The main objective of this investigation was to examine the ultrastructural features of gills from @entity5660 experimentally infected with Loma salmonae to determine the morphological events that occur during the late stages of development of this parasite. Peripheral distribution of the mature parasites inside round xenomas was observed at weeks 5 and 6 postexposure (PE), but eventually the parasite occupied the entire xenoma. Degenerative changes were observed only in immature parasites at week 7 PE, and eventually an @entity32 reaction with a cellular infiltration was directed against mature spores. Round, flattened, and irregular shaped xenomas were observed at week 8 PE. The round xenomas showed a severe @entity32 response with disintegration of the xenoma membrane. This event was accompanied by @entity5274 and by the simultaneous presence of 2 tubular appendages, the type I and II tubules. Flattened xenomas were observed below the endothelium of gill lamella arteries. The irregular xenomas were located in the connective tissue of the gill filament and showed multiple projections occupied by spores. Both flattened and irregular xenomas showed no evidence of @entity32 reaction. An earlier proposed hypothesis is expanded to explain how L. salmonae is implanted beneath lamellar endothelium and within filament connective tissue.

Ultrastructural study of the late stages of Loma salmonae development in the gills of experimentally infected XXXX .

@entity32 :: ('MESH:D007249', 'Disease') :: ['inflammatory'] @entity5660 :: ('8022', 'Species') :: ['rainbow trout'] @entity5274 :: ('MESH:D005184', 'Disease') :: ['eversion of polar tubes within the attacked xenoma']
@entity5660 :: (8022,Species) :: ['rainbow trout']
