Demonstration of toxicity to fish and to mammalian cells by Pfiesteria species: Comparison of assay methods and strains

摘要: Toxicity and its detection in the dinoflagellate fish predators Pfiesteria piscicida shumwayae depend on strain use of reliable assays. Two assays, standardized bioassays (SFBs) with juvenile microassays (FMAs) larval fish, were compared for their utility to detect toxic Pfiesteria. The comparison included strains confirmed toxicity, negative controls (noninducible a related nontoxic cryptoperidiniopsoid dinoflagellate), P. CCMP2089, which previously had been reported as nontoxic. SFBs, by using (coupled tests confirming toxin) conditions conducive toxicity expression, reliably detected actively Pfiesteria, but FMAs did not. toxin was found fish- algae-fed clonal cultures, including not controls. In contrast, noninducible cryptoperidiniopsoids caused no mortality SFBs even at high densities, low physical attack FMAs. Filtrate from spp. bacteria-free media cytotoxic. enhanced bacteria other prey, especially live fish. Purified extract adversely affected mammalian cells well it death environmentally relevant cell densities. These data show importance testing multiple when assessing potential genus or species level, appropriate culturing techniques