Necrotic enteritis (NE) is a pervasive enteric disease responsible for large scale economic losses within the global poultry industry. The etiologic agent of NE is Clostridium perfringens (CP), an opportunistic pathogen that utilizes numerous extracellular toxins and glycoside hydrolases (GH) as key virulence and nutrient acquisition factors. Notably, some GH, mucinases, degrade components of mucin in the gastrointestinal tract as an energy source. Targeting this mechanism may serve to reduce the incidence of disease associated with CP. Two experiments were completed that evaluated mucinase vaccine targets sourced from conserved peptide sequences of carbohydrate binding module 32 of CP mucinases. In experiment 1, 37 antigen peptides were synthetically generated and used to produce hyper-immune sera, which was then evaluated for ability to obstruct CP growth in vitro. Total CFU of CP were measured at 4, 6, and 8 h incubation to determine growth rate. Peptides 4, 5, 22, 24, and 30 were selected for further in vivo testing based on conservation or the ability to inhibit CP growth by over 50% at 6 and 8 h. In experiment 2, the aforementioned peptides were conjugated to an agonistic, CD40-targetting antibody and evaluated in vivo. Broilers were given an Eimeria maxima and CP in order to induce NE and assess vaccine efficacy. Treatments included a non-vaccinated non-inoculated control, non-vaccinated inoculated control (NVIC), vaccination with peptide 4, 5, 22, 24, or 30 (VP4-VP30), or a combination of all 5 peptides (MC). There was a significant increase (P < 0.05) in the percent change in BWG relative to NVIC for vaccination with peptide 22 and MC of 18.54 and 17.43%, respectively. MC vaccinated group had the lowest lesions with a mean score of 0.63 ± 0.18. These results suggest the MC combination was the most successful in alleviating overall performance losses associated with NE-infected broilers and encourage future testing of MC in the development of an NE vaccine.

中文翻译：

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开发针对产气荚膜梭菌粘液溶解酶的新型亚单位疫苗用于控制肉鸡坏死性肠炎的初步研究。


坏死性肠炎（NE）是一种普遍存在的肠道疾病，造成全球家禽业大规模经济损失。 NE 的病原体是产气荚膜梭菌 (CP)，这是一种机会性病原体，利用大量细胞外毒素和糖苷水解酶 (GH) 作为关键毒力和营养获取因子。值得注意的是，一些 GH（粘蛋白酶）可降解胃肠道中的粘蛋白成分作为能量来源。针对这一机制可能有助于降低脑瘫相关疾病的发病率。完成了两个实验，评估源自 CP 粘蛋白酶碳水化合物结合模块 32 的保守肽序列的粘蛋白酶疫苗靶标。在实验1中，合成产生了37种抗原肽并用于产生超免疫血清，然后评估其在体外阻碍CP生长的能力。在孵育 4、6 和 8 小时时测量 CP 的总 CFU，以确定生长速率。基于保守性或在 6 小时和 8 小时抑制 CP 生长超过 50% 的能力，选择肽 4、5、22、24 和 30 进行进一步的体内测试。在实验2中，将上述肽与激动性CD40靶向抗体缀合并进行体内评估。给肉鸡注射极大艾美耳球虫和 CP，以诱导 NE 并评估疫苗功效。治疗包括未接种疫苗的未接种对照、未接种疫苗的接种对照(NVIC)、用肽4、5、22、24或30(VP4-VP30)疫苗接种，或所有5种肽的组合(MC)。相对于 NVIC，接种肽 22 和 MC 的 BWG 百分比变化显着增加 (P < 0.05)，分别为 18.54% 和 17.43%。 MC 疫苗接种组的病变最低，平均得分为 0.63 ± 0.18。 这些结果表明，MC 组合在减轻与 NE 感染肉鸡相关的整体性能损失方面最为成功，并鼓励未来在 NE 疫苗开发中对 MC 进行测试。