Antiviral Effects of a Probiotic Metabolic Products against Transmissible Gastroenteritis Coronavirus

The Transmissible Gastroenteritis Virus (TGEV) causes severe diarrhea and other symptoms which end up in death in young piglets. We have studied the protective effects of the probiotic Lactobacillus plantarum strain N4(Lp) which metabolic products were added to the swine testis (ST) cells with three different orders using MTT cell proliferation assay and CPE analysis. Metabolic products led to dose-dependent rescue of viability of infected cells in a certain order: pre-treatment, post-infection, co-incubation. Pre-treatment of cells with probiotic metabolic products reduced viral proliferation up to 78% at non-cytotoxic concentration 1/4 dilution. The viral yields in pretreatment groups were reduced by over three log10 units. Quantitative real-time PCR revealed the optimal inhibition of TGEV RNA replication was 24 h apply pretreatment way that up to 71% of N gene. Analysised the composition of metabolic products by GC-MS revealed the major component is sugars. Then Exopolysaccharides (EPS) was extracted and showed inhibition effect that co-incubation with TGEV.