Selection of autochtone probiotic for Astyanax bimaculatus

Abstract

This study aimed to isolate native lactic acid bacteria of yellow tail lambari (Astyanax bimaculatus) and evaluate their effect on host microbiota and gut morphology, as well as survival after experimental challenge. The isolated bacterial strains were evaluated for their inhibition against pathogenic bacterial strains in vitro, and the strain with highest inhibitory ability was molecularly identified as Lactobacillus spp. For in vivo testing, eighty fish were distributed in ten tanks equipped with a recirculation system. The experimental units were divided into two treatments: fish fed with Lactobacillus spp. supplement and fish fed an unsupplemented diet (control). After 30 days, guts from three fish from each experimental unit were pooled for microbiological and histological analysis. The other five fish were inoculated with 2.1x10 4 CFU.mL -1 of Aeromonas hydrophila to evaluate survival after 24h. Lambaris fed with the probiotic diet had a lower count of Vibrios spp., Pseudomonas spp. and Staphylococcus spp., and a higher count of lactic acid bacteria compared to control treatment, as well as, increased length, width and perimeter of intestinal villi, as well as higher survival rate (16.2%) after experimental challenge compared to the unsupplemented group. The results show that the Lactobacillus spp. used has effect probiotic for yellow tail lambari.Keywords: Lactobacillus, yellow tail lambari, gut morphology, microbiota, experimental challenge RESUMO Este estudo objetivou isolar bactéria ácido-láctica nativa do lambari-do-rabo-amarelo (Astyanax bimaculatus) e seu efeito na microbiota e morfologia do trato digestório do hospedeiro, assim como a sobrevivência após um desafio experimental. As bactérias isoladas foram avaliadas quanto a suas inibições in vitro

Frequency in the supply of Lactobacillus influence its probiotic effect for yellow tail lambari

“…However, several authors observed greater weight gain and weekly growth in conjunction with better AFE and/or FC (JATOBÁ et al, 2011;CORNÉLIO et al, 2013;JATOBÁ & MOURIÑO 2015;SCHWARZ et al, 2016;YAMASHITA et al, 2017), despite Lactobacillus spp. (same strain) to increase the villus length and number of villi in the intestinal mucosa of lambari of the yellow tail (JATOBÁ et al, 2017), in this research no better absorption of nutrients was observed.…”

“…Nile tilapia supplemented with Bacillus subtilis and B. cereus obtained a better percentage of relative survival and also improving intestinal morphology (MELLO et al, 2013), the same was observed for yellow tail lambari fed with probiotic Lactobacillus spp. (same strain used in this study) that survival rate was 16.2% higher after experimental challenge against Aeromonas hydrophila compared to the unsupplemented group (JATOBÁ et al, 2017). Due to the changes presented in the intestinal microbiota in this study it is suggested higher resistance of the animals fed with probiotic against bacterial infections.…”

“…The Lactobacillus strain CPQBA 1168-15 DRM-01 with proven probiotic effect in vitro and in vivo (JATOBÁ et al, 2017) and 1200 yellow tail lambari (A. bimaculatus), average weight 1.0±0.2g, were used.…”

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

“…In a previous study, Jatoba et al. () observed a decrease in the concentrations of Vibrios spp., Pseudomonas spp. and Staphylococcus spp., and increased lactic acid bacteria compared with control, as well as increased length, width and perimeter of intestinal villi for A. bimaculatus fed diet supplemented with Lactobacillus spp.…”

“…The research was approved by the National Council for the Control of Animal Experimentation (CONCEA) under protocol number 0006/2013. The experimental design was completely randomized, using the Lactobacillus spp.strain CPQBA 1168‐15 DRM‐01 with proven probiotic effect in vitro and in vivo (Jatoba, Moraes, Steckert, & Jesus, ), indigenous A. bimaculatus , and 800 postlarvae of the species, with a mean weight of 0.19 ± 0.22 g, distributed into eight experimental units (800 L polyethylene containers) of 100 fish each and equipped with a recirculation aquaculture system (RAS) and biological filter.…”