Effect of moderately elevated temperatures on dermatophyte survival in clinical and laboratory-infected specimens

The effect of increased temperature during transportation of clinical dermatophyte specimens was investigated. Recovery rates from untransported specimens cultured at dermatologists' offices and from duplicate transported specimens were compared. During the months of hot weather specimens could be exposed intermittently to temperatures as high as 60 degrees C during transportation from Tucson area clinics to the University laboratory. The rates of recovery from known positive specimens were found not to be significantly different at these places regardless whether specimens were transported during the hot months or cooler months of the year. In a controlled experimental approach to the effect of this elevated temperature on clinical specimens weighed amounts of skin scales collected from guinea pigs artificially infected with Trichophyton mentagrophytes were exposed to 60 degrees C for up to four hours and then digested with 0.5% (:300) trypsin for one hour. Analysis of plate counts done from the digestion mixture showed no significant difference between counts obtained from specimens exposed to elevated temperature and unexposed controls.