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Bacterial Pathogens and Indicators in Catfish and Pond Environments
Cheong-Kit Leung1, Yao-Wen Huang1, Oscar C Pancorbo1
1Department of Food Science and Technology, The University of Georgia, Athens, Georgia 30602.
Journal of Food Protection
|May 11, 2019
Summary
Dietary protein and feeding methods impact microbial loads in channel catfish ponds. Higher aeromonad and Pseudomonas aeruginosa counts were found in fish viscera, suggesting cross-contamination risks during processing.
Area of Science:
- Aquaculture Microbiology
- Food Safety
- Fish Processing
Background:
- Understanding microbial contamination in aquaculture is crucial for food safety.
- Channel catfish (Ictalurus punctatus) farming practices can influence bacterial presence.
- Dietary protein and feeding strategies are key variables in fish production.
Purpose of the Study:
- To investigate the effects of dietary protein levels and feeding methods on microbial populations in channel catfish.
- To quantify specific bacteria (fecal streptococci, fecal coliforms, Aeromonas hydrophila, Pseudomonas aeruginosa, Listeria spp.) on fish surfaces, viscera, water, and sediment.
- To assess the risk of cross-contamination during fish processing.
Main Methods:
- Channel catfish were fed diets with 26% or 38% protein using restricted or satiety feeding.
- Microbial analysis included fecal streptococci, fecal coliforms, Aeromonas hydrophila, Pseudomonas aeruginosa, presumptive Listeria spp., and psychrotrophic bacteria.
- Samples were collected from pond water, sediment, fish surface rinses, and fish viscera.
Main Results:
- No significant differences in fecal streptococci or fecal coliform counts were observed across sample types.
- Aeromonas hydrophila and Pseudomonas aeruginosa counts were significantly higher in fish visceral samples compared to water and sediment.
- Presumptive Listeria spp. were detected in fish visceral samples at a mean count of 1.99 log CFU/g.
- Feed protein level and feeding method significantly influenced bacterial concentrations in water, sediment, fish surface, and visceral samples.
Conclusions:
- Elevated bacterial concentrations in fish viscera indicate a high potential for cross-contamination during evisceration.
- Aquaculture management practices, including diet composition and feeding strategies, play a critical role in controlling microbial loads.
- Further research into mitigating bacterial contamination during catfish processing is warranted.
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