L. SERRACCA, M. PREARO, I. ROSSINI, R. BATTISTINI, M. CORSI, C. ERCOLIN

Four- year surveillance of Marteilia refringens in shellfish farms in the Gulf of La Spezia (Liguria, Italy)

The paramyxean protistan parasites Marteilia refringens and M. maurini, two Marteilia species detected in Europe, infect several bivalve mollusc species of economic interest. Marteiliosis, caused by infection with M. refringens , is included in the World Organization for Animal Health (OIE) list of diseases (OIE Aquatic Animal Health Code 2014) and is listed as a nonexotic pathogen under European Union legislation (2006/88/EC). As mandated by Italian Legislative Decree 148/2008, an annual sampling program is in place to monitor the health status of the Mediterranean mussel Mytilus galloprovincialis farmed in the Gulf of La Spezia (northwest Italy), test for the presence of the parasite in mussels, and evaluate abnormal mortality as an indicator of disease presence. During the four -year period 2010 -2013, 4460 samples of M. galloprovincialis were collected from six farming areas and analyzed by cytological methods for the detection of M. refringens. Suspe cted positive diagnosis was confirmed by PCR assay performed according to the Manual of Diagnostic Tests for Aquatic Animals (OIE, 2012). Although infection rates generally decreased between 2010 and 2013, samples from all six areas tested positive for M. refringens , with an overall positivity rate of 4.05%.

PDF

___

Audemard, C., Sajus, M.C., Barnaud, A., Sautour, B., Sauriau, P.G. and Berthe, F.J.C. 2004. Infection dynamics of Marteilia refringens in flat oyster Ostrea edulis and copepod Paracartia grani in a claire pond of Marennes -Oléron Bay. Disease of Aquatic Organisms, 61: 103 111. doi:10.3354/dao061103

Carrasco, N., Villa lba, A., Andree, K.B., Engelsma, M.Y., Lacuesta, B., Ramilo, A., Gairìn, I. and Furones, M.D. 2012a. Bonamia exitiosa (Haplosporidia) observed infecting the European flat oyster Ostrea edulis cultured on the Spanish Mediterranean coast. Journal of Inverteb rate Pathology, 110: 307 -313. doi: 10.1016/j.jip.2012.03.015

Carrasco, N., Andree , K.B., Lacuesta, B., Roque, A., Rodgers, C. and Furones , M.D. 2012b. Molecular Characterization of the Marteilia parasite infecting the common edible cockle Cerastoderma edu le in the Spanish Mediterranean coast A new Marteilia species affecting bivalves in Europe? Aquaculture, 324 -325: 20 -26. doi: 10 .1016/j.aquaculture.2011.10.017

Elgharsalli, R., Aloui-Bejaoui, N., Salah, H., Chollet, B., Joly, J.P., Robert, M., Couraleau, Y. and Arzul, I. 2012. Characterization of the protozoan parasite Marteilia refringens infecting the dwarf oyster Ostrea stentina in Tunisia. Journal of Invertebrate Pathology, 112 : 175 183. doi: 10.1016/j.jip.2012.11.004

Fuentes, J., Villalba, A., Zapata , C. and Alvarez, G. 1995. Effects of stock and culture environment on infections by Marteilia refringens and Mytilicola intestinalis in the mussel Mytilus galloprovincialis cultured in Galicia (NW Spain). Disease of Aquatic Organisms, 21: 221 -226. doi: 1 0.3354/dao021221

Le Roux, F., Lorenzo, G., Peyret, P., Audemard, C., Figueras, A., Vivarès, C., Gouy, M. and Berthe, F.C.J. 2001. Molecular evidence for the existence of two species of Marteilia in Europe. Journal of Eukaryotic Microbiology, 48: 449 -454. doi: 10.1111/j.1550 -7408. 2001.tb00178.x

López-Flores, I., Robles, F., Valencia, J.M., Grau, A., Villalba, A., de la Herràn, R., Garrido -Ramos, M.A., Ruiz-Rejòn, C., Ruiz-Rejòn, M. and Navas, J.I. 2008. Detection of Marteilia refringens using nested PCR an d in situ hybridisation in Chamelea gallina from the Balearic Islands (Spain). Disease of Aquatic Organisms, 82: 79 87. doi:10.3354/dao01966

OIE 2012. Manual of diagnostic tests for aquatic animals. Part 2, section 2.4, chapter 2.4.4 - Infection with Marte ilia refringens . Paris : 475 -486.

OIE 2014. Aquatic Animal Health Code 2014. Section 11, 4 - Infection with Marteilia refringens . Paris .

Rayyan, A., Damianidis, P., Antoniadou, C. and Chintiroglou, C.C. 2006. Protozoan parasites in cultured mussels Mytilus g alloprovincialis in the Thermaikos Gulf (north Aegean Sea, Greece). Disease of Aquatic Organisms, 70: 251 254. doi:10.3354/dao070251

Villalba, A., Mourelle, S.G., López, M.C., Carballal, M.J. and Azevedo, C. 1993. Marteiliasis affecting cultured mussels Mytilus galloprovincialis of Galicia (NW Spain). I. Etiology, phases of the infection, and temporal and spatial variability in prevalence. Disease of Aquatic Organisms, 16: 61 -72.

Virvilis, C., Angelidis, P. and Photis, G. 2003. Presence of the parasite Mar teilia sp. in the shellfish of the Thermaikos Gulf in northern Greece. Bulletin of European Association of Fish Pathologists, 23: 157 - 162.

Zrnčić, S., Le Roux, F., Oraić, D., otarić, B. and Berthe, F.C.J. 2001. First record of Marteilia sp. in mussel Mytilus galloprovincialis in Croatia. Disease of