Impact of BL23 on the Host Transcriptome, Growth and Disease Resistance in Larval Zebrafish.

In this study, zebrafish were treated with strains as probiotics from hatching to puberty, and the effect of treatment with BL23 on the development and immunity response of the host was investigated. Genes that were differentially expressed (DEGs) in the overall body and intestine were detected at 14 days post fertilization (dpf) and 35 dpf, respectively, using whole transcriptome sequencing (mRNAseq). We showed that zebrafish raised by continuous immersion with BL23 showed a higher final body weight at 14 dpf ( < 0.

The Hepatotoxicity of Palmitic Acid in Zebrafish Involves the Intestinal Microbiota.

Background: Palmitic acid (PA) is the main saturated fatty acid naturally occurring in animal fats and vegetable oils. In recent decades, palm oil, an alternative lipid source containing high amounts of PA, has been widely used to replace fish oil in aquafeed.

Objective: We investigated the hepatotoxicity of PA in zebrafish and the underlying mechanism.

Anti-Infective Effect of Adhesive Probiotic Lactobacillus in Fish is Correlated With Their Spatial Distribution in the Intestinal Tissue.

In this study, we tested the distribution of 49 Lactobacillus strains in the mucus and mucosa of the intestine tissue of zebrafish. We observed a progressive change in the spatial distribution of Lactobacillus strains, and suggested a division of the strains into three classes: mucus type (>70% in mucus), mucosa type (>70% in mucosa) and hybrid type (others). The hybrid type strains were more efficient in protection of zebrafish against Aeromonas hydrophila infection.

Antibiotic growth promoter olaquindox increases pathogen susceptibility in fish by inducing gut microbiota dysbiosis.

Low dose antibiotics have been used as growth promoters in livestock and fish. The use of antibiotics has been associated with reduced pathogen infections in livestock. In contrast, antibiotic growth promoter has been suspected of leading to disease outbreaks in aquaculture.

The Growth-Promoting Effect of Dietary Nucleotides in Fish Is Associated with an Intestinal Microbiota-Mediated Reduction in Energy Expenditure.

Nucleotides have been used as functional nutrients to improve the growth and health of animals, including fish. The mechanism involved in the growth-promotion effect of nucleotides is still unclear. We investigated the bioenergetic mechanism underlying the growth-promotion effect of nucleotides in zebrafish and the associated roles played by the intestinal microbiota.

Effects of dietary live and heat-inactive baker's yeast on growth, gut health, and disease resistance of Nile tilapia under high rearing density.

In this study, the effects of baker's yeast as probiotics was evaluated in Nile tilapia reared at high density. Juvenile tilapia were distributed to tanks at high density (436 fish/m(3)) and fed with basal diet (CK) or diets supplemented with live (LY) or heat-inactivated yeast (HIY). Another group of fish reared at low density (218 fish/m(3)) and fed with basal diet was also included (LowCK).

[Characterization of an exo-chitinase from a Citrobacter strain isolated from the intestine content of large yellow croakers].

Objective: We isolated bacterial strains with chitin-degrading activity from the digesta of large yellow croakers (Pseudosciaena crocea) fed with chitin-enriched trash fish, and characterized potential chitinases thereof.

Methods: Chitin-degrading strains were screened with colloidal chitin agar from the digesta of P. crocea fed with trash fish.

Dietary microbial phytase exerts mixed effects on the gut health of tilapia: a possible reason for the null effect on growth promotion.

The present study evaluated the effects of dietary microbial phytase on the growth and gut health of hybrid tilapia (Oreochromis niloticus ♀×Oreochromis aureus ♂), focusing on the effect on intestinal histology, adhesive microbiota and expression of immune-related cytokine genes. Tilapia were fed either control diet or diet supplemented with microbial phytase (1000 U/kg). Each diet was randomly assigned to four groups of fish reared in cages (3×3×2 m).

Thymol and Carvacrol Affect Hybrid Tilapia through the Combination of Direct Stimulation and an Intestinal Microbiota-Mediated Effect: Insights from a Germ-Free Zebrafish Model.

Background: Essential oils (EOs) are commonly used as animal feed additives. Information is lacking on the mechanisms driving the beneficial effects of EOs in animals, especially the role played by the intestinal microbiota of the host.

Objective: The purpose of this study was to clarify the relative contribution of direct effects of EOs on the physiology and immune system of tilapia and indirect effects mediated by the intestinal microbiota by using a germ-free zebrafish model.

Effects of dietary yeast nucleotides on growth, non-specific immunity, intestine growth and intestinal microbiota of juvenile hybrid tilapia ♀ × ♂.

This study investigated the effect of dietary supplementation of yeast nucleotides on the growth, non-specific immunity, intestine growth and intestinal microbiota of juvenile hybrid tilapia. Tilapia (initial average weight of 8.02 g) was fed test diets supplemented with a yeast-originated nucleotide mixture (0, 0.

A Novel Lipase as Aquafeed Additive for Warm-Water Aquaculture.

A novel Acinetobacter lipase gene lipG1 was cloned from DNA extracted from intestinal sample of common carp (Cyprinus carpio), and expressed in E. coli BL21. The encoded protein was 406 amino acids in length.

