Wild Animals as Sentinels of Paracoccidioides brasiliensis in the State of Rio Grande do Sul, Brazil

Abstract

Paracoccidioides brasiliensis, a dimorphic pathogenic fungus, causes the principal form of systemic mycosis in Brazil. The literature furnishes only limited data on the ecology of this fungus in the state of Rio Grande do Sul, the southernmost state of Brazil. The purpose of this study was to evaluate the prevalence of fungal infection in wild animals, using serological tests and using the animals as sentinels of the presence of P. brasiliensis in three specified mesoregions of Rio Grande do Sul. A total of 128 wild animals from the three mesoregions were included in the study. The serum samples were evaluated by immunodiffusion and the enzyme-linked immunosorbent assay (ELISA) technique to detect anti-gp43 antibodies from P. brasiliensis. Two conjugates were tested and compared with the ELISA technique. Although no positive samples were detected by immunodiffusion, 26 animals (20%), belonging to 13 distinct species, were found to be seropositive by the ELISA technique. The seropositive animals were from two mesoregions of the state. The results were similar according to the gender, age, and family of the animals, but differed significantly according to the conjugate used (p < 0.001), showing more sensitivity to protein A-peroxidase than to protein G-peroxidase. The finding that wild animals from the state of Rio Grande do Sul are exposed to P. brasiliensis suggests that the fungus can be found in this region despite the often-rigorous winters, which frequently include below-freezing temperatures.

Paracoccidioides brasiliensis Infection in Small Wild Mammals

“…Although infection by P. brasiliensis has been demonstrated in several wild animal species [15,16,26,[31][32][33], this is the first evidence of PCM in Akodon sp., E. russatus, T. nigrita and O. nigripes. The negativity observed in histopathological examination, immunodiffusion and culture probably is due to the lower sensitivity of these methods.…”

“…An epidemiological study with several species of wild mammals from a Brazilian zoo showed higher positivity to paracoccidioidin skin test in terrestrial animals (82.98 %) than arboreal animals (22.45 %), reinforcing that soil is the habitat of P. brasiliensis [32]. A seroepidemiological study evaluated P. brasiliensis infection in several wild animal species from the State of Rio Grande do Sul, Brazil, and showed positivity in animals from the orders Artiodactyla, Rodentia, Xenarthra, Carnivora, Marsupialia and Primata [33].…”

Paracoccidioidomycosis infection in domestic and wild mammals by Paracoccidioides lutzii

“…Seropositivity for IgG anti‐CFA of P. lutzii was detected in 13% of horses (26/200), 26.5% of dogs (52/196) and 31.8% of wild mammals (27/85). Of these, sera from 15 horses, 22 dogs and 17 wild mammals also had IgG anti‐gp‐43 from P. brasiliensis . However, seropositivity only for P. lutzii occurred in 5.5% (11/200) of horses, 15.3% (30/196) of dogs and 11.8% (10/85) of wild animals (Table ).…”

“…According to recent studies, P. lutzii has its epicentre in the central‐west region of Brazil, unlike P. brasiliensis , which was also described in the south and southeast regions of the country . However, P. lutzii was reported in the Amazon region .…”

“…Although Rio Grande do Sul is considered endemic to PCM in humans for several decades, recent studies using animals as sentinels demonstrated for the first time the presence of the fungus P. brasiliensis in the state . Data concerning the presence of P. lutzii in the state of RS are not yet described.…”