Investigating dynamics, etiology, pathology, and therapeutic interventions of Caligus clemensi and Vibrio alginolyticus co-infection in farmed marine fish
Abdelsalam, M.; Attia, M.M.; Marzouk, M.S.; Korany, M.S.; Elgendy, M.Y.; Soliman, A.W.; Prince, A.; Hamada, A.H. (2024). Investigating dynamics, etiology, pathology, and therapeutic interventions of Caligus clemensi and Vibrio alginolyticus co-infection in farmed marine fish. NPG Scientific Reports 14(1). https://dx.doi.org/10.1038/s41598-024-70528-x
In: Scientific Reports (Nature Publishing Group). Nature Publishing Group: London. ISSN 2045-2322; e-ISSN 2045-2322, more
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| Keyword |
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| Author keywords |
Caligus clemensi, Vibrio alginolyticus, European seabass, Flathead grey mullet, aquaculture, secondary infections, nature-identical compound, probiotics |
| Authors | | Top |
- Abdelsalam, M.
- Attia, M.M.
- Marzouk, M.S.
- Korany, M.S.
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- Elgendy, M.Y.
- Soliman, A.W.
- Prince, A.
- Hamada, A.H.
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| Abstract |
This study investigated a disease outbreak characterized by caligid copepod infestations and subsequent secondary bacterial infections in European seabass (Dicentrarchus labrax) and fathead grey mullet (Mugil cephalus) cultivated at a private facility in the Deeba Triangle region of Egypt. Moribund fsh displayed brown spots on the skin, tongue, and gills, along with lethargy and excess mucus. The fsh sufered severe infections, exhibiting external hemorrhages, ulcers, and ascites. The fsh had pale, enlarged livers with hemorrhaging. Comprehensive parasitological, bacteriological, molecular, immunity and histopathological analyses were conducted to identify the etiological agents and pathological changes. Caligid copepod infestation was observed in wet mounts from the buccal and branchial cavities of all examined fsh, and the caligids were identifed as Caligus clemensi through COI gene sequencing and phylogenetic analysis. Vibrio alginolyticus was confrmed as a secondary bacterial infection through biochemical tests, recA gene sequencing, and phylogenetic analyses. Antibiotic susceptibility testing revealed resistance to β-lactams, aminoglycosides, and trimethoprim-sulfamethoxazole in V. alginolyticus isolates. Upregulation of the infammatory marker IL-1β in gill and skin tissues indicated a robust cell-mediated immune response against the pathogens. Histopathological examination revealed severe tissue damage, hyperplasia, hemorrhage, and congestion in the gills, along with hepatocellular degeneration and steatosis in the liver, providing initial insights into this outbreak. A comprehensive therapeutic regimen was implemented, comprising prolonged hydrogen peroxide immersion baths, followed by the application of the nature-identical plant-based compound Lice-less and probiotic Sanolife Pro-W supplementation. This integrated approach efectively eliminated C. clemensi infestations, controlled secondary bacterial infections, and restored fsh health, reducing morbidity and mortality rates to minimal levels. |
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