Publications by authors named "Russell E Bock"
Endemic stability is a widely used term in the epidemiology of ticks and tick-borne diseases. It is generally accepted to refer to a state of a host-tick-pathogen interaction in which there is a high level of challenge of calves by infected ticks, absence of clinical disease in calves despite infection, and a high level of immunity in adult cattle with consequent low incidence of clinical disease. Although endemic stability is a valid epidemiological concept, the modelling studies that underpinned subsequent studies on the epidemiology of tick-borne diseases were specific to a single host-tick-pathogen system, and values derived from these models should not be applied in other regions or host-tick-pathogen systems.
View Article and Find Full Text PDFThe merozoite surface antigen 2 (MSA-2) proteins of Babesia bovis are members of the variable merozoite surface antigen (VMSA) family that have been implicated in erythrocyte invasion and are important targets for antibody-mediated blocking of invasion. Extensive sequence variation in another VMSA member, MSA-1, has been shown in all vaccine breakthrough isolates. To test the hypothesis that the msa-2 genes of vaccine breakthrough isolates would also encode a diverse set of proteins, the complete msa-2 locus was characterized from 12 Australian B.
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- The study investigates the Babesia bovis merozoite surface antigen 1 (MSA-1), focusing on its sequence variation and its implications for vaccine efficacy.
- Researchers sequenced MSA-1 from Australian vaccine strains and breakthrough isolates, finding low sequence identity, particularly in the extracellular region, which affected immunologic cross-reactivity.
- Despite significant amino acid variation, certain conserved regions indicate a functional role for MSA-1, but the antigenic differences lead to vaccine escape in some B. bovis isolates.
Article Synopsis
- Sensitive assays are crucial for detecting bovine retroviruses in cattle, which are needed for Australian tick fever vaccine preparation.
- Researchers developed and compared advanced 5' Taq nuclease assays (TaqMan MGB) to traditional PCR tests for better detection of bovine syncytial virus (BSV) and bovine immunodeficiency virus (BIV).
- The TaqMan MGB assays showed significantly improved sensitivity, enhancing detection by 10-fold for BIV and 100-fold for BSV compared to conventional methods, marking a key advancement in understanding Australian strains of these viruses.
Article Synopsis
- Sensitive assays are essential for detecting bovine leukemia virus (BLV) in donor cattle for Australian tick fever vaccines.
- The study developed a sensitive 5' Taq nuclease assay using specific DNA probes and compared it with traditional PCR methods.
- The TaqMan MGB assay proved to be the most sensitive and specific for BLV detection among various tested methods, marking a significant advancement in the field.
A 14-year-old cow (Dawn) born and kept in a Boophilus microplus-free region gave birth to a calf, which showed the presence of an Anaplasma marginale infection after splenectomy. The calf's grand dam was from a B. microplus infected area and we assume the infection originated via the transplacental route over two generations.
View Article and Find Full Text PDFDemand for live trivalent tick fever vaccine containing Babesia bovis, Babesia bigemina and Anaplasma centrale produced by the Department of Primary Industries, Queensland, has increased from less than 10,000 doses in 1988 to 500,000 doses in 2001. This paper describes a series of trials aimed at overcoming certain constraints to obtain B. bigemina parasitised erythrocytes (PEs) on a large enough scale from infected splenectomised calves to meet the demand.
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