Improved method for the initiation of continuous cultures of the oyster pathogen perkinsus marinus (apicomplexa)

A simple method for initiating continuous cultures of Perkinsus marinus with hypnospores is described. The visceral mass of an infected eastern oyster Crassostrea virginica was first incubated in Ray’s fluid thioglycollate medium in order to produce large hypnospores from the smaller histozoic stages of the protozoan. Hypnospores were then purified and transferred into the eulture medium JL-ODRP-1 where, within a relatively short period of time, they further divided by either progressive cleavage or successive bipartition. These divisions produced large numbers of merozoites and flagellated cells. This two-step procedure surpassed the previously described method of initiating cultures from hearts of infected eastern oysters because a much higher number of purified, larger P. marinus cells could be obtained from a single infected eastern oyster. © 1995 Taylor & Francis Group, LLC