Ultrastructural Aspects of the Causative Agent and Renal Histopathology of Bacterial Kidney Disease in Brook Trout (<i>Salvelinus fontinalis</i>)

Abstract

The renal histopathology of bacterial kidney disease in both naturally and experimentally infected brook trout (Salvelinus fontinalis) was investigated here on the ultrastructural level. Abnormal changes in the glomerulus and renal tubule during the experimental infection are described chronologically and compared with the changes observed in the fully developed natural infection. These abnormalities are similar to those occurring in mammalian renal disease. Evidence of a host immune and inflammatory response is presented. The bacterial strains involved in the two infections are compared in cell size, internal morphology, and manner of division to help characterize the as yet unclassified causative agent. Key words: morphology, fine structure, pathology, Corynebacterium, renal, bacterium, trout, disease, Salmonidae