A Medium for the Study of the Ecology of Human Cutaneous Diphtheroids

SUMMARY: A new medium (FTO), selective for Gram-positive bacilli from human skin, was developed, consisting of trypticase-soy, yeast-extract agar supplemented with (i) Tween 80 (0.5%) to support growth of lipophilic corynebacteria, (ii) Oil Red O (0.0005%) to distinguish lipophilic from non-lipophilic bacteria, and (iii) Furoxone (50 to 100 μg./ml.) to inhibit growth of Gram-negative bacilli and Gram-positive cocci. Furoxone may be used to render other media selective for more fastidious diphtheroids.