Characteristics of environmental Paracoccidioides brasiliensis isolates.
The ecological niche or exact habitat of the fungus Paracoccidioides brasiliensis is not known, and few isolates have been obtained from the environment. In this study, ten isolates were analyzed with respect to antigenic composition, serology, pathogenicity, and molecular aspects. Gp43 is considered to be the molecular basis for the serodiagnosis of paracoccidioidomycosis; however, in this study only six of the environmental isolates secreted this molecule (four in great amounts and two in small amounts). Other molecules were also produced. When exoantigens from these isolates were tested using immunodiffusion, only four preparations were positive by ID tests. However, when these exoantigens were tested by ELISA, all of them except one were able to detect anti-P. brasiliensis antibodies. In Western blot assays, these exoantigens showed different reactivities. Isolates that secreted gp43 presented positive reactions for this molecule, and isolates that did not secrete gp43 gave positive reactions for other minor molecules. RAPD analysis revealed that there is great genetic variation between these environmental isolates. These isolates were non-pathogenic: no mortality was observed among the inoculated mice during an 18-month follow-up period.
Costa
Patricia Fagundes
PF
Discipline of Mycology, Federal University of Pará, Pará, Brazil.
Fernandes
Geisa Ferreira
GF
dos Santos
Priscila Oliveira
PO
Amaral
Cristiane Candida
CC
Camargo
Zoilo Pires
ZP
D000818:Animals; D000908:Antibodies, Fungal / Q000097:blood; D000946:Antigens, Fungal / Q000235:genetics / Q000276:immunology; D001135:Armadillos; D004271:DNA, Fungal / Q000032:analysis / Q000235:genetics; D004285:Dogs; D004783:Environmental Microbiology; D005656:Fungal Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014644:Genetic Variation; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D010228:Paracoccidioides / Q000302:isolation & purification / Q000472:pathogenicity / Q000502:physiology*; D010229:Paracoccidioidomycosis / Q000097:blood / Q000276:immunology / Q000382:microbiology*; D046429:Spheniscidae; D014774:Virulence
C103180:43 kDa protein, Paracoccidioides; D000908:Antibodies, Fungal; D000946:Antigens, Fungal; D004271:DNA, Fungal; D005656:Fungal Proteins; D006023:Glycoproteins