Mansoura Veterinary Medical Journal

Investigation Of Nile Tilapia Mortalities During Summer 2019 In El-Manzala Fish Farms In Dakahlia Governorate, Egypt

Amira M. M. EL- Sherbiny, Veterinary Teaching Hospital, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt.Follow
Moustafa M. S. Fouda, Department of Aquatic Animal Medicine, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt
Medhat S. Shakweer, Department of Aquatic Animal Medicine, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt
Viola H. Zaki, Department of Aquatic Animal Medicine, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt

Corresponding Author

Amira Mohamed Mohamed El- Sherbiny

Document Type

Original Article

Subject Areas

Aquatic medicine

Keywords

Nile tilapia, A. hydrophila, Histopathology, Antibiogram.

Abstract

Objective: To identify suspected causes of mass mortality in Oreochromis niloticus at El-Manzala fish farms in Dakahlia Governorate, Egypt, during disease outbreaks in the summer of 2019.

Design: Observational study.

Animals: Two hundred diseased and freshly dead Oreochromis niloticus (Nile tilapia) weighting 100-150 g.

Procedures: Collected fish samples were subjected to clinical, postmortem and bacteriological investigations regarding histopathological alterations, pathogenicity tests, and antibiogram susceptibility of the main isolated bacterial species.

Results: A total of 286 bacterial isolates were detected from all examined fish samples. Bacteriological examination revealed that all bacteria were gram-negative rods, which were identified as A. hydrophila (43.36%), A. sobria (20.28%), V. fluvialis (12.24%), V. parahemolyticus (10.14%), V. cholera (7.34%) and Ps. putida (4.895%). Confirmatory identification of the most predominant isolated species (A. hydrophila) was carried out using conventional PCR. An antibiogram was performed for the isolated A. hydrophila strains, revealing that the isolates showed high sensitivity to flumequine (UB) and cefepime (FEP), with a percent (83.33%) for each. The Multiple Antibiotic Resistance (MAR) indices of the 12 identified A. hydrophila ranged from 0.2 to 0.6 with an average (0.32).

Conclusion and clinical relevance: This study concluded that A. hydrophila is one of the main causes of summer mass mortality in O. niloticus in the study area.

How to Cite This Article

EL- Sherbiny, Amira M. M.; Fouda, Moustafa M. S.; Shakweer, Medhat S.; and Zaki, Viola H. (2023) "Investigation Of Nile Tilapia Mortalities During Summer 2019 In El-Manzala Fish Farms In Dakahlia Governorate, Egypt," Mansoura Veterinary Medical Journal: Vol. 24: Iss. 3, Article 11.
DOI: https://doi.org/10.35943/2682-2512.1012