Genome Features and In Vitro Activity against Influenza A and SARS-CoV-2 Viruses of Six Probiotic Strains.

PURPOSE: The aim of this work was to analyze the complete genome of probiotic bacteria Lactobacillus plantarum 8 RA 3, Lactobacillus fermentum 90 TC-4, Lactobacillus fermentum 39, Bifidobacterium bifidum 791, Bifidobacterium bifidum 1, and Bifidobacterium longum 379 and to test their activity against influenza A and SARS-CoV-2 viruses. METHODS: To confirm the taxonomic affiliation of the bacterial strains, MALDI TOF mass spectrometry and biochemical test systems were used. Whole genome sequencing was performed on the Illumina Inc. MiSeq platform. To determine the antiviral activity, A/Lipetsk/1V/2018 (H1N1 pdm09) (EPI_ISL_332798) and A/common gull/Saratov/1676/2018 (H5N6) (EPI_ISL_336925) influenza viruses and SARS-CoV-2 virus strain Australia/VIC01/2020 (GenBank: MT007544.1) were used. RESULTS: All studied probiotic bacteria are nonpathogenic for humans and do not contain the determinants of transmission-type antibiotic resistance and integrated plasmids. Resistance to antibiotics of different classes is explained by the presence of molecular efflux pumps of the MatE and MFS families. Cultures of L. fermentum 90 TC 4, L. plantarum 8 RA 3, and B. bifidum 791 showed a pronounced activity against influenza A viruses in MDCK cells. Activity against the SARS-CoV-2 virus was demonstrated only by the L. fermentum 90 TC 4 strain in VERO cells. CONCLUSIONS: The studied probiotic bacteria are safe, have antiviral activity, and are of great importance for the prevention of diseases caused by respiratory viruses that can also infect the human intestine.

Medicinal Mushrooms against Influenza Viruses.

This review provides results obtained by scientists from different countries on the antiviral activity of medicinal mushrooms against influenza viruses that can cause pandemics. Currently, the search for antiviral compounds is relevant in connection with the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Medicinal mushrooms contain biologically active compounds (polysaccharides, proteins, terpenes, melanins, etc.) that exhibit an antiviral effect. The authors present the work carried out at the State Research Center of Virology and Biotechnology Vector in Russia, whose mission is to protect the population from biological threats. The research center possesses a collection of numerous pathogenic viruses, which allowed screening of water extracts, polysaccharides, and melanins from fruit bodies and fungal cultures. The results of investigations on different subtypes of influenza virus are presented, and special attention is paid to Inonotus obliquus (chaga mushroom). Compounds produced from this mushroom are characterized by the widest range of antiviral activity. Comparative data are presented on the antiviral activity of melanin from natural I. obliquus and submerged biomass of an effective strain isolated in culture against the pandemic strain of influenza virus A/California/07/09 (H1N1 pdm09).