Comparison of fecundity and offspring immunity in zebrafish fed Lactobacillus rhamnosus CICC 6141 and Lactobacillus casei BL23.

To increase the knowledge of probiotic effects on zebrafish (Danio rerio), we compare the effects of two probiotic strains, Lactobacillus rhamnosus CICC 6141 (a highly adhesive strain) and Lactobacillus casei BL23 (a weakly adhesive strain), on zebrafish reproduction and their offsprings' innate level of immunity to water-borne pathogens. During probiotics treatments from 7 to 28 days, both the Lactobacillus strains, and especially L. casei BL23, significantly increased fecundity in zebrafish: higher rates of egg ovulation, fertilization, and hatching were observed.

High-yield production of a chitinase from Aeromonas veronii B565 as a potential feed supplement for warm-water aquaculture.

Chitin, present in crustacean shells, insects, and fungi, is the second most plentiful natural organic fiber after wood. To effectively use chitin in a cost-saving and environmentally friendly way in aquaculture, crustacean shells (e.g.

Lactobacillus planarum subsp. plantarum JCM 1149 vs. Aeromonas hydrophila NJ-1 in the anterior intestine and posterior intestine of hybrid tilapia Oreochromis niloticus ♀ × Oreochromis aureus ♂: an ex vivo study.

To investigate the ex vivo interactions of probiotic-pathogen-host in warm-water fish, hybrid tilapia (Oreochromis niloticus♀ × Oreochromis aureus♂) were sacrificed to isolate anterior and posterior intestine for incubation with phosphate-buffered saline (PBS; pH 7.2) as the control, Lactobacillus plantarum JCM 1149 at 1.0 × 10(9) CFU/ml, Aeromonas hydrophila NJ-1 at 1.

Comparison of adhesive gut bacteria composition, immunity, and disease resistance in juvenile hybrid tilapia fed two different Lactobacillus strains.

This study compares the effects of two Lactobacillus strains, highly adhesive Lactobacillus brevis JCM 1170 (HALB) and less-adhesive Lactobacillus acidophilus JCM 1132 (LALB), on the survival and growth, adhesive gut bacterial communities, immunity, and protection against pathogenic bacterial infection in juvenile hybrid tilapia. During a 5-week feeding trial the fish were fed a diet containing 0 to 10(9) cells/g feed of the two Lactobacillus strains. Samples of intestine, kidney, and spleen were taken at the start and at 10, 20, and 35 days for analysis of stress tolerance and cytokine gene mRNA levels and to assess the diversity of adhesive gut bacterial communities.

Do dietary betaine and the antibiotic florfenicol influence the intestinal autochthonous bacterial community in hybrid tilapia (Oreochromis niloticus ♀ × O. aureus ♂)?

The attractant betaine and the antibiotic growth promoter florfenicol are commonly used together in Chinese fresh water aquaculture, but there is no information about the effect of these two feed additive on the intestinal autochthonous bacterial community in hybrid tilapia (Oreochromis nilotica ♀ × O. aureas ♂). Hybrid tilapia (240 fish in total; 20 fish per net cage; three cages per group) were divided into four dietary groups: control group, no betaine or florfenical addition (CK); betaine group, 0.

Orally administered thermostable N-acyl homoserine lactonase from Bacillus sp. strain AI96 attenuates Aeromonas hydrophila infection in zebrafish.

N-Acylated homoserine lactone (AHL) lactonases are capable of degrading signal molecules involved in bacterial quorum sensing and therefore represent a new approach to control bacterial infection. Here a gene responsible for the AHL lactonase activity of Bacillus sp. strain AI96, 753 bp in length, was cloned and then expressed in Escherichia coli.

A Chitinase from Aeromonas veronii CD3 with the potential to control myxozoan disease.

Background: The class Myxosporea encompasses about 2,400 species, most of which are parasites of fish and cause serious damage in aquaculture. Due to the concerns about food safety issues and limited knowledge of Myxozoa life cycle and fish immune system, no chemicals, antibiotics or immune modulators are available to control myxozoa infection. Therefore, little can be done once Myxozoa establishment has occurred.

Gut microbial status induced by antibiotic growth promoter alters the prebiotic effects of dietary DVAQUA® on Aeromonas hydrophila-infected tilapia: production, intestinal bacterial community and non-specific immunity.

The purpose of the present study was to investigate whether dietary antibiotic-induced changes in the fish intestinal microbiota altered host physiological responses to the infection with Aeromonas hydrophila in hybrid tilapia (Oreochromis niloticus ♀ × O. aureus ♂). After an 8-week induction period with an antibiotic-supplemented or antibiotic-non-supplemented diet, 160 hybrid tilapias in 16 tanks were each injected with phosphate buffered saline (PBS) or A.

Effects of the antibiotic growth promoters flavomycin and florfenicol on the autochthonous intestinal microbiota of hybrid tilapia (Oreochromis niloticus ♀ × O. aureus ♂).

The 16S rDNA PCR-DGGE and rpoB quantitative PCR (RQ-PCR) techniques were used to evaluate the effects of dietary flavomycin and florfenicol on the autochthonous intestinal microbiota of hybrid tilapia. The fish were fed four diets: control, dietary flavomycin, florfenicol and their combination. After 8 weeks of feeding, 6 fish from each cage were randomly chosen for the analysis.