Comparison of light microscopic techniques for the diagnosis of the infection of the European flat oyster Ostrea edulis by the protozoan Bonamia ostreae.
A comparison among various histological techniques for the detection of the parasite Bonamia ostreae in oysters Ostrea edulis was performed to evaluate their sensitivity and suitability for different purposes. The comparison involved examination of histological sections, tissue imprints from gills, digestive gland, gonad and heart, and haemolymph cell monolayers, prepared through various protocols. Every technique produced some false negative. The haemolymph cell monolayers were more sensitive than tissue imprints and histological sections. Heart imprints provided the highest sensitivity among tissue imprints. Examination of histological sections was among the least sensitive techniques. Four procedures for estimation of infection intensity were compared. Some differences in accuracy for the estimation of infection intensity between haemolymph cell monolayers and histological sections (HS) were detected: there was a very good agreement when the infection appeared low or heavy in HS but it was not so good in the remaining cases. The results suggest the need for a critical review of the recommendations of the "Office Internationale des Epizooties" and the European Union for diagnosis of bonamiosis.
da Silva
P Mirella
PM
Centro de Investigacións Mariñas, Consellería de Pesca e Asuntos Marítimos, Xunta de Galicia, Aptdo. 13, E-36620 Vilanova de Arousa, Spain.
Villalba
Antonio
A
D000818:Animals; D005188:False Negative Reactions; D041602:Haplosporida / Q000302:isolation & purification*; D006321:Heart / Q000469:parasitology*; D006458:Hemolymph / Q000469:parasitology*; D006652:Histological Techniques / Q000379:methods*; D008853:Microscopy / Q000379:methods; D010125:Ostreidae / Q000469:parasitology*; D011529:Protozoan Infections, Animal / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity