4.6 Article

Bacterial survey of skin ulcers in Anguilla anguilla L. females during artificial maturation under controlled conditions

Journal

AQUACULTURE REPORTS
Volume 25, Issue -, Pages -

Publisher

ELSEVIER
DOI: 10.1016/j.aqrep.2022.101259

Keywords

Artificial reproduction; Bacterial flora; Ulcerative ulcer; European eel; Mortality

Categories

Funding

  1. [OR14-61724-OR1400003/09/10/11]

Ask authors/readers for more resources

Controlled indoor reproduction of European eel is considered a promising method to prevent the extinction of this fish species. Limited information is available on the diversity of bacterial microflora in European eel during long maturation under changing temperature and salinity conditions. Changes in the bacterial microflora during indoor reproduction may increase the risk of bacterial infection, especially during the freshwater phase of female maturation.
Controlled indoor reproduction of European eel is commonly recognized as a prospective tool to prevent extinction of this fish species. There is a little information about diversity of bacterial microflora of European eel during long maturation under controlled but changing thermal and salinity conditions. Characteristics of the composition of the bacterial microflora inhabiting the body surface of fish kept firstly in fresh and then in salt water, may help enhance the survival of spawners and spawning efficiency. Knowledge about the presence of potentially pathogenic bacterial species and their antibiotic resistance is particularly important. Methods: This study analyzed the bacterial microflora of two types of necrotic changes on the skin of eel females during artificial maturation under fresh and saltwater conditions. Results: A total of two hundred and forty bacterial strains were isolated from necrotic dermal changes on fish in freshwater and saltwater conditions. Both the bacterial number and biodiversity were greater in freshwater than in saltwater. Psychrophilic bacterial strains in freshwater were twice as abundant as in saltwater, especially among isolates which were cultured from the mucus or from ulcerative changes around the chip injection point (up to 10(10) cfu/mL). 16 S ribosomal RNA gene sequencing of isolates from the freshwater conditions revealed the presence of twenty genera of bacteria, including: Pseudomonas sp., Comamonas sp., Escherichia sp., Aeromonas sp., Citrobacter sp., Burkholderia sp., Pantoea sp., Enterobacter sp., Yersinia sp., Edwardsiella sp., Serratia sp., Bordetella sp., Morganella sp. and Chromobacterium sp. In saltwater conditions, five genera of bacteria were found dominantly: Pseudomonas sp., Aeromonas sp., Yersinia sp., Vibrio sp., Edwardsiella sp. In freshwater conditions, the bacteria were mostly resistant or resistant to all tested antimicrobial drugs. Conclusions: Changes in bacterial microflora during controlled indoor reproduction of European eel predispose fish to bacterial infection especially during the first freshwater step of female maturation. New, alternative to antibiotic therapy, methods should be adopted to prevent infections and enhance spawning efficiency.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available