Main Article Content



food safety, depuration, clams, V. parahaemolyticus, V. vulnificus


Vibrio spp are widely distributed in the marine environments and are responsible for common illnesses in many countries. The main objective of this study was to investigate the depuration capacity of Venus gallina artificially contaminated with Vibrio parahaemolyticus and Vibrio vulnificus. Contamination experiments were used to assess the accumulation capacity of clams in poorly, moderate and highly contaminated waters (Vibrio spp103/ml, 104/ml, 106/ml). All bivalves were exposed to contamination for 72 h and 8 experiments were performed. Accumulation capacity varied with respect to initial level. Comparing experiments dataset with two vibrios species, clams showed a different specific accumulation: in particular, molluscs evidenced a scarce accumulation capacity of V.vulnificus. Depuration trials were performed in close-circuit seawater-disinfection system that uses filtration, Ultra violet (UV) and ozone. Bivalves samples were collected every 12h until 3 days of depuration. Most of the depuration trials with V.parahaemolyticus showed a decrease in initial bacterial loads (4times lower values) after36-48 hours, but in subsequent periods, the trend remained stationary. In V. vulnificus tests, clams showed a scarce depuration capacity instead. Future studies are still required to assess the efficacy of the depuration process in reducing pathogenic Vibrio strain naturally accumulated in clams and to prevent significant economic losses to stakeholders due to long depuration periods.

Abstract 372 | pdf Downloads 300


Anonymous. (2004a). Corrigendum to regulation (EC) N.853/2004 of the European Parliament and of the Council of 29th April 2004 laying down specific hygiene rules for food of animal origin (in official Journal of the European Union L 139 of 30th April 2004). Official Journal of the European Union, L 226.

Anonymous. (2004b). Corrigendum to Regulation (EC) N.854/2004 of the European Parliament and of the Council of 29th April 2004 laying down specific rules for the organization of official controls on products of animal origin intended for human consumption (in Official Journal of the European Union L 139 of 30th April 2004). Official Journal of the European Union, L 226.

Anacleto P., Maulvault A.L., Chaguri M., Pedro S., Nunes M. L., Rosa R. and Marques A. 2013. Microbiological responses to depuration and transport of native and exotic clams at optimal and stressful temperatures. Food Microbiology 36, 365-373.

Barbieri E., Falzano L., Fiorentini C., Pianetti A., Baffone W., Fabbri A., Matarrese P., Casiere A., Katouli M., Kühn I., Mollby R., Bruscolini F. and DonelliG. 1999. Occurrence, diversity and pathogenicity of halophilic Vibrio spp. and non-O1 Vibrio choleraefrom estuarine waters along the Italian Adriatic coast. Appl. Environ. Microbiol. 65:2748-2753.

Barile, N.B., Scopa, M., Nerone, E., Mascilongo, G., Recchi, S., Cappabianca, S., and Antonetti, L. 2009. Study of the efficacy of closed cycle depuration system on bivalve molluscs. Veterinaria Italiana 45(4):555-566.

Berthou P., Poutiers J.M., Goulletquer P., and DaoJ.C., 2005. Shelled molluscs. In: Fisheries and Aquaculture. Encyclopedia of Life Support Systems (EOLSS), Developed under the Auspices of the UNESCO, vol. II. Eolss Publishers, Oxford, UK.

Blackwell K.D. and Oliver J.D. 2008. Ecology of Vibrio vulnificus, Vibrio cholerae and Vibrio parahaemolyticus in North Carolina Estuaries. J. Microbiol. 46:146-153.

Burkhardt W., III, Watkins W.D., and Rippey, S. R. 1992. Seasonal effects on accumulation of microbial indicator organisms by Mercenaria mercenaria. Applied and Environmental Microbiology 58(3):826-831.

Burkhardt W. 3rd and Calci K.R. 2000. Selective accumulation may account for shellfish-associated viral illness. Appl. Environ Microbiol. 66(4):1375-8.

Butt, A.A., Aldridge K.E., and Sanders C.V. 2004. Infections related to the ingestion of seafood part I: viral and bacterial infections. The Lancet Infectious Diseases 4(4):201-212.

Cantet F., Hervio-Heath D., Caro A., Le Mennec C., Monteil C., Quéméré C., Jolivet-Gougeon A., Colwell R.R. and Monfort P. 2013. Quantification of Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio cholerae in French Mediterranean coastal lagoons. Res Microbiol. 164(8):867-74.

Cao R., Xue C.H., Liu Q., and Xue Y. 2009. Microbiological, chemical, and sensory assessment of Pacific Oysters (Crassostrea gigas) stored at different temperatures. Czech Journal of Food Sciences 27, 102:108.

Chae, M.J., Cheney, D., and Su andY.C. 2009. Temperature effects on the depuration of Vibrio parahaemolyticus and Vibrio vulnificus from the American oyster (Crassostrea virginica). J. Food Sci. 74:M62-M66.

