Revista do Instituto de Medicina Tropical de São Paulo
On-line version ISSN 1678-9946
SHIKANAI-YASUDA, M. A. et al. In vitro action of some disinfectants on Paracoccidioides brasiliensis yeast forms. Rev. Inst. Med. trop. S. Paulo [online]. 1991, vol.33, n.1, pp.37-43. ISSN 1678-9946. http://dx.doi.org/10.1590/S0036-46651991000100008.
The fungicidal action of sodium hypochlorite (0.3, 1, 2.5, 5 and 10%); formaldehyde (2, 5, and 10%); and ethyl alcohol (70%) on yeast forms of Paracoccidioides brasiliensis Pb 18 and a newly-isolated Goiana strain was described. Contact between the fungus and the disinfectants was maintained for 1, 2, 24, 48 and 72 hours at room temperature. Viability was evaluated by the fluorescein diacetate-ethidium bromide treatment, culture in solid and liquid media (36ºC and 26ºC); yeast to mycelial germination at room temperature; and radiometric study of metabolic activity. All concentrations of disinfectants were found to be effective in inactivating Pb 18 and Goiana strains, except for the 1-hour contact with 2% formaldehyde, in which fluorescein diacetate-ethidium bromide treatment was found to reveal 40 and 27% of viable cells, respectively. The yeast to mycelial germination method was considered to reveal faster and similar results as compared to culture in solid and liquid media.
Keywords : Paracoccidioides brasiliensis; Disinfectants; Fluorescein diacetate-ethidium bromide; Yeast to mycelial germination; Radiometric method; Sodium hypochlorite.