Department of Veterinary Parasitology, West Bengal University of Animal and Fishery Sciences, 37 K. B. Sarani, Kolkata 700 037, West Bengal, India.
Department of Veterinary Microbiology, West Bengal University of Animal and Fishery Sciences, 37 K. B. Sarani, Kolkata 700 037, West Bengal, India.
Vet Parasitol Reg Stud Reports. 2020 Dec;22:100477. doi: 10.1016/j.vprsr.2020.100477. Epub 2020 Oct 7.
Parasitological and immunological responses to the experimentally induced Haemonchus contortus infection were compared between Garole and Sahabadi breeds of sheep. The experiment was conducted in a 2 (breed) × 2 (infection status) factorial arrangement with a completely randomised design. Two breeds of sheep were divided into infected (n = 10) and control (n = 6) groups, and the infected groups were orally infected with H. contortus (500 stage 3 larvae per kilogram of body weight). Faecal egg counts (FEC) were determined from 18 days post infection (DPI) at 3-day intervals until 42 DPI. Average daily body weight gain, packed cell volume (PCV), concentrations of serum immunoglobulin (Ig) G, IgG, IgE and peripheral eosinophil count were measured at 14-day intervals from 0 to 42 DPI. Lymphocyte proliferation in response to somatic antigen of H. contortus was determined by in vitro lymphoproliferation assay, and concentrations of interferon gama (IFN-γ) and interleukin 4 (IL-4) in lymphocyte culture supernatant were measured at 14-day intervals until 42 DPI. Variables were analysed using the repeated measures mixed model procedure over DPI. Faecal egg count was significantly (p < 0.01) lower in Garole sheep than Sahabadi sheep and no faecal eggs were detected in the infected Garole sheep on 30 DPI. Infected Garole sheep had significantly (p < 0.05) higher body weight gain and PCV% than the infected Sahabadi sheep. In the infected Garole sheep, serum Ig except IgE increased significantly (p < 0.05) compared to infected Sahabadi sheep. On 28 DPI, peripheral eosinophil number, in vitro lymphoproliferation as well as concentrations of IFN-γ and IL-4 in culture supernatant were significantly (p < 0.05) higher in the infected Garole sheep than in the infected Sahabadi sheep. Parasitological observations indicated that Garole sheep were resistant to H. contortus and they exhibited greater cellular as well as humoral immune responses compared to Sahabadi sheep.
本研究比较了加罗莱和萨哈巴迪绵羊对实验诱导的捻转血矛线虫感染的寄生虫学和免疫学反应。试验采用完全随机设计，在 2（品种）×2（感染状态）因子设计下进行。将两种绵羊分为感染（n=10）和对照（n=6）组，感染组经口感染 H. contortus（每千克体重 500 期 3 幼虫）。从感染后 18 天（DPI）开始，每隔 3 天进行粪便卵计数（FEC），直至 42 DPI。从 0 到 42 DPI，每隔 14 天测量平均日体重增加、红细胞压积（PCV）、血清免疫球蛋白（Ig）G、IgG、IgE 浓度和外周嗜酸性粒细胞计数。通过体外淋巴细胞增殖试验测定对 H. contortus 体抗原的淋巴细胞增殖，每隔 14 天测量淋巴细胞培养上清液中干扰素 gama（IFN-γ）和白细胞介素 4（IL-4）的浓度，直至 42 DPI。通过重复测量混合模型程序分析 DPI 上的变量。加罗莱绵羊的粪便卵计数明显（p<0.01）低于萨哈巴迪绵羊，感染的加罗莱绵羊在 30 DPI 时未检测到粪便卵。感染的加罗莱绵羊的体重增加和 PCV%明显（p<0.05）高于感染的萨哈巴迪绵羊。在感染的加罗莱绵羊中，血清 Ig 除 IgE 外均显著（p<0.05）高于感染的萨哈巴迪绵羊。在 28 DPI 时，感染的加罗莱绵羊的外周嗜酸性粒细胞数、体外淋巴细胞增殖以及培养上清液中 IFN-γ和 IL-4 的浓度均明显（p<0.05）高于感染的萨哈巴迪绵羊。寄生虫学观察表明，加罗莱绵羊对 H. contortus 具有抗性，与萨哈巴迪绵羊相比，它们表现出更强的细胞和体液免疫反应。
