Demonstration of Sulfonamide Inhibitor Production by Bacteria on Agar Containing Sulfonamide

Abstract

Growth was obtained from small inocula of streptococci, staphylococci, pneumococci and Shigella sonnei on concs. of sulfonamide ordinarily inhibitory provided growth of certain other bacteria was also present on the same plate. A satellite phenomenon resulted with colonies of susceptible bacteria appearing within the zone of influence of colonies of the resistant strain. In general, the ability of a microorganism to induce satellite growth was associated with its production of extracellular sulfonamide inhibitor. Highly resistant bacteria did not necessarily stimulate satellite formation.