T. Nishikawa et W. Naka, EVALUATION OF ANTIFUNGAL EFFECTS OF TERBINAFINE AND ITRACONAZOLE USING NEUTRAL RED STAINING, British journal of dermatology, 130, 1994, pp. 4-6
Neutral red staining is a newly described method for evaluating the vi
ability of fungal cells. Using this method, the antifungal effects of
terbinafine and itraconazole were evaluated in vitro. When the number
of neutral red-positive Trichophyton mentagrophytes conidia treated wi
th these two oral antifungals was compared with the number of culture-
proved viable T. mentagrophytes conidia, a strong positive correlation
was found. This result confirms that neutral red staining is a useful
method for evaluating the viability of T. mentagrophytes in vitro, an
d that it can be used for the evaluation of antifungal activity. We co
nclude that the effectiveness of an antifungal drug should not be eval
uated by direct microscopic examination alone, but with the additional
aid of mycological culture or neutral red staining.