THE EFFECT OF CA(++) AND MG(++) ON LYSIS, GROWTH, AND PRODUCTION OF VIRULENCE ANTIGENS BY PASTEURELLA PESTIS
Abstract
Experiments were designed to define further the previously described phenomena of virulence antigen production, bacterial stasis, and lysis in virulent Pasteurella pestis. The observations made by Lawton (1960) that Mg(++) 'induces' and Ca(++) 'represses' virulence antigen production were verified. Optimal production of these antigens occurred in a chemically defined medium containing 0.02 M MgC12 and no added CaC12. As shown by Higuchi and others, this environment results in stasis of cells possessing the genetic potential to produce virulence antigens. The addition of 0.0025 M Ca(++) in the presence of 0.02 M Mg(++) completely repressed the production of these antigens and permitted cell division to occur. Cells of the rare avirulent mutant type that produce virulence antigens and form atypical colonies on agar made Ca(++)- deficient grow more slowly in Ca(++)-deficient broth than do those avirulent cells that produce no virulence antigens. Under these conditions, the former type produces a lower titer of virulence antigens than do virulent cells that remain static.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 27, 1963
- Accession Number
- AD0638407
Entities
People
- M. J. Surgalla
- R. R. Brubaker
Organizations
- United States Army Biological Warfare Laboratories