Çolakolu F. A., Çardak M., Çolakoglu S., Künili I.E., 2014. Depuration Times of Donax trunculus and Tapes decussatus. Brazilian Journal of Microbiology 45(3):1017-1022.

Colwell R.R., and Grimes D.J. 2000. Nonculturable Microorganisms in the Environment. ASM Press, Washington, DC.

Cook, D.W. 1991. Indicators and alternate indicators of growing waters. In: Ward, D.R., Ackney, C.H. (Eds.), Microbiology of Marine Food Products AVI Book.Van Nostrand Reinhold, New York, US, pp. 19-39.

Cozzi L., Suffredini E., Ciccaglioni G., and CrociL., 2009. Depuration treatment of mussels experimentally contaminated with V. parahaemolyticus and V. vulnificus. In: Proceeding ICMSS09, Nantes, France.

Croci L., Suffredini, E. Cozzi, L. and Toti L. 2002. Effects of depuration of molluscs experimentally contaminated with Escherichia coli, Vibrio cholerae O1 and Vibrio parahaemolyticus. Journal of Applied Microbiology 92:460-465.

DePaola A., Nordstrom J.L., Bowers J.C., Wells J.G., and Cook D.W. 2003. Seasonal abundance of total and pathogenic Vibrio parahaemolyticus in Alabama oysters. Appl. Environ. Microbiol. 69:1521-1526.

EC, 2001. Opinion of the Scientific Committee on Veterinary Measures Relating to Public Health on Vibrio vulnificus and Vibrio parahaemolyticus (in Raw and Undercooked Seafood). European Commission Health & Consumer Protection Directorate General. Directorate Cd Scientific Opinions, pp.1e 64.

El-Shenawy N.S. 2004. Heavy metal and microbial depuration of the clam Ruditapes decussatus and its effect on bivalve behavior and physiology. Environmental Toxicology 19:143-153.

Hamamoto A., M. Mori, A. Takahashi, M. Nakano, N. Wakikawa, M. Akutagawa, T. Ikehara, Y. Nakaya and Y. Kinouchi. 2007. New water disinfection system using UVA light-emitting diodes. Journal of Applied Microbiology 103:2291-2298.

Hernroth B.E., Conden-Hansson A.-C., Rehnstam-Holm A.-S., Girones R., and Allard A.K. 2002. Environmental factors influencing human viral pathogens and their potential indicator organisms in the blue mussel, Mytilus edulis: the First Scandinavian Report. Applied and Environmental Microbiology 68(9):4523-4533.

Hervio-Heath D., Colwell R.R., Derrien A., Robert-Pillot A., Fournier J.M., and Pommepuy M., 2002. Occurrence of pathogenic vibrios in coastal areas of France. J. Appl. Microbiol. 92:1123-1135.

Ho B.S.W. and Tam T.Y. 2000. Natural depuration of shellfish for human consumption: a note of caution. Water Research, 34(4):1401-1406.

Howard G., Heron J., Turriff J. and Kinnear S., 2003. Preliminary Trials to Assess the Viability of Purifying Venerupis spp. by Depuration Using Ultra Violet Sterilisation. Fisheries Research Services Internal Report No 09/03. Marine Laboratory, Aberdeen, UK, p. 16

Hsieh J.L., Fries J.S., and Noble R.T. 2008. Dynamics and predictive modelling of Vibrio spp. in the Neuse river estuary, North Carolina, USA. Environ. Microbiol. 10:57-64.

Kaspar C.W. and Tamplin M.L. 1993. Effects of temperature and salinity on the survival of Vibrio vulnificus in seawater and shellfish. Applied and Environmental Microbiology 59(8):2425-2429.

Lees D. 2000. Viruses and bivalve shellfish. International Journal of Food Microbiology 59(1e2):81-116.

Lees D., Younger A. and Dore B. 2010. Depuration and relaying. In: Rees, G., Pond, K., Kay, D., Bartram, J., Santo Domingo, J. (Eds.), Safe Management of Shellfish and Harvest Waters. World Health Organization (WHO), IWA Publishing, London, UK, p. 37.

Lopez-Joven C., Ruiz-Zarzuela I., de Blas I., Furones M.D. and Roque A. 2011. Persistence of sucrose fermenting and nonfermenting vibrios in tissues of Manila clam species, Ruditapes philippinarum, depurated in seawater at two different temperatures. Food Microbiology 28:951-956.

Joven C.L., De Blas I., Zarzuela I.R., Furones M.D. and Roque A. 2011. Experimental uptake and retention of pathogenic and nonpathogenic Vibrio parahaemolyticus in two species of clams: Ruditapes decussatus and Ruditapes philippinarum. J. Appl. Microbiol. 111:197-208.

Maffei M., Vernocchi P., Lanciotti R., Guerzoni M.E., Belletti N. and Gardini F. 2009. Depuration of striped Venus clam (Chamelea gallina L.): effects on microorganisms, sand content, and mortality. Journal of Food Science 74(1): M1-M7.

