Ionic requirements of Treponema pallidum. III. Divalent ions

Abstract

Doak, G. O. (University of North Carolina, Chapel Hill), Leon D. Freedman, and John W. Clark, Jr. Ionic requirements of Treponema pallidum. III. Divalent ions. J. Bacteriol. 82:909-912. 1961.-Suspensions of Treponema pallidum, prepared by extracting the testes of syphilitic rabbits with normal rabbit serum or with a culture medium, were shaken with Amberlite IRC-50 resin in the sodium ion form. This procedure did not noticeably reduce the number of motile organisms, but markedly decreased their ability to survive in vitro. The addition of calcium, strontium, or barium ions to the treated suspensions largely restored this loss of motility. These same ions, when added to suspensions of T. pallidum not treated with the ion exchange resin, were without effect. Magnesium ion also had a beneficial effect, but considerably less than that produced by calcium ion. Cobaltous, manganous, ferrous, and zinc ions gave no beneficial effect, and, except for manganous ion, were toxic to the organisms at 5 x 10(-3)m.