Evaluation of the Efficacy of BCG in Protecting Against Contact Challenge With Bovine Tuberculosis in Holstein-Friesian and Zebu Crossbred Calves in Ethiopia.
Evaluation of the Efficacy of BCG in Protecting Against Contact Challenge With Bovine Tuberculosis in Holstein-Friesian and Zebu Crossbred Calves in Ethiopia.
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DOI：
10.3389/fvets.2021.702402
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发表时间：
2021
影响因子：
3.2
通讯作者：
Ameni G
中科院分区：
文献类型：
--
作者：
Bayissa B;Sirak A;Worku A;Zewude A;Zeleke Y;Chanyalew M;Gumi B;Berg S;Conlan A;Hewinson RG;ETHICOBOTS Consortium;Wood JLN;Vordermeier HM;Ameni G
牛结核病（bTB）在埃塞俄比亚的集约化奶牛场中流行。鉴于检测和屠宰控制策略的社会经济挑战，疫苗接种可能是一种替代控制方法。从皮内宫颈比较结核菌素试验（SICCT）阴性的牛群中招募40头黑白花（HF）和瘤牛杂交犊牛，随机分为两组，评价卡介苗的疗效。22头小牛在2周龄内接种疫苗，18头作为对照。接种后6周，将两组奶牛与已知SICCT试验阳性奶牛接触并混合饲养1年。通过干扰素γ（IFN-γ）释放试验（IGRA）、SICCT试验和抗体试验监测免疫应答。接种小牛在接种后第6周对SICCT试验产生强烈应答，但对基于ESAT-6/CFP-10肽抗原的IGRA无应答。在暴露期间，两组中IFN-γ对特异性肽混合物的反应[F（2.44，92.67）= 26.96; p < 0.001]和皮肤对特异性蛋白混合物的反应[F（1.7，64.3）; p < 0.001]逐渐增加，而它们的抗体反应较低。基于牛分枝杆菌分离，对照组和接种组小牛的bTB患病率分别为88.9%（95% CI：65.3-98.6）和63.6%（95% CI：40.7-83.8），直接保护效力估计值为28.4%（95% CI：−2.7 - 50.1）。接种小牛中出现病变的比例为7.0%（34/484），对照小牛为11.4%（45/396），表明病变患病率降低38%（95% CI：5.8-59.4）。此外，接种疫苗的小牛（中位评分= 2.0，IQR = 0-4.75）的病理严重程度显着低于对照小牛（中位评分= 5，IQR = 3.0-6.25）（Mann-Whitney U检验，p < 0.05）。此外，从M.免疫犊牛的牛感染率显著高于对照犊牛（log-rank检验：χ2 = 6.749，p < 0.01）。总之，BCG的效力较低，但接种小牛病变的频率和严重程度降低，表明其在遏制继续传播方面具有潜在作用。
Bovine tuberculosis (bTB) is prevalent in intensive dairy farms in Ethiopia. Vaccination could be an alternative control approach given the socio-economic challenges of a test-and-slaughter control strategy. The efficacy of the BCG was evaluated on 40 Holstein-Friesian (HF) and zebu crossbred calves recruited from single intradermal cervical comparative tuberculin (SICCT) test negative herds and randomly allocated into two groups. Twenty-two calves were vaccinated within 2 weeks of age, and 18 were kept as a control. Six weeks post-vaccination, the two groups were exposed and kept mixed with known SICCT test positive cows for 1 year. Immune responses were monitored by interferon gamma (IFN-γ) release assay (IGRA), SICCT test, and antibody assay. Vaccinated calves developed strong responses to the SICCT test at the sixth week post-vaccination, but did not respond to ESAT-6/CFP-10 peptide antigen-based IGRA. During the exposure, IFN-γ response to the specific peptide cocktail [F(2.44, 92.67) = 26.96; p < 0.001] and skin reaction to the specific proteins cocktail [F(1.7, 64.3); p < 0.001] increased progressively in both groups while their antibody responses were low. The prevalence of bTB was 88.9% (95% CI: 65.3–98.6) and 63.6% (95% CI: 40.7–83.8) in the control and vaccinated calves, respectively, based on Mycobacterium bovis isolation, giving a direct protective efficacy estimate of 28.4% (95% CI: −2.7 to 50.1). The proportion of vaccinated calves with lesion was 7.0% (34/484) against 11.4% (45/396) in control calves, representing a 38% (95% CI: 5.8–59.4) reduction of lesion prevalence. Besides, the severity of pathology was significantly lower (Mann–Whitney U-test, p < 0.05) in vaccinated (median score = 2.0, IQR = 0–4.75) than in control (median score = 5, IQR = 3.0–6.25) calves. Moreover, survival from M. bovis infection in vaccinated calves was significantly (log-rank test: χ2 = 6.749, p < 0.01) higher than that of the control calves. In conclusion, the efficacy of BCG was low, but the reduced frequency and severity of lesion in vaccinated calves could suggest its potential role in containing onward transmission.
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影响因子：
3.1
作者：
Brandt, L;Cunha, JF;Andersen, P
通讯作者：
Andersen, P
影响因子：
4.3
作者：
Flynn, R. J.;Mulcahy, G.;McNair, J.
通讯作者：
McNair, J.
影响因子：
9.4
作者：
Kamerbeek, J;Schouls, L;vanEmbden, J
通讯作者：
vanEmbden, J
影响因子：
4.6
作者：
Arrieta-Villegas C;Allepuz A;Grasa M;Martín M;Cervera Z;Mercader I;López-Soria S;Domingo M;Pérez de Val B
通讯作者：
Pérez de Val B
影响因子：
4.3
作者：
Ameni G;Tafess K;Zewde A;Eguale T;Tilahun M;Hailu T;Sirak A;Salguero FJ;Berg S;Aseffa A;Hewinson RG;Vordermeier HM
通讯作者：
Vordermeier HM