Bacterial Diseases of Abalone

Category

Category 4 (Negligible Regulatory Significance in Canada)

Common, generally accepted names of the organism or disease agent

Various bacterial diseases including juvenile vibriosis but not blister disease.

Scientific name or taxonomic affiliation

Vibrio spp. including Vibrio harveyi, Vibrio carchariae (possibly a junior synonym of V. harveyi), Vibrio splendidus I, Vibrio alginolyticus, Vibrio parahaemolyticus as well as other bacteria such as Clostridium lituseberense, Flavobacterium-like bacteria and long Flexibacter/Cytophaga-like rod bacteria. Vibrio parahaemolyticus was associated with mass mortalities of Haliotis diversicolor supertexta postlarvae on the south coast of China (Cai et al. 2006) and Klebsiella oxytoca was associated with mass mortalities of postlarvae of the same abalone species in Fujian, China (Cai et al. 2008). Note: Vibrio fluvialis II has been described as the cause of blister disease in abalone in China.

Geographic distribution

Abalone in culture facilities around the world including hatcheries in California, USA; Baja California, Mexico; Australia, New Zealand and British Columbia, Canada. Also associated with mass mortalities of wild abalone on the northern coast of France.

Host species

Haliotis rufescens, Haliotis kamtschatkana (Bower, S.M., unpublished records), Haliotis rubra, Haliotis laevigata, Haliotis tuberculata, Haliotis midae, Haliotis iris and larval and juvenile bivalves under intensive culture including oysters, clams and scallops.

Impact on the host

Systemic infection of the soft-tissues of cultured juvenile abalone, resulting in tissue necrosis (due to production of exotoxin by the bacteria) and death. Vibrio spp. are usually not considered a problem for abalone larval culture because the larval period is relatively short and stringent sanitary practices are effective in avoiding potential problems.

In Tasmania, Australia, disease outbreaks among cultured abalone (Haliotis rubra, H. laevigata and their hybrids) were associated with two species of Vibrio (V. harveyi and V. splendidus I) and Flavobacterium-like bacterium. In most cases, stress factors (e.g., high temperatures, grading trauma, anaesthetics, gradual increase in salinity in the recirculation system, etc.) were reported to have precipitated the diseases (Handlinger et al. 2001, 2002, 2005). In Kanagawa Prefecture, Japan, Vibrio carchariae (possibly a junior synonym of Vibrio harveyi) was isolated from cultured abalone (Haliotis (=Sulculus) diversicolor supratexta) experiencing a mass mortality. In this case, white spots consisting of necrotic muscle fibres and bacteria on the abalone foot accompanied by high mortalities were characteristic of the disease (Nishimori et al. 1998). Vibrio carchariae was also identified as the probable cause of mass mortalities of Haliotis tuberculata in the natural environment along the Brittany and Normandy coasts of France and in a land-based abalone farm in Normandy (Nicolas et al. 2002). Travers et al. (2008a) found a rare pathogenic strain of V. harveyi responsible for epizootic mass mortalities of H. tuberculata in France at the end of the summers between 1998 and 2005 with the highest mortalities among mature abalone at temperatures above 19 °C. Travers et al. (2008b) reported a clear concordance between the maturation and spawning processes, immune status and H. tuberculata susceptibility to V. harveyi. In New Zealand, abalone cultured at high densities often (up to 45% of the cultured H. iris) had lesions of erosion and exfoliation of the epithelium of the foot and epipodium that were usually associated with infections of various bacteria (Diggles and Oliver 2005).

Diagnostic techniques

Histology: Indications of tissue necrosis and the presence of rod-shaped bacteria (usually slightly curved) within the tissues.

Molecular Characteristics: Vibrio harveyi can be differentiated from closely related species of Vibrio by toxR gene sequence analysis using toxR-targeted PCR primers that amplifies a 390 base-pair fragment of the gene (Conejero and Hedreyda 2003).

