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ISSN : 1225-3480
This study was conducted in order to elucidate the dissemination mechanism of P. olseni using field and laboratory experiments. For this purpose, we quantified the level of P. olseni infection in buried (healthy) and surfaced (gapped) R. philippinarum from a clam bed on Wi-do Island on the west coast of Korea. In addition, the levels of internal and released P. olseni cells from artificially infected (and later dead) R. philippinarum were monitored for 8 days using the RFTM–2 M NaOH lysis method. Our results indicate that P. olseni cells in buried R. philippinarum was 2,655,625 ± 1,536,936 cells/clam; the level in gapped R. philippinarum was considerably lower, 28,203 ± 24,889 cells/clam (p < 0.05). In the laboratory experiment, the P. olseni cells remained in the host tissue 2 days after death was approximately 50% lower than the level of infection measured in living clams. The level dropped to 20% 4 days after death and to 1.5% 6 days after death; eight days after death, P. olseni cells were undetectable since the R. philippinarum flesh had completely decomposed. The level of released cells on the day of death was only 0.05% of the internal level in live R. philippinarum; however, the level increased to 2.3% 5 days after death then gradually decreased and no released cells were detected 8 days after death. Therefore, our laboratory experiment suggest that the low level of P. olseni infection observed in gapped R. philippinarum at Wi-do Island could be caused by lysis of the most of P. olseni cells during the decomposition of dead R. philippinarum tissues. Until the end of decomposition of R. philippinarum, 6.68% of the total amount of P. olseni was released within 8 days. Our study showed that the amount of P. olseni cells from dead host is a considerably higher level than naturally released from healthy R. philippinarum, suggesting that death of the host plays an important role in the dissemination of P. olseni.
Auzoux-Bordenave, S., Vigario, A.M., Ruano, F., Domart-Coulon, I., Doumenc, D. (1995) In vitro sporulation of the clam pathogen Perkinsus atlanticus (Apicomplexa, Perkinsea) under various environmental conditions. Journal of Shellfish Research, 14: 469-475.
Bushek, D., Ford S.E., Chintala, M.M. (2002)Comparison of in vitro-cultured, wild-type Perkinsus marinus. III. Fecal elimination, its role in transmission. Diseases of Aquatic Organisms, 51:217-225.
Chu, F.-L., La Peyre, J.F., Burrenson, C.S. (1993)Perkinsus marinus infection, potential defense related activities in eastern oysters C. virginica:salinity effects. Journal of Invertebrate Pathology, 62:225-232.
Chung, E.Y., Hur, S.B., Hur, Y.B., Lee, J.S. (2001)Gonadal maturation, artificial spawning of the Manila clam Ruditapes philippinarum (Bivalvia:Veneridae), in Komso Bay, Korea. Journal of Fisheries Science, Technology, 4: 208-218.
Donaghy, L., Lambert, C., Choi, K.S., Soudant. P. (2009) Hemocytes of the carpet shell clam (Ruditapes decussatus), the Manila clam (Ruditapes philippinarum): Current knowledge, future prospects. Aquaculture, 297: 10-24.
Eaton, C.D. (2008) Co-evolution. in; Encyclopedia of ecology. (ed. by Sven Erik Jorgensen, Brian D. Fath, 1st Edition). pp. 659-663, Elsevier B.V., Oxford.
Eugenia, R., Pazo, J.P., Garcia, A., Fernandez Cortes, F. (1992) Reproductive cycle of Manila clam, Ruditapes philippinarum (Adams & Reeve 1850) in ria of Vigo (NW Spain). Scientia Marina, 56(1):61-67.
Hamaguchi, M.N., Suzuki, N., Usuki, H., Ishioka, H. (1998) Perkinsus protozoan infection in short-necked clam Tapes (= Ruditapes) philippinarum in Japan. Journal of Fish Pathology, 33: 473-480.
Lee, Y.H., Chang, Y.J., Lim, H.K., Chung, G.S. (1996) Comparison of growth, survival rate in Shortnected clams, Ruditapes philippinarum from different seeding production area. Aquaculture, 9:223-232.
Mandal, F.B. (2011) Human parasitology. PHI Learning Private Limited, New Delhi.
Moodie, E. (2005) Microsporidia (microsporans). In:Marine parasitology. (ed. by L. Rohde). pp 30-46, CSIRO, Australia.
OIE. (2006) Infection with Perkinsus olseni. In: Manual of diagnostic test for aquatic animals 2006. pp 335-342.
OIE. Paris. Park, K.I., Choi, K.S. (2001) Spatial distribution of the protozoan parasite Perkinsus sp. found in the Manila clams, Ruditapes philippinarum, in Korea. Aquaculture, 203: 9-22.
Park, K.-I., Figueras, A., Choi, K.-S. (2006)Application of enzyme-linked immunosorbent assay(ELISA) for the study of reproduction in the Manila clam, Ruditapes philippinarum: (Mollusca:Bivalvia): II. Impacts of Perkinsus olseni on clam reproduction. Aquaculture, 251: 182-191.
Park, K.I, Park, J.K. Lee, J., Choi, K.S. (2005) Use of molecular markers for species identification of Korean Perkinsus sp. isolated from Manila clam Ruditapes philippinarum. Diseases of Aquatic Organisms, 66: 255-263.
Park, K.-I., Yang, H.-S., Kang, H.-S., Cho, M., Park, K.-J., Choi, K.-S. (2010) Isolation, identification of Perkinsus olseni from feces, marine sediment using immunological, molecular techniques. Journal of Invertebrate Pathology, 105:261–269.
Perkins, F.O. (1996) The structure of Perkinsus marinus. (Mackin, Owen,, Collier, 1950) Levine, 1978, with comments on the taxonomy, phylogency of Perkinsus sp. Journal of Shellfish Research, 15:67-87.
Ragone-Calvo, L.M., Dungan, C.F., Roberson, B.S., Burreson, E.M. (2003) Systematic evaluation of factors controlling Perkinsus marinus transmission dynamics in lower Chesapeake Bay. Diseases of Aquatic Organisms, 56: 75-86.
Ray, S.M. (1954) Studies of pathogenesis of Dermocystidium marinum. Proceedings of the National Shellfisheries Association, 45: 164-167.
Song, J.H. (2015) Strategy for the sustainable development of Manila clam farming industry. Aqua Culture, 9: 70-74.
Waki, T., Shimokawa, J., Watanabe, S., Yoshinaga, T., Ogawa, K. (2012) Experimental challenges of wild Manila clams with Perkinsus species isolated from naturally infected wild Manila clams. Journal of Invertebrate Pathology, 111: 50-55.