We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Pathology of bacterial gill disease: sequential development of lesions during natural outbreaks of disease.
- Authors
Speare, D. J.; Ferguson, H. W.; Beamish, F. W. M.; Yager, J. A.; Yamashiro, S.
- Abstract
This study examines the sequential pattern of bacterial colonization and the sequential development of branchial lesions during typical outbreaks of bacterial gill disease (BGD) among four groups of commercially reared rainbow trout fingerlings, Oncorhynchus mykiss (Richardson). During a 5-month monitoring regime, prior to the onset of natural outbreaks of BGD, gill morphology of examined fish remained unaltered. Bacterial colonization of the gills was immediately preceded by several gill changes which were widely present in fish from all groups under study. These changes, which were detectable at the ultrastructural level only, included cytoplasmic blistering and degeneration of the microridges of the superficial filament epithelium, in addition to slight topographical irregularity of the filament tips suggestive of mild hyperplasia. Bacterial colonization began at these altered filament tips before spreading to more proximal regions of the filament and adjacent lamellar surfaces. Explosive increases in proportional morbidity and mortality coincided with the development of the following gill lesions: extensive bacterial colonization of lamellar surfaces, lamellar epithelial hydropic degeneration and necrosis, and lamellar oedema. In contrast, gill lesions such as lamellar fusion, epithelial hyperplasia and various metaplastic responses were detected later either as subacute (3-5 days) or chronic (7-14 days) changes. The role of epithelial necrosis as an important event during BGD is discussed as a possible mechanism leading to the development of sub-acute and chronic gill lesions.
- Subjects
BACTERIAL gill disease; PATHOLOGY; RAINBOW trout; EPITHELIUM; BACTERIAL diseases in fishes; HYPERPLASIA
- Publication
Journal of Fish Diseases, 1991, Vol 14, Issue 1, p21
- ISSN
0140-7775
- Publication type
Article
- DOI
10.1111/j.1365-2761.1991.tb00573.x