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molecular epidemiological survey and genetic characterization of anaplasma species in mongolian livestock.anaplasma species are obligate intracellular rickettsial pathogens that cause great economic loss to the animal industry. few studies on anaplasma infections in mongolian livestock have been conducted. this study examined the prevalence of anaplasma marginale, anaplasma ovis, anaplasma phagocytophilum, and anaplasma bovis by polymerase chain reaction assay in 928 blood samples collected from native cattle and dairy cattle (bos taurus), yaks (bos grunniens), sheep (ovis aries), and goats (capra a ...201728678004
anaplasma marginale and a. phagocytophilum in cattle in tunisia.tick-borne diseases caused by anaplasma species put serious constraints on the health and production of domestic cattle in tropical and sub-tropical regions. after recovering from a primary infection, cattle typically become persistent carriers of pathogens and play a critical role in the epidemiology of the disease, acting as reservoirs of the anaplasma spp.201627765073
molecular study on infection rates of anaplasma ovis and anaplasma marginale in sheep and cattle in west-azerbaijan province, iran.this study was carried out to determine the presence and frequency of anaplasma ovis and anaplasma marginale in sheep and dairy cattle in west-azerbaijan province, iran. a total number of 200 blood samples were randomly collected via the jugular vein from apparently healthy cattle (100) and sheep (100). the extracted dna from blood cells was screened using genus-specific (anaplasma spp.) nested-polymerase chain reaction (pcr) based on 16s rrna gene primer sets. species-specific pcr was set up us ...201627482362
outbreak of anaplasmosis associated with the presence of different anaplasma marginale strains in dairy cattle in the states of são paulo and goiás, brazil.the present study reports the genetic diversity of anaplasma marginale during anaplasmosis outbreaks in rural properties of the states of goiás and são paulo, brazil. mortality rates of 3.5% (37/1,050) in calves, 4.7% (45/954) in heifers and 1.1% (25/2,200) in lactating cows were observed in a cattle herd of the municipality of mambaí, state of goiás, central-western brazil. in a cattle herd from the municipality of lins, state of são paulo, in southeastern brazil, none of the animals died, desp ...201526648009
transplacental transmission of bovine tick-borne pathogens: frequency, co-infections and fatal neonatal anaplasmosis in a region of enzootic stability in the northeast of brazil.bovine tick-borne disease (tbd) constitutes a worldwide group of diseases that result in great losses for dairy and beef cattle. with regard to the epidemiological profile of the diseases, the importance of transplacental transmission is still not very well understood. the aim of this study was to determine the transplacental transmission of tbd agents (anaplasma marginale, babesia bovis and b. bigemina) in a herd of dairy cattle that had been naturally infected in an area of enzootic stability ...201626613663
low genetic diversity of anaplasma marginale in calves in an endemic area for bovine anaplasmosis in the state of são paulo, brazil.major surface protein 1a has been used as a marker for genetic stability in identifying geographical isolates of anaplasma marginale. we conducted a longitudinal study to ascertain the genetic diversity of a. marginale in a dairy cattle herd with a history of clinical anaplasmosis. a total of 20 calves were evaluated every 3 months, from birth to 1 year of age. they were evaluated using blood smears, ifat, elisa, and qpcr. additionally, samples positive for the msp1a gene using npcr were sequenc ...201626318264
bovine babesiosis and anaplasmosis complex: diagnosis and evaluation of the risk factors from bahia, brazil.direct diagnoses were made by using - blood smears and nested pcr (npcr) tests on 309 blood samples from crossbred dairy cattle in the municipality of ibicaraí, bahia. from diagnostic blood smear slides, the observed parasitic frequencies were 31.1% for anaplasma marginale and 20.4% for babesia sp. from npcr diagnoses, they were 63% for a. marginale, 34% for babesia bigemina and 20.4% for babesia bovis. there were significant differences (p <0.01) between the two diagnostic methods (npcr and blo ...201625271452
risk factors for anaplasmosis in dairy cows during the peripartum.anaplasma marginale is endemic in tropical and subtropical areas around the world. some studies have suggested that cows during peripartum may present a transient immunosuppression state and development of clinical signs of anaplasmosis. the aim of this study was to investigate the relationship between some risk factors and the seroprevalence of a. marginale in dairy cows during peripartum in rio de janeiro, brazil. the risk factors analyzed in association with the prevalence of antibodies again ...201424307390
association of bola-drb3 alleles with tick-borne disease tolerance in dairy cattle in a tropical environment.tick-borne disease is one of the most harmful tropical diseases in dairy production. selection of dairy cows for tolerance to tick-borne disease is a challenging concept for dairy breeders in the tropics. the objectives of this study were (1) to detect specific tick-borne pathogen in cattle of different genetics and (2) to examine the polymorphisms of drb3.2 alleles in thai dairy cattle and find the allelic association with tick-borne disease tolerance. specific primers to anaplasma marginale (a ...201323571121
prevalence and haemato-biochemical profile of anaplasma marginale infection in dairy animals of punjab (india).to do the systematic comparison of prevalence of anaplasmosis by pcr and giemsa stained thin blood smear (gstbs) based parasitological assays in dairy cattle of punjab, which has not been reported yet. to analyse the haematobiochemical alterations in infected animals to arrive at the conclusion regarding the pathogenicity induced by anaplasma marginale (a. marginale) in latent and patent infection.201323339917
development of a multiplex pcr assay for simultaneous detection of theileria annulata, babesia bovis and anaplasma marginale in cattle.tropical theileriosis, bovine babesiosis and anaplasmosis are tick-borne protozoan diseases that impose serious constraints on the health and productivity of domestic cattle in tropical and sub-tropical regions of the world. a common feature of these diseases is that, following recovery from primary infection, animals become persistent carriers of the pathogen and continue to play a critical role in disease epidemiology, acting as reservoirs of infection. this study describes development and eva ...201223183165
