Randomly amplified polymorphic DNA (RAPD) has been successfully used to detect genetic variations among isolates of Paracoccidioides brasiliensis. However, the usefulness of this technique for assessing important parasitic properties is still unconfirmed. In the present work we further investigated the applicability of RAPD in revealing important intrinsic and extrinsic features of this fungus associated with geographical origin, time of isolation, source of clinical specimen, clinical forms of human disease and also in vitro and in vivo susceptibility to antimicrobial and antifungal drugs. The RAPD patterns allowed us to distinguish all of the analyzed strains, which included 26 clinical isolates, 2 animal isolates, and 1 environmental isolate of P. brasiliensis obtained from different geographic regions, confirming the strong discriminating power of this technique. A phenetic tree, build from the RAPD data, showed that although the two nonclinical Brazilian strains were set together the majority of the clinical Brazilian strains were randomly distributed through different sub-branches of a major cluster without any correlation to any of the parameters analyzed. A second major cluster, however, has grouped isolates from Mato Grosso and Roraima (Brazil) that not only were susceptible in vitro to trimethoprim-sulfamethoxazole but also produced a good in vivo response. These results open new vistas for epidemiological and clinical studies of P. brasiliensis.Paracoccidioides brasiliensis is a dimorphic fungus alternating between the mycelial form observed in room temperatures and the yeast form found in infected tissues or in culture at 35 to 37°C. The human paracoccidioidomycosis caused by this fungus is characterized by a range of clinical manifestations from benign or asymptomatic forms to severe and disseminated disease that is often fatal. The exact causes of the clinical pleomorphism are not understood, but it is reasonable to presume that factors associated with both the fungus and the patient are involved. In relation to the fungus, although wide biological and biochemical diversity has been observed, no clear correlation with pathogenesis has been demonstrated (3,9,12,13,17,20,23). Until now very little has been known about the genome sequences of P. brasiliensis; hence, the use of molecular approaches for isolate typing has been difficult.The development of the randomly amplified polymorphic DNA (RAPD) technique represented a landmark in the molecular characterization of diverse organisms, especially for microbial strain identifications when very few genomic sequences are available. In relation to other molecular techniques, RAPD analysis offers the advantage of requiring small amounts of DNA, simpler procedures, and the use of arbitrary primers (26). Due to these characteristics, RAPD has been widely used for human diseases to detect genomic variations among isolates of fungi such as Histoplasma capsulatum (27), Cryptococcus neoformans (19), Aspergillus fumigatus (1), and P. brasiliensis (3,9,12,13,23). ...

In vitro, terbinafine is highly active against a broad spectrum of pathogenic fungi. We evaluated the activities of terbinafine and itraconazole against 31 isolates of Paracoccidioides brasiliensis. The tests were conducted by using a broth macrodilution procedure. MICs, in micrograms per milliliter, were as follows: terbinafine, 0.015 to 1.0 (geometric mean, 0.1188); itraconazole, 0.007 to 0.5 (geometric mean, 0.03165). The usual therapy for paracoccidioidomycosis is sulfonamides, amphotericin B, and azole derivatives (ketoconazole, itraconazole, and fluconazole). In comparison to amphotericin B, azole derivatives allow shorter treatment courses, can be administered orally, and are equally effective. Itraconazole has as high efficacy as ketoconazole, but with superior tolerance. It is the current drug of choice for treatment of paracoccidioidomycosis. The data obtained in this study indicate that terbinafine is active against P. brasiliensis in vitro and suggest that this allylamine can be considered a new option as drug therapy for paracoccidioidomycosis.Paracoccidioidomycosis, caused by the dimorphic fungus Paracoccidioides brasiliensis, is a systemic human mycosis geographically confined to Latin America (1,25,28). In vitro tests of the susceptibility of P. brasiliensis to antimycotic drugs have been scarce, and the results have not always been consistent; the discrepancies are attributed to the diversity of techniques employed in such studies (7,8,10,11,22,28).Organisms belonging to the kingdom Fungi share eukaryotic characteristics with their human host cells, implying similarities in biochemistry and physiology that limit therapeutics. Therefore, when systemic administration of drugs is required for deep human mycoses, few compounds are sufficiently selective (12). Compounds currently used in the control of infection caused by P. brasiliensis include amphotericin B, trimethoprimsulfamethoxazole, and azole derivatives (26). Unfortunately, amphotericin B has been associated with substantial toxicity, while trimethoprim-sulfamethoxazole has been associated with relapses. Thus, in many clinical situations, the azole derivatives present the best therapeutic option for control of paracoccidioidomycosis (17, 18).Owing to the fact that itraconazole, among the azoles, permits shorter treatment courses and has been shown to be more effective, we decided to compare this drug with the antifungal agent terbinafine, which operates by interfering with the ergosterol biosynthetic pathway and has shown MICs similar to those of itraconazole for filamentous fungi in in vitro studies (10,15). Thus, we aim to determine whether terbinafine might have a role in the management of infections caused by P. brasiliensis. MATERIALS AND METHODSFungal strains and culture conditions. Thirty-one isolates of the P. brasiliensis yeast form, including clinical, environmental, and animal isolates, were examined in this study. Samples consisted of 28 strains isolated from humans, 1 from penguin feces, 1 from dog food, and 1 from an armadillo....

Swabs collected from the external ears of 942 cattle, including both European and zebu breeds, were used to evaluate the epidemiology of Malassezia species. High numbers of Malassezia isolates were significantly associated with maturity of the animals and with diagnosed otitis. In healthy animals, a particularly low prevalence of the genus was found in Holstein cows, especially in the summer months, a finding perhaps correlating with the open, air-exposed ears of this breed. Pendutlous-eared zebu breeds and hybrids had higher levels of colonization, although this effect was more pronounced in humid regions, and was least in the dry north and west of the state. The most common species seen was M. sympodialis, which accounted for 47.1% of isolates from healthy cattle and 39.1% from cattle with otitis. In cattle with otitis sampled in summer, we found that the relatively thermotolerant M. sympodialis made up 80.8% of isolates. By contrast, during the winter the less thermotolerant M. globosa was the most common species from otitis, making up 56% of the isolates. Humidity and temperature may be the main factors explaining the epidemiology of Malassezia diseases and colonizations in both animals and humans.