Whitney J G, Funderburk S S, Westhead J E, Lively D H, Solenberg J M, Denney J W
Appl Microbiol. 1972 Dec;24(6):907-10. doi: 10.1128/am.24.6.907-910.1972.
In addition to its implication in the virulence of Streptococcus pyogenes, the hyaluronic acid capsule produced by this bacterium renders it resistant to infection by bacteriophage. A method employing S. pyogenes and a bacteriophage incorporated into an agar plate was devised as a screen to detect compounds that inhibit the formation of the hyaluronic acid capsule. Filter-paper discs saturated with experimental compounds were applied to the surface of test plates containing host plus phage and control plates of host only. After incubation, inhibition of capsule synthesis was indicated by the presence of clear zones where phage infection and lysis had occurred. Zones of growth inhibition on control plates represented classical antibacterial activity. During the testing of over 6,000 fermentation samples, anticapsin, a unique metabolite, was discovered. Modification of incubation temperature, thickness of agar layers, and host-phage input ratios resulted in a quantitative assay method having a dose-response range of 4 to 160 mug of anticapsin.
除了与化脓性链球菌的毒力有关外，这种细菌产生的透明质酸荚膜使其对噬菌体感染具有抗性。设计了一种将化脓性链球菌和噬菌体掺入琼脂平板的方法作为筛选手段，以检测抑制透明质酸荚膜形成的化合物。将浸有实验化合物的滤纸圆盘应用于含有宿主加噬菌体的测试平板表面以及仅含宿主的对照平板表面。孵育后，通过噬菌体感染和裂解发生的清晰区域表明胶囊合成受到抑制。对照平板上的生长抑制区域代表经典的抗菌活性。在对6000多个发酵样品进行测试的过程中，发现了一种独特的代谢产物抗荚膜素。改变孵育温度、琼脂层厚度和宿主 - 噬菌体输入比例，得到了一种剂量反应范围为4至160微克抗荚膜素的定量测定方法。
