RESUMO
The reservoirs and the modes of transmission of the most frequent microsporidial species in humans, Enterocytozoon bieneusi, are still unknown. We have examined fecal samples of 26 humans and 350 animals from 37 species to find 18 samples containing this parasite from humans, cats, pigs, cattle, and a llama. Genotypic characterization of the internal transcribed spacer of the rRNA gene resulted in 14 different genotypes, 6 of them previously undescribed. Phylogenetic analysis revealed the lack of a transmission barrier between E. bieneusi from humans and animals (cats, pigs, and cattle). Thus, E. bieneusi appears to be a zoonotic pathogen.
Assuntos
Enterocytozoon/classificação , Enterocytozoon/genética , Microsporidiose/transmissão , Zoonoses/parasitologia , Zoonoses/transmissão , Doenças dos Animais/parasitologia , Doenças dos Animais/transmissão , Animais , Sequência de Bases , Gatos , Bovinos , DNA Espaçador Ribossômico/análise , Enterocytozoon/isolamento & purificação , Fezes/parasitologia , Genes de RNAr , Genótipo , Humanos , Microsporidiose/parasitologia , Microsporidiose/veterinária , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNARESUMO
The reservoirs and the routes of transmission of Enterocytozoon bieneusi are still unknown. In humans, it is the most commonly found microsporidial species. It has also been found repeatedly in pigs, too. The first detection of E. bieneusi in cattle is reported herein. Two distinct genotypes were characterized and compared with 4 other genotypes from humans, 6 from pigs, and 1 from a cat. From these 13 E. bieneusi genotypes known to date, 25 polymorphic sites could be identified in the internal transcribed spacer of the rRNA gene. The spectrum of polymorphisms within and between each of the 4 host species indicates a close relationship between E. bieneusi strains from humans and pigs, whereas those from cattle are more distantly related. The data suggest the absence of a transmission barrier between pigs and humans for this pathogen.