Screening of Lactic Acid Bacterial Strains with Antiviral Activity Against Porcine Epidemic Diarrhea
Journal
Probiotics and Antimicrobial Proteins
Journal Volume
14
Journal Issue
3
Pages
546-559
Date Issued
2022
Author(s)
Abstract
Newly emerging and re-emerging viral infectious diseases cause significant economic losses in swine production. Efficacious vaccines have not yet been developed for several major swine infectious diseases, including porcine epidemic diarrhea virus (PEDV). We used the PEDV-infected Vero cell model to screen lactic acid bacteria (LAB) strains with antiviral activity. Sixty LAB strains were isolated from the feces of nursing piglets. After the elimination of LAB strains with high cytotoxicity to Vero cells, the protective effects of the remaining 6 strains against PEDV infection were determined. Vero cells pretreated with the intracellular extracts or cell wall fractions of YM22 and YM33 strains for 24 h before infection with PEDV showed significantly higher cell viabilities and lower mRNA expression of PEDV nucleocapsid (PEDV-N) than the unpretreated cells, indicating that the intracellular extracts and cell wall fractions of YM22 and YM33 possessed prophylactic effects on Vero cells against PEDV infection. PEDV-infection significantly increased the mRNA expression of proinflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) in Vero cells. However, pretreatment of Vero cells with the cell wall fractions of YM22 and YM33 decreased the mRNA expression of TNF-α and IL-8, which could be a mechanism associated with the protective effects of YM22 and YM33 against PEDV. Based on the biochemical characteristics and phylogenetic analyses, YM22 and YM33 were identified as Ligilactobacillus agilis (basonym: Lactobacillus agilis) and Ligilactobacillus salivarius (basonym: Lactobacillus salivarius), respectively. These findings suggest that L. agilis YM22 and L. salivarius YM33 could provide some levels of protective effects against PEDV infections. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Subjects
Antiviral activity; Ligilactobacillus agilis; Ligilactobacillus salivarius; Porcine epidemic diarrhea virus
SDGs
Other Subjects
alpha2b interferon; carboxyfluorescein diacetate succinimidyl ester; interferon; interleukin 8; probiotic agent; tumor necrosis factor; antivirus agent; interleukin 8; lactic acid; messenger RNA; plant extract; tumor necrosis factor; animal cell; antiviral activity; Article; cell viability; controlled study; cytotoxicity; cytotoxicity assay; epithelium cell; feces; flow cytometry; gene expression; lactic acid bacterium; Lactobacillus; Lactobacillus salivarius; mRNA expression level; MTT assay; nonhuman; nucleotide sequence; phylogenetic tree; piglet; porcine epidemic diarrhea; Porcine epidemic diarrhea virus; real time reverse transcription polymerase chain reaction; screening; Vero cell line; virus nucleocapsid; virus replication; animal; Chlorocebus aethiops; Coronavirus infection; diarrhea; dysentery; genetics; Lactobacillales; phylogeny; pig; Porcine epidemic diarrhea virus; swine disease; veterinary medicine; Animals; Antiviral Agents; Chlorocebus aethiops; Coronavirus Infections; Diarrhea; Dysentery; Interleukin-8; Lactic Acid; Lactobacillales; Phylogeny; Plant Extracts; Porcine epidemic diarrhea virus; RNA, Messenger; Swine; Swine Diseases; Tumor Necrosis Factor-alpha; Vero Cells
Type
journal article