Administration of microencapsulated Enterococcus faecium ABRIINW.N7 with fructo-oligosaccharides and fenugreek on the mortality of tilapia challenged with Streptococcus agalactiae

• Published in: Frontiers in veterinary science 2022-08, Vol.9, p.938380-938380
• Main Authors: Nami, Yousef, Kahieshesfandiari, Mahdi, Lornezhad, Gilda, Kiani, Amir, Elieh-Ali-Komi, Daniel, Jafari, Mahdieh, Jaymand, Mehdi, Haghshenas, Babak
• Format: Article
• Language: English
• Subjects: aquaculture; fenugreek; fructooligosaccharide; microencapsulated E. faecium; Streptococcus agalactiae; tilapia; Veterinary Science
• ISSN: 2297-1769; 2297-1769
• DOI: 10.3389/fvets.2022.938380

We investigated the probiotic potential of a microencapsulated Enterococcus faecium ABRIINW.N7 for 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 fructooligosaccharide (FOS) and fenugreek (Fk) product of optimal concentration. The FOS and Fk products were assessed in a 90-days in vivo challenge study, in which red hybrid tilapia were allocated to one of five treatments: (1) No Streptococcus agalactiae (Sa) challenge (CON); (2) Sa challenge only (CON + ); (3) Sa challenge in a free cell (Free Cell); (4) Sa challenge with 0.8% (w/v) Alginate; (5) Microencapsulated FOS and Fk. In vitro results showed high encapsulation efficiency (≥98.6 ± 0.7%) and acceptable viability of probiotic bacteria within the simulated fish digestive system and high stability of viable cells in all gel formulations (34 < SR%