title: Characterization of Neoparamoeba pemaquidensis strains: PCR-RFLP of the internal transcribed spacer region from the amoeba and endosymbiont.
abstract: Neoparamoeba pemaquidensis continues to be an ongoing problem for commercial finfish aquaculture and has also sporadically been associated with mass mortalities of commercially relevant marine invertebrates. Despite the ubiquity and importance of this amphizoic amoeba, our understanding of the biology as it applies to host range, pathogenicity, tissue tropism, and geographic distribution is severely lacking. This may stem from the inability of current diagnostic tests based on morphology, immunology, and molecular biology to differentiate strains at the subspecies level. In the present study, we developed a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method based on the internal transcribed spacer (ITS) region that can accurately differentiate amoeba strains of N. pemaquidensis. The investigation focused on the complications of the amoeba ITS microheterogeneity in the development of a subspecies marker and the use of the endosymbiont, Ichthyobodo necator related organism (IRO), ITS region as an alternative marker. The combination of host amoeba and endosymbiont ITS PCR-RFLP analyses was successfully used to correctly identify and characterize an N. pemaquidensis isolate from an outbreak of amoebic gill disease in Atlantic salmon Salmo salar from the west coast of North America (Washington State, USA).
authors.affiliation: AVC Lobster Science Centre, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island C1A 4P3, Canada.
authors.forename: Charles G B
authors.initials: CG
authors.lastname: Caraguel
authors.forename: Nathanaëlle
authors.initials: N
authors.lastname: Donay
authors.forename: Salvatore
authors.initials: S
authors.lastname: Frasca
authors.forename: Charles J
authors.initials: CJ
authors.lastname: O'Kelly
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cawthorn
authors.forename: Spencer J
authors.initials: SJ
authors.lastname: Greenwood
mesh_terms: D000818:Animals; D017931:DNA Primers / Q000737:chemistry; D004262:DNA Restriction Enzymes / Q000378:metabolism; D021903:DNA, Ribosomal Spacer / Q000235:genetics*; D016840:Lobosea / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary*; D012150:Polymorphism, Restriction Fragment Length; D011528:Protozoan Infections / Q000469:parasitology; D011529:Protozoan Infections, Animal; D020317:Salmo salar / Q000469:parasitology*; D013997:Time Factors
chemical_list: D017931:DNA Primers; D021903:DNA, Ribosomal Spacer; D004262:DNA Restriction Enzymes