Geographic Discrimination of Paracoccidioides brasiliensis Strains by Randomly Amplified Polymorphic DNA Analysis

Abstract

Randomly amplified polymorphic DNA (RAPD) analysis of 33Paracoccidioides brasiliensis strains from Argentina, Brazil, Colombia, Peru, and Venezuela produced reproducible amplification products which were sufficiently polymorphic to allow differentiation of the strains. Types generated with five primers (OPG 03, OPG 05, OPG 14, OPG 16, and OPG 18) resulted in a high discriminatory index (0.956). The discriminatory index was slightly reduced (0.940) when only two primers (OPG 3 and OPG 14) were used. A dendrogram based on these results showed a high degree of similarity among the strains, and genetic differences were expressed in clusters related to geographical regions but not to pathological features of the disease. With a few exceptions, strains were sorted into five groups by geographical origin as follows: group I, Venezuelan strains; group II, Brazilian strains; group III, Peruvian strains; group IV, Colombian strains; and group V, Argentinian strains. The group containing the most disparate strains was group V (discriminatory index, 0.633); the discriminatory index for the other four groups was 0.824. The use of primer OPG 18 by itself was sufficient to discriminate species specificity, and the use of primer OPG 14 by itself was sufficient to discriminate among the geographical locations of the strains in the sample. This method may be helpful for epidemiological studies ofP. brasiliensis.

Polymorphism in the Gene Coding for the Immunodominant Antigen gp43 from the Pathogenic Fungus Paracoccidioides brasiliensis

“…Despite their distinct sources (one from soil and another from a patient with acute PCM), isolates Pb15 and Pb16 were both from Venezuela. That might not be coincidental, since by randomly amplified polymorphic DNA (RAPD) analysis with a selected primer, Calcagno et al (6) were able to cluster P. brasiliensis isolates according to the country of isolation, suggesting that the fungus might be under environmental genetic pressure. Although Pb2, also from Venezuela, was in a genetically distant group in terms of gp43 sequences, it shared two substitution sites (sites 617 and 799) with the Venezuelan group.…”

“…Genetic polymorphism in P. brasiliensis has been detected in the past by RAPD analysis (6,32,37) and chromosome analyses (8,21). It is also known that individual isolates show different degrees of pathogenicity in susceptible inbred mice (15,33,35).…”

What is your diagnosis? Subcutaneous mass fluid from a febrile dog

“…do not have a yeast form, and the adiaspores do not divide by budding. P. brasiliensis is found only in Central and South America, and yeast forms resemble a steering wheel 8 . Yeast forms of H. capsulatum are round to oval and 2–4 μm in diameter 9…”

Cloning and expression analysis of the ornithine decarboxylase gene (PbrODC) of the pathogenic fungus Paracoccidioides brasiliensis

“…DNA was isolated as previously described (Calcagno et al , 1998). For RNA isolation, 100 ml aliquots of a 700 ml quantity of PYG liquid culture were vacuum‐filtered through Whatman No.…”