Physiological and pathogenic characteristics of Nocardia brasiliensis isolated from human mycetomas.

A previous analysis of the physiological properties of Nocardia brasiliensis strains isolated from soil of Tucumán proves that non-pathogenic strains have a different behaviour pattern from the pathogenic strains. In the present paper, 16 Nocardia brasiliensis strains isolated from human mycetomas were studied in the same way. The object is to determine if any of the Nocardia brasiliensis present in soil can produce human mycetomas. The macro and micromorphological, biochemical (17 tests), physiological (4 tests) and pathological characteristics were determined for each of the strains. Experimental pathogenicity was determined using albino Swiss mice by inoculation into the footpads. The strains of Nocardia brasiliensis that cause human mycetomas have the same physiological pattern and experimental pathogenicity as the virulent strains present in soil.