ABSTRACT
Pythium insidiosum causes pythiosis, a life-threatening disease that occurs in tropical regions and affects man and animals. Although pythiosis in Brazil had been described in various animal species, the first human case was only recently reported. The present study aimed to characterize the morphologic and molecular characteristics of a new equine isolate of P. insidiosum and compare them with those of the first Brazilian human isolate. Both isolates were recovered from the same region of the country. Macroscopic and microscopic features were evaluated in two culture media. Sporangia formation and zoospore release were obtained after culturing the isolates with fragments of grasses and crops in an appropriate liquid induction medium. The molecular analysis of the isolates consisted of the complete sequencing of the ITS-5.8S rDNA region and sequences of both showed identical composition of 836 bp and 99% similarity with the isolates M16, 65, M12, 339 and 394 deposited at GenBank. Simple mycological procedures such as the production of sporangia and zoospores may distinguish P. insidiosum from zygomycetes. The rDNA sequencing indicates that, in Brazil, both humans and animals might be infected by a common genotype of the pathogen.
Subject(s)
Horse Diseases/microbiology , Infections/microbiology , Infections/veterinary , Pythium/cytology , Pythium/isolation & purification , Animals , Brazil , DNA, Algal/genetics , DNA, Ribosomal Spacer/genetics , Horses , Humans , Male , Molecular Sequence Data , Phylogeny , Pythium/classification , Pythium/genetics , RNA, Ribosomal, 5.8S/genetics , Spores/cytology , Spores/genetics , Spores/isolation & purificationABSTRACT
Paracoccidioides brasiliensis infections have been little studied in wild and/or domestic animals, which may represent an important indicator of the presence of the pathogen in nature. Road-killed wild animals have been used for surveillance of vectors of zoonotic pathogens and may offer new opportunities for eco-epidemiological studies of paracoccidiodomycosis (PCM). The presence of P. brasiliensis infection was evaluated by Nested-PCR in tissue samples collected from 19 road-killed animals; 3 Cavia aperea (guinea pig), 5 Cerdocyon thous (crab-eating-fox), 1 Dasypus novemcinctus (nine-banded armadillo), 1 Dasypus septemcinctus (seven-banded armadillo), 2 Didelphis albiventris (white-eared opossum), 1 Eira barbara (tayra), 2 Gallictis vittata (grison), 2 Procyon cancrivorus (raccoon) and 2 Sphiggurus spinosus (porcupine). Specific P. brasiliensis amplicons were detected in (a) several organs of the two armadillos and one guinea pig, (b) the lung and liver of the porcupine, and (c) the lungs of raccoons and grisons. P. brasiliensis infection in wild animals from endemic areas might be more common than initially postulated. Molecular techniques can be used for detecting new hosts and mapping 'hot spot' areas of PCM.
