Bacillus licheniformis (B. licheniformis) is commonly used as probiotic and its secondary metabolites are attractive anti-microbial candidate. In the present study, we aimed to evaluate the antiviral activity of crude extracts from B. licheniformis against porcine epidemic diarrhea virus (PEDV), a highly contagious enveloped porcine virus that has caused great economic loss in pigs. In vivo, PEDV-infected piglets supplemented with air-dried solid state fermentative cultivate containing B. licheniformis-fermented products (BLFP) showed milder clinical symptoms and decreased viral shedding. Importantly, no significant systemic pathological lesions and no reduction in average daily gain were noted in pigs supplemented with the BLFP, which suggests that it is safe for use in pigs. In vitro experiments revealed that while B. licheniformis crude extracts exhibited no toxicity in Vero cells, co-cultivation of B. licheniformis crude extracts with PEDV significantly reduced viral infection and replication. Summarized current results suggest that the B. licheniformis-fermented products could be a novel candidate food additive for reducing the impact of PED on the swine industry.

中文翻译：

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评价地衣芽孢杆菌发酵产品对猪流行性腹泻病毒的抗病毒活性。

地衣芽孢杆菌（B. licheniformis）通常用作益生菌，其次生代谢产物是有吸引力的抗微生物候选物。在本研究中，我们旨在评估地衣芽孢杆菌粗提物对猪流行性腹泻病毒（PEDV）的抗病毒活性，该病毒是一种具有高度传染性的包膜猪病毒，已在猪中造成了巨大的经济损失。在体内，PEDV感染的仔猪补充了含有地衣芽孢杆菌的风干固态发酵培养物发酵产品（BLFP）表现出较轻的临床症状，并减少了病毒脱落。重要的是，在补充BLFP的猪中，没有发现明显的全身性病理病变，平均日增重也没有减少，这表明在猪中使用它是安全的。体外实验显示，地衣芽孢杆菌粗提物在Vero细胞中无毒性，而地衣芽孢杆菌粗提物与PEDV的共培养可显着减少病毒感染和复制。总结的当前结果表明，地衣芽孢杆菌发酵产品可能是减少PED对养猪业影响的新型候选食品添加剂。