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Electron Microscopy (SEM-EDAX & TEM) Studies on Streptococcosis in Egyptian Nile Tilapia (Oreochromis niloticus)
International Journal of Ecotoxicology and Ecobiology
Volume 2, Issue 3, September 2017, Pages: 119-124
Received: Jun. 9, 2017; Accepted: Jun. 16, 2017; Published: Jul. 25, 2017
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Hosam Saleh, Fish Diseases Lab., National Institute of Oceanography and Fisheries (NIOF), Alexandria, Egypt
Fatma A. S. Mohamed, Fish Diseases Lab., National Institute of Oceanography and Fisheries (NIOF), Alexandria, Egypt
Mohamed Abd Al-Razik, Fish Breeding & Production Department, National Institute of Oceanography and Fisheries (NIOF), Alexandria, Egypt
Nader Mahmoud, Fish Diseases Lab., National Institute of Oceanography and Fisheries (NIOF), Alexandria, Egypt
Abeer H. Younis, Biotechnology Lab., National Institute of Oceanography and Fisheries (NIOF), Alexandria, Egypt
Madiha Salah Ibrahim, Department of Microbiology, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
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A field study on Streptococcus infection as a major cause for epidemic infections in Nile Tilapia aquaculture in Kafr El-Shikh Governorate was conducted. This study was carried out to study the gross lesions and post mortem finding of Streptococcsis in Nile Tilapia. Streptococcus was isolated, then identified by Electron Microscopy (Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Analysis (EDAX) and Transmission Electron Microscope (TEM)) to investigate the phenotypic characteristics, ultra-structure of the bacterial cells. Clinical signs of the infected fish showed presence of hemorrhagic patches on different external body regions, ascitis and exophthalmia. Post mortem examinations revealed presence of inflammation of the liver, spleen and kidney. Microbial identification by Gram stain showed Gram positive cocci in shape arranged in chains and the biochemical tests displayed negative catalase and oxidase tests. Electron Microscopy (SEM, EDAX & TEM) confirmed these results and showed the clear cocci shape of streptococcus species and the arrangement of the chains with a bacterial average length of 700 nm. The EDAX results revealed that the elemental structure of the bacterial sample were C,N,O with the concentration 46.93%, 16.61% and 36.46%, respectively.
Streptococcus species, Oreochromis niloticus, SEM, TEM, EDAX
To cite this article
Hosam Saleh, Fatma A. S. Mohamed, Mohamed Abd Al-Razik, Nader Mahmoud, Abeer H. Younis, Madiha Salah Ibrahim, Electron Microscopy (SEM-EDAX & TEM) Studies on Streptococcosis in Egyptian Nile Tilapia (Oreochromis niloticus), International Journal of Ecotoxicology and Ecobiology. Vol. 2, No. 3, 2017, pp. 119-124. doi: 10.11648/j.ijee.20170203.14
Copyright © 2017 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License ( which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Hassanin AA. Studies on Intensive Culture of Nile Tilapia (Oreochromis Niloticus) in Tanks; 2009. Department of Animal Production - Faculty of Agriculture, Cairo. Al-Azhar University.
Kei Y, Takashi K., Kishio H, Meliya B. Prasatporn B. Two cases of streptococcal infections of cultured tilapia in Asia; 2008. pp. 259-268.
Riccardo R, Hugh M, Roy PE Yanong. Characterization of Streptococcus iniae isolated from ornamental cyprinid fishes and development of challenge models; 2006. Aquaculture 256. 105–110.
Nehal MF, Kamelia MO, Mai EEI, Mohamed NMA, and Sahar SA. Streptococcosis in tilapia. Clinico-pathological picture of experimentally infected tilapia. Life Science Journal 2014; 11(9).
C. T. K.-H. Stadtländer. Scanning Electron Microscopy and Transmission Electron Microscopy of Mollicutes: Challenges and Opportunities; 2007. Modern Research and Educational Topics in Microscopy. Méndez-Vilas and J. Díaz (Eds.).
Conroy, D. A. and Hermann, L. R. Text book of fish diseases; 1981. T. F. H. Pub, West Sylvania, U.S.A.
Austin B, Austin DA. Bacterial fish pathogens, Diseases of Farmed and Wild Fish; 2007. (4th edn.). Chichester, UK: Pringer-Praxis Publishing, 16-8.
J. Goldberg, H. Gonzalez, TE Jensen, WA. Corpe. Quantitative Elemental Analysis of bacterial Polyphosphate bodies using Scanning Transmission Electron Microscopy and Energy X-Ray Spectroscopy. Microbiology Soc; 1996. 802-803.
Huu TN, Kinya K, Kazuma Y. Immunohistochemical Examination of Experimental Streptococcus iniae Infection in Japanese Flounder Paralichthys olivaceus. Fish Pathology. 2001, 36 (3), 169-178.
Haghighi KS, Soltani M, Nikbakhat BG, Ghasemi M, Skall HF. Molecular epidemiology of zoonotic streptococcosis / lactococcosis in rainbow trout (Oncorhynchus mykiss). Aquaculture in Iran. 2010. 198-209.
Rogério S, Ernst EM, Julio C, Julio HL, Lucienne GPG, Juliana AD. Isolation and characterization of Streptococcus spp. group B in Nile tilapias (Oreochromis niloticus) reared in hapas nets and earth nurseries in the northern region of Parana State, Brazil; 2005. v.35, n.6, p.1374-1378.
Abuseliana A, Daud H, Abdul Aziz, Bejo, Alsaid M. Pathogenicity of Streptococcus agalactiae Isolated from a Fish Farm in Selangor to Juvenile Red Tilapia (Oreochromis sp.). Journal of Animal and Veterinary Advances; 2011. 10. 914-919.
D. K. Whittaker and D. b. Drucker (1970): Scanning Electron Microscopy of Intact Colonies of Microorganisms. Journal of Bacteriology; 1970. 104 (2).
C. Barnes, M. Young, T. Horne, E. Ellis. Streptococcus iniae: serological differences, presence of capsule and resistance to immune serum killing. Diseases of Aquatic Organisms; 2003. 53: 241–247.
T. Buchanan, M. Colvin, R. Vicknair, K. Patel, M. Timmer, Nizet. Strain-associated virulence factors of Streptococcus iniae in hybrid-striped bass. Veterinary Microbiology; 2008. 131. 145–153.
B. Locke, M. Colvin, K. Datta, K. Patel, N. Naidu, N. Neely, Nizet, T. Buchanan. Streptococcus iniae Capsule Impairs Phagocytic Clearance and Contributes to Virulence in Fish; 2007. Journal of bacteriology, p. 1279–1287.
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