Control of tick infestations in cattle vaccinated with bacterial membranes containing surface-exposed tick protective antigens.Vaccines containing the Rhipicephalus (Boophilus) microplus BM86 and BM95 antigens protect cattle against tick infestations. Tick subolesin (SUB), elongation factor 1a (EF1a) and ubiquitin (UBQ) are new candidate protective antigens for the control of cattle tick infestations. Previous studies showed that R. microplus BM95 immunogenic peptides fused to the Anaplasma marginale major surface protein (MSP) 1a N-terminal region (BM95-MSP1a) for presentation on the Escherichia coli membrane were prot ...201222085549
Acute phase response in cattle infected with Anaplasma marginale.This study was undertaken to evaluate the acute phase responses via the assessment of the concentration of serum sialic acids (total, lipid bound and protein bound), inflammatory mediators (IFN-? and TNF-a) and acute phase proteins (Hp and SAA) in 20 adult crossbred cattle naturally infected by Anaplasma marginale. The infected animals were divided into 2 subgroups on the basis of parasitemia rate (<20% and >20%). Also, as a control group, 10 clinically healthy cattle from the same farms were sa ...201121940118
Molecular Study of Free-ranging Mule Deer and White-tailed Deer from British Columbia, Canada, for Evidence of Anaplasma spp. and Ehrlichia spp.Twenty-three free-ranging white-tailed deer (WTD; Odocoileus virginianus) and six mule deer (MD; Odocoileus hemionus) from south-central British Columbia, Canada, were tested for Anaplasma marginale by msp5 gene-specific PCR and Ehrlichia spp. by 16S rRNA or citrate synthase (gltA) gene-specific PCR, as well as by PCR with universal 16S rRNA primers detecting a wide range of bacteria. No deer tested positive for A. marginale. Amplification with universal 16S rRNA primers followed by sequencing o ...201121933360
identification of anaplasma marginale outer membrane protein antigens conserved between a. marginale sensu stricto strains and the live a. marginale subsp. centrale vaccine.live vaccination with anaplasma marginale subsp. centrale (synonym for anaplasma centrale) induces protection against severe disease upon challenge with a. marginale sensu stricto strains. despite over a century of field use, the targets of protective immunity remained unknown. using a broad proteomic approach, we identified the proteins in a challenge sensu stricto strain that were bound by the relevant antibody isotype induced by live vaccination with anaplasma marginale subsp. centrale. a cor ...201021189322
epidemiological analysis of tick-borne diseases in zambia.tick-borne diseases are a constraint to livestock production in many developing countries as they cause high morbidity and mortality, which results in decreased production of meat, milk and other livestock by-products. the most important tick-borne diseases of livestock in sub-saharan africa are east coast fever (caused by theileria parva), babesiosis (caused by babesia bigemina and b. bovis), anaplasmosis (caused by anaplasma marginale) and heartwater (caused by ehrlichia ruminantium). despite ...201021106294
haemoparasite prevalence and theileria parva strain diversity in cape buffalo (syncerus caffer) in uganda.cape buffalo (syncerus caffer) are considered to be an important reservoir for various tick-borne haemoparasites of veterinary importance. in this study we have compared the haemoparasite carrier prevalence in buffalo from four geographically isolated national parks in uganda [lake mburo national park (lmnp), queen elizabeth national park (qenp), murchison falls national park (mfnp) and kidepo valley national park (kvnp)]. differences were seen in haemoparasite prevalence in buffalo from the fou ...201021074945
an update on bovine anaplasmosis (anaplasma marginale) in canada. 201021037882
detecting and differentiating theileria sergenti and theileria sinensis in cattle and yaks by pcr based on major piroplasm surface protein (mpsp).theileria sergenti and theileria sinensis are closely related members of benign theileria species found in cattle and yaks in china. they are morphologically indistinguishable. a polymerase chain reaction (pcr) targeting major piroplasm surface protein of t. sergenti and t. sinensis was developed in this study. the newly developed oligonucleotide primer set was able to specifically amplify the dna of t. sinensis and in conjunction with primers for t. sergenti and these two species could be detec ...201020685208
development and laboratory evaluation of a lateral flow device (lfd) for the serodiagnosis of theileria annulata infection.several dna-based and serological tests have been established for the detection of theileria annulata infection, including polymerase chain reaction, reverse line blot and loop-mediated isothermal amplification, indirect enzyme-linked immunosorbent assay (elisa), and competitive elisa. in this study, we have applied knowledge from the development and application of a recombinant protein-based indirect elisa and competitive elisa to establish a rapid test for point-of-care diagnosis of t. annulat ...201020680339
a novel ehrlichia genotype detected in naturally infected cattle in north america.during a research investigation to determine if cattle from british columbia (bc), canada were infected with anaplasma marginale or other related rickettsial blood parasites, a novel ehrlichia genotype was revealed. blood from seven bc source cattle was bioassayed by intravenous inoculation into naïve splenectomised calves. additional splenectomised calves were used as uninoculated negative control or a. marginale-inoculated positive control. newly designed sets of primers specific for the msp5 ...201020663613
a comparison of six primer sets for detection of trypanosoma evansi by polymerase chain reaction in rodents and thai livestock.to face the worldwide threat of surra caused by trypanosoma evansi, international organizations have stressed the need to evaluate and standardize diagnostic tools. pcr detection of t. evansi has known a great expansion during the last 20 years, but primer sets are often insufficiently assessed and compared. in this work, we compared the performances of six primer pairs-tbr1/2 (masiga et al., 1992), esag6/7 (holland et al., 2001a, b), tepan1/2 (panyim et al., 1993), pmutec f/r (wuyts et al., 199 ...201020466489
differential expression of genes in salivary glands of male rhipicephalus (boophilus)microplus in response to infection with anaplasma marginale.bovine anaplasmosis, caused by the rickettsial tick-borne pathogen anaplasma marginale (rickettsiales: anaplasmataceae), is vectored by rhipicephalus (boophilus)microplus in many tropical and subtropical regions of the world. a. marginale undergoes a complex developmental cycle in ticks which results in infection of salivary glands from where the pathogen is transmitted to cattle. in previous studies, we reported modification of gene expression in dermacentor variabilis and cultured ixodes scapu ...201020298599
