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1.
D W Brocklesby S A Sellwood D L Harradine E R Young 《International journal for parasitology》1973,3(5):671-680
A strain of Babesia major, originally isolated from field collections of Haemaphysalis punctata in Kent, England was maintained in splenectomized calves by the intravenous inoculation of infected blood. Rapid passage from carrier calves, that had recovered from a tick-induced infection, resulted in a marked increase in virulence; 4 out of 6 calves of the second passage underwent fatal infections and the others suffered severe reactions.Five splenectomized and 5 intact calves of the same breed and age were infected with the same number of infected erythrocytes (RBC). The intact calves reacted mildly with maximum parasite counts ranging from < RBC to RBC; haemoglobin levels and packed cell volume values, however, fell sharply but recovered swiftly. The group of splenectomized calves exhibited one fatal case, 2 severe reactions and 2 mild infections; maximum parasitaemias varied from RBC to RBC. Packed cell volumes and haemoglobin concentrations declined to low levels and took several weeks to return to normal.It is concluded that B. major should be regarded as a potential pathogen of British cattle. 相似文献
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B V Goodger 《Zeitschrift für Parasitenkunde (Berlin, Germany)》1977,53(1):47-52
Rabbit antisera were prepared against the soluble and insoluble fractions of a cryofibrinogen complex that formed in plasma of cattle acutely infected with Babesia argentina. Analyses of the rabbit antisera indicated that the cryofibrinogen complex contained proteins from erythrocytes and parasites as well as fibrinogen and related proteins. 相似文献
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An electron microscopic study of intravascular agglutination in the cerebral cortex due to Babesia argentina infection 总被引:3,自引:0,他引:3
I G Wright 《International journal for parasitology》1972,2(2):209-215
The progressive changes in brain capillaries of calves infected with Babesia argentina are described. Initially, the parasitaemia was low (about 5 per cent) and infected red cells had an essentially normal appearance. Terminally, the parasitaemia was > 90 per cent and by this time infected cells were stellate in appearance, connected by fine strands to other infected cells, and to the capillary endothelium which also showed pathological changes. Uninfected cells appeared normal at all stages of the infection. In severe cases most infected cells were haemolysed. The presumed stickiness of infected cells was probably due to changes in the erythrocyte membrane. Parasites were larger than normal and usually possessed two or three nuclei, containing aggregations of chromatin. 相似文献
5.
Effects of various radiation dosages on the infectivity and immunogenicity of Babesia bigemina were studied. Calves infected with 1 × 1010, B. bigemina parasitized erythrocytes exposed to 24 krad developed progressive parasitemias. Some calves receiving 1 × 1010 parasitized erythrocytes irradiated at 36 krad did not develop progressive infections. Progressive infections were prevented by exposure to irradiation at 48 and 60 krad. A degree of acquired resistance to infection with B. bigemina developed in calves after inoculation with parasites irradiated at 48 and 60 krad. The resistance developed was sufficient to suppress multiplication of the Babesia and to permit calves to survive otherwise severe clinical infections due to challenge with nonirradiated parasites. Irradiated parasites were frozen without apparent loss of immunizing properties. 相似文献
6.
The results of this paper indicate that cattle infected with B. bovis (argentina) have a markedly altered and activated coagulation system. A degree of thrombin activation occurs due partly to release of thromboplastin-like substances from lysed erythrocytes but due primarily to activation of kallikrein by babesial proteases. This produces a hyperfibrinogenaemia, particularly in intact cattle, with soluble fibrin complexes constituting up to one-third of the total fibrinogen concentration. High molecular weight non-coagulable fibrinogen-like proteins are detected terminally but more so in splenectomized cattle. Plasminogen concentration decreases in splenectomized but not intact cattle while low molecular weight fibrinogen degradation products are not easily detected. It is suggested that a hypercoagulable intermediate state with little or no fibrin deposition occurs rather than terminal disseminated intravascular coagulation. 相似文献
7.
