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C. G. D. Brown - One of the best experts on this subject based on the ideXlab platform.

  • Theileria annulata: reduced host MMP activity profile of long-term culture is transmitted as a parasite-encoded trait.
    Experimental Parasitology, 2020
    Co-Authors: Rachel Adamson, C. G. D. Brown, T. Ilhan, G.f Wilkie, Patricia M. Preston, F.r. Hall
    Abstract:

    Abstract Adamson, R. E., Ilhan, T., Wilkie, G. F., Preston, P. M., Brown, C. G. D., and Hall, F. R. 2000. Theileria annulata: Reduced host MMP activity profile of long-term culture is transmitted as a parasite-encoded trait. Experimental Parasitology94, 45–47.

  • innate and adaptive immune responses co operate to protect cattle against Theileria annulata
    Parasitology Today, 1999
    Co-Authors: Patricia M. Preston, Jabbar S Ahmed, R L Spooner, Frans Jongejan, Mohamed Aziz Darghouth, F.r. Hall, Jd Campbell, Elizabeth Glass, Brian Shiels, C. G. D. Brown
    Abstract:

    For many years it was assumed that Theileria annulata resembled T. parva, parasitizing lymphocytes and causing lymphoproliferative disease, with the two species being controlled by similar protective immune responses. Patricia Preston et al. here review the evidence that has led to a different view of T. annulata. It is now thought that the schizonts of T. annulata inhabit macrophages and B cells, and that tropical theileriosis is not a lymphoproliferative disease. Both innate and adaptive responses contribute to recovery from infection and resistance to challenge and cytokines produced by infected and uninfected cells influence the outcome of infection. Partial protection has been stimulated recently by defined recombinant antigens; efficacy depended upon the delivery system.

  • Metastasis of Theileria annulata macroschizont-infected cells in scid mice is mediated by matrix metalloproteinases
    Parasitology, 1998
    Co-Authors: R. P. T. Somerville, C. G. D. Brown, Rachel Adamson, F.r. Hall
    Abstract:

    Theileria annulata (Ta)-infected leucocytes are able to disseminate in scid mice. The dose of virulent parasites of the Ta-Ode line required to achieve quantifiable dissemination was found to be 2 x 10(6) cells given i.p. Dissemination was higher on day 11 post-inoculation than on day 18. The attenuated Ta-Ode cells were found to disseminate very poorly compared to their virulent progenitors, which correlates with a marked reduction in matrix metalloproteinase (MMP) expression. A daily i.p. injection of mice with BB94, a synthetic inhibitor of MMPs, almost completely ablated dissemination compared to controls. This provides strong evidence that metastasis of Theileria annulata macroschizont-infected host cells is mediated by host MMPs induced by the parasite. This has important implications for explaining a number of pathological features of tropical theileriosis in cattle.

  • Genomic and phenotypic diversity of Tunisian Theileria annulata isolates
    Parasitology, 1994
    Co-Authors: L. Ben Miled, Mohamed Aziz Darghouth, K. Dellagi, Giacomo Bernardi, T. R. Melrose, A. Bouattour, Jane Kinnaird, Brian Shiels, Andy Tait, C. G. D. Brown
    Abstract:

    This study describes polymorphism in Theileria annulata, an intracellular protozoan parasite of bovine leucocytes an blood cells. Fifty-three different stocks of T. annulata, isolated from 17 sites (districts) in Tunisia, have been characterized by anti-parasite monoclonal antibody (MAb) reactivity, glucose phosphate isomerase (GPI) isoenzyme electrophoresis, and Southern blotting with two genomic DNA probes. There appears to be considerable diversity amongst T. annulata stocks from Tunisia, no two isolates being identical, even those from animals on the same farm. Two distinct antigenic populations were detected by MAb 7E7. They were defined by negative and positive cells in the indirect fluorescent antibody test

  • Common and stage-specific antigens of Theileria annulata
    Veterinary Immunology and Immunopathology, 1992
    Co-Authors: M. Kachani, C. G. D. Brown, R. A. Oliver, H. Ouhelli, R L Spooner
    Abstract:

    Abstract Western blot analysis of Theileria annulata antigens was carried out using sera collected from cattle which had been immunised and challenged with either T. annulata sporozoites or schizont-infected cells. Three antigens between 71 and 73 kDa proved to be common to the three stages of parasite studied: sporozoites, schizonts and piroplasms. An antigen was found at 32 kDa which was specific to T. annulata piroplasms. Results were reproducible using sera from Morocco and the UK. At least one of the proteins at 71–73 kDa, but not that at 32 kDa were also recognised by sera from animals infected with Babesia species.