diagnostic accuracy of methods for detecting anaplasma marginale infection in lactating dairy cattle of puerto rico.bovine anaplasmosis (ba) is a hemoparasitic disease of great importance in cattle within the tropical and subtropical regions of the world. control programs for ba require accurate diagnostic assays but validation can be challenging because the true disease status of all animals is frequently not known with certainty. the objective of this study was to estimate the accuracy of assays for detection of anaplasma marginale infection in lactating dairy cattle of puerto rico using bayesian methods wi ...201020224076
molecular epidemiology of bovine anaplasmosis with a particular focus in mexico.bovine anaplasmosis, caused by the rickettsia anaplasma marginale, has a worldwide distribution and is the cause of great economic losses in developing countries where it is highly endemic. transmission is carried mainly by ixodid ticks: dermacentor spp. and rhipicephalus (boophilus) spp. mechanical transmission is important in disseminating the disease within and across herds. the relationship between the rickettsia, the host and the vector is complex. several surface proteins (msps) have been ...200919786123
validation and field assessment of a rapid lateral flow assay for detection of bovine antibody to anaplasma marginale.the lateral flow assay (lfa) is a rapid diagnostic test which may be performed under most conditions and is especially useful for field applications. this type of assay was applied to the detection of antibody to bovine anaplasma marginale using sera from endemic areas and from areas which have been free from infection for more than 25 years. briefly, the test uses recombinant a. marginale major surface protein 5 peptide (msp5), immobilized on a cellulose acetate membrane. a serum sample is adde ...200919591044
[seroprevalence of anaplasma marginale in cattle from center-south region of paraná state, brazil by a competitive elisa test with recombinant msp5-pr1 protein].anaplasma marginale prevalence was determined in 223 sera samples in 2-year old or older cattle, from the center-southern region of the paraná state, including ponta grossa, guarapuava and laranjeiras do sul municipalities. a survey of antibodies igg class against anaplasma marginale was performed through a competitive immune absorbent assay (celisa-pr1). from the 223 sera examined, 130 (58.74%) reacted to celisa-pr1 test, suggesting an region of enzootic instability, with a significant percenta ...200919500456
first report of trypanosoma vivax infection in dairy cattle from costa rica.an outbreak of haemoparasitoses occurred from october 2007 to july 2008 in cattle from the district of rio cuarto, province of alajuela, costa rica. fifty animals of various ages out of 450 brown swiss were affected. the animals presented fever, severe anemia, jaundice, abortion or premature birth, loss of appetite, decrease milk production and accentuated weight loss in a short period of time. haemoparasites were observed in the blood smears: anaplasma marginale was present in 17 animals (60.7% ...200919414224
seroprevalence estimation and management factors associated with high herd seropositivity for anaplasma marginale in commercial dairy farms of puerto rico.a cross-sectional study was conducted to determine individual cow seroprevalence of anaplasma marginale in adult lactating dairy cattle of puerto rico (pr) and to assess the associations of farm management factors on herd seroprevalence. antibody activity against a. marginale was determined using the msp-5 competitive enzyme-linked immunosorbent assay. serum samples were obtained from 2,414 adult lactating dairy cattle from 76 randomly selected commercial dairy farms. herd seroprevalence ranged ...200919337849
prevalence of anaplasma marginale in different tick species from ngorongoro crater, tanzania.in 2001, ngorongoro crater was infested with high density of ticks on grassland, livestock and wildlife which was also associated with high mortality. adult ticks were collected, identified, processed for nucleic acids extraction and a molecular analysis was performed to determine the range of tick species harboring anaplasma marginale. the real-time pcr was used in the amplification of rickettsia dna in tick pools (n=527) from 11 identified tick species. six tick species were detected with a. m ...200919201099
independence of anaplasma marginale strains with high and low transmission efficiencies in the tick vector following simultaneous acquisition by feeding on a superinfected mammalian reservoir host.strain superinfection occurs when a second pathogen strain infects a host already carrying a primary strain. anaplasma marginale superinfection occurs when the second strain carries a variant repertoire different from that of the primary strain, and the epidemiologic consequences depend on the relative efficiencies of tick-borne transmission of the two strains. following strain superinfection in the reservoir host, we tested whether the presence of two a. marginale (sensu lato) strains that diff ...200919188360
first report of bovine anaplasmosis caused by anaplasma centrale in europe.anaplasma centrale (rickettsiales: anaplasmataceae) is used as a live vaccine for cattle against the pathogenic anaplasma marginale in tropical and subtropical areas. herein we report a clinical case of bovine anaplasmosis associated with a. centrale infection in italy, together with the first molecular identification and phylogenetic analysis of this anaplasma species or subspecies in europe.200819120185
quantitative differences in salivary pathogen load during tick transmission underlie strain-specific variation in transmission efficiency of anaplasma marginale.the relative fitness of arthropod-borne pathogens within the vector can be a major determinant of pathogen prevalence within the mammalian host population. strains of the tick-borne rickettsia anaplasma marginale differ markedly in transmission efficiency, with a consequent impact on pathogen strain structure. we have identified two a. marginale strains with significant differences in the transmission phenotype that is effected following infection of the salivary gland. we have proposed competin ...200918955472
frequency of antibodies to babesia bigemina, b. bovis, anaplasma marginale, trypanosoma vivax and borrelia burgdorferi in cattle from the northeastern region of the state of pará, brazil.babesiosis, anaplasmosis, and trypanosomosis are relevant diseases, potentially causing morbidity in cattle, leading to economic losses. borreliosis is import as a potential zoonosis. the objective of this study was to determine, by indirect enzyme-linked immunosorbent assay (elisa), the frequency of seropositive cattle to babesia bigemina, b. bovis, anaplasma marginale, trypanosoma vivax and borrelia burgdorferi in cattle from the northeastern region of pará, brazil. sera samples from 246 femal ...200818823579
