I. Effect of Dyes on Colonies of Certain Pathogenic Fungi

Abstract

In the present work observations were made of the growth of certain pathogenic fungi on a medium containing alcoholic nigrosine and one containing litmus.∗

The medium† consisted of 4% peptone, 1% dextrose, 1 1/2% agar in distilled water and was adjusted to pH 5.5 and saturated with dye by heating, filtered and autoclaved. Sabouraud's proof medium and a control medium without dye also were planted. The dyes were incorporated in the 4% peptone, 1% dextrose medium instead of Sabouraud's proof medium since we felt that with this medium moisture was retained better, there was better differentiation, growth was as rapid and slightly more profuse and, as a rule, less aerial. In many instances the growth showed a frosted surface effect resembling the growth of yeasts which type of growth was absent in the case of Sabouraud's proof medium. Difco products were used.

The following pathogenic fungi and 2 saprophytes, Lichtheimia sp. and Scopulariopsis brevicaulis were observed: Achorion schoenleinii, Acladium castellani, Candida candida, Endodermophyton tropicale, Endomyces capsulatus, Endomyces dermatitidus, Epidermophyton inguinale, Glenospora gammeli, Geotrichum bachmann, Indiella americana, Monosporum apiospermum, Microsporon audouini, Monilia albicans, Oöspora humi, Trichophyton crateriforme, Trichophyton granulosum, Trichophyton japonicum, Trichophyton interdigitale, Willia anomala. Observations were limited to 30 days. The tubes were kept at room temperature and growth occurred in all within 3 days.