Proliferative kidney disease: first reported outbreak in North America

Abstract

Proliferative kidney disease (PKD) was diagnosed in rainbow trout, Salmo gairdneri Richardson, at the Hagerman, Idaho, State Fish Hatchery. Wild fish from Riley Creek, one of the hatchery water supplies, were infected with PKD organisms. Clinical signs, gross pathology and histopathology of affected fish were typical of those reported for PKD in salmonids from European hatcheries. In addition to lesions normally seen, we observed a severe vasculitis and occlusion of renal and hepatic vessels. Ultrastructure of the PKD organism and possible inclusion body production sites are described. The disease outbreak was complicated by the presence of other infectious diseases. This is the first recorded outbreak of PKD in North America.

Observations on the electron-dense bodies of the PKX parasite, agent of proliferative kidney disease in salmonids

“…This fusing of membranes was previously noted by Ferguson & Needham (1978). However, exocytosis of the bodies' contents as described by Smith et al (1984) was never observed in this study, suggesting that it is a relatively rare phenomenon. When the bodies fused with the plasmalemma in this study, their electron-dense contents were not ejected extracellularly; rather the bodies appeared to interact with the plasmalemma, adding, exchanging or removing a substance from it.…”

“…When the bodies fused with the plasmalemma in this study, their electron-dense contents were not ejected extracellularly; rather the bodies appeared to interact with the plasmalemma, adding, exchanging or removing a substance from it. Due to the density of the plasmalemma in areas where the bodies fuse, it has been suggested that it is the dense substance of the cell membrane that is being transported (Smith et al 1984). The purpose of this material is unclear although it may be involved in evasion of the immune response or in the physical strengthening of the membrane.…”

“…This may be due to the orientation of the EDBs in the section or may be because the lucent 'T's represent a specific part of the EDBs developmental pathway, where they possess relatively large concentrations of unsaturated lipids. Smith et al (1984) described the production of the EDBs in PKX both by the Golgi apparatus and by a vesicular entity. Although these 2 structures were apparently morphologically dissimilar, these authors did not rule out the possibility these structures were part of the same production system.…”

Interrelationships of cytoplasmic structures in Bonamia sp. (Haplosporidia) infecting oysters Tiostrea chilensis: an interpretation

“…There is evidence they are exocytosed (Perkins 1968, Smith et al 1984, Azevedo & corral 1985, Scro & Ford 1990, and may cause host cell lysis (Perkins 1979, Scro & Ford 1990. Alternatively, it has also been suggested that they participate in spore wall formation (Newman et al 1976), and Golgi-derived dense bodies in Paramarteilia orchestiae appear to fulfil this function (Ginsburger-Vogel & Desportes 1979).…”

“…Structures resembling haplosporosomes are not confined to haplosporidians, but also occur in Pararnyxa paradoxa (Desportes 1981), in the vegetative stages of myxozoans (Smith et al 1984, Kent & Hedrick 1985, Lom et al 1989, and in the primary cells of Marteilia sydneyi and its relatives (Perkins 1976 (Perkins 1969, Desportes & Nashed 1983, Smith et al 1984, Azevedo & Corral 1987, Larsson 1987, Lom et al 1989, from dense or formative inclusions derived from the spherule (Perkins 1975, Marchand & Sprague 1979, Ball 1980, Ormieres 1980, La Haye et al 1984, Hillman et al 1990), or from MVB (Perkins 1968, 1976, Perkins & Wolf 1976, Seagrave et al 1980, Desportes 1981.…”