anaplasma marginale major surface protein 1a directs cell surface display of tick bm95 immunogenic peptides on escherichia coli.the surface display of heterologous proteins on live escherichia coli using anchoring motifs from outer membranes proteins has impacted on many areas of biochemistry, molecular biology and biotechnology. the anaplasma marginale major surface protein 1a (msp1a) contains n-terminal surface-exposed repeated peptides (28-289 amino acids) that are involved in pathogen interaction with host cell receptors and is surface-displayed when the recombinant protein is expressed in e. coli. therefore, it was ...200818582976
clinical features associated with seroconversion to anaplasma marginale, babesia bigemina and theileria parva infections in african cattle under natural tick challenge.a longitudinal study was conducted in southeast uganda for 14 months on 640 zebu cattle kept under natural tick challenge, with a view to identifying clinical features for prediction of seroconversion to anaplasma marginale, babesia bigemina and theileria parva infections. physical examination, condition scoring and tick counts were undertaken on all cattle every 4 weeks. in addition, 5300 sera were collected and analysed for antibodies against a. marginale, b. bigemina and t. parva infections u ...200818579313
induced immune response of dna vaccine encoding an association msp1a, msp1b, and msp5 antigens of anaplasma marginale.the outer membrane proteins of anaplasma marginale have been the focus of research to obtain an improved vaccine against bovine anaplasmosis. we evaluated the capacity of the recombinant plasmids pcdna-msp1alpha, pcdna-msp1beta, and pcdna-mp5 to express msp1a, msp1b, and msp5 proteins, and to determine the immunogenicity of balb/c mice immunized with these plasmids individually or in association. expression of proteins was confirmed in vero cells by ifa. the combination of recombinant plasmids s ...200818502005
productivity and health effects of anaplasmosis and babesiosis on bos indicus cattle and their crosses, and the effects of differing intensity of tick control in australia.tick fever is an important disease of cattle where rhipicephalus (boophilus) microplus acts as a vector for the three causal organisms babesia bovis, babesia bigemina and anaplasma marginale. bos indicus cattle and their crosses are more resistant to the clinical effects of infection with b. bovis and b. bigemina than are bos taurus cattle. resistance is not complete, however, and herds of b. indicus-cross cattle are still at risk of babesiosis in environments where exposure to b. bovis is light ...200818472219
parasitic infections in dairy cattle around hanoi, northern vietnam.in northern vietnam, dairy cattle are mainly managed in small-scale farms, where animals are kept confined and feeding occurs by cut and carry methods. in the present study the occurrence of parasitic infections was examined in five provinces around hanoi. a total of 201 farms were visited, and 334 stool and 239 blood samples were collected from calves younger than 3 months, animals between 3 and 24 months and adult cows. furthermore, 254 milk samples were collected from lactating animals. copro ...200818328629
high-throughput identification of t-lymphocyte antigens from anaplasma marginale expressed using in vitro transcription and translation.the ability to rapidly screen a complex pathogen proteome for proteins that elicit recall t-lymphocyte responses from immune individuals would accelerate vaccine development. an outer membrane fraction of the rickettsial pathogen anaplasma marginale induces protective immunity against infection and disease in cattle. we have used this immunization model to evaluate high-throughput screening of proteins expressed by in vitro transcription and translation (ivtt) for recognition by memory cd4(+) t- ...200818243240
physical linkage of naturally complexed bacterial outer membrane proteins enhances immunogenicity.the outer membrane proteins (omps) of bacterial pathogens are essential for their growth and survival and especially for attachment and invasion of host cells. since the outer membrane is the interface between the bacterium and the host cell, outer membranes and individual omps are targeted for development of vaccines against many bacterial diseases. whole outer membrane fractions often protect against disease, and this protection cannot be fully reproduced by using individual omps. exactly how ...200818086812
development of a lateral flow assay for rapid detection of bovine antibody to anaplasma marginale.a rapid lateral flow assay for detection of bovine antibody to anaplasma marginale was developed. the assay used a recombinant peptide of major surface protein 5 as the antigen and a monoclonal antibody specific for bovine igg(1) conjugated with colloidal gold beads for detection. serum and anticoagulated blood samples were obtained from cattle in an area where anaplasmosis was endemic. the samples were selected based on positive identification of the organism in blood smears. the unclotted bloo ...200818080877
[natural infection by hemoparasites in calves submitted to chemoprophylaxis at 30 days of age].the tick-borne disease (tbd) brings great damages to cattle breeding. the most important etiologic agents are babesia bigemina, b. bovis and anaplasma marginale, being the tick boophilus microplus the main vector. this work reports the occurrence of natural infection by hemoparasites of tbd in 36 calves with high ticks natural infestation submitted to chemoprophylaxis with 30 days year-old. the blood smears from animals of different ages were analized and were found b. bigemina (33.3%), b. bovis ...200718078605
[transcription of genes of membrane proteins of brazilians isolates of anaplasma marginale].this work shows the transcription profile of membrane protein genes in three brazilian isolates of anaplasma marginale (rio grande do norte, pernambuco-zona da mata, and pernambuco-sertão). rna was purified from cattle blood experimentally-infected with the three isolates of a. marginale. after reverse transcription, genes omp1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 12, 13, and 14; opag1-3; virb3, 9, and 10; am097, 197, 254, 854, and 956 were amplified by pcr, with specific primers. transcripts were dete ...200718078602
