The life history of Marteilia refringens was investigated. The infectivity of purified early and late stages of M. refringens to oysters (Ostrea edulis) was tested in the laboratory using different routes of inoculation. Naturally infected oysters were monitored in experimental tanks to study infect...

Bonamia sp. is a pathogenic parasite that occurs in the haemocytes of dredge oysters Ostrea chilensis Philippi in New Zealand. Ultrastructurally it resembles other haplosporidians in the possession of haplosporosomes, haplosporogenesis, persistence of mitotic microtubules during interphase and of th...

This supplement presents the results of a survey on Mediterranean aquaculture diagnostic laboratories, which has been implemented by the Mediterranean Institute of Zaragoza (IAMZ) in collaboration with the FAO Fisheries Department. The aim of the survey is to acquire greater knowledge on the Mediter...

Since 1990, outbreaks of haemorrhagic septicaemia, frequently associated with keratitis, have occurred on gilthead sea bream (Sparus aurata [Pagrus aurata]), farmed along the French Mediterranean and Atlantic coasts. Several bacterial isolates obtained from diseased sea bream, sea bass (Dicentrarchu...

Bonamia ostreae is a protozoan parasite of the flat oyster, Ostrea edulis, which has caused significant loss of oysters in Europe over the last decade. B. ostreae was purified from infected flat oysters and DNA was extracted. The nearly complete small subunit rDNA gene of B. ostreae was amplified us...

In France abnormal mortalities of mollusks affect many species of bivalves. They occur mainly in summer and concern all the French coastline. For Crassostrea gigas, they affect all life's stages but more particularly spat. A pathology monitoring network, REPAMO, was created at the beginning of ...

The pathogens related to summer mortality outbreaks are a herpes virus and two bacterial strains one belonging to Vibrio splendidus biovar II and the other to Vibrio splendidus spp. However, the feature pathogen/opportunist of these strains is still unknown. Several strains belonging to the genus Vi...

Marteilia refringens is one of the most significant pathogens of bivalve molluscs. Previous sequencing of the small subunit ribosomal RNA gene of M. refringens isolates derived from the infected mussels (Mytilus edulis and Mytilus galloprovinciallis) and the oyster (Ostrea edulis) in Europe did not ...

Different strains related to Vibrio splendidus have been associated with infection of aquatic animals. An epidemiological study of V. splendidus strains associated with Crassostrea gigas mortalities demonstrated genetic diversity within this group and suggested its polyphyletic nature. Recently 4 sp...

Marteilia refringens is recognized as one of the most significant pathogens of bivalve molluscs. The nucleotide sequence of the small subunit ribosomal RNA gene of Marteilia refringens is used to elucidate the phylogenetic position of the phylum Paramyxea. Genomic DNA was extracted from sporangia of...

Since 1968, Marteilia refringens bas caused serious and recurrent mortalities in the European flat oyster (Ostrea edulis) and continues nowadays to cause high mortalities in the Atlantic coast of France. Under the EEC Council directive 91/67 this parasite is included in list 2 of Annex A. This list ...

Viral gametocytic hypertrophy has been reported for the first time in 2001 in Pacific oyster Crassostrea gigas in France. Male and female gametes were hypertrophied, and basophilic inclusions were observed in gamete nuclei. Electron microscopy revealed the presence of viral particles with characteri...

A molecular typing study on Vibrio strains implicated in shrimp disease outbreaks in New Caledonia and Japan was conducted by using AP-PCR (arbitrarily primed PCR). It allowed rapid identification of isolates at the genospecies level and studies of infraspecific population structures of epidemiologi...

The French mollusc production is mainly based on the Pacific cupped oyster, Crassostrea gigas. Since 1991, outbreaks of mass mortality of juveniles have been reported during the summer period. These outbreaks are a major concern for the oyster industry. Several studies have established given bacteri...

We have cloned and characterized a cDNA encoding Cg-TIMP, the first tissue inhibitor of metalloproteinase identified in mollusks. The isolated cDNA encodes a protein of 221 residues that has a domain organization similar to that of vertebrate TIMPs including a signal sequence, and the 12 cysteines c...

Among mollusc pathogens, paramyxeans are an important group of protistan parasites belonging to the genera Marteilia and Marteilioides. Martelia refringens and M. sydneyi are of particular concern given their potential impact on mollusc aquaculture world-wide. Aber disease and QX disease are current...

In 1999, the world aquaculture production of molluscs was estimated at 9.4 million tonnes which represents approximately a 23% contribution to the global aquaculture production. Aquaculture of molluscs has been growing at an average annual rate of 11% over the past decades, although some activities ...

A nested polymerase chain reaction (PCR) has been developed for the diagnosis of Marteilia refringens in mussels (Mytilus galloprovincialis) from Galicia (NW Spain). Specific primers were used in two consecutive amplification reactions, that were able to detect 15 fg of Marteilia DNA. The nested PCR...

Disseminated neoplasia (DN) is a disorder referred to as hemic neoplasia (HN) in the soft-shell clam Mya arenaria. Traditionally, diagnosis is performed by hematocytology or histology. The intensity of the disease is generally given as the percentage of transformed neoplastic cells Out of total numb...

The molecular mechanisms by which haemocytes of clams are transformed in the course of haemic neoplasia remain by far unknown. The aim of this study was to quantify the expression of p53/p73 and mortalin genes, in relation with the ploidy status of clam haemocytes and to correlate the p53 expression...