RFLP analysis reveals marked geographical isolation between strains of Paracoccidioides brasiliensis

Restriction fragment length polymorphism (RFLP) was performed on 32 isolate s of the pathogenic fungus Paracoccidioides brasiliensis from geographicall y separated regions of South America. The use of HinfI and HincII gave clea r RFLP patterns, for which high discriminatory indices could be calculated. Computational analysis of the RFLP patterns for the 32 isolates suggested that at least five groups of strains existed, each of which was geographica lly distinct and corresponded closely with present country borders. These r esults underline the belief that P. brasiliensis infections are acquired fr om exogenous sources and that this fungus occupies specialist endemic niche s within the natural environment.