Administration of Microencapsulated Enterococcus Faecium ABRIINW.N7 With Fructo- Oligosaccharides and Fenugreeko the Mortality of Tilapia Challenged with Streptococcus Agalactiae

Abstract

The aim of study was to examine the probiotic potential of a microencapsulated E. faecium ABRIINW.N7 in the control of Streptococcus agalactiae infection in hybrid (Oreochromis niloticus × Oreochromis mossambicus) red tilapia. A two-phase experiment approach was completed in which E. faecium bacteria were propagated, from which a culture was isolated, identified using molecular techniques, and microencapsulated to produce a stable commercial fructo-oligosaccharides (FOS) and fenugreek (Fk) product of optimal concentration. This FOS and Fk product was assessed in a 12-week in vivo challenge study completed, in which red hybrid tilapia were allocated to one of five treatments: No Streptococcus agalactiae (Sa) challenge (G01) (CON); Sa challenge only (G02) (CON+); Sa challenge in a free cell (Free Cell) G03; Sa challenge with 2% (w/v) Alginate (G04); Microencapsulated FOS and Fk (G05-G011). In vitro results showed a high encapsulation efficiency and acceptable viability of probiotic bacteria within the simulated fish digestive system and high stability of viable cells in all gel formulations. In vivo challenges demonstrated that the G05-G011 FOS and Fk product could be used to control tilapia fish infected with S. agalactiae and represented a novel investigation using microencapsulation E. faecium as a probiotic diet tilapia fish to control S. agalactiae and lower fish mortality. It is recommended that local herbal gums such as PG and Fk in combination with ALG can be used as a suitable scaffold and an ideal matrix for the encapsulation of probiotics. These herbal gums as prebiotic also promote the growth of probiotic cells in the food environment and digestive tract.