M Magzoub - One of the best experts on this subject based on the ideXlab platform.

  • Biochemical Profiles in Friesian Cattle Naturally Infected with Theileria annulata in Saudi Arabia
    Veterinary Research Communications, 2003
    Co-Authors: O H Omer, O M Mahmoud, E M Haroun, A Hawas, M Magzoub, K.h. El-malik, H.m. Omar
    Abstract:

    The biochemical parameters were studied in adult and young Friesian cattle naturally infected with Theileria annulata in the Qassim Region, Saudi Arabia. Forty-three clinical cases of tropical theileriosis were studied, together with 40 clinically healthy Friesian cattle. Cattle clinically infected with T. annulata had significantly lower serum total protein, albumin, globulin, creatinine, calcium, phosphorus, magnesium, potassium, iron and copper concentrations and significantly higher AST activity and bilirubin concentration than the healthy cattle.

  • haematological profiles in pure bred cattle naturally infected with Theileria annulata in saudi arabia
    Veterinary Parasitology, 2002
    Co-Authors: O H Omer, K H Elmalik, O M Mahmoud, E M Haroun, A Hawas, D Sweeney, M Magzoub
    Abstract:

    The Abbott Cell Dyn 3500 haematology analyzer was employed to study haematological parameters in 41 adult and young Friesian cattle naturally infected with Theileria annulata in the Qassim region of Saudi Arabia. Comparison was made with clinically healthy adult and young Friesian cattle. Changes in blood parameters in T. annulata-infected cattle indicated severe macrocytic hypochromic anaemia, panleukopenia, lymphocytopenia, eosinopenia, neutropenia and thrombocytopenia but no reticulocytosis.

G. C. Bansal - One of the best experts on this subject based on the ideXlab platform.

  • Comparative seroreactivity of piroplasm antigens of Theileria annulata
    Indian Journal of Animal Sciences, 2020
    Co-Authors: B. Dutta, G. C. Bansal, S. K. Ghorui
    Abstract:

    Host cell free piroplasms of Theileria annulata were disrupted by repeated freezing (- 196°C) and thawing (37°C) to obtain soluble protein antigen of the parasite (fraction I). The insoluble cellular precipitates were sequentially extracted first with Triton x 100 (fraction II) and then with Nonidet P-40 (fraction III). The fraction I showed highest seroreactivity in ELISA when tested against bovine antisera with optimum concentrations of antigens and antibodies. Slab gel electrophoresis of fractionated antigens revealed negligible contamination of host cellular protein. The presence of the major immunodominant proteins of 32.5 and 97 KDa molecular weight was most conspicuous in fraction I.

  • Theileria annulata Parbhani strain exhibits single genotype of 32 kDa merozoite surface antigens
    Journal of Veterinary parasitology, 2020
    Co-Authors: C. Rajendran, G. C. Bansal
    Abstract:

    The 32 kDa merozoite surface antigen of Theileria annulata (Parbhani) has been characterized by using merozoites derived from differentiating macroschizont-infected bovine lymphoblast cell line. This molecule was found to be major polypeptide in extracts of both merozoites and piroplasms and was strongly detected by serum from an immune cow. The result indicated the presence of one genotype of major merozoite/piroplasm surface antigen in the Parbhani strain of T. annulata.

  • Use of labelled genomic DNA for detection of Theileria annulata in bovine carriers
    Indian Journal of Animal Sciences, 2020
    Co-Authors: D.s. Upadhyay, G. C. Bansal
    Abstract:

    The ECOR 1 digested genomic DNA of Theileria annulata was labelled with a non-radioactive steroid hapten digoxigenin and used to detect infection of T. annulata in bovine blood by hybridization. The signal of hybridization was recorded with blood showing intraerythrocytic parasitaemia up to 0.00032%. No cross-hybridization occurred with a labelled repetitive fragment of bovine DNA. The hybridization assay yielded positive result in experimentally infected calves for a longer period than that of ELISA.

