title: Viability, infectivity and fatty acid synthetic activity of Perkinsus marinus meront cells incubated in estuarine and artificial seawater.
abstract: We investigated the viability and fatty acid synthetic activity of in vitro cultured Perkinsus marinus (Dermo) in lipid-free medium and estuarine water, and the infectivity of P. marinus maintained in artificial seawater (ASW). Viability and fatty acid synthetic activity in 7 d old P. marinus meronts maintained in lipid-free medium and estuarine water were tested. The infectivity of meronts incubated in ASW was examined by first incubating P. marinus meronts in ASW for 2, 3 or 7 d, and then inoculating viable ASW-incubated meronts into the shell cavity of individual oysters Crassostrea virginica. P. marinus infection prevalence and intensity in oysters were determined 9 wk post-inoculation. Heavy mortality occurred in meronts maintained in estuarine water, a drop from an initial value of 100% viable to 7.8 and 6.1% after 3 and 14 d incubation, respectively. Viability was 85 and 67% in meronts maintained in lipid-free medium for 3 and 24 d, respectively. Meronts kept in lipid-free medium for 14 d retained their ability to synthesize fatty acids. Viable meronts incubated in ASW remained infective for up to 7 d. The infection prevalences were 85, 48 and 100%, in the treatments inoculated with viable meronts that were incubated in ASW for 2, 3 and 7 d, respectively. Infection prevalence in the group inoculated with viable meronts immediately after they were transferred to ASW ranged from 61 to 85%. Our results suggest that in nature meronts can survive for at least 14 d outside the host. Viable meronts are not only infective, but are also able to replicate and retain their fatty acid synthetic ability for 7 d.
authors.affiliation: Virginia Institute of Marine Science, College of William and Mary, Gloucester Point 23062, USA. chu@vims.edu
authors.forename: Fu-Lin E
authors.initials: FL
authors.lastname: Chu
authors.forename: Eric D
authors.initials: ED
authors.lastname: Lund
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D049896:Crassostrea / Q000469:parasitology*; D056890:Eukaryota / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*; D005227:Fatty Acids / Q000032:analysis / Q000096:biosynthesis*; D008018:Life Cycle Stages / Q000502:physiology; D012623:Seawater / Q000469:parasitology*; D013997:Time Factors
chemical_list: D005227:Fatty Acids