scholarly journals Meningoencephalitis in farmed monosex Nile tilapia (Oreochromis niloticus L.) caused by Streptococcus agalactiae

2017 ◽  
Vol 25 (3) ◽  
pp. 187-200 ◽  
Author(s):  
Harresh Adikesavalu ◽  
Sayani Banerjee ◽  
Avijit Patra ◽  
Thangapalam Jawahar Abraham

Abstract Aquaculture of tilapia is a new research venture in India. With intensification in farming practices, tilapia are increasingly susceptible to bacterial infections. This article describes the isolation and identification of pathogenic bacteria from cultured monosex Nile tilapia, Oreochromis niloticus (L.), that experienced moderate to severe mortalities in West Bengal, India between September and August 2014 and histopathological alterations in various organs. Gram-positive diplococci, identified as Streptococcus agalactiae with Streptococcus identification kits and 16S rDNA sequencing analysis, were isolated from the brain, operculum, and kidney. Other bacteria from the kidney were identified as Aeromonas sobria, A. caviae, Klebsiella pneumoniae ssp. pneumoniae, Escherichia coli, and Enterobacter cloacae. Staphylococcus epidermis was isolated from opercular hemorrhages. Histological sections of the infected tilapia brain revealed meningoencephalitis and granulomatous lesions. Sections from other organs indicated congestion, hemorrhagic and hyperplastic cells, necrosis, vacuolation, hemosiderin deposition, hypertrophic nuclei, melanomacrophage aggregation, and ruptured veins. This report is the first description of S. agalactiae as a primary pathogen causing meningoencephalitis in cultured tilapia in India.

2020 ◽  
Vol 21 (3) ◽  
pp. 61-66
Author(s):  
Ola Hashem ◽  
Viola Zaki ◽  
Rawia Adawy

Objective: To study the incidence and seasonal dynamics of different fungi affected freshwater fishes in Lake Manzala with molecular identification of the isolated fungi. Animals: 300 Nile tilapia (Oreochromis niloticus) and 300 catfish (Clarias gariepinus). Design: Descriptive study. Procedures: Random samples of Oreochromis niloticus (O. niloticus) and Clarias gariepinus (C. gariepinus) were collected from Manzala fish farms. Clinical and postmortem examination of fish was applied. Isolation and identification of different fungi were performed by conventional methods. Furthermore, the molecular characterization of isolated fungi was carried out. Results: C. gariepinus had a higher rate of infection with different fungal species than O. niloticus. Aspergillus spp. (Aspergillus niger and Aspergillus flavus) were the most fungal isolated from the examined fishes, followed by Penicillium spp. and Candida albicans. Aspergillus spp were detected in all seasons with a higher rate in summer and spring. A. flavus, A. niger, Penicillium spp. and C.albicans isolates were amplified from both C. gariepinus and O. niloticus at the specified molecular weight using PCR. Conclusion and clinical relevance: Fungal infection affected the fish showing different external and internal lesions, all species of Aspergillus were found in all seasons with a high rate in, hot seasons, summer and spring. The Prevalence of Penicillium and C. albicans were also reported. All fungal isolates were identified on the phenotypic and molecular bases.


Aquaculture ◽  
2016 ◽  
Vol 454 ◽  
pp. 237-242 ◽  
Author(s):  
Guilherme Campos Tavares ◽  
Frederico Augusto de Alcântara Costa ◽  
Raquel Ribeiro Dias Santos ◽  
Gustavo Morais Barony ◽  
Carlos Augusto Gomes Leal ◽  
...  

Elkawnie ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 222
Author(s):  
Opik Taupik Kurahman ◽  
Astri Yuliawati ◽  
Lusi Haerunnisa ◽  
Ateng Supriyatna ◽  
Tri Cahyanto ◽  
...  

