Abstract
Paracoccidioides spp. isolation from environmental samples is rare and hardly reproducible. Molecular techniques have facilitated the fungal detection. However, it can be still difficult. Some strategies to enhance the capacity of DNA detection have been adopted, including the analysis of soil samples belonging to the habitat of animals from which Paracoccidioides spp. have already been isolated, notably armadillo burrows. To date, the detection of Paracoccidioides spp. has not yet been reported from outbreak hotspots. Clusters and outbreaks of acute paracoccidioidomycosis (PCM), usually a more severe clinical form, have currently occurred in urban areas being associated to climate changes, deforestation, and great constructions. These occurrences potentially signalise the fungus’ environmental niche, a riddle not yet solved. The authors performed an environmental investigation in a deeply disturbed area, after a highway construction in Rio de Janeiro, Brazil, where a recent outbreak of acute PCM occurred. Specific DNA sequences of Paracoccidioides brasiliensis were detected in shallow soil samples around the highway, reinforcing the association between the road construction and this PCM outbreak.
Highlights
Acute forms of paracoccidioidomycosis (PCM), a systemic mycosis caused by inhalation of Paracoccidioides spp. conidia present in soil from endemic areas, are usually more severe and less common than the chronic PCM form.[1]. In 2017 we reported an outbreak of acute PCM after a highway construction in Rio de Janeiro, Brazil, involving eight young patients and characterised by severe clinical presentations, complications, and one death.[2]. After this outbreak, 18 additional cases of acute PCM were diagnosed in the same study area, a rate 4.3 times higher than that expected for this period
Considering the outbreak, the road construction, the ongoing diagnosis of new cases of acute PCM, and the knowledge that the fungus lives in soil, the authors performed an environmental investigation along the roadside to reinforce the hypothesis that the outbreak was related to the road construction
Molecular analyses through nested-polymerase chain reaction (PCR) were performed as described.[3]. The following controls were used: [1] soil artificially seeded with Paracoccidioides brasiliensis, following the protocols published by Theodoro et al.;(3) [2] P. brasiliensis Pb18 strain; [3] beach sand from Barra da Tijuca, Rio de Janeiro; [4] all PCR reagents without any DNA template
Summary
Acute forms of paracoccidioidomycosis (PCM), a systemic mycosis caused by inhalation of Paracoccidioides spp. conidia present in soil from endemic areas, are usually more severe and less common than the chronic PCM form.[1].
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