Culture: Isolation and culture (TCBS bacterial culture agar) of colonies of Vibrio spp. from the tissues of sick abalone.

Methods of control

Vibrio bacteria are ubiquitous, hence eradication of the aetiologic agent is impossible. Vibriosis appears to be directly related to poor husbandry and other stressful conditions that predispose the abalone to infection. Sources of infection are broodstock, food supply (e.g., algal cultures), surfaces utilized by abalone, incoming sea water and air-borne contaminants (Lizárraga-Partida et al. 1998). In order to alleviate the problem, the source of infection should be determined by culturing bacteria from the above possible sources. Also, stress factors that precipitate the disease should be identified and disease control can be directed towards eliminating the stress (Handlinger et al. 2005). Culturing larvae under optimal conditions (i.e., suitable temperature and salinity for the abalone species) and the use of sterilised seawater (e.g., irradiated with ultraviolet light) can reduce the development of vibriosis. Batches of abalone containing infected individuals should be destroyed in an approved manner followed by disinfection of all containers and equipment in contact with the infected stock. Vibriosis can also be avoided by limiting the exposure of cultured abalone to physical and chemical stresses (Elston and Lockwood 1983).

Dixon et al. (1991) reported that exposure to ozonated water and treatment (bath and injection) with a broad spectrum antibiotic was effective against bacterial infections (caused by Clostridium lituseberense or Vibrio alginolyticus) in some abalone (Haliotis midae) in a South African experimental facility. However, Handlinger et al. (2002, 2005) found antibiotic use to give equivocal results on bacterial infections in Tasmanian farmed abalone. Also, Anguiano-Beltrán and Searcy-Bernal (2007) reported that antibiotic treatment slowed postlarval growth and reduced survival of H. rufescens and suggested that bacteria were important to nutrition and/or digestion of abalone postlarvae.

References

Anguiano-Beltrán, C. and R. Searcy-Bernal. 2007. Effects of antibiotics on the concentrations of bacteria in biofilms and on the growth of Haliotis rufescens postlarvae. Journal of Shellfish Research 26: 795-799.

Bower, S.M. 2000. Infectious diseases of abalone (Haliotis spp.) and risks associated with transplantation. In: Campbell, A. (ed.) Workshop on Rebuilding Abalone Stocks in British Columbia. Canadian Special Publication of Fisheries and Aquatic Sciences 130: 111-122.

Cai, J., Y. Han and Z. Wang. 2006. Isolation of Vibrio parahaemolyticus from abalone (Haliotis diversicolor supertexta L.) postlarvae associated with mass mortalities. Aquaculture 257: 161–166.

Cai, J., Z. Wang, C. Cai and Y. Zhou. 2008. Characterization and identification of virulent Klebsiella oxytoca isolated from abalone (Haliotis diversicolor supertexta) postlarvae with mass mortality in Fujian, China. Journal of Invertebrate Pathology 97: 70-75.

Conejero, M.J.U. and C.T. Hedreyda. 2003. Isolation of partial toxR gene of Vibrio harveyi and design of toxR-targeted PCR primers for species detection. Journal of Applied Microbiology 95: 602-611.

Diggles, B.K. and M. Oliver. 2005. Diseases of cultured paua (Haliotis iris) in New Zealand. In: Walker, P.J., R.G. Lester, M.G. Bondad-Reantaso (eds.) Diseases in Asian Aquaculture V. Proceedings of the 5th Symposium on Diseases in Asian Aquaculture. Fish Health Section, Asian Fisheries Society, Manila. pp. 275-287.

Dixon, M.G., T. Hecht and C.R. Brandt. 1991. Identification and treatment of a Clostridium and Vibrio infection in South African abalone, Haliotis midae L. Journal of Fish Diseases 14: 693-695.

Ebert, E.E. and J.L. Houk. 1989. Abalone cultivation methods used at the California Department of Fish and Game's marine resources laboratory. In: K. O. Hahn, K.O. (ed.) Handbook of Culture of Abalone and Other Marine Gastropods. CRC Press, Inc., Boca Raton, FL. pp. 239-254.