targeting the tick/pathogen interface for developing new anaplasmosis vaccine strategies.bovine anaplasmosis is a tick-borne hemolytic disease of cattle that occurs worldwide caused by the intraerythrocytic rickettsiae anaplasma marginale. control measures, including use of acaricides, administration of antibiotics and vaccines, have varied with geographic location. our research is focused on the tick-pathogen interface for development of new vaccine strategies with the goal of reducing anaplasmosis, tick infestations and the vectorial capacity of ticks. toward this approach, we hav ...200717682853
comparison of the complement fixation test and competitive elisa for serodiagnosis of anaplasma marginale infection in experimentally infected steers.to compare sensitivity of a complement fixation (cf) test and competitive elisa (celisa) for detection of anaplasma marginale in experimentally infected steers.200717669027
molecular detection of ehrlichia ruminantium infection in amblyomma variegatum ticks in the gambia.in west africa, losses due to heartwater disease are not known because the incidence/prevalence has not been well studied or documented. to develop a diagnostic tool for molecular epidemiology, three pcr-based diagnostic assays, a nested pcs20 pcr, a nested map1 pcr and a nested reverse line blot (rlb) hybridization assay, were evaluated to determine their ability to detect infection in vector ticks, by applying them simultaneously to a. variegatum field ticks to detect ehrlichia ruminantium, th ...200717476576
prevalence and genetic diversity of anaplasma marginale strains in cattle in south africa.bovine anaplasmosis, caused by the tick-borne rickettsia anaplasma marginale, is endemic in south africa and results in considerable economic loss to the cattle industry. this study was designed to characterize strains of a. marginale at the molecular level from cattle raised in communal and commercial farms in the north-eastern and south-western regions of the free state province, south africa, that varied in rainfall and vegetation. seroprevalence to a. marginale was determined in 755 cattle b ...200717359443
immunogenicity of anaplasma marginale type iv secretion system proteins in a protective outer membrane vaccine.rickettsial pathogens in the genera anaplasma and ehrlichia cause acute infection in immunologically naive hosts and are major causes of tick-borne disease in animals and humans. immunization with purified outer membranes induces protection against acute anaplasma marginale infection and disease, and a proteomic and genomic approach recently identified 21 proteins within the outer membrane immunogen in addition to the well-characterized major surface proteins msp1 to msp5. among the newly descri ...200717339347
in vitro cultivation of a south african isolate of an anaplasma sp. in tick cell cultures.this paper describes the first successful in vitro cultivation of a south african isolate of an anaplasma sp., initially thought to be anaplasma marginale, in the continuous tick cell line ide8. blood from a bovine naturally infected with a. marginale kept on the farm kaalplaas (28 degrees 08' e, 25 degrees 38' s) was collected, frozen, thawed and used as inoculum on confluent ide8 cell cultures. twenty days after culture initiation small intracellular colonies were detected in a cytospin smear ...200617283724
cloning, sequencing, expression, and antigenic characterization of rmsp4 from anaplasma marginale isolated from paraná state, brazil.anaplasmosis is a bovine intraerythrocytic disease caused by the bacterium anaplasma marginale; it causes significant economic losses in tropical and subtropical regions, worldwide. the msp4 gene of an a. marginale strain isolated in paran , brazil, was amplified by pcr and sequenced; its cloning into the pet102/d-topo vector produced an msp4-6xhis-v5-hp thioredoxin fusion gene construct. this recombinant clone was over-expressed in escherichia coli bl21(de-3); the expressed fusion protein was f ...200717278086
in vivo endothelial cell infection by anaplasma marginale.anaplasma marginale has recently been shown to infect endothelial cells in vitro, but it remains unknown as to whether endothelial infection also occurs in vivo. in this report, we demonstrate through dual fluorescence microscopy that a marginale, detected by the monoclonal antibody anaf16c1, co-localizes with the endothelial cell marker, von willebrand factor, in tissue sections from an experimentally inoculated calf. the results indicate that a marginale infection includes endothelial cells an ...200717197636
development of an immunosensor for the diagnosis of bovine anaplasmosis.an optical immunosensor based in major surface protein 5 (msp5) of anaplasma marginale was developed towards detection of anti-anaplasma sp. antibodies in acute infection as well as in vaccinated cattle. this study was performed using recombinant msp5 covalently immobilised in controlled pore glass (cpg) beads to detect anti-msp5 antibodies in serum samples. the quantification is based on the measurement of the cy5 fluorescence of the detection antibody, anti bovine igg, after reaction with seru ...200617135541
anaplasmosis: focusing on host-vector-pathogen interactions for vaccine development.anaplasma marginale and a. phagocytophylum are intracellular rickettsiae that cause bovine anaplasmosis and human granulocytic anaplasmosis, respectively. the ultimate vaccine for the control of anaplasmosis would be one that reduces infection and transmission of the pathogen by ticks. effective vaccines for control of anaplasmosis are not available despite attempts using different approaches, such as attenuated strains, infected erythrocyte and tick cell-derived purified antigens, and recombina ...200617114750
comparative gene expression by wc1+ gammadelta and cd4+ alphabeta t lymphocytes, which respond to anaplasma marginale, demonstrates higher expression of chemokines and other myeloid cell-associated genes by wc1+ gammadelta t cells.the functions of gammadelta t cells are enigmatic, and these cells are often considered as evolutionary remnants of well-characterized alphabeta t cells. however, their conservation throughout evolution suggests that gammadelta t cells are biologically unique. in ruminants, gammadelta t cells expressing the workshop cluster 1 (wc1) scavenger receptor comprise a large proportion of circulating lymphocytes, suggesting these cells are biologically relevant and functionally different from alphabeta ...200617005908
prevalence of blood parasites in cattle from wilayates of annaba and el tarf east algeria.between june and september 2002, a preliminary study was conducted to assess the prevalence of blood parasites of cattle in eastern algeria. fifty-four bovines of different genotypes were submitted to clinical examination. from each animal, blood smears were made and stained by giemsa. four species of parasites, namely theileria annulata, t. orientalis, babesia bovis and anaplasma marginale were encountered. fifty animals carried single or multiple infections with blood parasites and four were f ...200416929762
