STUDIES ON HISTOPLASMOSIS FARCIMINOSSII ( EPIZOOTIC LYMPHANGITIS ) IN EGYPT IV- The biochemical characters of local isolates of Histoplasma Farcimonosum and their sensitiity to antimycotic and disinfectants in vitro

Document Type : Research article

Authors

Abstract

The biochemical activities of the mycelial form of 4 locally isolated strains of Histoplasma farciminosum were identical, they were catalase positive, urease positive within 1-2 hours and could assimilate ammonium chloride as a sole source of nitrogen. At the same time, there was no growth on sugars, nitrate and gelatine media even after 6 weeks inculation at 25°C or 37°C.
The sensitivity of both yeast parasitic and mycelial cultural forms to diferent dilutions of 4 types of antimycotic drugs in dextrose-glycerol-PPLO media revealed that Canestin was the most effective drug and the Minimal Inhibitory Concentra tion (M.I.C.) on both forms was 1.25 ug/ml. On contrary fun gizone showed the least activity with M.I.C. of 100.0 ug/ml for both forms.
Regarding the effeciency of the commonly used disinfectants, it was found that 1% Crown for 20 minutes, 3% Longlife for 5 minutes and 3% Quanternary Ammonium for 10 minutes were effective in vitro on the mycelial cultural form. On the contrary, the yeast parasitic form was more sensitive to a lower concent ration, where 0.5% of Crown and Longlife were effective after 5 minutes application in vitro.