The Relationship Between Gorgonian Coral (Cnidaria: Gorgonacea) Diseases and African Dust Storms
Tóm tắt
The number of reports of coral diseases has increased throughout the world in the last 20 years. Aspergillosis, which primarily affects Gorgonia ventalina and G. flabellum, is one of the few diseases to be characterized. This disease is caused by Aspergillus sydowii, a terrestrial fungus with a worldwide distribution. Upon infection, colonies may lose tissue, and ultimately, mortality may occur if the infection is not sequestered. The spores of A. sydowii are <5 μm, small enough to be easily picked up by winds and dispersed over great distances. Aspergillosis is prevalent in the Caribbean, and it appears that this primarily terrestrial fungus has adapted to a marine environment. It has been proposed that dust storms originating in Africa may be one way in which potential coral pathogens are distributed and deposited into the marine environments of the Caribbean. To test the hypothesis that African dust storms transport and deposit pathogens, we collected air samples from both dust storms and periods of non-dust in St. John, U.S. Virgin Islands. Because we focused on fungal pathogens and used A. sydowii as a model, we isolated and cultured fungi on various types of media. Fungi including Aspergillus spp. were isolated from air samples taken from dust events and non-dust events. Twenty-three separate cultures and seven genera were isolated from dust event samples whereas eight cultures from five genera were isolated from non-dust air samples. Three isolates from the Virgin Islands dust event samples morphologically identified as Aspergillus spp. produced signs of aspergillosis in seafans, and the original pathogens were re-isolated from those diseased seafans fulfilling Koch's Postulates. This research supports the hypothesis that African dust storms transport across the Atlantic Ocean and deposit potential coral pathogens in the Caribbean.
Tài liệu tham khảo
Applied Biosystems: 1998, ABI Prism Big-Dye terminator cycle sequencing protocol. P/N 4303237 Rev. B. PerkinElmer, Foster City, California, USA.
Atlas R. M.: 1997, In L. C. Parks (ed), Handbook of Microbiological Media, CRC Press: Boca Raton, pp. 803, 1560.
Garrett P. and Ducklow H.: 1975, Coral diseases in Bermuda. Nature 253, 349–350.
Geiser D. M., Taylor J. W., Ritchie K. B. and Smith G. W.: 1998, Cause of sea fan death in the West Indies. Nature 394, 138.
Green E. P. and Bruckner A. W.: 2000, The significance of coral disease epizootiology for coral reef conservation. Biol. Conserv. 96, 347–361.
Griffin D. W., Garrison V. H., Herman J. R. and Shinn E. A.: 2001, African desert dust in the Caribbean atmosphere: Microbiology and public health. Aerobiologia 17, 203–213.
Kellogg C. A., Griffin D. W., Garrison V. H., Peale K. K., Royall N., Smith R. R. and Shinn E. A.: in press, Characterization of aerosolized bacteria and fungi from desert dust events in Mali, West Africa, Aerobiologia.
Kendrick B., Rish M. J., Michaelides J. and Bergman K.: 1982, Amphibious microborers: bioeroding fungi isolated from live corals. Bull. Mar. Sci. 32, 862–867.
Koh L. L., Tan T. K., Chou L. M. and Goh N. K. C.: 2002, Antifungal properties of Singapore gorgonians: a preliminary study. J. Exp. Mar. Biol. Ecol. 273, 121–130.
Nagelkerken I., Buchan K., Smith G. W., Bonair K., Bush P., Garzon-Ferreira J., Botero L., Gayle P., Herberer C., Petrovic C., Pors L. and Yoshioka P.: 1997a, Widespread disease in Caribbean sea fans: I. Spreading and general characteristics. Proc. 8th Int. Coral Reef Symposium, 1997, Panama 1, 679–682.
Nagelkerken I., Buchan K., Smith G. W., Bonair K., Bush P., Garzon-Ferreira J., Botero L., Gayle P., Harvell C. D., Herberer C., Kim K., Petrovic C., Pors L. and Yoshioka P.: 1997b, Widespread disease in Caribbean sea fans: II. Patterns of infection and tissue loss. Mar. Ecol. Prog. Ser. 160, 255–263.
Patterson K. L., Porter J. W., Ritchie K. B., Polson S. W., Mueller E., Peters E. C., Santavy D. L. and Smith G. W.: 2002, The etiology of white pox, a lethal disease of the Caribbean elkhorn coral, Acropora palmata. Proc. Natl. Acad. Sci. USA 99, 8725–8730.
Peters E. C.: 1984, A survey of cellular reactions to environmental stress and disease in Caribbean scleractinian corals. Hegoländer Meeresuntersuchungen 37, 113–137.
Peters E. C.: 1997, Diseases of coral-reef organisms. In C. Birkeland (ed), Life and Death of Coral Reefs. Chapman and Hall: New York, pp. 114–139.
Pivkin M. V.: 2000, Filamentous fungi associated with holothurians from the Sea of Japan, off the coast of Russia. Biol. Bull. 198, 101–109.
Posada D. and Crandall K. A.: 1998, Modeltest: testing the model of DNA substitution. Bioinformatics 14, 817–818.
Richardson L. L.: 1998, Coral diseases: what is really known? Trends in Ecol. Evol. 13, 438–443.
Shinn E. A., Smith G. M., Prospero, J. M., Betzer, P., Hayes, M. L., Garrison, V. and Barber, R. T.: 2000, African Dust and the Demise of Caribbean Coral Reefs. Geophysical Research Letters 27, 3129–3032.
Smith G. W. and Weil E.: in press, Aspergillosis of Gorgonians, in Loya and Rosenberg (eds), Coral Health and Disease. Springer-Verlag: New York, pp. 279–286.
Swofford D. L.: 1999, PAUP*. Phylogenentic analysis using parsimony (and other methods). Version 4. Sinauer Associates, Sunderland, Massachusetts, USA.
Weil E., Urreiztieta I. and Garzon-Ferreira J.: 2002, Geographic variability in the incidence of coral and octocoral diseases in the wider Caribbean. Proc. 9th Coral Reef Symp. 2, 1231–1238.