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Further Characterization of a Complement-Sensitive Mutant of a Virulent Avian Escherichia coli Isolate
Avian Diseases (1997)
  • Theodore J. Kottom, North Dakota State University
  • Lisa K. Nolan, North Dakota State University
  • Michael Robinson, North Dakota State University
  • John Brown, University of Georgia
  • Tom Gustad, North Dakota State University
  • Shelley M. Horne, North Dakota State University
  • Catherine W. Giddings, North Dakota State University
An attempt was made to characterize the mechanism of complement resistance operating in a virulent avian Escherichia coli isolate. Using flow cytometry to detect antibody to C3, we found that there was significantly more antibody bound to a complement-sensitive mutant of this wild type than to the parent organism, suggesting that more C3 subunits were bound to the wild type. Neither the wild type nor the mutant degraded C3. Further, the mutant was phagocytosed to a significantly greater degree than the wild type by cultured phagocytes in the presence of C5-deficient serum. These data suggest that the wild type is resistant to complement, at least in part, because of its ability to restrict C3 deposition on its surface. Therefore, the decrease in virulence seen in the mutant may be related to its increased sensitivity to complement-mediated bacteriolysis or its enhanced susceptibility to complement-opsonized phagocytosis or both.
  • avian Escherichia coli,
  • avian colibacillosis,
  • virulence,
  • complement resistance,
  • phagocytosis resistance
Publication Date
December, 1997
Publisher Statement
Copyright 1997 American Association of Avian Pathologists. Posted with permission.
Citation Information
Theodore J. Kottom, Lisa K. Nolan, Michael Robinson, John Brown, et al.. "Further Characterization of a Complement-Sensitive Mutant of a Virulent Avian Escherichia coli Isolate" Avian Diseases Vol. 41 Iss. 4 (1997)
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