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Extracellular Products Associated with Virulent and Avirulent Strains of Edwardsiella ictaluri from Channel Catfish
Author(s) -
Stanley L. A.,
Hudson J. S.,
Schwedler T. E.,
Hayasaka S. S.
Publication year - 1994
Publication title -
journal of aquatic animal health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 52
eISSN - 1548-8667
pISSN - 0899-7659
DOI - 10.1577/1548-8667(1994)006<0036:epawva>2.3.co;2
Subject(s) - virulence , edwardsiella ictaluri , catfish , biology , microbiology and biotechnology , extracellular , virology , gene , ictalurus , fish <actinopterygii> , genetics , fishery
Little is known about the pathogenic mechanisms possessed by Edwardsiella ictaluri , the etiological agent of enteric septicemia of catfish (ESC). Extracellular products probably play a major role in the pathogenesis of the disease. Comparative studies were done to assess the extracellular products present in virulent and in avirulent (attenuated) strains of E. ictaluri . Virulence factors studied were capsule production, detection of surface proteins, and hemolytic and chondroitinase activities. Electron microscopy showed a fibrilar network connecting virulent cells. Virulent isolates had greater amounts of capsular material and surface proteins, and they demonstrated a greater ability to degrade chondroitin than avirulent forms. There was no clear correlation between hemolytic activity and virulence.