Characterization of an isolated reovirus from the paradise fish Macropodus opercularis imported from Southeast Asia

동남아시아로부터 수입된 paradise fish Macropodus opercularis로부터 분리한 reovirus의 특성

  • Kim, Wi-Sik (Department of Aqualife Medicine, College of Fisheries and Ocean Science, Chonnam National University) ;
  • Kim, Soo-Jin (Department of Aqualife Medicine, College of Fisheries and Ocean Science, Chonnam National University) ;
  • Kim, Jeong-Ho (Faculty of Marine Bioscience and Technology, Gangneung-Wonju National University) ;
  • Jung, Sung-Ju (Department of Aqualife Medicine, College of Fisheries and Ocean Science, Chonnam National University) ;
  • Kim, Do-Hyung (Department of Aqualife Medicine, College of Fisheries and Ocean Science, Chonnam National University) ;
  • Oh, Myung-Joo (Department of Aqualife Medicine, College of Fisheries and Ocean Science, Chonnam National University)
  • 김위식 (전남대학교 수산생명의학과) ;
  • 김수진 (전남대학교 수산생명의학과) ;
  • 김정호 (강릉원주대학교 해양자원육성) ;
  • 정성주 (전남대학교 수산생명의학과) ;
  • 김도형 (전남대학교 수산생명의학과) ;
  • 오명주 (전남대학교 수산생명의학과)
  • Received : 2010.09.28
  • Accepted : 2010.12.03
  • Published : 2010.12.31

Abstract

In 2008, mass mortality was observed in paradise fish Macropodus opercularis which was imported from Indonesia. PCR of these fish found positive for megalocytivirus and Mycobacterium sp., while an unidentified virus was culture-isolated using CHSE-214 cells. In the present study, we investigated characterization of the unidentified virus and its pathogenicity to determine whether the virus was the causative agent of the mass mortality of paradise fish. The unidentified virus induced cytopathic effect (CPE) with syncytia in CHSE-214 and other fish cells, BF-2, GF, SSN-1, FSP and FFN. The virus was resistant against treatments with IUdR, chloroform, acidity at pH 3, basicity at pH 11 and high temperature at $56^{\circ}C$ for 3h. By electron microscopy, the viral particles were spherical having a double capsid structure with approximately 65 nm in external diameter. Viral genome was composed of at least 10-segmented RNA with sizes ranging from 0.7 kb to 3.6 kb. Based on these characters, this virus can be classified into family Reoviridae. This reovirus did not cause any mortality in an artificial experiment conducted by injecting the virus to paradise fish. This indicates that the reovirus is not only responsible for the mass mortality of paradise fish in 2008.

2008년 3월 인도네시아로부터 수입된 paradise fish에서 대량폐사가 발생하여 병원체 검사를 실시한 결과, megalocytivirus 및 Mycobacterium sp.가 검출되었으며, CHSE-214세포에서 미동정 바이러스가 분리되었다. 본 연구에서는 미동정 바이러스의 특성을 조사하였으며, 또한 병원성 실험을 통해 paradise fish의 대량 폐사와의 연관성을 조사하였다. 분리 바이러스는 CHSE-214, BF-2, GF, SSN-1, FSP 및 FFN 세포에서 합포체의 세포변성효과를 나타내었고 IUdR 및 chloroform 처리에 감염성이 상실되지 않으며, 산 (pH 3), 알카리 (pH 11) 및 열 ($56^{\circ}C$, 30분)에 안정하였다. 핵산 분석 결과에서는 적어도 10개의 segment (0.7-3.6 kb)를 지닌 RNA 바이러스로 확인되었으며, 전자현미경 관찰 결과, 약 65 nm 크기로 인벨롭이 없으며 2중의 capsid를 지닌 바이러스가 세포질에서 관찰되었다. 이상의 결과는 Reoviridae family에 속하는 바이러스의 전형적인 특성과 일치하므로 paradise fish에서 분리된 바이러스는 reovirus로 확인되었다. Reovirus를 사용한 감염실험에서는 병원성이 나타나지 않아, reovirus는 paradise fish의 대량 폐사의 직접적인 원인이 아닐 것으로 사료되었다.

