Comparison of diagnosis techniques for the protozoan parasite Bonamia ostreae in flat oyster Ostrea edulis

In recent years, the cultured production of the flat oyster Ostrea edulis has suffered a dramatic decrease in Europe partially attributed to the protozoan parasite Bonamia ostreae, the causative agent of the Bonamiosis. In this paper the results of a PCR assay for the diagnosis of B. ostreae were compared with those obtained using two classical methods of diagnosis recommended by the OIE (Office International des Epizooties) and the European Union, histology and cytology. The same samples were analyzed by two different laboratories, showing that the results obtained with the PCR method have high sensitivity and good correlation between laboratories. This method is cheaper and faster than histopathology and cytology, with no need of specifically trained personnel to perform the diagnoses. It is appropriate for fast screening of stocks of great numbers of oysters.