Dextrans produced by lactic acid bacteria exhibit antiviral and immunomodulatory activity against salmonid viruses. (25th June 2015)

• Record Type: Journal Article
• Authors: Nácher-Vázquez, Montserrat; Ballesteros, Natalia; Canales, Ángeles; Rodríguez Saint-Jean, Sylvia; Pérez-Prieto, Sara Isabel; Prieto, Alicia; Aznar, Rosa; López, Paloma
• Is Part Of: Carbohydrate polymers. Volume 124(2015)
• Page Start: 292
• Page End: 301
• Publication Date: 2015-06-25
• Subjects: Lactic acid bacteria -- Exopolysaccharide -- Dextran -- Antiviral -- Immunostimulants -- Salmonid virus -- IPNV -- IHNV; BF-2 bluegill fry -- CC50 dextran concentration provoking 50% inhibition of cell growth -- CDM defined medium containing 0.8% glucose -- CDMS CDM without glucose and supplemented with 0.8% sucrose -- TCID50 mL−1 virus titer infecting 50% of the cell culture -- DOSY diffusion ordered spectroscopy -- EC50 dextran concentration reducing the viral cytopathic effect to 50% of control value -- EPC epithelioma papulosum cyprinid -- EPS exopolysaccharide -- FBS fetal bovine serum -- HK head kidney -- IHNV infectious hematopoietic necrosis virus -- IPNV infectious pancreatic necrosis virus -- IR infrared, LAB, lactic acid bacteria -- MM L15 medium with 2% FBS -- MOI multiplicity of infection -- MRS Man Rogosa Sharpe broth -- MRSS MRS medium supplemented with 2% sucrose instead of glucose -- NMR nuclear magnetic resonance -- PBS Phosphate buffered saline -- qPCR quantitative real time PCR polymerase change reaction -- RT-qPCR reverse transcription qPCR -- SI selective index; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2015.02.020
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Dextrans from 2 Gram positive bacteria were tested for activity vs 2 salmonid viruses. Both had in vitro activity (1.0 mg mL −1 ) vs infectious pancreatic necrosis virus. Lb. sakei dextran had best in vitro activity (500 μg mL −1 ) vs . hematopoietic necrosis virus. A range of commercial dextrans had little or no antiviral activity. Lb. sakei dextran pretreatment markedly increased survival in trout infected with either virus. Abstract: Viral infections in the aquaculture of salmonids can lead to high mortality and substantial economic losses. Thus, there is industrial interest in new molecules active against these viruses. Here we describe the production, purification, and the physicochemical and structural characterization of high molecular weight dextrans synthesized by Lactobacillus sakei MN1 and Leuconostoc mesenteroides RTF10. The purified dextrans, and commercial dextrans with molecular weights ranging from 10 to 2000 kDa, were assayed in infected BF-2 and EPC fish cell-line monolayers for antiviral activity. Only T2000 and dextrans from MN1 and RTF10 had significant antiviral activity. This was similar to results obtained against infectious pancreatic necrosis virus. However the dextran from MN1 showed ten-fold higher activity against hematopoietic necrosis virus than T2000. In vivo assays using the MN1 polymer confirmed the in vitro results and revealed immunomodulatory activity. These results together with the high levels of dextran production (2 g L −1 ) by Lb. sakei MN1, indicate the compounds potential utility as an antiviral agent in aquaculture.