginale antibodies ingested by dermacentor andersoni ticks (acari:ixodidae) with their blood meal on infections in salivary glands. | the effect of anaplasma marginale antibodies ingested with the tick blood meal was tested on infected male ticks that were allowed to feed on cattle immunized with the erythrocytic stage of a. marginale. the experiments were done in two trials. trial 1 was done using splenectomized calves (two calves per treated and control groups) while ticks in trial 2 were fed on intact yearling cattle (four cattle per treated and control groups). the cattle were immunized with purified outer membrane protein ... | 1996 | 8674360 |
| establishment of the tick (acari:ixodidae)-borne cattle pathogen anaplasma marginale (rickettsiales:anaplasmataceae) in tick cell culture. | anaplasma marginale is a tick-borne rickettsia that causes bovine anaplasmosis worldwide. despite its importance, a. marginale has thus far not been established in a continuous culture system. we have propagated a. marginale continuously for the 1st time in a tick cell line derived from the black-legged tick, ixodes scapularis say, using infected bovine blood as the inoculum. erythrocytic stages invaded the tick cells and multiplied in membrane-lined vacuoles to form colonies typical of those ob ... | 1996 | 8699463 |
| morphology and development of anaplasma marginale in midgut of engorged female ticks of boophilus microplus. | morphology and development of anaplasma marginale were studied in midgut epithelial cells of adult boophilus microplus females using light and transmission electron microscopy. hemoparasite-free b. microplus larvae were used to infest holstein calves experimentally inoculated with a. marginale. when a. marginale parasitemia varied from 0.4% to 4.3%, 140 engorged female ticks were collected and kept individually in steel wire tubes and incubated outdoors on brachiaria decumbens grass pasture. fem ... | 1996 | 8750681 |
| comparative sensitivity of two tests for the diagnosis of multiple hemoparasite infection of cattle. | the purpose of this study was to evaluate the efficacy of light microscopy (lm) examination of blood smears and a multiplex polymerase chain reaction (mpcr) assay, in terms of their ability to detect cattle experimentally infected with babesia bovis, babesia bigemina, and anaplasma marginale. blood samples were collected from 32 intact, 1-2 year old, holstein bulls, previous to and after simultaneous inoculation of culture-derived or field isolates of b. bovis- and b. bigemina-infected erythrocy ... | 1996 | 8784493 |
| strategies to interrupt the development of anaplasma marginale in its tick vector. the effect of bovine-derived antibodies. | anaplasma marginale is a rickettsia transmitted by ticks that invades and multiplies in bovine erythrocytes causing the disease anaplasmosis. a complex developmental cycle occurs within ticks that begins in midgut cells, with subsequent infection in gut muscle cells. final development occurs in salivary glands from where the rickettsia is transmitted to the vertebrate host. at each site of development, a. marginale multiplies within membrane-bound inclusions. attempts to control anaplasmosis hav ... | 1996 | 8784497 |
| enrofloxacin to control anaplasma marginale infections. | | 1996 | 8784531 |
| evaluation of anaplasma marginale major surface protein 3 (msp3) as a diagnostic test antigen. | an immunodominant surface protein, major surface protein 3 (msp3), has been proposed as an antigen suitable for use in the diagnosis of bovine anaplasmosis. we further characterized msp3 to examine its potential as a test antigen for the serological diagnosis of carrier cattle. the specificity of this antigen in detecting infected cattle as well as the conservation of msp3 between strains of anaplasma marginale was evaluated by using immunoblots of a. marginale proteins separated by one- and two ... | 1996 | 8788999 |
| peripheral blood lymphocyte proliferative responses in cattle infected with or vaccinated against anaplasma marginale. | an assay was developed for measurement of the peripheral blood lymphocyte proliferative response (pblpr) in cattle infected with or immunised against anaplasma marginale. pblpr was not evident in all cattle that had recovered from a. marginale infection. however, a. marginale-sensitised lymphocytes were detected in the spleens of all immune cattle tested in the absence of detectable pblpr. during the course of initial infection, cattle exhibited detectable pblpr for a period corresponding with a ... | 1996 | 8832738 |
| improving the specificity of indirect immunofluorescence for the serological diagnosis of bovine anaplasmosis. | fluorescing inclusion appendages were detected consistently in preparations of anaplasma centrale and anaplasma marginale when they were used as antigen in indirect immunofluorescence serological tests for the diagnosis of anaplasmosis in cattle. the presence of the inclusion appendages made it possible to confirm the specificity of the immunofluorescent reaction and to determine end-points with accuracy. | 1996 | 8848303 |
