IgY

Campylobacter jejuni (C.jejuni) is a common pathogen that often causes diarrhea, loss of appetite, and even enteritis in domestic cats, affecting their growth and development, especially in kittens under six months of age. Oral passive immunization with chicken yolk antibody Y has been proved effective for the treatment of gastrointestinal pathogen infections due to its high specificity. In this study, C.jejuni was isolated from diarrheal cat feces, and the specific egg yolk antibody Y against C.jejuni was demonstrated to effectively inhibit its proliferation in vitro experiments. To evaluate the effect of anti-C.jejuni IgY, the mouse C.jejuni infection model was established and it was found that IgY could alleviate C.jejuni-induced clinical symptoms. Consistent with these results, the reduction of pro-inflammatory factors and intestinal colonization by C. jejuni, and the improvement of intestinal morphology were observed in the IgY-treated groups, especially in the high dose group. We then evaluated the protective effect of IgY on young Ragdoll cats infected with C.jejuni. This specific antibody reduced the rate of feline diarrhea, protected the growth of young cats, inhibited systemic inflammatory hyperactivation, and increased fecal short-chain fatty acid concentrations. Notably, IgY may have a protective role by changing intestinal amino acid metabolism and affecting C.jejuni chemotaxis. Collectively, specific IgY is a promising therapeutic strategy for C.jejuni-induced cat diarrhea.

空肠弯曲菌（Campylobacter jejuni，C.jejuni）是一种常见病原体，常可导致家猫出现腹泻、食欲减退甚至肠炎，影响其生长发育，尤其对6月龄以下的幼猫危害更为显著。采用鸡源IgY（免疫球蛋白Y）进行口服被动免疫的疗法，因具备高特异性，已被证实可有效治疗胃肠道病原体感染。本研究从腹泻家猫的粪便中分离得到空肠弯曲菌，并通过体外实验证实，针对该菌的特异性IgY可有效抑制其增殖。为评估抗空肠弯曲菌IgY的干预效果，本研究构建了小鼠空肠弯曲菌感染模型，结果发现IgY可缓解空肠弯曲菌诱导的临床症状。与上述结果一致，IgY处理组可降低促炎因子水平、减少空肠弯曲菌在肠道的定植，并改善肠道形态，其中高剂量组的改善效果尤为突出。随后，本研究进一步评估了IgY对感染空肠弯曲菌的幼年布偶猫的保护作用。该特异性抗体可降低家猫腹泻发生率，保护幼猫的生长发育，抑制全身性炎症过度激活，并提升粪便短链脂肪酸浓度。值得注意的是，IgY或可通过改变肠道氨基酸代谢、影响空肠弯曲菌的趋化性发挥保护作用。综上，特异性IgY是一种极具应用前景的空肠弯曲菌诱导的家猫腹泻治疗策略。