Martinez-Urtaza J., Lozano-Leon A., Varela-Pet J., Trinanes J., Pazos Y. and Garcia-Martin O. 2008. Environmental determinants of the occurrence and distribution of Vibrio parahaemolyticus in the rias of Galicia, Spain. Appl. Environ. Microbiol. 74:265-274.

Mead P.S., Slutsker L., Dietz V., McCaig L.F., Bresee J.S., Shapiro C., Griffin P.M.Tauxe R.V.1999. Food-related illness and death in the United States. Emerging Infectious Diseases 5:607e625.

Morello E.B., Froglia C., Atkinson R.J.A. and Moore P.G. 2005. Hydraulic dredge discards of the clam (Chamelea gallina) fishery in the western Adriatic Sea, Italy. Fisher Res 76:430-44.

Moschino V. and Marin M.G. 2006. Seasonal changes in physiological responses and evaluation of “well-being” in the Venus clam Chamelea gallina from the Northern Adriatic Sea. Comp Biochem Physiol Part A 145:433-40.

Murphee R.L. and Tamplin M.L. 1991. Uptake and retention of Vibrio cholerae O1 in the Eastern oyster, Crassostrea virginica. Appl Environ Microbiol 61:3656-3660.

Normanno, G., Parisi, A., Addante, N., Quaglia, N. C., Dambrosio, A., Montagna, C. and Chiocco D. (2006). Vibrio parahaemolyticus, Vibrio vulnificus and microorganisms of fecal origin in mussels (Mytilus galloprovincialis) sold in the Puglia region (Italy). International Journal of Food Microbiology, 106(2):219-222.

Oliveira J., Cunha A., Castilho F., Romalde J.L. and Pereira M.J. 2011. Microbila contamination and purification of bivalve shellfish: Crucial aspects in monitoring and future perspective-Amini-review. Food Control 22:805-816.

Orban E., Di Lena G., Nevigato T., Casini I., Caproni R., Santaroni G. and Giulini G. 2006. Nutritional and commercial quality of the striped venus clam, Chamelea gallina, from the Adriatic sea. Food Chem.101:1063-70.

Pfeffer C.S., Hite M.F. and Oliver J.D. 2003. Ecology of Vibrio vulnificus in estuarine waters of eastern North Carolina. Appl. Environ. Microbiol. 69:3526-3531.

Randa M.A., Poltz M.F. and Lim E. 2004. Effects of temperature and salinity on Vibrio vulnificus population dynamics as assessed by quantitative PCR. Appl. Environ. Microbiol. 70:5469-5476.

Ren T. and SU Y.C. 2006. Effects of electrolyzed oxidizing water treatment on reducing Vibrio parahaemolyticus and Vibrio vulnificus in raw oysters. J.Food Prot. 69(8):1829-34.

Richards, G. P. 1988. Microbial purification of shellfish: a review of depuration and relaying. Journal of Food Protection, 51(3): 218-251.

Ripabelli G., Sammarco M. L., Grasso G. M., Fanelli I., Caprioli A. and Luzzi I. 1999. Occurrence of Vibrio and other pathogenic bacteria in Mytilus galloprovincialis (mussels) harvested from Adriatic Sea, Italy. International Journal of Food Microbiology, 49(1e2):43-48.

Robertson L.J. 2007. The potential for marine bivalve shellfish to act as transmission vehicles for outbreaks of protozoan infections in humans: a review. International Journal of Food Microbiology, 120(3):201-216.

Roque A., Lopez-Joven C., Lacuesta B., Elandaloussi L., Wagley S., Furones M.D., Ruiz-Zarzuela I., de Blas I., Rangdale R. and Gomez-Gil B. 2009. Detection and Identification of tdh-and trh-Positive Vibrio parahaemolyticus Strains from Four Species of Cultured Bivalve Molluscs on the Spanish Mediterranean Coast. Appl. Environ. Microbiol. Vol. 75, No. 23p.7574-7577.

Roszak D.B. and Colwell R.R. 1987. Survival strategies of bacteria in the natural environment. Microbiol. Rev. 51: 365-379.

Schneider K.R., Cevallos J. and Rodrick G.E. 2009. Molluscan shellfish depuration. In: Shumway, S.E., Rodrick, G.E. (eds). Shellfish safety and quality. Woodhead Pub Lmt, Cambridge, pp.509-541.

Tamplin M.L. and Capers G.M. 1992. Persistence of Vibrio vulnificusin tissues of Gulf Coast oysters, Crassostrea virginica, exposed to seawater disinfected with UV light. 1992. Appl Environ Microbiol. 58(5):1506 -1510.

Wang D., Zhang D., Chen W., Yu S. and Shi X. 2010. Retention of Vibrio parahaemolyticus in oyster tissues after chlorine dioxide treatment. Int J Food Microbiol 137:76-80.

Wittman R.J. and Flick G.J. 1995. Microbial contamination of shellfish: prevalence, risk to human health, and control strategies. Ann Rev Pub Health 16:123-40.

WHO -World Health Organization, 2011. Risk Assessment of Vibrio parahaemolyticus in Seafood: Interpretative Summary and Technical Report, p. 200.