analysis of the anaplasma marginale major surface protein 1 complex protein composition by tandem mass spectrometry.the protective major surface protein 1 (msp1) complex of anaplasma marginale is a heteromer of msp1a and msp1b, encoded by a multigene family. the msp1beta sequences were highly conserved throughout infection. however, liquid chromatography-tandem mass spectrometry analysis identified only a single msp1b protein, msp1b1, within the msp1 complex.200616788207
louse-borne bacterial pathogens in lice (phthiraptera) of rodents and cattle from egypt.we collected 1,023 lice, representing 5 species, from rats and domestic cattle throughout 13 governorates in egypt and tested these lice for anaplasma marginale, bartonella spp., brucella spp., borrelia recurrentis, coxiella burnetii, francisella tularensis, and rickettsia spp. by pcr amplification and sequencing. five different louse-borne bacterial agents were detected in lice from rodents or cattle, including "bartonella rattimassiliensis", "b. phoceensis", and bartonella sp. near bartonella ...200616729688
sequencing a new target genome: the boophilus microplus (acari: ixodidae) genome project.the southern cattle tick, boophilus microplus (canestrini), causes annual economic losses in the hundreds of millions of dollars to cattle producers throughout the world, and ranks as the most economically important tick from a global perspective. control failures attributable to the development of pesticide resistance have become commonplace, and novel control technologies are needed. the availability of the genome sequence will facilitate the development of these new technologies, and we are p ...200616506442
genetic diversity of anaplasma species major surface proteins and implications for anaplasmosis serodiagnosis and vaccine development.the genus anaplasma (rickettsiales: anaplasmataceae) includes several pathogens of veterinary and human medical importance. an understanding of the diversity of anaplasma major surface proteins (msps), including those msps that modulate infection, development of persistent infections, and transmission of pathogens by ticks, is derived in part, by characterization and phylogenetic analyses of geographic strains. information concerning the genetic diversity of anaplasma spp. msps will likely influ ...200516164010
spatial and management factors associated with exposure of smallholder dairy cattle in tanzania to tick-borne pathogens.a cross-sectional study of serum antibody responses of cattle to tick-borne pathogens (theileria parva, theileria mutans,anaplasma marginale, babesia bigemina and babesia bovis) was conducted on smallholder dairy farms in tanga and iringa regions of tanzania. seroprevalence was highest for t. parva (48% in iringa and 23% in tanga) and b. bigemina (43% in iringa and 27% in tanga) and lowest for b. bovis (12% in iringa and 6% in tanga). we use spatial and non-spatial models, fitted using classical ...200516023121
identification of functional promoters in the msp2 expression loci of anaplasma marginale and anaplasma phagocytophilum.organisms in the family anaplasmataceae are important tick-borne pathogens of livestock worldwide and cause recently emergent infections in humans. despite their medical importance, very little is known about how these organisms regulate gene expression in the mammalian host, the tick vector, or during transition between the host and vector. however, it is clear that gene regulation, in addition to recombinatorial mechanisms, is essential for these small genome pathogens to adapt to distinctly d ...200515935572
detection of antibodies against anaplasma marginale in milk using a recombinant msp5 indirect elisa.an indirect enzyme linked immunosorbent assay (ielisa) for diagnosis of anaplasmosis using undiluted individual milk samples from dairy cows was developed. the recombinant 19 kda major surface protein 5 (rmsp5) of anaplasma marginale was used as antigen. a monoclonal antibody against bovine igg1 conjugated with peroxidase and the chromogen 3,5,3',5'-tetramethylbenzidine were used in the test. strong and weak, positive and negative milk samples were set up as reference controls. results were expr ...200515778035
lack of infectivity of a brazilian anaplasma marginale isolate for boophilus microplus ticks.previous studies have shown that one brazilian anaplasma marginale isolate presents an inclusion appendage (tail), while other isolates do not present such inclusion. studies on tick transmission have been carried out with tailless isolates but little is known about transmission of tailed isolates by boophilus microplus. two splenectomized calves were experimentally inoculated with the tailed a. marginale isolate. during ascending rickettsemia, b. microplus larvae, free from hemoparasites, were ...200415740870
recent studies on the 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. many geographic isolates of a. marginale occur worldwide that have been identified by major surface protein (msp) 1a, which varies in sequence and molecular weight owing to different numbers of tandem 28-29 amino acid repeats. although serologic tests have identified american bison, bison bison, as being infected with a. marginale, the present studie ...200415604478
detection of anaplasma marginale dna in larvae of boophilus microplus ticks by polymerase chain reaction.boophilus microplus larvae from two different sources were used for the detection of anaplasma marginale dna: larvae a, which were collected from a pasture of an endemic farm, and larvae b, which originated from engorged female ticks fed on calves with no clinical signs of disease and with low rickettsemia (approximately 0.01 to 1.0%). larvae a were collected monthly, from january to may in 2001. two hundred engorged female ticks fed on calves that provided larvae b were divided into groups of 1 ...200415604475
anaplasma marginale major surface protein 2 cd4+-t-cell epitopes are evenly distributed in conserved and hypervariable regions (hvr), whereas linear b-cell epitopes are predominantly located in the hvr.organisms in the genus anaplasma express an immunodominant major surface protein 2 (msp2), composed of a central hypervariable region (hvr) flanked by highly conserved regions. throughout anaplasma marginale infection, recombination results in the sequential appearance of novel msp2 variants and subsequent control of rickettsemia by the immune response, leading to persistent infection. to determine whether immune evasion and selection for variant organisms is associated with a predominant respon ...200415557669
