Investigação sorológica e molecular da presença de Paracoccidioides spp. em três mesorregiões do Rio Grande do Sul

Abstract

Paracoccidioidomycosis (PCM) has been described in humans in Rio Grande do Sul (RS) since the 40s, however, the ecological aspects that involve its etiological agents have not yet been fully clarified. Soil is described as the habitat of Paracoccidioides spp., however, due to the difficulty of isolating the agent from the environment, specific data about its ecological niche are still little known. This, together with the long latency that the disease can present, makes it difficult to determine the source of infection of the individuals by the pathogen. Serological and molecular techniques have been used to better understand the ecoepidemiology of Paracoccidioides spp. demonstrating that there is a geographical expansion of their endemic areas. Therefore, this study aimed to investigate the presence of Paracoccidioides spp. in three mesoregions of RS. For this purpose, animal studies were conducted as sentinels of the presence of the fungus, from the search for antibodies by serology, and using molecular biology to detect the fungal DNA of soil samples. For serology, samples from 481 domestic and wild animals were included, which were submitted to the indirect ELISA test for antibodies anti-P.lutzii. For the molecular study, soil samples from the cities of Bagé (n = 30) and Rio Grande (n = 16) were duly collected and submitted to DNA extraction protocol by commercial kit (Norgen Biotek Corp.) and PCR and Nested-PCR with primers specific for the genus. Of the 481 animals studied, 51 (10.6%) were seropositive for IgG anti-P.lutzii. Of the 46 soil samples studied, the DNA of Paracoccidioides spp. was found in 19 (41.3%), ten in Bagé (52.6%) and nine in Rio Grande (47.4%). This study provided important data on the habitat of PCM agents in RS, demonstrating for the first time the presence of P. lutzii in RS and a high DNA detection rate of Paracoccidioides spp. in soils of the Pampa Biome, which had not yet been described in the literature. These data help to understand the ecology of PCM agents as a whole, making this neglected disease even more visible in the region and indirectly in the country.