Elston, R.A. and G.S. Lockwood. 1983. Pathogenesis of vibriosis in cultured juvenile red abalone, Haliotis rufescens Swainson. Journal of Fish Diseases 6: 111-128.

Handlinger, J., D. Taylor and J. Carson. 2001. Flavobacterium-like infection of abalone. (Abstract). Book of Abstracts, European Association of Fish Pathologists, Tenth International Conference "Diseases of Fish and Shellfish. Trinity College Dublin, Ireland, 9 - 14 September 2001. pg. P-209.

Handlinger, J., J. Carson, L. Donachie, L. Gabor and D. Taylor. 2002. Bacterial infection in Tasmanian farmed abalone: causes, pathology, farm factors and control options. (Abstract). Handbook and Abstracts, Fifth Symposium on Diseases in Asian Aquaculture, Queensland, Australia, 24-28 November 2002. Pg. 139.

Handlinger, J., J. Carson, L. Donachie, L. Gabor and D. Taylor. 2005. Bacterial infection in Tasmanian farmed abalone: causes, pathology, farm factors and control options. In: Walker, P.J., R.G. Lester, M.G. Bondad-Reantaso (eds.) Diseases in Asian Aquaculture V. Proceedings of the 5th Symposium on Diseases in Asian Aquaculture. Fish Health Section, Asian Fisheries Society, Manila. pp. 289-299.

Lizárraga-Partida, M.L., C. Anguiano-Beltrán, R. Searcy-Bernal and E. Vázquez-Moreno. 1998. Bacterial water quality in abalone farms of Baja California. Journal of Shellfish Research 17: 689-692.

Mortensen, S., I. Arzul, L. Miossec, C. Paillard, S. Feist, G. Stentiford, T. Renault, D. Saulnier and A. Gregory. 2007. Molluscs and crustaceans, 5.3.10 Vibrio harveyi-infections in abalone. In: Raynard, R., T. Wahli, I. Vatsos, S. Mortensen (eds.) Review of disease interactions and pathogen exchange between farmed and wild finfish and shellfish in Europe. VESO on behalf of DIPNET, Oslo. pp. 355-357. (For electronic publication see www.dipnet.info under "Documents", subgroup "Reports and project deliverables").

Nicolas, J.L., O. Basuyaux, J. Mazurié and A. Thébault. 2002. Vibrio carchariae, a pathogen of the abalone Haliotis tuberculata. Diseases of Aquatic Organisms 50: 35-43.

Nishimori, E., O. Hasegawa, T. Numata and H. Wakabayashi. 1998. Vibrio carchariae causes mass mortalities in Japanese abalone, Sulculus diversicolor supratexta. Fish Pathology (Tokyo) 33: 495-502.

Reuter, R.E. and S. McOrist. 1999. Mortality due to Vibrio harveyi in farmed blacklip abalone, Notohaliotis ruber. In: C.L. Browdy and R. Fletcher (co-program chairs). Book of Abstracts. The Annual International Conference and Exposition of the World Aquaculture Society, 26 April-2 May, 1999, Sydney, Australia. p. 629.

Travers, M.-A., O. Basuyaux, J.L. Nicolas, C. Friedman, S. Huchette, M. Koken and C. Paillard. 2008a. Temperature dependant vibriosis of the European abalone, Haliotis tuberculata. Journal of Shellfish Research 27: 1058.

Travers, M.-A., N. Le Goïc, S. Huchette, M. Koken and C. Paillard. 2008b. Summer immune depression associated with increased susceptibility of the European abalone, Haliotis tuberculata to Vibrio harveyi infection. Fish and Shellfish Immunology 25: 800–808.

Citation Information

Bower, S.M. (2010): Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish: Bacterial Diseases of Abalone.

Date last revised: April 2010
Comments to Susan Bower

Date modified: