High frequency of <emph type="2">Paracoccidioides brasiliensis</emph> infection in armadillos (<emph type="2">Dasypus novemcinctus):</emph> an ecological study

Abstract

The fungus Paracoccidioides brasiliensis has been isolated from nine-banded armadillos (Dasypus novemcinctus) in different regions where paracoccidiodomycosis (PCM) is endemic. The link between PCM and these animals has provided the first valuable clue in the effort to elucidate the ecological niche of P. brasiliensis. The present study was aimed at correlating P. brasiliensis infection in armadillos with local ecological features and, if possible, the presence of the fungus in the soil in the Botucatu hyperendemic area of PCM. In this region the mean temperature ranges from 14.8 to 25.8 degrees C and the annual average precipitation is 1520 mm. The sites where 10 infected animals (positive group) were collected were studied and compared with the sites where five uninfected animals were found. The occurrence of the fungus in soil samples collected from the positive armadillos' burrows and foraging sites was investigated by the indirect method of animal inoculation. Environmental data from the sites of animal capture, such as temperature, rainfall, altitude, vegetation, soil composition, presence of water and proximity of urban areas, were recorded. All 37 soil samples collected from the sites had negative fungal cultures. Positive animals were found much more frequently in sites with disturbed vegetation, such as riparian forests and artificial Eucalyptus or Pinus forests, in altitudes below 800 m, near water sources. The soil type of the sites of positive animals was mainly sandy, with medium to low concentrations of organic matter. The pH was mainly acidic at all the sites, although the concentrations of aluminum cations (H+Al) were lower at the sites where positive animals were found. Positive armadillos were also captured in sites very close to urban areas. Our data and previous studies indicate that P. brasiliensis occurs preferentially in humid and shady disturbed forests in a strong association with armadillos.

Paracoccidioides brasiliensis: phylogenetic and ecological aspects

“…In this experimental study, we have also observed that P. brasiliensis is unable to grow in some soils containing high amounts of Exchangeable Aluminum (H+Al) and low Bases Saturation. These results also corroborate some previous reporting on P. brasiliensis isolation from armadillos in our endemic area, in which we aimed to address the associated ecological factors [55]. Firstly, positive-culture armadillos were observed living in both in clay and sandy soil; secondly, the frequency of animal infection was heterogeneous in the different counties composing our endemic area; and finally, all armadillos captured in a restricted site (from Pardinho County), where soil analysis had revealed a high concentration of Exchangeable Aluminum, proved to be negative for P. brasiliensis culture.…”

“…The demonstration of a high incidence of P. brasiliensis infection in the nine-banded armadillo, Dasypus novemcinctus, a wild mammal that typically has evolved in South America and lives immersed in soil [52][53][54][55][56][57][58], has opened new perspectives for comprehending the pathogen's ecology and evolution. In this animal species and also in the naked-tailed armadillo, Cabassous centralis [59], P. brasiliensis can be isolated regularly.…”

“…These animals typically present a short home range, the area necessary for them to obtain food and to reproduce, and in this manner, an infected animal indicates that the fungus occurs in the vicinity. Infected armadillos have been observed mainly in shady and disturbed vegetation areas located near small rivers, on soil of both sandy and clayey type, and positive armadillos have also been detected near small urban sites in Botucatu, a hyperendemic area for PCM [55].…”

Lung Diseases - Selected State of the Art Reviews

“…One hypothesis postulated that fish and aquatic birds would be required around the microniche to allow survival and dispersion of the fungus in nature (Conti-Díaz, 2007). Of ecological importance is the regular isolation of the fungus from armadillos (Dassypus novemcinctus, Cabassous centralis) captured in the endemic areas, some of which revealed internal lesions (Bagaggli et al, 2003). Dogs and other domesticated and feral animals have also been implicated (Ricci et al, 2004;Richini-Pereira et al, 2008).…”

Epidemiology, Clinical, and Therapeutic Aspects of Paracoccidioidomycosis

“…Paracoccidioides has been repeatedly recovered from human clinical samples and tissues from some armadillo species (Dasypus novemcinctus) [11,12], and the first association with these animals was observed in the Amazon region by Naiff et al [13]. Although the Paracoccidioides was recovered from soil and related material in many situations, the exact places where this fungus exists in nature have not yet been determined; however, the soil continues to be an important element in the ecological study of this fungus [14].…”