  • β-Tubulin gene based PCR-RFLP method for specific detection of Babesia bigemina and Theileria annulata isolates.
    Journal of Applied Animal Research, 2010
    Co-Authors: Harkirat Singh, A. K. Mishra, P. S. Cheema, Anurag Tewari, Reghu Ravindran, G. C. Bansal
    Abstract:

    Abstract Singh, H., Cheema, P.S., Mishra, A.K., Tewari, A.K., Rao, J.R., Ravindran, R., Ray, D. and Bansal, G.C. 2010. β-tubulin gene based PCR-RFLP method for specific detection of Babesia bigemina and Theileria annulata isolates. J. Appl. Anim. Res., 37: 233–238. For early detection of Babesia bigemina and Theileria annulata β-tubulin gene was targeted based on PCR assays. Subsequently, on the basis of sequence analysis of β-tubulin gene fragment of various isolates, a new PCR-RFLP method based on enzymes EcoRI and HindIII has been developed for species identification of B. bigemina and T. annulata isolates.

  • A PCR-RFLP Method for Specific Detection of Theileria annulata
    Journal of Applied Animal Research, 2007
    Co-Authors: Reghu Ravindran, A. K. Mishra, B. C. Saravanan, G. C. Bansal
    Abstract:

    Abstract Ravindran, R., Saravanan, B. C, Rao, J. R., Mishra, A. K., Bansal, G.C. and Ray, D. 2007. A PCR-RFLP method for specific detection of Theileria annulata. J. Appl. Anim. Res., 32: 111–112. A polymerase chain reaction amplifying the ribosomal RNA gene from the genomic DNA was standardized and it amplified monomorphic ∼564 bp product from B. bigemina, T. annulata, and host leucocyte genomic DNA templates. Use of the enzyme kpn I resulted in restriction digestion only with T. annulata, specific PCR product yielding 466 and 98 bp fragments.

Jabbar S Ahmed - One of the best experts on this subject based on the ideXlab platform.

  • assessment of the first commercial elisa kit for the diagnosis of Theileria annulata
    Journal of Parasitology Research, 2015
    Co-Authors: Amira Adel Taha Alhosary, Jabbar S Ahmed, Ann Nordengrahn, Malik Merza
    Abstract:

    The present study assesses the efficacy of SVANOVIR Theileria annulata-Ab, the first commercial ELISA kit for the diagnosis of Theileria annulata infection in cattle based on a recombinant protein known as T. annulata surface protein (TaSp). As a reference test, a polymerase chain reaction (PCR) assay depending on T. annulata merozoite surface antigen (Tams-1) was applied. A total of 468 blood samples as well as serum samples were randomly collected from cattle and tested in the PCR as well as in the ELISA developed in this study. Moreover, all samples were also analyzed by conventional Giemsa-stained blood smear. The results of this study revealed a good correlation between the results obtained by PCR and the ELISA, whereas all PCR positive samples scored correctly positive in the ELISA and 73 of the 125 PCR negative samples scored correctly negative. Taken together, a sensitivity of 91.25% and a specificity of 78.4% were recorded, when compared to the PCR data. In conclusion, the SVANOVIR Theileria annulata-Ab is a suitable diagnostic assay for use in the diagnosis and epidemiological surveys of Theileria annulata infection in chronic and carrier animals.

  • Identification and Characterization of Theileria annulata Heat-Shock Protein 90 (HSP90) Isoforms
    Transboundary and Emerging Diseases, 2013
    Co-Authors: S. B. Mohammed, Jabbar S Ahmed, Mohammed A Bakheit, Martin Ernst, Ulrike Seitzer
    Abstract:

    Summary Heat-shock proteins (HSPs) refer to a group of proteins whose synthesis is enhanced upon sudden increase in temperature or exposure to a variety of other stressors. In this study, Theileria annulata (T. annulata) HSP90 was identified and characterized as a first step to understand the function of this molecule in T. annulata-infected cells. Our results indicated the existence in the genome of T. annulata of two HSP90 genes: one located in chromosome one (TaHSP90-Chr1) and the other in chromosome four (TaHSP90-Chr4). The amino acid alignment between the two isoforms has shown identity and similarity values of 23.52% and 30.26%, respectively. Theileria annulata recombinant HSP90 proteins were expressed using a bacterial expression system and could be recognized in Western blots by rabbit anti-serum raised against an antigenic peptide derived from a unique sequence of TaHSP90-Chr1. On the other hand, bovine HSP90 was detected in T. annulata-infected cells using Western blot and immunocytostaining. To demonstrate the effect of the inhibition of HSP90 on the survival of T. annulata-infected cells, Geldanamycin (GA), a specific inhibitor for HSP90, was used. Upon GA treatment, p53 was observed to translocate into the host cell nucleus, a phenomenon that occurs in cells undergoing apoptosis. Using flowcytometry, a significant increase (P = 0.028) in cell death (%) was observed in T. annulata-infected cells treated with two different GA concentrations, 0.5 and 1 μm, and incubated for 24, 48 and 72 h.

