title: Patterns of occurrence and 18S rDNA sequence variation of PKX (Tetracapsula bryosalmonae), the causative agent of salmonid proliferative kidney disease.
abstract: Recent progress in understanding the etiology of proliferative kidney disease (PKD) includes the identification of freshwater bryozoans as the natural hosts of the myxozoan parasite that causes the disease in salmonid fish and formal description of the parasite as Tetracapsula bryosalmonae. This paper presents data on patterns of occurrence of T. bryosalmonae and sequence variation among isolates. T. bryosalmonae infects bryozoans that range from primitive to more derived genera within the Phylactolaemata and that differ in growth form and habits. Infected bryozoans have been collected in diverse habitats including cold, clear streams and warm, eutrophic lakes. Temporal surveys reveal intra- and interannual variation in infection levels, and spatial variation in incidence of infection is implicit by the apparent absence of T. bryosalmonae from many bryozoan populations. The significance of minor variation in partial sequences of 18S rDNA requires further investigation. The information presented here provides the first significant insights into the ecology of T. bryosalmonae.
authors.affiliation: School of Animal and Microbial Sciences, The University of Reading, Whiteknights, UK.
authors.forename: B
authors.initials: B
authors.lastname: Okamura
authors.forename: C L
authors.initials: CL
authors.lastname: Anderson
authors.forename: M
authors.initials: M
authors.lastname: Longshaw
authors.forename: S W
authors.initials: SW
authors.lastname: Feist
authors.forename: E U
authors.initials: EU
authors.lastname: Canning
mesh_terms: D000818:Animals; D002013:Bryozoa / Q000469:parasitology*; D002170:Canada / Q000453:epidemiology; D004275:DNA, Ribosomal / Q000737:chemistry*; D056890:Eukaryota / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D005393:Fish Diseases / Q000453:epidemiology / Q000469:parasitology*; D014644:Genetic Variation; D006790:Host-Parasite Interactions / Q000235:genetics; D007674:Kidney Diseases / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D008018:Life Cycle Stages; D017686:Oncorhynchus mykiss; D015995:Prevalence; D011529:Protozoan Infections, Animal / Q000453:epidemiology* / Q000469:parasitology; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D017422:Sequence Analysis, DNA; D014481:United States / Q000453:epidemiology
chemical_list: D004275:DNA, Ribosomal; D012337:RNA, Ribosomal, 18S