Experimental infections with Paracoccidioides brasiliensis obtained from armadillos: comparison to clinical isolates

Abstract

Paracoccidioides brasiliensis causes paracoccidioidomycosis (PCM) that is one of the most prevalent systemic human mycoses in Latin America. Armadillos show a high incidence of PCM infection and could, therefore, be a natural reservoir for this fungus. In this study were compared the virulence profiles of isolates obtained from nine-banded armadillos (Dasypus novemcinctus) (PbT1 and PbT4) and isolates from PCM patients (Pb265 and Bt83). Pathogenicity was evaluated by fungal load and analysis of colony morphology. Immunity against the fungus was tested by delayed type hypersensitivity test (DTH) and antibody quantification by ELISA. The higher virulence of PbT1 and PbT4 was suggested by higher fungal load in spleen and lungs. Armadillo isolates and Bt83 presented a cotton-like surface contrasting with the cerebriform appearance of Pb265. All isolates induced cellular and humoral immune responses in infected BALB/c mice. DTH reactions were similarly induced by the four isolates, however, a great variability was observed in specific antibody levels, being the highest ones induced by Bt83 and PbT4. The present work confirms that armadillos harbor P. brasiliensis, whose multiplication and induced immunity in experimentally infected mice are heterogeneous, resembling the behavior of isolates from human PCM. This study reinforces the possibility that armadillos play an important role in the biological cycle of this pathogen.

A hidden battle in the dirt: soil amoebae interactions withParacoccidioidesspp

“…after prolonged in vitro subculturing. Our results are also compatible with previous work from other groups showing that P. brasiliensis armadillo isolates can be more virulent to mice and hamster models than some clinical strains submitted to prolonged in vitro culturing such as Pb18 [38, 42, 43].…”

Cytokines Expressed in the Granulomatous Lesions in Experimental Paracoccidioidomycosis: Role in Host Protective Immunity and as Fungal Virulence Factor

“…Briefly, slides sections were deparaffinized and rehydrated, then incubated with hydrogen peroxide (30%) for 30 min at room temperature in a shaker, for blocking endogenous peroxidase. After that, blocking of nonspecific sites with normal serum/bovine serum albumin 10% (1:1 dilution) was carried out for 30 min at room temperature and followed by application of Tris-buffered saline (TBS) for blocking endogenous biotin in tissues for 2 h. Slides were incubated with adequate volume of rabbit pan-specific polyclonal antibody anti-TNF-α or anti-TGF-β (1/30) (R&D SYSTEMS, Inc., Minneapolis, MN, USA) and monoclonal antibody anti-IFN-γ (according to the protocol described previously by [20][21][22], overnight at 4°C, diluted in PBS/Tween 20 0.3%. After incubation with primary biotinylated anti-IgG antibody (1/1000) (Rockland, Gilbertsville, PA, USA) was applied on tissues for 1 h at room temperature, followed by incubation with streptavidin-peroxidase (1/50) (Vector Laboratories, Burlingame, CA, USA).…”

Uso antropogénico, hábitat, abundancia y hábitos alimentarios del armadillo de nueve bandas (Dasypus novemcinctus) en el centro y sur del estado de Veracruz, México

“…Sarcocystis neurona (Tanhauser et al, 2001), como para el hombre, p. ej. Mycobacterium leprae (Paige et al, 2002;Loughry et al, 2009), Coccidioides immitis (Eulálio et al, 2000), Paracoccidioides brasiliensis (Bagagli et al, 2003;Nishikaku et al, 2008), Trypanosoma cruzi (Paige et al, 2002;Yeo et al, 2005), Toxoplasma gondii (da Silva et al, 2006) y Leishmania naiffi (Naiff et al, 1991). Todo esto, aunado a la caza y pérdida de hábitat, ha reducido sus poblaciones en México y lo ponen en riesgo de extinción local (Ceballos & Oliva, 2005;SEMARNAT, 2012).…”