  • Comparison of the Molecular Structure of the TaSP Gene of Theileria annulata from Sudanese Isolates
    Annals of the New York Academy of Sciences, 2008
    Co-Authors: D. A. Salih, Mohammed A Bakheit, Jabbar S Ahmed, Abdel Rahim M. El Hussein, Shawgi M. Hassan, Maowia M. Mukhtar, Ulrike Seitzer
    Abstract:

    The polymorphic region of the Theileria annulata surface protein (TaSP) was cloned and sequenced from different isolates of cattle and cell lines from different areas of Sudan. Amino acid sequence alignment revealed a high diversity showing amino acid and length polymorphism, both within and between parasite isolates. The generation of TaSP diversity may allow the evasion of host immunity by the parasite since TaSP is a highly antigenic parasite protein.

  • development of a competitive elisa for detection of Theileria annulata infection
    Transboundary and Emerging Diseases, 2008
    Co-Authors: S Renneker, Mohammed A Bakheit, Jabbar S Ahmed, Brian Shiels, Andy Tait, Birgit Kullmann, S Gerber, J Dobschanski, D Geysen, Ulrike Seitzer
    Abstract:

    Summary In previous studies, Theileria annulata surface protein (TaSP) was identified as an immunodominant antigen and successfully used to develop and validate a recombinant-protein-based ELISA for the detection of circulating antibodies in serum of T. annulata–infected animals. In this study, the same antigen was used to develop a competitive ELISA (cELISA) using a monoclonal antibody that was found to bind to TaSP. The cELISA accurately differentiated T. annulata-infected from uninfected animals and demonstrated a satisfactory performance with a calculated sensitivity and specificity of 77.4% and 100%, respectively. Thus the test proved its suitability for the diagnosis of tropical theileriosis and has application for use in serological surveys to monitor the prevalence of the disease or identify carrier animals with high specificity.

  • from molecule to diagnostic tool Theileria annulata surface protein tasp
    Parasitology Research, 2007
    Co-Authors: Ulrike Seitzer, Mohammed A Bakheit, Dia Eldin A Salih, Daniel Haller, Leonhard Schnittger, Jabbar S Ahmed
    Abstract:

    Isolation and characterization of the Theileria annulata macroshizont stage protein TaSP showed that this parasite surface membrane protein is a highly antigenic protein suitable for the development of diagnostic tools for tropical theileriosis. An enzyme-linked immunosorbent assay (ELISA) for the detection of circulating antibodies against Theileria annulata was established and validated using the recombinantly expressed TaSP protein. The ELISA has subsequently been applied for cross-sectional surveys to determine the distribution and prevalence of tropical theileriosis in Sudan.

Brian Shiels - One of the best experts on this subject based on the ideXlab platform.

  • population diversity of Theileria annulata in portugal
    Infection Genetics and Evolution, 2016
    Co-Authors: Jacinto Gomes, Brian Shiels, Andrew Tait, Patricia Salgueiro, Joao Inacio, Ana Amaro, Joao Pinto, Isabel Pereira Da Fonseca, Gabriela Santosgomes
    Abstract:

    The tick-borne protozoan parasite Theileria annulata causes tropical theileriosis, a severe disease of cattle that occurs across the Mediterranean littoral, the Middle East and Southern Asia. In the Mediterranean region, the disease has long been perceived as being a constraint to livestock production in North Africa and Turkey but was believed to have minimal impact in Southern European countries. It has recently been demonstrated that in Southern Portugal the prevalence of T. annulata is approximately 30%. While the population genetics of the parasite and the multiplicity of infection in the bovine host have been studied in a number of countries, no information is currently available on the composition of the parasite population in Southern Europe or its relationship to populations in bordering regions. A parasite genotyping system, based on micro- and mini-satellite amplification, was used to perform genetic analysis of T. annulata populations from T. annulata infected cattle in twelve farms in Southern Portugal. A diversity of genotypes and a high multiplicity of infection were found, suggesting that the parasite possesses a panmictic population in this region. In comparison with genotypes found in Tunisia and Turkey, parasites from Portugal form a genetically distinct group and show lower genetic diversity.