identification of a novel anaplasma marginale appendage-associated protein that localizes with actin filaments during intraerythrocytic infection.the rickettsial pathogen anaplasma marginale assembles an actin filament bundle during intracellular infection. unlike other bacterial pathogens that generate actin filament tails, a. marginale infects mature erythrocytes, and the f-actin appendages are assembled on the cytoplasmic surface of a vacuole containing several organisms. to identify a. marginale molecules associated with these filaments, two complementary approaches were used: matrix-assisted laser desorption ionization-time-of-flight ...200415557651
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 ...200415528749
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 ...200515522917
disease survey of free-ranging grey brocket deer (mazama gouazoubira) in the gran chaco, bolivia.samples from 17 free-ranging hunter-killed grey brocket deer (mazama gouazoubira) in the gran chaco, bolivia, were collected during june-august 1999. all 17 deer appeared to be in good condition at the time of death. gross necropsies were performed, serum was collected for serologic evaluation of selected infectious disease agents, and feces and ectoparasites were collected for evaluation of internal and external parasites. serologic tests were positive for antibodies against bovine respiratory ...200415137493
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 ...200415135871
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 ...200415135513
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 ...200415102815
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.200315080428
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 ...200312682152
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 ...200212665106
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 ...200312535066
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 ...200212381611
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 ...200212228278
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 ...200211809330
immunization of cattle with anaplasma marginale derived from tick cell culture.anaplasmosis is a hemolytic disease of cattle caused by the ehrlichial tick-borne pathogen anaplasma marginale. killed vaccines used for control of anaplasmosis in the us used antigen harvested from infected bovine erythrocytes which was often contaminated with bovine cells and other pathogens. in this study, we performed an initial cattle trial to test a. marginale harvested from tick cell culture as an immunogen for cattle. eleven yearling holstein cattle were immunized with the cell culture-d ...200111705661
seroprevalences of vector-transmitted infections of small-holder dairy cattle in coastal kenya.a cross-sectional study was carried out from july to september 1989 in kaloleni division, coast province, kenya to estimate the prevalence of vector-transmitted diseases in small-holder dairy cattle and to identify the risk factors associated with different management systems. one hundred and thirty of the 157 herds with dairy cattle in kaloleni division were surveyed. these were from three agro-ecological zones (coconut-cassava, cashew nut-cassava and livestock-millet), comprised two management ...200111566374
differential adhesion of major surface proteins 1a and 1b of the ehrlichial cattle pathogen anaplasma marginale to bovine erythrocytes and tick cells.anaplasma marginale is a tick-borne ehrlichial pathogen of cattle for which six major surface proteins (msps) have been described. the msp1 complex, a heterodimer composed of msp1a and msp1b, was shown to induce a protective immune response in cattle and both proteins have been identified as putative adhesins for bovine erythrocytes. in this study the role of msp1a and msp1b as adhesins for bovine erythrocytes and tick cells was defined. msp1alpha and msp1beta1 genes from the oklahoma isolate of ...200111239934
analysis of the 16s rrna gene sequence of anaplasma centrale and its phylogenetic relatedness to other ehrlichiae.the nucleotide sequence of the anaplasma centrale 16s rrna gene was determined and compared with the sequences of ehrlichial bacteria. the sequence of a. centrale was closely related to anaplasma marginale by both level-of-similarity (98.08% identical) and distance analysis. a species-specific pcr was developed based upon the alignment data. the pcr can detect a. centrale dna extracted from 10 infected bovine red blood cells in a reaction mixture. a. centrale dna was amplified in the reaction, b ...200111238202
integrated molecular diagnosis of theileria and babesia species of cattle in italy.a reverse line blot hybridization (rlb) test was developed to specifically identify six theileria spp. (t. annulata, t. parva, t. mutans, t. velifera, t. taurotragi, and t. buffeli/orientalis) and three babesia spp. (b. bovis, b. bigemina, and b. divergens). no cross reaction was observed with other livestock pathogens (such as anaplasma marginale, a. centrale, a. ovis, cowdria ruminantium, trypanosoma brucei, t. congolense, and t. vivax). this method was used to test bovine blood samples collec ...200011193668
identification and characterization of corpuscular, soluble and secreted antigens of a venezuelan isolate of anaplasma marginale.anaplasma marginale is the etiological agent of anaplasmosis, a tick-transmitted disease with an important economic impact that affects cattle throughout the world. although, north american isolates of a. marginale and their antigens have been extensively studied, relatively little information is available on the antigenic composition of south american isolates. the characterization of diverse geographical isolates of a. marginale will result in a thorough antigenic profile and may lead to the i ...200011078939
anaplasma marginale inactivated vaccine: dose titration against a homologous challenge.the present study was performed to dose-titrate an anaplasma marginale experimental immunogen derived from partially purified initial bodies from three geographically different mexican strains. three five-bovine groups were inoculated twice on days zero and 21 with a. marginale initial bodies equivalent to 1.5 x 10(10) (group i), 3 x 10(10) (group ii) or 6 x 10(10) (group iii) infected erythrocytes mixed with stdcm adjuvant. a similar group served as non-vaccinated controls. all four groups were ...200011038126
evaluation of a commercially available elisa kit for detection of antibodies to anaplasma marginale and anaplasma centrale in cattle in australia and zimbabwe.a newly available competitive inhibition elisa kit for the serological diagnosis of anaplasmosis was evaluated in australia and zimbabwe. in australia the performance of the test was compared with the card agglutination test (cat). the assay was evaluated using negative sera collected from anaplasma-free herds, positive sera from experimentally infected cattle and sera from anaplasma marginale-endemic herds. the sensitivity and specificity of the elisa in australia were 100 % and 83,3 %, respect ...200011028743
