AUTHOR=Wang Xiaoli , Hao Guijuan , Zhou Meng , Chen Meng , Ling Hongli , Shang Yingli 

TITLE=Secondary metabolites of Bacillus subtilis L2 show antiviral activity against pseudorabies virus

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1277782

DOI=10.3389/fmicb.2023.1277782

ISSN=1664-302X

ABSTRACT=<p><italic>Bacillus subtilis</italic> (<italic>B. subtilis</italic>) is a commercially important probiotic known to produce secondary metabolites with antibacterial, antifungal and anti-inflammatory activities. However, the potential ability of <italic>B. subtilis</italic> to combat viruses, especially DNA viruses, has not been extensively investigated. In this study, we identified two distinct <italic>B. subtilis</italic> strains and examined the efficiency of their secondary metabolites against pseudorabies virus (PRV), a swine herpesvirus resulting in economic losses worldwide. We found that treatment with the secondary metabolites of <italic>B. subtilis</italic> L2, but not the metabolites of <italic>B. subtilis</italic> V11, significantly inhibited PRV replication in multiple cells. Notably, the antiviral activity of the metabolites of <italic>B. subtilis</italic> L2 was thermal stable, resistant to protease digestion. Moreover, these metabolites effectively impeded PRV binding, entry and replication. Importantly, oral administration of the metabolites of <italic>B. subtilis</italic> L2 protected mice from lethal PRV infection, rescuing weight loss and reducing the viral load <italic>in vivo</italic>. In summary, our results reveal that the metabolites of <italic>B. subtilis</italic> L2 exhibit anti-PRV activity both <italic>in vitro</italic> and <italic>in vivo</italic>, providing a potential candidate for novel antiviral drugs.</p>