Diabb Rasha, El-Gbily Shaimaa, Albadrani Ghadeer M, Albarrak Saleh M, Abdel-Daim Mohamed M, El-Shall Nahed A
Immunity department, Alexandria regional Lab., Animal Health Research Institute (AHRI), Agriculture Research Center (ARC), Egypt.
Virology department, Alexandria regional Lab., Animal Health Research Institute (AHRI), Agriculture Research Center (ARC), Egypt.
Poult Sci. 2025 Aug 6;104(11):105658. doi: 10.1016/j.psj.2025.105658.
This study assessed the efficacy of a bivalent IBV vaccination (H120/D274) against GI-23 (variant II) and the antiviral and immunostimulatory properties of dietary Nigella sativa plus β-glucan (NSG). A total of 186 one-day-old broiler chicks were used as follows: 1st group (n=42) received IBV vaccine (prime: 7- and post: 14- day of age) (VAX), 2nd group (n=42) received the additive without vaccination (NSG), 3rd group (n=42) received both the vaccine and additive (VAX-NSG), and 4th group (n=60) received neither vaccine nor additive (CTRL). The 4th group was subdivided on the challenging day to negative (CTRL-N) and positive (CTRL-P) control subgroups. All groups except CTRL-N were challenged via naso/ocular route with IBV Variant II at 14 days post 2nd vaccination (PV). Clinical protection, antibody titers, cytokine expression, immune organ indices, viral shedding, and renal and tracheal histopathological lesions were evaluated. Body weight loss% at 1-week post-challenge (pc) in VAX, NSG, and VAX-NSG was 28.47%, 31.28%, and 23.54%, respectively, compared to CTRL-P (43.72 %) (P<0.05). Remarkably, NSG group showed milder tracheal and renal histopathological lesions than VAX group at 3 and 7 dpc, while VAX-NSG group displayed normal histology. Oropharyngeal IBV shedding was successfully reduced by the vaccination regimen; the VAX-NSG group showed the lowest level (P<0.05). Splenic IL-6 and TNF-α mRNA expression was upregulated at 3- and 7-dpc in CTRL-P birds (P<0.05). They were significantly downregulated in VAX-NSG, VAX, and NSG groups (P<0.05). At 7 dpc, IBV reduced the CTRL-P group's bursa, thymus, and spleen indices (P<0.05) that were significantly reversed in other challenged groups. VAX, NSG, and VAX-NSG groups induced higher lacrimal IgA titers than the control (P<0.05) at weekly intervals PV; while pc, they were lower than CTRL-P (P<0.05). However, serum IgG titers were higher in the VAX group than VAX-NSG group PV, and the opposite was observed at 7 and 10 dpc (P<0.05). Conclusion, the combination of dietary NSG with the heterologous IBV vaccine (H120/D274) showed synergistic effects to stop variant II viral shedding by the 10th dpc, increase anti-inflammatory effects, prevent renal and tracheal histopathological lesions, and significantly reduce body weight loss post challenge.
本研究评估了二价传染性支气管炎病毒（IBV）疫苗（H120/D274）对GI-23（变异株II）的效力以及日粮中黑种草籽加β-葡聚糖（NSG）的抗病毒和免疫刺激特性。总共使用了186只1日龄的肉鸡雏鸡，分组如下：第1组（n = 42）接受IBV疫苗（首免：7日龄，二免：14日龄）（VAX）；第2组（n = 42）未接种疫苗仅接受添加剂（NSG）；第3组（n = 42）既接受疫苗又接受添加剂（VAX - NSG）；第4组（n = 60）既不接受疫苗也不接受添加剂（CTRL）。在攻毒日，第4组又细分为阴性（CTRL - N）和阳性（CTRL - P）对照亚组。除CTRL - N组外，所有组在第二次接种疫苗（PV）后14天通过鼻/眼途径用IBV变异株II进行攻毒。评估了临床保护、抗体滴度、细胞因子表达、免疫器官指数、病毒排出以及肾脏和气管的组织病理学损伤。与CTRL - P组（43.72%）相比，攻毒后1周（pc）时，VAX组、NSG组和VAX - NSG组的体重减轻百分比分别为28.47%、31.28%和23.54%（P<0.05）。值得注意的是，在攻毒后3天和7天，NSG组的气管和肾脏组织病理学损伤比VAX组更轻，而VAX - NSG组的组织学表现正常。疫苗接种方案成功减少了口咽部位的IBV排出；VAX - NSG组的排出水平最低（P<0.05）。在攻毒后3天和7天，CTRL - P组鸡的脾脏IL - 6和TNF-α mRNA表达上调（P<0.05）。在VAX - NSG组、VAX组和NSG组中它们显著下调（P<0.05）。在攻毒后7天，IBV降低了CTRL - P组的法氏囊、胸腺和脾脏指数（P<0.05），而在其他攻毒组中这些指数显著恢复。在接种疫苗后的每周间隔时间，VAX组、NSG组和VAX - NSG组诱导产生的泪液IgA滴度均高于对照组（P<0.05）；而在攻毒后，它们低于CTRL - P组（P<0.05）。然而，在接种疫苗时，VAX组的血清IgG滴度高于VAX - NSG组，而在攻毒后7天和10天观察到相反的情况（P<0.05）。结论：日粮NSG与异源IBV疫苗（H120/D274）联合使用显示出协同作用，在攻毒后第10天停止变异株II的病毒排出，增强抗炎作用，预防肾脏和气管的组织病理学损伤，并显著减少攻毒后的体重减轻。
