title: Antiviral effects of a probiotic Enterococcus faecium strain against transmissible gastroenteritis coronavirus.
abstract: The enteropathogenic coronavirus transmissible gastroenteritis virus (TGEV) causes severe disease in young piglets. We have studied the protective effects of the probiotic Enterococcus faecium NCIMB 10415 (E. faecium), which is approved as a feed additive in the European Union, against TGEV infection. E. faecium was added to swine testicle (ST) cells before, concomitantly with, or after TGEV infection. Viability assays revealed that E. faecium led to a dose-dependent rescue of viability of TGEV-infected cells reaching nearly to complete protection. Virus yields of the E. faecium-treated cultures were reduced by up to three log10 units. Western blot analysis of purified TGEV revealed that the levels of all viral structural proteins were reduced after E. faecium treatment. Using transmission electron microscopy, we observed attachment of TGEV particles to the surface of E. faecium which might be a means to trap virus and to prevent infection. Increased production of nitric oxide in the cells treated with E. faecium and elevated expression of interleukin 6 and 8 pointed to stimulated cellular defense as a mechanism to fight TGEV infection.
authors.affiliation: Institute of Immunology, Freie Universität Berlin, Philippstrasse 13, 10115, Berlin, Germany.
authors.forename: Weidong
authors.initials: W
authors.lastname: Chai
authors.forename: Michael
authors.initials: M
authors.lastname: Burwinkel
authors.forename: Zhenya
authors.initials: Z
authors.lastname: Wang
authors.forename: Christiane
authors.initials: C
authors.lastname: Palissa
authors.forename: Bettina
authors.initials: B
authors.lastname: Esch
authors.forename: Sven
authors.initials: S
authors.lastname: Twardziok
authors.forename: Juliane
authors.initials: J
authors.lastname: Rieger
authors.forename: Paul
authors.initials: P
authors.lastname: Wrede
authors.forename: Michael F G
authors.initials: MF
authors.lastname: Schmidt
mesh_terms: D000821:Animal Feed; D000818:Animals; D002460:Cell Line; D002470:Cell Survival; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004032:Diet / Q000662:veterinary; D016984:Enterococcus faecium / Q000502:physiology*; D005761:Gastroenteritis, Transmissible, of Swine / Q000517:prevention & control*; D005786:Gene Expression Regulation; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D019936:Probiotics; D013552:Swine; D013737:Testis / Q000166:cytology; D005760:Transmissible gastroenteritis virus; D014776:Virus Cultivation
chemical_list: D016207:Cytokines; D009569:Nitric Oxide