Contreras Catalina, Alegría-Moran Raúl, Duchens Mario, Ábalos Pedro, López Renata, Retamal Patricio
Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile.
Escuela de Medicina Veterinaria, Sede Santiago, Facultad de Recursos Naturales y Medicina Veterinaria, Universidad Santo Tomás, Santiago, Chile.
Front Vet Sci. 2023 Oct 6;10:1278329. doi: 10.3389/fvets.2023.1278329. eCollection 2023.
Bovine tuberculosis (bTB) is a chronic disease mainly caused by , a zoonotic pathogen with economic significance as it leads to reduced milk and meat production, and high costs for control measures. The Bacillus Calmette-Guérin (BCG) vaccine, primarily used to prevent tuberculosis in humans, has also been studied for controlling bTB. While showing effectiveness in preventing infection and disease in cattle, the BCG vaccine can induce non-specific effects on the immune system, enhancing responses to infections caused by unrelated pathogens, and also having non-specific effects on lactation. The aim of this study is to describe both the specific and non-specific effects of BCG vaccination in calves from a commercial dairy herd in central Chile. Diagnosis of infection was performed through the IFNγ release assay (IGRA) using ESAT6/CFP-10 and Rv3615c antigens. The records of milk production, somatic cell count (SCC), clinical mastitis (CM) and retained placenta (RP) during the first lactation were compared between vaccinated and non-vaccinated animals. The breed (Holstein Friesian [HF] v/s HF × Swedish Red crossbred [HFSR]) and the season (warm v/s cold) were also analyzed as categorical explanatory variables. Results of IGRA showed significant differences between vaccinated and control groups, indicating a vaccine efficacy of 58.5% at 18 months post vaccination in HFSR crossbred animals. Although milk production did not vary, SCC and CM showed differences between groups, associated to the breed and the season, respectively. When analyzing CM and RP as a whole entity of disease, BCG showed protection in all but the cold season variables. Overall, the BCG vaccine induced protective specific and non-specific effects on health parameters, which may be influenced by the breed of animals and the season. These results provide new features of BCG protection, supporting initiatives for its implementation as a complementary tool in bTB control.
牛结核病（bTB）是一种主要由[病原体名称缺失]引起的慢性疾病，它是一种人畜共患病原体，具有经济意义，因为它会导致牛奶和肉类产量下降，以及控制措施成本高昂。卡介苗（BCG）疫苗主要用于预防人类结核病，也已被研究用于控制牛结核病。虽然卡介苗疫苗在预防牛感染和发病方面显示出有效性，但它可对免疫系统产生非特异性影响，增强对无关病原体引起的感染的反应，并且对泌乳也有非特异性影响。本研究的目的是描述智利中部一个商业奶牛场犊牛接种卡介苗疫苗的特异性和非特异性影响。通过使用ESAT6/CFP - 10和Rv3615c抗原的γ干扰素释放试验（IGRA）进行结核分枝杆菌感染的诊断。比较了接种和未接种动物在第一个泌乳期的产奶量、体细胞计数（SCC）、临床乳腺炎（CM）和胎衣不下（RP）记录。品种（荷斯坦弗里生牛[HF]与HF×瑞典红牛杂交牛[HFSR]）和季节（温暖与寒冷）也作为分类解释变量进行了分析。IGRA结果显示接种组和对照组之间存在显著差异，表明在接种后18个月，HFSR杂交动物的疫苗效力为58.5%。虽然产奶量没有变化，但SCC和CM在组间显示出差异，分别与品种和季节有关。当将CM和RP作为一个整体疾病实体进行分析时，卡介苗在除寒冷季节变量外的所有情况下都显示出保护作用。总体而言，卡介苗疫苗对健康参数诱导了保护性的特异性和非特异性影响，这可能受动物品种和季节的影响。这些结果提供了卡介苗保护的新特征，支持将其作为牛结核病控制的补充工具加以实施的倡议。
