School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
Poult Sci. 2021 Mar;100(3):100886. doi: 10.1016/j.psj.2020.11.063. Epub 2020 Dec 3.
The primary cause of necrotic enteritis (NE) disease in chickens is the NetB-positive Clostridium perfringens bacterium. Many factors are known to affect the severity of NE in the challenge models of broiler chickens, and one of these factors is the virulence of C. perfringens strain. This study was conducted to evaluate the effect of 2 pathogenic C. perfringens strains in a NE challenge model on gut health and mRNA expression of genes encoding apoptosis, tight junction, immunity, and nutrient transporters in broilers. Day-old Ross-308 male broilers (n = 468) were allocated in a 2 × 3 factorial arrangement of treatments with in-feed antibiotics (no or yes) and challenge (Non, C. perfringens strain NE18, and C. perfringens strain NE36) as the factors. The birds in the challenged groups were inoculated with Eimeria species on day 9 and with a fresh suspension of C. perfringens NE18 or NE36 on day 14 and 15. Sample collection was performed on 2 birds of each pen on day 16. Necrotic enteritis challenge, impaired feed conversion ratio during day 0 to 16 compared with the control group where the effect of the NE36 challenge was more severe than that with NE18 (P < 0.001). The mRNA expression of mucin-2, immunoglobulin-G, occludin (P < 0.001), and tight junction protein-1 (P < 0.05) genes were downregulated in both challenged groups compared with the nonchallenged counterparts. Antibiotic supplementation, on the other hand, increased weight gain, and feed intake in all challenged birds (P < 0.01), but upregulated mucin-5ac and alanine, serine, cysteine, and threonine transporter-1 (P < 0.05) only in the NE18 challenged birds. The challenge with NE36 significantly upregulated caspase-8 and claudin-1 (P < 0.001), but downregulated glucose transporter-2 (P < 0.001) compared with the NE18 challenge. These results suggest that NE challenge is detrimental to the performance of broilers through compromised intestinal health, and different C. perfringens strains can affect the severity of the disease through modulating the expression of intestinal genes encoding proteins responsible for apoptosis, gut integrity, immunity, mucus production, and nutrient transporters.
坏死性肠炎(NE)是由 NetB 阳性的产气荚膜梭菌引起的。许多因素被认为会影响肉鸡 NE 攻毒模型的严重程度,其中一个因素是产气荚膜梭菌菌株的毒力。本研究旨在评估 2 种致病性产气荚膜梭菌菌株在 NE 攻毒模型中对肠道健康和编码凋亡、紧密连接、免疫和营养转运蛋白的基因的 mRNA 表达的影响。将 468 只 1 日龄罗斯 308 雄性肉鸡按饲料中添加抗生素(有或无)和攻毒(无、产气荚膜梭菌 NE18 株和产气荚膜梭菌 NE36 株)的 2×3 因子设计分配到处理组中。攻毒组鸡于第 9 天感染艾美尔球虫,第 14 天和第 15 天接种新鲜产气荚膜梭菌 NE18 或 NE36 悬浮液。第 16 天每个鸡笼采集 2 只鸡的样本。与对照组相比,坏死性肠炎攻毒降低了 16 日龄的肉鸡生长性能,16 日龄时 NE36 攻毒组的料重比显著低于 NE18 攻毒组(P<0.001)。与未攻毒组相比,两组攻毒组的黏蛋白-2、免疫球蛋白-G、闭合蛋白(P<0.001)和紧密连接蛋白-1(P<0.05)基因的 mRNA 表达均下调。另一方面,抗生素添加显著提高了所有攻毒鸡的增重和采食量(P<0.01),但仅在 NE18 攻毒组中上调了黏蛋白-5ac 和丙氨酸、丝氨酸、半胱氨酸和苏氨酸转运蛋白-1(P<0.05)。与 NE18 攻毒相比,NE36 攻毒显著上调了半胱氨酸天冬氨酸蛋白酶-8 和紧密连接蛋白-1(P<0.001),但下调了葡萄糖转运蛋白-2(P<0.001)。这些结果表明,NE 攻毒通过损害肠道健康对肉鸡的生产性能造成损害,不同的产气荚膜梭菌菌株可以通过调节负责凋亡、肠道完整性、免疫、黏液产生和营养转运蛋白的肠道基因的表达来影响疾病的严重程度。