Effects of anEnterococcus faecium‐based probiotic on growth performance and health of Pirarucu,Arapaima gigas

Abstract

Intensive fish farming has resulted in an increased concern for disease outbreaks. Probiotic use is one of the strategies being developed to improve fish health and productivity. Measures of probiotic colonization, growth performance, haematological characteristics and parasite load were used to evaluate the effect of diets supplemented with Enterococcus faecium on growth and health of Arapaima gigas juveniles. A completely randomized design with four treatments (diet with E. faecium at 1 × 106 CFU/g and 1 × 108 CFU/g, control diet and diet with the culture medium MRS) and three replicates was used. Ninety‐six Arapaima juveniles were distributed in 12 cages fed with the specified diet for 68 days. Colonization of the intestinal tract by lactic acid bacteria reduced the total number of heterotrophic bacteria in fish fed with probiotics compared to controls. Fish fed a supplemented diet containing 1 × 108 CFU/g presented higher values of weight gain, survival and fish growth uniformity, and lower values of feed conversion ratio. The prevalence of Trichodina sp. could have affected the survival of fish in the control group. Reduction in parasite load and an increase in haematocrit, the number of erythrocytes, thrombocytes, neutrophils and monocytes were also observed in fish fed the diet containing 1 × 108 CFU/g. Enterococcus faecium presented a probiotic effect in A. gigas juveniles and can be recommended for use at a concentration of 1 × 108 CFU/g to modify the gut microbiota, improve growth performance and haematology and reduce parasitic load.

Evaluation of Dietary Probiotic Bacteria and Processed Yeast (GroPro-Aqua) as the Alternative of Antibiotics in Juvenile Olive Flounder Paralichthys olivaceus

“…In addition, B. subtilis SJ-10 was isolated from a Korean traditional fermented fish (5 fish), Jeotgal [ 18 ] and the probiotic bacteria was inoculated on LB agar at single colony and then the bacteria was transferred to a production medium at 37 °C with incubation for 16 h in a vibrating incubator (HB 201SF; Hanbaek Scientific Co., Seoul, Rep. of Korea). On the other hand, E. faecium was collected from the anterior intestine of healthy Nile tilapia (7 fish) and identified as described previously [ 29 ]. Briefly, the E. faecium was grown in de Man, Rogosa & Sharpe (MRS) broth at 36 °C for 48 h [ 40 ].…”

“…The viable number of bacterial colonies in 1 mL of aliquots was also counted using a colony counter (Suntex automatic colony counter, Taiwan) on the solid medium for establishing the growth curve of the bacterial colonies. All the live probiotic bacterial colonies were cleaned with sterile saline water and the amounts of the bacterial cells in sterile solution was adjusted at 1 × 10 8 , 1 × 10 8 and 1 × 10 7 CFU (colony forming unit)/g diets for B. subtilis WB60 [ 17 ], B. subtilis SJ-10 based on [ 18 ], and E. faecium SH30 [ 29 ], respectively.…”

“…Likewise, Chen et al [ 27 , 28 ] reported the positive effects of B. subtilis with multi-strains of probiotics in the diets of freshwater grass carp fish and whiteleg shrimp. Furthermore, the Enterococcus faecium is a Gram-positive, alpha-hemolytic or non-hemolytic bacterium which has a potential probiotic effect in aquaculture, as previously described by Da Costa Sousa et al [ 29 ]. The researchers found that the dietary supplementation of E. faecium has probiotic effects and can be used at 1 × 10 8 CFU/g to improve growth, hematology, gut microbiota, and reduce parasitic infestation in Pirarucu fish.…”

Enterococcus faecium Regulates Honey Bee Developmental Genes

“…Our study has shown the effect of E. faecium in increasing host gut weight in honey bees by regulating development-associated genes. However, as E. faecium is used in a wide variety of settings, including swine [27], chicken [26], and fish [28] production for human consumption, the safety concern of E. faecium cannot be ignored. Certain E. faecium strains cause bacteremia, endocarditis, and other infections [41].…”

“…Although E. faecium strains isolated from hospitals and others from diseased animals have been considered as opportunistic pathogens with strong antibiotic resistance [24], other strains of E. faecium have been widely used as probiotics in animal breeding. E. faecium has shown varied probiotic effects in different animals, including improving nutrient metabolism [25] and modulating the gut barrier in broiler chickens [26], reducing infection in swine [27], improving growth in fish [28], and protecting honey bees from AFB [7]. However, the molecular interactions at the transcriptional and post-transcriptional levels between probiotic E. faecium and animals remain unclear.…”