sequence and expression analysis of a surface antigen gene family of the rickettsia anaplasma marginale.the tick-borne rickettsial organism, anaplasma marginale, causes a disease in cattle of world-wide economic significance. this disease, anaplasmosis, is characterized by severe hemolytic anemia, high levels of rickettsemia and, often, death in animals over 3years of age. animals that survive acute infection remain carriers, with continuous sub-microscopic cycles of rickettsemia that can persist for the lifetime of the animal. in the search for potential recombinant immunogens, it was discovered ...200010925201
expression of polymorphic msp1beta genes during acute anaplasma marginale rickettsemia.immunization of cattle with native msp1 induces protection against anaplasma marginale. the native immunogen is composed of a single msp1a protein and multiple, undefined msp1b polypeptides. in addition to the originally sequenced gene, designated msp1beta(f1), we identified three complete msp1beta genes in the florida strain: msp1beta(f2), msp1beta(f3), and msp1beta(f4). each of these polymorphic genes encodes a structurally unique msp1b protein, and unique transcripts can be identified during ...200010722587
effect of breed of cattle on innate resistance to infection with anaplasma marginale transmitted by boophilus microplus.to assess the innate resistance of and transmission in naive bos taurus cross bos indicus and purebred bos indicus cattle when placed in a paddock with cattle infected with anaplasma marginale and carrying boophilus microplus ticks.199910685172
simultaneous detection of bovine theileria and babesia species by reverse line blot hybridization.a reverse line blot (rlb) assay was developed for the identification of cattle carrying different species of theileria and babesia simultaneously. we included theileria annulata, t. parva, t. mutans, t. taurotragi, and t. velifera in the assay, as well as parasites belonging to the t. sergenti-t. buffeli-t. orientalis group. the babesia species included were babesia bovis, b. bigemina, and b. divergens. the assay employs one set of primers for specific amplification of the rrna gene v4 hypervari ...199910325324
epidemiology of tick-borne diseases of cattle in botshabelo and thaba nchu in the free state province.a seroepidemiological study was conducted on 151 cattle from the botshabelo and thaba nchu areas in the central free state province of south africa, two areas where small scale, peri-urban cattle farming is practised. an indirect fluorescent antibody test was used to test for babesia bigemina and b. bovis antibodies. to test for anaplasma marginale antibodies a competitive inhibition enzyme-linked immunosorbent assay method was used. there were no significant differences in serological test resu ...199810192841
restriction of major surface protein 2 (msp2) variants during tick transmission of the ehrlichia anaplasma marginale.anaplasma marginale is an ehrlichial pathogen of cattle that establishes lifelong persistent infection. persistence is characterized by rickettsemic cycles in which new a. marginale variant types, defined by the sequence of the expressed msp2 transcripts, emerge. the polymorphic msp2 transcripts encode structurally distinct msp2 proteins and result in an antigenically diverse and continually changing a. marginale population within the blood. in this manuscript, we used sequence analysis of msp2 ...199910077656
comparison of surface proteins of anaplasma marginale grown in tick cell culture, tick salivary glands, and cattle.anaplasma marginale, a tick-borne rickettsial pathogen of cattle, infects bovine erythrocytes, resulting in mild to severe hemolytic disease that causes economic losses in domestic livestock worldwide. recently, the virginia isolate of a. marginale was propagated in a continuous tick cell line, ide8, derived from embryonic ixodes scapularis. development of a. marginale in cell culture was morphologically similar to that described previously in ticks. in order to evaluate the potential of the cel ...19999864202
the absence of clinical disease in cattle in communal grazing areas where farmers are changing from an intensive dipping programme to one of endemic stability to tick-borne diseases.a two-year field study was conducted in four communal grazing areas in south africa. sera were collected from young cattle (6-18 months old) in these areas during the winters of 1991 to 1993. the sera were tested for antibodies to babesia bovis, babesia bigemina, anaplasma marginale and cowdria ruminantium. in two of the four areas, treatment with acaricide was erratic and dependent on the discretion of individual owners. in these areas the drought of 1992 had a major impact on tick burdens and ...19989809321
cd4(+) t-lymphocyte and immunoglobulin g2 responses in calves immunized with anaplasma marginale outer membranes and protected against homologous challenge.protective immunity against the ehrlichial pathogen anaplasma marginale has been hypothesized to require induction of immunoglobulin g2 (igg2) antibody against outer membrane protein epitopes and coordinated activation of macrophages for phagocytosis and killing. in the present study, cell-mediated immune responses, including induction of igg isotype switching, were characterized in calves immunized with purified outer membranes of the florida strain of a. marginale. importantly, these calves we ...19989784551
development of an enzyme-linked immunosorbent assay for detection of antibodies to babesia bigemina in cattle.monoclonal antibodies, directed against a 58-kda babesia bigemina merozoite antigen that reacted strongly with immune sera from experimentally and naturally infected cattle in western blots, were used to develop a competitive-inhibition enzyme-linked immunosorbent assay (elisa). as based on the testing of 70 antibody-positive sera from experimentally infected cattle and 166 antibody-negative sera collected in non-endemic areas of australia, the sensitivity and specificity of the elisa were 95.7% ...19989747938
observations on the use of anaplasma centrale for immunization of cattle against anaplasmosis in zimbabwe.a total of 93 bos taurus cattle was used in pen trials to compare vaccine stocks of anaplasma centrale from south africa and australia (which stock came from south africa in 1934) in protecting against three virulent field isolates from clinical anaplasma marginale infections. in addition, field observations were made on the use of a vaccine, prepared from the australian stock, in over 9553 cattle of mixed age and breeds on 16 co-operator farms and at one communal dip. the results of the pen tri ...19989741051
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