Loma salmonae is an intracellular obligate parasite of farmed chinook salmon (Oncorhynchus tshawtscha) and is the causative agent for microsporidial gill disease (MGD). The infection occurs mainly in secondary gill lamellae, with the formation of large white spore-laden xenomas within the endothelia...

Cytokine genes in fish -- Environmental effects on the ontogeny of non-specific and specific defenses in turbot larvae -- Antibacterial proteins in skin mucus from rainbow trout -- Interferon-induced genes in the rainbow trout -- IPN recombinant vaccines -- DNA vaccination during low temperature and...

We studied the morphology and occurrence of splenic Langerhans-like (LL) cells in species representing 11 orders of ray-finned fishes, Actinopterygii. LL cells were frequent in spleen tissue of species among Cypriniformes, Esociformes, Salmoniformes, and Pleuronectiformes. These cells contained gran...

Two distinct monoclonal antibodies (MAB) were prepared for testing with kidney, spleen, and retrobulbar tissue imprints made from chinook salmon (Oncorhynchus tshawytscha) affected with plasmacytoid leukemia. (PL). Hybridomas were prepared from mice immunized with whole and lysed cells purified from...

Physiological, immunological and biochemical parameters of blood and mucus, as well as skin histology, were compared in 3 salmonid species (rainbow trout Oncorhynchus mykiss, Atlantic salmon Salmo salar and coho salmon O. kisutch) following experimental infection with sea lice Lepeophtheirus salmoni...

The intracellular microsporidian parasite Loma salmonae affects salmonids of the genus Oncorhynchus and is a significant cause of economic losses in pen-reared Chinook salmon (O. tshawytscha) in British Columbia. Loma salmonae infection is easily recognized by the xenomas that form in the gills, but...

In contrast to mammalian therapeutics, the use of pharmaceutical substances is rather limited in fish. It is basically restricted to anaesthetic agents and anti-infective agents for parasitic and microbial diseases. Anaesthetic agents are used primarily in fish farm and laboratory settings to provid...

Lepeophtheirus salmonis is capable of causing severe damage to Atlantic salmon and this study was conducted to examine the physiological response of salmon to the stress of sea lice infestation. Smoltified salmon were acclimatized in 30% saltwater and exposed to high levels of lice infestation. The ...

The presence of dendritic cells in fish is studied with immunohistochemistry using a commercially available antibody developed against Langerin/CD207 present in human Langerhans cells. Langerin/CD207, a protein known to be associated with the development of Birbeck granules in human and murine syste...

Immune response to fish microsporidia is still unknown and there are current research trying to elucidate the events involved in the immune response to this parasite. There is evidence suggesting the role of innate immune response and it is clear that adaptive immunity plays an essential part for el...

Pond-reared channel catfish Ictalurus punctatus with proliferative gill disease (PGD), caused by the myxozoan parasite Henneguya spp., were examined with light and transmission electron microscopy to better characterize the inflammatory response during infection. The early stages of disease are char...

Infection of rainbow smelt Osmerus mordax with the microsporidian Glugea hertwigi was diagnosed for the first time in Prince Edward Island, Canada. The prevalence of infection was 24%, 45 infected out of 187 examined fish captured in February and March 2009. Both large and small xenomas of G. hertwi...

The induction of protection against xenoma development by vaccinated (previously exposed to a low-virulence strain of Loma salmonae; n=40) and naive (n=40) rainbow trout (Oncorhynchus mykiss) challenged with the virulent typical strain of L. salmonae, was determined. Prevalence of infection was lowe...

In determining the effective vaccine spore dose of a low-virulence strain of Loma salmonae to limit micro-sporidial gill disease in trout, we found that fish receiving 10(3) to 10(5) killed spores had the best protection against experimental infection, with 85% fewer xenomas in their gills than in t...

Resistance to re-infection of rainbow trout to Loma salmonae, a microsporidian gill parasite has been previously documented and this study examined how rapidly this resistance develops. Naive rainbow trout were inoculated intraperitoneally (IP) with an inactivated spore-based vaccine and were then g...

The early ultrastructural stages of Loma salmonae were studied in the gills of experimentally infected rainbow trout. No parasitic stages were identified during the first 2 wk of the infection. By week 3 postexposure (PE), uninucleate and binucleate meronts were recognized within host cells (no xeno...

Epidemic mortalities of chinook salmon alevins (Oncorhynchus tshawytscha) have occurred annually at a freshwater hatchery at the Chehalis River, British Columbia, Canada, since 1982. Previous work has identified branchial epithelial hyperplasia as the predominant pathological change. Our initial wor...

Two studies were designed to quantify the effect of water temperature and flow rate on the transmission potential of the important salmonid gill pathogen, Loma salmonae. Using survival analysis, increased water temperature and low flow rates were determined as risk factors for the transmission of mi...

Infection by a microsporidian of the genus Loma was found in gills of cod Gadus morhua. Xenomas contained parasites in multiple stages of development. Some spores looked empty and had everted polar tubes, which were either straight or coiled. These polar tubes were scattered throughout the xenoma cy...

We used hydrogen peroxide to reproduce gill lesions typical of a broad assemblage of gill diseases encountered in aquaculture, and examined the degree of growth rate depression that it caused. Additionally, we compared growth rates of 60 gill-damaged fish when they were either kept separate from (n=...