RESUMO
The present report describes a novel etiological agent of cutaneous leishmaniasis in horses that, at least for some cases, sporadically appeared as autochthonous infections in geographically distant regions of Germany and Switzerland. The infection was initially diagnosed upon clinical and immunohistological findings. Subsequent comparative sequence analysis of diagnostic PCR products from the internal transcribed spacer 1 (ITS1) of ssrRNA classified the respective isolates as neither Old World nor New World Leishmania species. However, four isolates subjected to molecular analyses all exhibited a close phylogenetic relationship to Leishmania sp. siamensis, an organism recently identified in a visceral leishmaniasis patient from Thailand. Future investigations will demonstrate if this form of leishmaniasis represents an emerging, and perhaps zoonotic, disease of European, or even global, importance.
Assuntos
Doenças dos Cavalos/epidemiologia , Leishmania/fisiologia , Leishmaniose/epidemiologia , Leishmaniose/veterinária , Dermatopatias Parasitárias/veterinária , Animais , Sequência de Bases , Europa (Continente)/epidemiologia , Feminino , Doenças dos Cavalos/parasitologia , Cavalos , Leishmania/classificação , Leishmaniose/parasitologia , Masculino , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Dermatopatias Parasitárias/epidemiologia , Dermatopatias Parasitárias/parasitologiaRESUMO
Adhesion is the first step in the pathogenesis of enterotoxigenic Escherichia coli infections. The genes encoding the most prevalent adhesion factors CFA/I, CS3 and CS6 were cloned into Vibrio cholerae strain CVD 103-HgR and expression of fimbriae was investigated in wildtype and recombinant strains by transmission electron microscopy in conjunction with immunolabelling and negative staining. Negative staining was effective in revealing CFA/I and CS3, but not CS6. Although morphology of fimbriae differed between wildtype and recombinant strains, corresponding surface antigens were recognized by specific antibodies. The present study provides evidence that ETEC-specific fimbriae can adequately be expressed in an attenuated V. cholerae vaccine strain and that immunoelectron microscopy is a critical tool to validate the surface expression of antigens in view of their possible suitability for recombinant vaccines.