Abstract: In the hadith, Rasulullah SAW prohibit human to consume meat and milk from manure-eating animal (Jallalah animal). In this study, tilapia fishes were fed chicken manure (being Jallalah). Then, it was analyzed based on the microbe in their intestine. The purposes of this study are to isolate and to identify the types of bacteria, and to determine the pathogenic and non-pathogenic bacteria in the intestines of fish that have been fed chicken manure. Bacteria samples were isolated from the intestine of fish with chicken manure and the commercial fish food as a control. Bacteria identification was done by using morphological characterization, macroscopic and microscopic identification, and biochemical test. The results show that 21 isolated bacteria in the fish intestine that was fed chicken manure and six of the bacteria are pathogenic. Based on this study, it can be concluded that tilapia fish by feeding with chicken manure contains many types of pathogens bacteria. Briefly, tilapia fish is not good for being consumption.Abstrak: Dalam hadis yang diriwayatkan oleh Ibnu Umar,  Rasulullah SAW. Melarang memakan daging dan meminum susu hewan pemakan kotoran (hewan Jallalah). Pada penelitian ini, ikan nila diberi pakan kotoran ayam (menjadi Jallalah). Selanjutnya ikan tersebut dianalisis kandungan mikroba yang terkandung didalam saluran pencernaannya. Tujuan penelitian ini adalah mengisolasi dan mengidentifikasi bentuk bakteri dan mendeterminasi bakteri patogen dan non-patogen yang terdapat didalam saluran pencernaan ikan ynag telah diberi pakan kotoran ayam. Sampel bakteri diisolasi dari saluran pencernaan ikan setelah diberi kotoran ayam dan ikan yang diberi pakan komersil (kontrol). Identifikasi bakteri dilakukan secara makroskopik, mikroskopik, dan uji biokimia. Hasil penelitian menunjukkan ditemukan 21 isolat bakteri dalam usus ikan yang diberi korotan ayam yang tergolong ke dalam genus Listeria, Staphylococcus, Alcaligenes, Cromobacterium, Edwardisiella, Micrococcus, Bacillus, dan Kurthia. Dari 21 jenis tersebut terdapat 6 jenis bakteri pathogen yaitu Edwarsiella sp, Micrococcus sp, Staphylococcus sp, Alcaligenes sp, Listeria sp dan Chromobacterium. Kesimpulan pada penelitian ini bahwa hewan ikan yang memakan kotoran ayam mengandung banyak jenis bakteri patogen sehingga tidak baik untuk di konsumsi.


2022 ◽  
Vol 10 (1) ◽  
pp. 100
Author(s):  
Po-Tsang Lee ◽  
Yu-Sheng Wu ◽  
Chung-Chih Tseng ◽  
Jia-Yu Lu ◽  
Meng-Chou Lee

This study evaluated the effects of the feeding of spent mushroom substrate from Agaricus blazei on Nile tilapia (Oreochromis niloticus). The safety of 0–1000 μg/mL A. blazei spent substrate water extract (ABSSE) was demonstrated in the primary hepatic and splenic macrophages and the THK cell line (a cell line with characteristics of melanomacrophages) using a cytotoxicity assay. Here, 10 μg/mL of crude ABSSE promoted the phagocytic activity of macrophages and THK cells. Stimulating ABSSE-primed THK cells with lipopolysaccharides or peptidoglycan resulted in higher expression levels of four cytokine genes (e.g., interleukinz (IL)-1β, IL-12b, IL-8 and tumor necrosis factor α (TNFα)) and one cytokine gene (TNFα), respectively. An in vitro bacterial growth inhibition assay demonstrated that ABSSE could inhibit the growth of Streptococcus agalactiae. In the first feeding trial, Nile tilapia were fed with experimental feed containing 0, 1, or 5% of A. blazei spent substrate (ABSS) for seven and fourteen days followed by bacterial challenge assay. The best result was obtained when Nile tilapia were continuously fed for seven days on a diet containing 1% ABSS, with the survival rate being higher than in groups with 0% and 5% ABSS after challenge with S. agalactiae. In the second trial, fish were fed diets supplemented with 0% or 1% ABSS for seven days, and then all the groups were given the control feed for several days prior to bacterial challenge in order to investigate the duration of the protective effect provided by ABSS. The results showed that the protective effects were sustained at day 7 after the feed was switched. Overall, spent mushroom substrate from A. blazei is a cost-effective feed additive for Nile tilapia that protects fish from S. agalactiae infection.


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