Antimicrobial resistance is a significant challenge for human and animal health, and developing effective antibiotic-free treatments is a strategy to help mitigate microbial resistance. The global poultry industry faces growing challenges from Eimeria-induced coccidiosis, a serious enteric disease of chickens that currently requires treatment using ionophore antibiotics. Eimeria stimulates interleukin-10 (IL-10) expression in the small intestine and caecum of infected chickens, suppressing their immune response and facilitating disease progression. Single-domain antibodies raised from llamas immunized with chicken IL-10 (cIL-10) were developed that bind cIL-10 in vitro, block cIL-10 receptor binding and induce interferon gamma (IFN-γ) secretion from cIL-10-repressed primary chicken splenocytes. Single-domain antibodies expressed in transgenic corn demonstrated significant accumulation in phenotypically normal plants. When fed to Eimeria-challenged chickens, the transgenic corn significantly improved body weight gain (equal to that of salinomycin-treated animals), normalized the feed conversion ratio (to the same level as uninfected control animals), lowered E. tenella lesion scores to those of salinomycin-treated control animals, and reduced oocyst counts below those of infected untreated control animals. Here, we propose that transgenic corn may have a role in reducing the use of antibiotics in poultry production and maintaining animal health and productivity, and may contribute to efforts against global antimicrobial resistance.

抗生素耐药性是人类和动物健康面临的重大挑战，开发有效的无抗生素治疗是帮助减轻微生物耐药性的一种策略。全球家禽业面临着艾美球虫引起的球虫病日益严峻的挑战，这是一种严重的鸡肠道疾病，目前需要使用离子载体抗生素进行治疗。艾美球虫属刺激受感染鸡的小肠和盲肠中白细胞介素 10 (IL-10) 的表达，抑制它们的免疫反应并促进疾病进展。开发了从用鸡 IL-10 (cIL-10) 免疫的美洲驼产生的单域抗体，其在体外结合 cIL-10，阻断 cIL-10 受体结合并诱导干扰素 γ (IFN-γ) 从 cIL-10 抑制中分泌原代鸡脾细胞。在转基因玉米中表达的单域抗体在表型正常的植物中表现出显着的积累。当喂给艾美球虫攻击的鸡时，转基因玉米显着提高了体重增加（与盐霉素处理的动物相同），使饲料转化率正常化（与未感染的对照动物相同），降低了球虫病变评分与盐霉素处理的对照动物相比，并且卵囊计数减少到低于感染的未处理对照动物的那些。在这里，我们提出转基因玉米可能在减少家禽生产中抗生素的使用以及维持动物健康和生产力方面发挥作用，并可能有助于应对全球抗菌素耐药性。