Keywords

References

  1. Andrews, C., Exell, A. and Carrington, N.: Manual of fish health: Everything you need to know about aquarium fish, their environment and disease prevention. Firefly Book, Singapore. 2003.
  2. Bernoth, E.M. and St J Crane, M.: Viral diseases of aquarium fish. Seminars in Avian and Exotic Pet Medicine, 4:103-110, 1995.
  3. Essbauer, S. and Ahne, W.: Viruses of lower vertebrates. J. Vet. Med., 48:403-475, 2001. https://doi.org/10.1046/j.1439-0450.2001.00473.x
  4. Gauthier, D.T. and Rhodes, M.W.: Mycobacteriosis in fishes: A review. Veterinary Journal., 180, 33-47, 2009. https://doi.org/10.1016/j.tvjl.2008.05.012
  5. Hossain, M., Song, J.Y., Kitamura, S.I., Jung, S.J., Oh, M.J.: Phylogenetic analysis of lymphocystis disease virus from tropical ornamental fish species based on a major capsid protein gene. J. Fish Dis., 31:473-479, 2008. https://doi.org/10.1111/j.1365-2761.2008.00917.x
  6. Jeong, J.B., Kim, H.Y., Jun, L.J., Lyu, J.H., Park, N.G., Kim, J.K. and Jeong, H.D.: Outbreaks and risks of infectious spleen and kidney necrosis virus disease in freshwater ornamental fishes. Dis. Aquat. Org., 78:209-215, 2008. https://doi.org/10.3354/dao01879
  7. Kim, W.S., Oh, M.J., Kim, J.O., Kim, D.W., Jeon, C.H. and Kim, J.H.: Detection of megalocytivirus from imported tropical ornamental fish, paradise fish Macropodus opercularis. Dis. Aquat. Org., 90:243-247, 2010.
  8. Lupiani, B., Subramanian K. and Samal, S.K.: Aquareoviruses. Annu. Rev. Fish Dis., 5:175-208, 1995. https://doi.org/10.1016/0959-8030(95)00006-2
  9. Mertens, P.P.C., Duncan, R., Attoui, H. and Dermody, T.S.: Family Reoviridae. In Fauquet, C.M., Mayo, M.A., Maniloff, J., Desselberger, U. and Ball, L.A. (eds.), Virus taxonomy, eighth report of the international committee on taxonomy of viruses. pp. 447-454. Academic Press, San Diego, USA. 2005.
  10. Paperna, I., Vilenkin, M. and de Matos, A.P.A.: Iridovirus infections in farm-reared tropical ornamental fish. Dis. Aquat. Org., 48:17-25, 2001. https://doi.org/10.3354/dao048017
  11. Reed, L.J. and Muench, H.: A simple method of estimating fifty percent endpoint. Am. J. Hyg., 27:493-497, 1938.
  12. Samal, S.K., Attoui, H., Mohd Jaafar, F. and Mertens, P.P.C.: Genus Aquareoviridae. In Fauquet, C.M., Mayo, M.A., Maniloff, J., Desselberger, U. and Ball, L.A. (eds.), Virus taxonomy, eighth report of the international committee on taxonomy of viruses. pp. 511-516. Academic Press, San Diego, USA. 2005.
  13. Sudthongkong, C., Miyata, M. and Miyazaki, T. Iridovirus disease in two ornamental tropical freshwater fishes: African lampeye and dwarf gourami. Dis. Aquat. Org., 48:163-173, 2002. https://doi.org/10.3354/dao048163
  14. Thilakaratne, I.D.S.I.P., Rajapaksha, G., Hewakopara, A., Rajapakse, R.P.V.J. and Faizal, A.C.M.: Parasitic infections in freshwater ornamental fish in Sri Lanka. Dis. Aquat. Org., 54:157-162, 2003. https://doi.org/10.3354/dao054157
  15. 관세청: http://www.customs.go.kr/ 무역통계. 2010.
  16. 류지효, 정준범, 김호열, 전려진, 조혜진, 이준우, 정현도: 담수관상어 5종에서의 iridoviruses 검출과 분포 분석. 한국어병학회지. 19:197-206, 2006.