  • development of a competitive elisa for detection of Theileria annulata infection
    Transboundary and Emerging Diseases, 2008
    Co-Authors: S Renneker, Mohammed A Bakheit, Jabbar S Ahmed, Brian Shiels, Andy Tait, Birgit Kullmann, S Gerber, J Dobschanski, D Geysen, Ulrike Seitzer
    Abstract:

    Summary In previous studies, Theileria annulata surface protein (TaSP) was identified as an immunodominant antigen and successfully used to develop and validate a recombinant-protein-based ELISA for the detection of circulating antibodies in serum of T. annulata–infected animals. In this study, the same antigen was used to develop a competitive ELISA (cELISA) using a monoclonal antibody that was found to bind to TaSP. The cELISA accurately differentiated T. annulata-infected from uninfected animals and demonstrated a satisfactory performance with a calculated sensitivity and specificity of 77.4% and 100%, respectively. Thus the test proved its suitability for the diagnosis of tropical theileriosis and has application for use in serological surveys to monitor the prevalence of the disease or identify carrier animals with high specificity.

  • Transient transfection of Theileria annulata.
    Molecular and Biochemical Parasitology, 2001
    Co-Authors: Rachel Adamson, Jane Kinnaird, Brian Shiels, Kim Lyons, Mike Sharrard, David G. Swan, Simon P. Graham, Roger Hall
    Abstract:

    Abstract We have developed a method to transiently transfect infective, uninucleate, Theileria annulata sporozoites. Transfection vectors have been constructed using a number of T. annulata 5′ gene flanking sequences linked to the enhanced green fluorescence protein (eGFP) reporter gene. Sporozoites were transfected with these constructs using the lipid transfection agent SuperFect™, then allowed to infect purified bovine mononuclear cells (PBMs). Green fluorescence was observed in developing trophozoites, 36–40 h post infection, using constructs containing the upstream regions of the T. annulata Hsp70, T. annulata merozite surface antigen 1 (TamS1) and T. annulata macroschizont-specific AT hook-containing protein2 (TashAT2) genes. A construct with the 5′ TamS1 upstream sequence in reverse orientation gave no detectable fluorescence indicating fluorescence was derived by expression from the T. annulata promoter. A cytomegalovirus (CMV) promoter construct showed no activity in this stage of the parasite. However, when this construct was introduced directly into schizont-infected cells by electroporation, fluorescence was observed in the bovine cells but not the schizont. We describe the significance of these results in relation to novel control strategies and the fundamental biology of Theileria parasites.

  • innate and adaptive immune responses co operate to protect cattle against Theileria annulata
    Parasitology Today, 1999
    Co-Authors: Patricia M. Preston, Jabbar S Ahmed, R L Spooner, Frans Jongejan, Mohamed Aziz Darghouth, F.r. Hall, Jd Campbell, Elizabeth Glass, Brian Shiels, C. G. D. Brown
    Abstract:

    For many years it was assumed that Theileria annulata resembled T. parva, parasitizing lymphocytes and causing lymphoproliferative disease, with the two species being controlled by similar protective immune responses. Patricia Preston et al. here review the evidence that has led to a different view of T. annulata. It is now thought that the schizonts of T. annulata inhabit macrophages and B cells, and that tropical theileriosis is not a lymphoproliferative disease. Both innate and adaptive responses contribute to recovery from infection and resistance to challenge and cytokines produced by infected and uninfected cells influence the outcome of infection. Partial protection has been stimulated recently by defined recombinant antigens; efficacy depended upon the delivery system.

  • Genomic and phenotypic diversity of Tunisian Theileria annulata isolates
    Parasitology, 1994
    Co-Authors: L. Ben Miled, Mohamed Aziz Darghouth, K. Dellagi, Giacomo Bernardi, T. R. Melrose, A. Bouattour, Jane Kinnaird, Brian Shiels, Andy Tait, C. G. D. Brown
    Abstract:

    This study describes polymorphism in Theileria annulata, an intracellular protozoan parasite of bovine leucocytes an blood cells. Fifty-three different stocks of T. annulata, isolated from 17 sites (districts) in Tunisia, have been characterized by anti-parasite monoclonal antibody (MAb) reactivity, glucose phosphate isomerase (GPI) isoenzyme electrophoresis, and Southern blotting with two genomic DNA probes. There appears to be considerable diversity amongst T. annulata stocks from Tunisia, no two isolates being identical, even those from animals on the same farm. Two distinct antigenic populations were detected by MAb 7E7. They were defined by negative and positive cells in the indirect fluorescent antibody test