Environmental Mapping of Paracoccidioides spp. in Brazil Reveals New Clues into Genetic Diversity, Biogeography and Wild Host Association

Abstract

BackgroundParacoccidioides brasiliensis and Paracoccidioides lutzii are the etiological agents of Paracoccidioidomycosis (PCM), and are easily isolated from human patients. However, due to human migration and a long latency period, clinical isolates do not reflect the spatial distribution of these pathogens. Molecular detection of P. brasiliensis and P. lutzii from soil, as well as their isolation from wild animals such as armadillos, are important for monitoring their environmental and geographical distribution. This study aimed to detect and, for the first time, evaluate the genetic diversity of P. brasiliensis and P. lutzii for Paracoccidioidomycosis in endemic and non-endemic areas of the environment, by using Nested PCR and in situ hybridization techniques.Methods/Principal FindingsAerosol (n = 16) and soil (n = 34) samples from armadillo burrows, as well as armadillos (n = 7) were collected in endemic and non-endemic areas of PCM in the Southeastern, Midwestern and Northern regions of Brazil. Both P. brasiliensis and P. lutzii were detected in soil (67.5%) and aerosols (81%) by PCR of Internal Transcribed Spacer (ITS) region (60%), and also by in situ hybridization (83%). Fungal isolation from armadillo tissues was not possible. Sequences from both species of P. brasiliensis and P. lutzii were detected in all regions. In addition, we identified genetic Paracoccidioides variants in soil and aerosol samples which have never been reported before in clinical or armadillo samples, suggesting greater genetic variability in the environment than in vertebrate hosts.Conclusions/SignificanceData may reflect the actual occurrence of Paracoccidioides species in their saprobic habitat, despite their absence/non-detection in seven armadillos evaluated in regions with high prevalence of PCM infection by P. lutzii. These results may indicate a possible ecological difference between P. brasiliensis and P. lutzii concerning their wild hosts.

Brazilian guidelines for the clinical management of paracoccidioidomycosis

“…Thus, the region where the disease is acquired is referred to as reservaria. Yet, sensitive molecular screening techniques have detected the fungus in soils and aerosols, especially among samples taken from animal burrows or sites with medium to high moisture content protected by vegetation cover 13 .…”

II Consenso Brasileiro em Paracoccidioidomicose - 2017*

“…Métodos sensíveis de biologia molecular, no entanto, indicam a presença frequente do fungo em solos e aerossóis, particularmente quando provenientes de tocas de animais ou de locais com teores de umidade média a alta, protegidos por coberturas vegetais. 13 Mudanças nas características demográficas e na distribuição geográfica têm sido observadas nas últimas décadas. Possivelmente, a urbanização, a aplicação de métodos diagnósticos e a presença de comorbidades e imunossupressão expliquem parte dessas alterações.…”

Molecular detection of fungi of public health importance in wild animals from Southern Brazil

“…These results also indicate the importance of rodents as hosts to pathogens with zoonotic potential . The molecular techniques used to this fungi, are used in other studies and is well established, however, for identify the new species of P. brasiliensis ( P. brasiliensis— S1a and S1b, P. americana— PS2, P. restrepiensis— PS3 and P. venezuelensis— PS4) this techniques are not available, one technique that should be used in this case is the Illumina or phylogenetic analysis using a new technique with the primers gp43 Exon 2 …”

“…39 These results also indicate the importance of rodents as hosts to pathogens with zoonotic potential. 40 The molecular techniques used to this fungi, are used in other studies 17,18 and is well established, 41 however, for identify the new species of P. brasiliensis (P. brasiliensis-S1a and S1b, P. americana-PS2, P. restrepiensis-PS3…”