Preliminary studies on a chlamydial agent in the digestive diverticular epithelium of hard clams Mercenaria mercenaria (L.) from Great South Bay, New York

Abstract. The prevalence of a chlamydial infection in hatchery-reared adult hard clams Mercenaria mercenaria (L.) from Great South Bay, Long Island, New York was relatively high and seasonally stable. Infection occurred early in life while juvenile clams were still within the hatchery. Fluorescent antibody tests suggested that the clam agent shares the group antigen specific for chlamydia, but to a lesser degree than a known chlamydial strain used as a positive control. The method of Gimenez failed to stain elementary bodies in clam cell inclusion bodies. Based on the observations of this study, the inclusion body agent in the hard clam differs from known strains of chlamydia. Characterization of the clam chlamydia must await the successful propagation of the agent.