Changes in cecal microbiota community of suckling piglets infected with porcine epidemic diarrhea virus

Diarrhea, caused by porcine epidemic diarrhea virus (PEDV), is a catastrophic gastrointestinal disease among suckling piglets, with high infectivity, morbidity, and mortality, causing huge economic losses to the pig industry. In the present study, we investigated the different microbiota from the cecal mucosa and cecal contents between healthy and PEDV-infected piglets. High-throughput 16S rRNA gene sequencing was performed to explore differences. The results revealed that microbial dysbiosis by PEDV infection occurred in the cecal mucosa and contents of suckling piglets at each microbial taxonomic level. The abundance of pathogenic bacteria associated with diseases, including diarrhea, was increased. The abundance of Fusobacterium was 26.71% and 33.91% in cecal mucosa and contents of PEDV-infected group, respectively, whereas that in the healthy groups was 17.85% and 9.88%. The proportion of Proteobacteria in the infected groups was relatively high (24.67% and 22.79%, respectively), whereas that in the healthy group was 13.13% and 11.34% in the cecal mucosa and contents, respectively. Additionally, the proportion of Bacteroidetes in the healthy group (29.89%, 37.32%) was approximately twice that of the PEDV-infected group (15.50%, 15.39%). “Nitrate reduction”, “Human pathogens diarrhea”, “Human pathogens gastroenteritis”, “Nitrite respiration”, and “Nitrite ammonification” were the enriched functional annotation terms in the PEDV-infected groups. Porcine epidemic diarrhea virus infection increased the proportion of harmful bacteria and decreased the proportion of beneficial bacteria in the cecal mucosa and contents of suckling piglets. Our findings suggest that determining the intestinal microbiota might provide a promising method to prevent PEDV and open a new avenue for future research.由猪流行性腹泻病毒（porcine epidemic diarrhea virus, PEDV）引发的腹泻是哺乳仔猪的灾难性胃肠道疾病，兼具高传染性、高发病率与高致死率，给养猪业造成巨额经济损失。本研究聚焦健康仔猪与PEDV感染仔猪的盲肠黏膜及盲肠内容物的菌群差异，采用高通量16S rRNA基因测序技术开展分析。结果显示，PEDV感染可导致哺乳仔猪盲肠黏膜及内容物在各微生物分类学水平上出现菌群失调，与腹泻等疾病相关的病原菌丰度显著升高。感染组仔猪盲肠黏膜及内容物中梭杆菌属（Fusobacterium）的丰度分别为26.71%和33.91%，而健康组仅为17.85%和9.88%；感染组仔猪盲肠黏膜及内容物中的变形菌门（Proteobacteria）占比较高，分别为24.67%和22.79%，健康组对应占比仅为13.13%和11.34%。此外，健康组仔猪盲肠黏膜及内容物中的拟杆菌门（Bacteroidetes）占比（29.89%、37.32%）约为PEDV感染组（15.50%、15.39%）的两倍。PEDV感染组中富集的功能注释条目包括"硝酸盐还原"、"人类致病性腹泻"、"人类致病性胃肠炎"、"亚硝酸盐呼吸"及"亚硝酸盐氨化作用"。PEDV感染可升高哺乳仔猪盲肠黏膜及内容物中有害菌的占比，同时降低有益菌的占比。本研究结果表明，解析肠道菌群或可为PEDV的防控提供极具前景的策略，同时为后续研究开辟全新路径。