| antibody against an anaplasma marginale msp5 epitope common to tick and erythrocyte stages identifies persistently infected cattle. | a protein epitope of major surface protein 5 (msp5), defined by monoclonal antibody (mab) anaf16c1, is conserved among anaplasma species (e. s. visser, t. c. mcguire, g. h. palmer, w. c. davis, v. shkap, e. pipano, and d. p. knowles, jr., infect. immun. 60:5139-5144, 1992) and is expressed in the salivary glands of infected ticks. a competitive inhibition elisa (celisa) for the detection of bovine anti-msp5 antibodies was developed by using purified recombinant msp5 fusion protein and mab anaf16 ... | 1996 | 8862589 |
| effect on intraerythrocytic anaplasma marginale of soluble factors from infected calf blood mononuclear cells. | blood mononuclear cells (lymphocytes and monocytes) were isolated from infected calves during in vivo control of acute anaplasmosis and cultured with anaplasma marginale organisms. supernatants from the cultures reduced the proportion of erythrocytes containing viable a. marginale in vitro, indicating that an antibody-independent mechanism of rickettsemia control might occur during acute anaplasmosis. | 1996 | 8890250 |
| developmental studies of anaplasma marginale (rickettsiales:anaplasmataceae) in male dermacentor andersoni (acari:ixodidae) infected as adults by using nonradioactive in situ hybridization and microscopy. | the development of anaplasma marginale theiler was studied in ticks using a nonradioactive in situ hybridization method developed in our laboratory. male rocky mountain wood ticks, dermacentor andersoni stiles, were infected intrastadially by allowing them to feed for 7 d on an infected calf (acquisition feeding). the ticks were then removed and held in a humidity chamber for 5 d before being fed on a 2nd susceptible call for 10 d (transmission feeding). two groups of 10 ticks were collected dai ... | 1996 | 8961639 |
| anaplasma marginale major surface protein 3 is encoded by a polymorphic, multigene family. | the immunodominant surface protein, msp3, is structurally and antigenically polymorphic among strains of anaplasma marginale. in this study we show that a polymorphic multigene family is at least partially responsible for the variation seen in msp3. the a. marginale msp3 gene msp3-12 was cloned and expressed in escherichia coli. with msp3-12 as a probe, multiple, partially homologous gene copies were identified in the genomes of three a. marginale strains. these copies were widely distributed th ... | 1997 | 8975906 |
| prospects for subunit vaccines against tick-borne diseases. | tick-borne parasites are a serious impediment to the improvement of live-stock production in the developing world. the major parasites affecting cattle include theileria parva, t. annulata, babesia bigemina, b. bovis, anaplasma marginale and cowdria ruminantium. the control of these infections is dependent on the use of acaricides to decrease transmission by the tick vectors, and immunization of susceptible animals with live vaccines. the use of acaricide is hampered by the development of resist ... | 1996 | 8979421 |
| anaplasma marginale: detection of carrier cattle by pcr-elisa. | a highly sensitive and specific polymerase chain reaction (pcr) based assay for the detection of the minute levels of anaplasma marginale present in the blood of long-term carrier cattle was developed. a simple lysis method was used to remove most of the haemoglobin from the blood to facilitate direct input of samples into the pcr reactions without prior purification of the dna. pcr product was detected by enzyme-linked immunosorbent assay (elisa) to simplify the processing of large numbers of s ... | 1996 | 8982791 |
| development and validation of an indirect enzyme immunoassay for detection of antibody to anaplasma marginale in bovine sera. | an indirect enzyme immunoassay (ielisa) for detection of bovine antibody activity to anaplasma marginale was developed. this assay used a crude antigen prepared from erythrocytes of infected calves, immobilized in a polystyrene matrix and a mouse monoclonal antibody to bovine igg1, conjugated with horseradish peroxidase. negative sera (n = 1842) were tested and the diagnostic specificity was 98.4 +/- 0.6% before retesting 29 positive samples. after retesting, eight samples remained positive and ... | 1996 | 9017861 |
| anaplasma marginale: effect of challenge of cattle with varying doses of infected erythrocytes. | three groups, each of 6 hereford cattle, were infected by the i.v. inoculation of 10(10), 10(8) or 10(6) anaplasma marginale-infected erythrocytes. the mean time taken to reach a 1% parasitaemia was 7.3, 13.9 and 19.9 days in the 10(10), 10(8)and 10(6) infection dose groups, respectively. the rates of increase in parasitaemias during the exponential phase of parasite multiplication were similar for the 3 groups (doubling time 0.9 days). the exponential increase of the parasitaemia in the 10(10) ... | 1996 | 9024896 |