Cho SH Kim TS Lee HW Tsuji M Ishihara C Kim JT Wee SH Lee CG 《The Korean journal of parasitology》2002,40(1):33-40
Attempts were made to isolate and identify Korean bovine Babesia parasite. Blood samples were collected from Holstein cows in Korea, and Babesia parasites were propagated in SCID mice with circulating bovine red blood cells for isolation. The isolate was then antigenically and genotypically compared with several Japanese isolates. The Korean parasite was found to be nearly identical to the Oshima strain isolated from Japanese cattle, which was recently designated as Babesia ovata oshimensis n. var. Haemaphysalis longicornis was the most probable tick species that transmitted the parasite. 相似文献
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B.V. Goodger 《International journal for parasitology》1976,6(3):213-216
A crude soluble haemagglutination antigen obtained from a mixture of Babesia argentina parasites and infected erythrocyte stromata contained fibrinogen. The fibrinogen was removed by precipitation in an initial attempt to purify the antigen. However, most if not all of the antigenic activity was located in the fibrinogen precipitate. After consideration of the evidence available, it was concluded that the antigen was either a babesial moiety complexed with fibrinogen or a fibrinogen molecule altered by the metabolic activity of the parasite. 相似文献
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Blood from a splenectomized calf infected with Babesia major was divided into 20 ml aliquots which were γ-irradiated at doses of 0, 23.3, 27.3, 31.4, 35.4 and 39.5 krad and then inoculated into groups of three intact calves. Animals receiving non-irradiated blood had typical mild B. major reactions, but those receiving blood irradiated at 23.3, 27.3 and 31.4 krad and 2 of 3 receiving blood irradiated at 35.4 krad had minimal reactions. The remaining 4 animals had no detectable parasitaemic reactions. When the calves were challenged with a similar number (6.0 × 109) of homologous parasites, they were all immune with the exception of the 4 animals which had not reacted initially. The immune status of individual cattle was reflected accurately in the results of the micro-ELISA test, which detected a significant rise in serum antibody titre of the 4 susceptible animals 7 days after challenge. 相似文献
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Massaro W. Ueti Wendell C. Johnson Lowell S. Kappmeyer David R. Herndon Michelle R. Mousel Kathryn E. Reif Naomi S. Taus Olukemi O. Ifeonu Joana C. Silva Carlos E. Suarez Kelly A. Brayton 《International journal for parasitology》2021,51(2-3):123-136
Throughout their life cycle, Babesia parasites alternate between a mammalian host, where they cause babesiosis, and the tick vector. Transition between hosts results in distinct environmental signals that influence patterns of gene expression, consistent with the morphological and functional changes operating in the parasites during their life stages. In addition, comparing differential patterns of gene expression among mammalian and tick parasite stages can provide clues for developing improved methods of control. Hereby, we upgraded the genome assembly of Babesia bovis, a bovine hemoparasite, closing a 139 kbp gap, and used RNA-Seq datasets derived from mammalian blood and tick kinete stages to update the genome annotation. Of the originally annotated genes, 1,254 required structural changes, and 326 new genes were identified, leading to a different predicted proteome compared to the original annotation. Next, the RNA-Seq data was used to identify B. bovis genes that were differentially expressed in the vertebrate and arthropod hosts. In blood stages, 28% of the genes were upregulated up to 300 fold, whereas 26% of the genes in kinetes, a tick stage, were upregulated up to >19,000 fold. We thus discovered differentially expressed genes that may play key biological roles and serve as suitable targets for the development of vaccines to control bovine babesiosis. 相似文献
12.
