A Study for the Survival Period of Dermatophytes According to Various Conditions

Suh, Moo Kyu; Sung, Yeol Oh; Yoon, Ki Seong

Abstract

BACKGROUND: Despite concern about prevention of dermatophytosis, little is known about the survival period of dermatophytes.
OBJECTIVE
The purpose of the study was to investigate the survival period of dermatophytes according to various environmental conditions.
METHODS
Scales for testing were collected from skin lesions of 25 patients with dermatophytosis. They were categorised into different treatment groups: kept scales themselves(S), scales in a humid condition(S+H), scales mixed with sterilized dusts(S+D), and scales mixed with sterilized dusts in a humid condition(S+D+H). They were then cultured on Sabouraud dextrose agar once a week until there was no colony growth. Data was evaluated with the Mann-Whitney U-test.
RESULTS
1) The mean survival period of Microsporum canis isolated from 5 patients with tinea(T.) capitis was 17.6(S+D+H), 16.6(S+D), 8.4(S+H) and 7 weeks(S). 2) The mean survival period of Trichophyton rubrum isolated from 20 patients of T. corporis, T. cruris, T. pedis & T. unguium was 11.8, 7.4, 9.4 and 12.2 weeks(S+D+H); 7.4, 6.8, 9.2 and 7.4 weeks(S+D); 6.6, 3.4, 8.0 and 10.4 weeks(S+H); 5.0, 2.8, 5.4, 8.2 weeks(S), respectively.
CONCLUSION
We found that the survival period of dermatophytes was longest in scales mixed with sterilized dusts in a humid condition.