Effects ofBacillus subtilisstrains and the prebiotic Previda^®on growth, immune parameters and susceptibility toAeromonas hydrophilainfection in Nile tilapia,Oreochromis niloticus

Abstract

This study was conducted to evaluate the individual and combined effects of long-term feeding of diets containing two probiotic Bacillus subtilis group strains (Aqua NZ and AP193) and the prebiotic Previda â , a commercial hemicellulose extract, on growth performance, immune parameters and Aeromonas hydrophila susceptibility of juvenile Nile tilapia, Oreochromis niloticus. Nile tilapia of average weight 7.47 AE 0.11 g were fed diets formulated with the probiotics and/or the prebiotic, or a control diet for 8 weeks and, subsequently, challenged with A. hydrophila by intragastric gavage at a dosage of 3.9 9 10 7 CFU per fish. Fish attained a mean weight of 59.5 AE 0.99 g at the end of the growth period. Under the conditions of the present trial, none of the diets significantly improved mean per cent weight gain (P = 0.70), thermal growth coefficient (P = 0.88) or feed conversion ratio (P = 0.87) of Nile tilapia. Except for the diet containing the prebiotic Previda â only (P = 0.17), all other diets resulted in significantly higher fish survival compared to the control (P < 0.05). The combined effect of the prebiotic and probiotic strains emerged as the most important diet with respect to mortality reduction. The mean lysozyme and respiratory burst activities did not show any significant differences between treatments and control (P = 0.14 and 0.32, respectively). Thus, these probiotic strains used in this study have the potential to prevent disease due to A. hydrophila in O. niloticus.

Untitled

“…In this work, no significant differences in fish survival between treatments were observed, but Addo et al (2017) observed a significant effect of the addition of probiotic B. subtilis on feeding (for 56 days) on the survival of Nile tilapia after challenge of oral infection with Aeromonas hydrophila. The effect of probiotics on the host is also related to feeding time and the type of stress caused.…”

“…count, in which probiotic treatments in the feed and control displayed lower results than the probiotic treatment in water. The effect of probiotics on growth performance in tilapia and other fish may be related to different interactions between probiotics, intestinal microbiota and host (Addo et al, 2017).…”

Autochthonous probiotic as growth promoter and immunomodulator forAstyanax bimaculatuscultured in water recirculation system

“…On the other hand, Addo et al. () found no statistical difference in the zootechnical parameters of O. niloticus after 8 weeks of feeding with diet containing Bacillus subtilis supplemented, or not, with Previda ® prebiotic.…”

“…Among the microorganisms used for this purpose, lactic acid bacteria are gram‐positive enterobacteria that produce lactic acid as the main product of their fermentation (Calo‐Mata et al., ). In recent years, several studies have demonstrated the ability of probiotics to improve the immune system of animals, especially when applied during the early stages of development (Addo et al., ; Dawood et al., ; Jatobá & Mouriño, ; Jatobá et al., ; Pereira et al., ; Pourgholam, Khara, Safari, Sadati, & Aramli, ).…”

Dietary administration of probiotics modulates non-specific immunity and gut microbiota of Nile tilapia (Oreochromis niloticus) cultured in low input ponds

“…In the past decade, interest in the use of probiotics for modulation of the non-specific immune system of fish against diseases has been increasing [19][20][21][22][23][24]. Dietary administration of bakers' yeast, Saccharomyces cerevisiae and Bacillus subtilis have been used to improve immune response in different species of fish [21,[23][24][25][26][27][28][29][30][31]. However, despite these studies, it is still worth noting that the application of probiotics in low input ponds remain unknown yet their effects could be more striking in poor conditions exhibited in low input ponds [32].…”