Culturable gut microbiota diversity in zebrafish

Area of Science:

• Microbiology
• Animal Science
• Aquatic Biology

Background:

• Zebrafish (Danio rerio) are vital models in research, increasing the need for optimized husbandry.
• Limited understanding exists on zebrafish intestinal microbiota and its relation to environmental factors and management.
• Culturable intestinal microbiota profiles can serve as indicators of zebrafish health and welfare.

Purpose of the Study:

• To characterize the culturable intestinal microbiota of zebrafish from different laboratories.
• To investigate correlations between microbiota composition and environmental/management factors.
• To assess the potential of microbiota analysis as a husbandry quality measure.

Main Methods:

• Bacterial culture, biochemical characterization, and 16S rDNA gene sequencing were employed.
• Antibiotic susceptibility testing was performed on Gram-negative isolates.
• Data were analyzed to correlate bacterial growth with laboratory, fish maturity, and intestinal segment.

Main Results:

• Thirteen prevalent bacterial species were identified, including Aeromonas, Vibrio, Pseudomonas, and Staphylococcus.
• Laboratory B showed significantly higher total bacterial growth compared to Lab A.
• Immature zebrafish and the posterior intestinal segment exhibited higher bacterial loads.

Conclusions:

• Zebrafish intestinal microbiota is influenced by husbandry practices and fish developmental stage.
• A diagnostic bacteriological assay for culturable microbiota can be a valuable tool for assessing zebrafish facility husbandry.
• Standardizing bacterial profiles can enhance zebrafish health and welfare in research settings.