Centro de Enseñanza, Investigación y Extensión en Ganadería Tropical, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Km. 5.5 Carretera Federal Tlapacoyan-Martínez de La Torre, C.P. 93600, Martínez de La Torre, Veracruz, Mexico.
Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Tamaulipas, Km. 5, Carretera Victoria‑Mante, CP 87000, Ciudad Victoria, Tamaulipas, Mexico.
Vet Parasitol. 2021 Nov;299:109577. doi: 10.1016/j.vetpar.2021.109577. Epub 2021 Sep 17.
The cattle tick Rhipicephalus microplus affect animal health, welfare, and cattle production in tropical and subtropical zones of the world. Anti-tick vaccines have been an effective alternative for cattle tick control instead of traditional chemical products. To date, Subolesin antigen has shown efficacy for the control of tick infestation in cattle, and previous studies showed that one peptide derived from this protein has demonstrated to elicit a strong and specific humoral immune response. Based on these findings, herein we characterized the efficacy of the peptide Subolesin for the control of cattle tick, R. microplus infestation under field conditions. Twenty-four female calves were assigned to four experimental groups and immunized with three subcutaneous doses of the peptide Subolesin, Bm86, both antigens (dual vaccine) and adjuvant/saline alone, respectively. Serum antibody levels (IgG) were assessed by ELISA and confirmed by Western blot; also, reproductive performance of naturally infested R. microplus was determined. The results showed that immunizations with the experimental antigens reduced tick infestations with vaccine's efficacy of 67 % (peptide Subolesin), 56 % (Bm86), and 49 % (dual vaccine) based on adult tick numbers, oviposition, and egg fertility between vaccinated and control animals. Peptide Subolesin-immunized calves developed a strong humoral immune response expressed by high anti-pSubolesin IgG levels, and the Western blot analysis confirmed that it is immunogenic. Cattle receiving Bm86 and dual vaccine showed less protection, although Bm86 was within the range reported previously. The negative correlation between antibody levels and reduction of naturally infested R. microplus strongly suggested that the effect of the vaccine was the result of the antibody response in immunized cattle. In conclusion, it was demonstrated that the peptide Subolesin induced a specific immune response in cattle under field conditions, resulting in reduced R. microplus populations in subsequent generations. Finally, integrated tick control must consider anti-tick vaccines as a cost-effective, sustainable, and successful tool for controlling cattle tick infestations.
牛蜱 Rhipicephalus microplus 影响世界热带和亚热带地区的动物健康、福利和牛的生产。抗蜱疫苗一直是控制牛蜱的一种有效替代传统化学产品的方法。迄今为止，Subolesin 抗原已被证明可有效控制牛的蜱虫感染，先前的研究表明，这种蛋白质的一种肽已被证明能引起强烈和特异性的体液免疫反应。基于这些发现，在此我们在田间条件下对控制牛蜱、R. microplus 感染的肽 Subolesin 的功效进行了表征。将 24 头雌性小牛分配到四个实验组中，分别用肽 Subolesin、Bm86 这两种抗原（双疫苗）和佐剂/盐水进行三次皮下免疫。通过 ELISA 评估血清抗体水平（IgG），并通过 Western blot 进行确认；还确定了自然感染 R. microplus 的生殖性能。结果表明，用实验抗原免疫可减少蜱虫的感染，其效果分别为肽 Subolesin（67%）、Bm86（56%）和双疫苗（49%），这是基于成虫蜱的数量、产卵和卵的生育能力来判断的。肽 Subolesin 免疫的小牛产生了强烈的体液免疫反应，表现为高抗 pSubolesin IgG 水平，Western blot 分析证实其具有免疫原性。尽管 Bm86 在先前报道的范围内，但接受 Bm86 和双疫苗的牛的保护作用较小。抗体水平与自然感染 R. microplus 的减少之间的负相关强烈表明，疫苗的效果是免疫牛的抗体反应的结果。总之，研究结果表明，肽 Subolesin 在田间条件下可诱导牛产生特异性免疫反应，从而减少后续世代中 R. microplus 的数量。最后，综合蜱虫控制必须将抗蜱疫苗视为控制牛蜱感染的一种具有成本效益、可持续且成功的工具。