| variations in seroprevalence and host factors for bovine anaplasmosis in illinois. | the modified card agglutination test (mcat) was used to detect antibodies to anaplasma marginale in 4994 samples collected from market cattle through the brucellosis eradication program in illinois. the mcat reactor rate in the sample was 6.4%. the statewide prevalence estimate increased to between 7.1% and 10.7% when corrected for sampling distribution and test sensitivity and specificity. while the sample reactor rate measures the proportion of infected cattle moving through the market system ... | 1997 | 9060138 |
| use of a nonradioactive dna probe for detection of anaplasma marginale infection in field cattle: comparison with complement fixation serology and microscopic examination. | a sensitive anaplasma marginale-specific 409-base pair dna probe was developed in a previous study for detection of a. marginale infection in experimentally infected cattle with a test that employed slot-blot and in situ hybridization. to test the suitability of the probe to detect a. marginale in the blood of naturally infected carrier cattle, slot-blot hybridization was used to determine the infection rate of a. marginale in cattle from 3 geographic areas in oklahoma. for comparison, blood sam ... | 1997 | 9087923 |
| serologic survey for infectious pathogens in free-ranging american bison. | from november 1991 through march 1992, we evaluated 101 free-ranging american bison (bison bison) from yellowstone national park, wyoming (usa) for exposure to infectious organisms that commonly infect cattle. no titers were detected for bluetongue virus, bovine leukemia virus, or campylobacter fetus in these 101 bison. detectable antibodies occurred against anaplasma marginale (eight of 76, 11%), bovine respiratory syncytial virus (31 of 101, 31%), bovine viral diarrhea (31 of 101, 31%), bovine ... | 1997 | 9131564 |
| transmission of anaplasma marginale with adult boophilus microplus ticks fed as nymphs on calves with different levels of rickettsaemia. | nine splenectomised calves were infested with dissimilar numbers of adult boophilus microplus ticks 72 h after collection as engorged nymphs from three non splenectomised calves with different levels of anaplasma marginale rickettsaemia. successful transmission of a. marginale appeared to be more dependent on the level of rickettsaemia of the donor calves than on the number of ticks attaching to the splenectomised calves, since infection was transmitted only when the rickettsaemia was 0.3% or gr ... | 1994 | 9140508 |
| western immunoblot analysis of haemobartonella muris and comparison of 16s rrna gene sequences of h. muris, h. felis, and eperythrozoon suis. | infectious agents were isolated from the spleens of three wild mice (apodemus argenteus) by intraperitoneal inoculation of the spleen homogenate into laboratory mice. the laboratory mice developed clinical signs and splenomegaly, and three isolates were maintained by passage in mice. tetracyclines were effective in preventing infection of mice with these agents, but streptomycin and penicillin were ineffective. the agents did not grow in bacterial growth media or chicken embryos. in smears of bl ... | 1997 | 9157135 |
| prevalence of granulocytic ehrlichia infection among white-tailed deer in wisconsin. | human granulocytic ehrlichiosis (hge) is caused by an agent that is nearly indistinguishable from the veterinary pathogens ehrlichia equi and ehrlichia phagocytophila. the deer tick, ixodes scapularis, is a vector of the hge agent, and the white-tailed deer is the primary host for adult ixodes ticks. we assessed the distribution of granulocytic ehrlichia infection among deer living within (wisconsin) and outside (western and southern iowa) the geographic range of l. scapularis. whole-blood sampl ... | 1997 | 9163463 |
| increased resistance to anaplasma marginale infection in cattle chronically infected with theileria buffeli (syn. t. orientalis). | calves chronically infected with the benign haemoprotozoan parasite theileria buffeli (syn. t. orientalis) and t. buffeli-free calves were experimentally infected with virulent anaplasma marginale. the daily mean maximum parasitaemia in the t. buffeli-carrier calves was lower and delayed relative to that of the theileria-free calves. anaemia was less marked in the theileria infected calves, although this difference was not statistically significant. the susceptibility of theileria-carrier and th ... | 1997 | 9195728 |
| effect of breed of cattle on innate resistance to infection with babesia bovis, b bigemina and anaplasma marginale. | to assess the innate resistance of naive bos taurus, bos taurus cross bos indicus and bos indicus cattle to virulent babesia bovis, b bigemina and anaplasma marginale parasites. | 1997 | 9196820 |
| immunisation of smallholder dairy cattle against anaplasmosis and babesiosis in malawi. | a field study was conducted in the southern region of malawi to evaluate the possible benefits of immunisation of improved dairy cattle against anaplasma marginale, babesia bigemina and babesia bovis. friesian crossbred heifers were immunised when they were being reared on government farms. they were then issued to smallholder farmers, together with unvaccinated controls, where many of them were exposed to heavy tick infestation. vaccination was shown to provide a significant degree of protectio ... | 1997 | 9203307 |