Vaccination with recombinant Boophilus annulatus Bm86 ortholog protein, Ba86, protects cattle against B. annulatus and B. microplus infestations

<p>Abstract</p> <p>Background</p> <p>The cattle ticks, <it>Boophilus </it>spp., affect cattle production in tropical and subtropical regions of the world. Tick vaccines constitute a cost-effective and environmentally friendly alternative to tick control. The recombinant <it>B. microplus </it>Bm86 protective antigen has been shown to protect cattle against tick infestations. Recently, the gene coding for <it>B. annulatus </it>Bm86 ortholog, Ba86, was cloned and the recombinant protein was secreted and purified from the yeast <it>Pichia pastoris</it>.</p> <p>Results</p> <p>Recombinant Ba86 (Israel strain) was used to immunize cattle to test its efficacy for the control of <it>B. annulatus </it>(Mercedes, Texas, USA strain) and <it>B. microplus </it>(Susceptible, Mexico strain) infestations. Bm86 (Gavac and Mozambique strain) and adjuvant/saline were used as positive and negative controls, respectively. Vaccination with Ba86 reduced tick infestations (71% and 40%), weight (8% and 15%), oviposition (22% and 5%) and egg fertility (25% and 50%) for <it>B. annulatus </it>and <it>B. microplus</it>, respectively. The efficacy of both Ba86 and Bm86 was higher for <it>B. annulatus </it>than for <it>B. microplus</it>. The efficacy of Ba86 was higher for <it>B. annulatus </it>(83.0%) than for <it>B. microplus </it>(71.5%). The efficacy of Bm86 (Gavac; 85.2%) but not Bm86 (Mozambique strain; 70.4%) was higher than that of Ba86 (71.5%) on <it>B. microplus</it>. However, the efficacy of Bm86 (both Gavac and Mozambique strain; 99.6%) was higher than that of Ba86 (83.0%) on <it>B. annulatus</it>.</p> <p>Conclusion</p> <p>These experiments showed the efficacy of recombinant Ba86 for the control of <it>B. annulatus </it>and <it>B. microplus </it>infestations in cattle and suggested that physiological differences between <it>B. microplus </it>and <it>B. annulatus </it>and those encoded in the sequence of Bm86 orthologs may be responsible for the differences in susceptibility of these tick species to Bm86 vaccines.</p