Chlamydia-like organisms in ctenidia and mantle cells of the Japanese oyster Crassostrea gigas from the French Atlantic coast

Abstract

Grossly visible lesions of the ctenidia and occasional mortalities in Japanese oyster Crassostrea gigas from the Atlantic French coast were reported in

Branchial lesions associated with abundant apoptotic cells in oysters Ostrea edulis of Galicia (NW Spain)

“…In this work, the oysters with gill lesions associated with profuse apoptosis did not show histological evidence of either Bonamia ostreae or gill disease, the latter of which is characterized by the presence of giant cells with hypertrophied nucleus and the occurrence of iridovirus (Comps & Duthoit 1979). Renault & Cochennec (1994, 1995 reported Rickettsia and Chlamydia in epithelial and mantle cells of the Japanese oyster caused heavy haemocytic infiltration, but they were not detected in this study. With regard to histology and cytology, the most remarkable characteristic of the lesions was the abundance of atypical cells showing apoptotic features similar to those described in human cells undergoing apoptosis (Arends & Wyllie 1991).…”

Characterization of intracytoplasmic prokaryote infections in Dreissena sp. (Bivalvia: Dreissenidae)

“…1). Gross indentations in the gills of Pacific oysters resulting from tissue destruction by chlamydia-like organisms have been reported (Renault & Cochennec 1995), but the prokaryote inclusion bodies themselves were too small for gross observation. Tumorlike lesions, considered the result of traumatic irritation or infection with rod-shaped bacteria, were observed in the mantle and gills of Dreissena polymorpha by Morton (1974).…”

“…Renault & Cochennec (1995) recorded a chlamydia-like infection in the connective tissue cytoplasm of the gills and mantle of Japanese oysters. In a study of the hard clam Mercenaria mercenaria, Otto et al (1979) found rickettsiae-like organisms most frequently in gill connective tissues.…”

“…A highly sensitive and specific diagnostic DNAbased probe (Kellner-Cousin et al 1993) could serve as a practical tool for detection and quantification of Dreissena's prokaryotes. Efforts to clarify the taxonomic position of Dreissena's prokaryotes could specifically make use of techniques such as antigenic structure determination (Renault & Cochennec 1995), protein electrophoresis (Le Gall & Mialhe 1992), and analysis of genomic content (e.g., 16S, internal transcribed spacer, and 23S ribosomal DNA sequencing, Mauel et al 1999).…”

Two Vibrio splendidus related strains collaborate to kill Crassostrea gigas: taxonomy and host alterations

“…As soon as mortality was observed in the individuals experimentally challenged by injection in the adductor muscle, moribund and live oysters in all conditions were fixed in Davidson's or Carson's fixative (Renault & Cochennec 1995). For oysters injected in the pallial cavity, individuals were fixed in Davidson's fixative as soon as they displayed a weakness of the adductor muscle.…”