Lesley P. Kahl G.F. Mitchell Robert J. Dalgliesh N.P. Stewart B.J. Rodwell L.T. Mellors P. Timms L.L. Callow 《Experimental parasitology》1983,56(2):222-235
Passage of the avirulent vaccine (K) strain of Babesia bovis (KA) through either Boophilus microplus ticks, intact calves, or intact calves and then ticks, resulted in two distinct protein and protein antigen profiles as analyzed by two-dimensional gel electrophoresis of biosynthetically labeled proteins and immunoprecipitates. Different degrees of expression of two major acidic antigens of KA designated Ka1 (Mr 47,500) and Ka2 (Mr 43,000) were observed. Ka1 was apparently lost following passage of KAB. bovis through intact calves but was strongly represented in the parasite population following a single tick passage. In contrast, passage through ticks of the virulent KVB. bovis (from which KA was derived by passage in splenectomized calves) did not lead to strong representation of the Ka1 protein although there was increased representation of another major acidic protein antigen, designated Kv (Mr 35,000). These data suggest that the previously recognized reversion to a strain-dependent basal antigenic type in the tick vector depends also on intrastrain characteristics such as virulence and strain heterogeneity. The data suggest that KA is a more heterogeneous population than KV although cloned isolates are required to establish this point. Comparable syringe passage of another strain of B. bovis, designated C strain, through splenectomized calves resulted in less marked differences between the putative CA and CVB. bovis. This may explain the less stable avirulence of CA compared to KAB. bovis. Various selection pressures must act, in either the tick or the vertebrate host, on subpopulations in heterogeneous isolates to produce the changes described in protein antigen profiles of B. bovis. The possible relevance of changes in representation of proteins to biological characteristics of B. bovis (such as virulence and tick transmissibility) is discussed. 相似文献
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Alloimmunizations with either lymphocytes or red cells from donor cows positive for BoLA w16 and blood group M' antigens into recipients negative for these antigens produced antisera reactive in the cytotoxic test with w16-positive lymphocytes and in the haemolytic test with M'-positive erythrocytes. Similarly, alloimmunizations of blood group M1-negative recipients with either lymphocytes or red cells from donor cows possessing the M1 blood group factor produced antisera specifically reactive with lymphocytes and erythrocytes from M1-positive cattle. Absorptions with either lymphocytes or erythrocytes from individual animals of the same M antigenic type as the donor removed all haemolytic and cytotoxic reactivity. The results indicate that blood group M' and BoLA w16 share a similar antigenic structure. Likewise, blood group M1 has an antigenically similar counterpart which is also part of the BoLA system. 相似文献
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B. Larsen N.E. Jensen P. Madsen S.M. Nielsen O. Klastrup P.S. Madsen 《Animal genetics》1985,16(3):165-173
Associations of the 11 bovine blood group systems with mastitis were examined in Red Danish dairy cattle. The mastitis status was followed during three lactational periods. A significant effect of the M blood group system on mastitis incidence was observed in the first and second lactation periods and a lower frequency of mastitis is found among animals lacking the M' factor as compared to those having the M' blood group factor. The significance of these results are discussed in view of the close relation between the M blood group system and the bovine lymphocyte antigens (BoLA), and the expected effect of eliminating the M' gene from the breed is estimated. Among the remaining 10 blood group systems, the T' system was the only system showing an overall effect on mastitis, and only in first and third lactation. However, the T' system was inconsistent with regard to the effect of the T' gene on the various mastitis diagnoses. 相似文献
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C. Bryant 《International journal for parasitology》1994,24(8):1089-1097
The characteristic respiratory metabolism of parasites consists of fermentation to carbon-rich, highly reduced volatile fatty acids which are excreted, and electron transport systems emphasising fumarate reductase and b-type cytochromes. The taxonomic groups that contribute major parasites (the heterogeneous protozoa and the helminths) have their evolutionary origins in environments from which oxygen was absent or present in very low concentrations. The Ediacarian period, about 700 million years ago, contains fossils of the appropriate grade of organisation to be contemporaneous with the ancestors of platyhelmiths, nematodes and acanthocephalans. With the oxygen transition, carbon flow in the biosphere resulted in conservative, anoxic environments together with oxygen rich ones. The organisms of the former retained their emphasis on anaerobic energy generation, while cytochrome systems were as much concerned with oxygen detoxification as energy generation. Metabolic pathways in the modern parasitic groups are echoes of such ancient biochemistries. 相似文献
17.
Iseki H Takabatake N Ota N Ishigame T Yokoyama N Igarashi I 《Experimental parasitology》2008,118(4):543-548
In the present study, we investigated the protective effects of killed Propionibacterium acnes on the infections of two rodent Babesia parasites in mice. Pre-treatment with "EqStim" (a commercially available immunostimulant containing killed P. acnes) showed significant resistance to both infections. To elucidate the immunological status in the mice, the concentrations of multiple cytokines were measured in serum collected from infected mice. After B. microti infection, the levels of interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12p70, and tumor necrosis factor (TNF)-alpha in the treated group were significantly lower than in the control group. In contrast, after B. rodhaini infection, only IL-12p70 and TNF-alpha were detectable at significantly higher levels in the treated group than in the control group. The present findings indicated the protective effects of killed P. acnes on rodent babesiosis even with different immune responses between the B. microti and B. rodhaini infections. Killed P. acnes might be a powerful tool for the control of serious livestock babesiosis. 相似文献
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Thomsen H Reinsch N Xu N Looft C Grupe S Kühn C Brockmann GA Schwerin M Leyhe-Horn B Hiendleder S Erhardt G Medjugorac I Russ I Förster M Brenig B Reinhardt F Reents R Blümel J Averdunk G Kalm E 《Animal genetics》2002,33(2):107-117
Genes determining the bovine erythrocyte antigens were mapped by linkage analysis. In total 9591 genotypes of 20 grandsire families with 1074 sires from a grand-daughter design were elucidated for the genes determining the erythrocyte antigens EAA, EAB, EAC, EAF, EAJ, EAL, EAM, EAN', EAR', EAS, EAT', and EAZ according to standard paternity testing procedures in the blood typing laboratories. Linkage analyses were performed with 248 microsatellite markers, eight SSCP markers and four polymorphic proteins and enzymes covering the 29 autosomes and the pseudoautosomal region of the sex chromosomes. The number of informative meioses for the blood group systems ranged from 76 to 947. Blood group systems EAM and EAT' were non-informative. Most of the erythrocyte antigen loci showed significant linkage to a single chromosome and were mapped unequivocally. The genes determining erythrocyte antigen EAA, EAB, EAC, EAL, and EAS were mapped to chromosomes 15, 12, 18, 3, and 21, respectively. Lod-score values ranged from 11.43 to 107.83. Moreover, the EAF system could be mapped to chromosome 17. However, the EAN' system previously known as part of the EAF system could be mapped to chromosome 5. In addition, the blood group systems EAJ, the new EAN', EAR', and EAZ, showed significant linkage to microsatellite markers on various chromosomes and also to other blood groups. The appearance of a single blood group system might be therefore either dependent on the existence of other blood group systems or because of an interaction between different loci on various chromosomes as is known in humans and in pigs. 相似文献
20.
The level of host specificity of blood-sucking invertebrates may have both ecological and evolutionary implications for the parasites they are transmitting. We used blood meals from wild-caught blackflies for molecular identification of parasites and hosts to examine patterns of host specificity and how these may affect the transmission of avian blood parasites of the genus Leucocytozoon . We found that five different species of ornithophilic blackflies preferred different species of birds when taking their blood meals. Of the blackflies that contained avian blood meals, 62% were infected with Leucocytozoon parasites, consisting of 15 different parasite lineages. For the blackfly species, there was a significant association between the host width (measured as the genetic differentiation between the used hosts) and the genetic similarity of the parasites in their blood meals. The absence of similar parasite in blood meals from blackflies with different host preferences is interpreted as a result of the vector–host associations. The observed associations between blackfly species and host species are therefore likely to hinder parasites to be transmitted between different host-groups, resulting in ecologically driven associations between certain parasite lineages and hosts species. 相似文献