RESUMO
Vicuñas (Vicugna vicugna) are wild South American camelids (SACs) protected by law in Argentina, and information on pathogens that infect them is scarce. In this study, an adult vicuña found dead in the province of Salta was examined, and evidence of infection by Sarcocystis sp. protozoans was sought. Infection of skeletal muscles by S. aucheniae, with the production of macroscopic sarcocysts, a disease known as SAC sarcocystosis, has been described in the other three SACs - llamas, alpacas, and guanacos - but its occurrence in vicuñas has so far remained unknown. In the analyzed individual, many macroscopic cysts compatible with S. aucheniae were found upon necropsy in the muscular tissue of the neck and diaphragm. Analysis of 18 S rRNA and cytochrome c oxidase subunit 1 (cox-1) gene sequences by BLAST searches and construction of phylogenetic trees demonstrated that the etiological agent was S. aucheniae. Our results show for the first time that vicuñas act as intermediate hosts in the life cycle of this parasite. In addition, this study provides the first cox-1 sequences for S. aucheniae isolates from the four SAC species acting as intermediate hosts and suggests that this marker could be useful for genotypification of this parasite species. The impact of SAC sarcocystosis on the health, well-being, and fitness of vicuñas, and the relevance of vicuña infections in the epidemiology of S. auchaniae, remain to be elucidated.
Assuntos
Filogenia , Sarcocystis , Sarcocistose , Animais , Sarcocystis/genética , Sarcocystis/isolamento & purificação , Sarcocystis/classificação , Sarcocistose/veterinária , Sarcocistose/parasitologia , Argentina , RNA Ribossômico 18S/genética , RNA Ribossômico 18S/análise , Camelídeos Americanos/parasitologia , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/análiseRESUMO
Lamanema chavezi (Family Molineidae) is a parasitic nematode of South American camelids (SACs). A few studies have reported this parasite in SACs, mainly in domestic camelid species (llama and alpaca). Parasite identification by means of copro-parasitological methods is non-invasive and allows performing epidemiological studies. However, egg misidentification and difficulty to culture third-stage larvae do not allow identifying nematodes to species level. In contrast, molecular tools allow identifying eggs of gastrointestinal nematodes more accurately. However, the little genomic information available in databases for some species prevents an accurate diagnosis. In the present work, L. chavezi females present in feces of llamas from northwestern Argentina were molecularly characterized to obtain genomic information and improve parasitological diagnosis of L. chavezi-like eggs present in guanaco feces from southeastern Argentina. An 833-bp fragment of nuclear ribosomal DNA (rDNA) and a 434-bp fragment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene from both L. chavezi females and eggs were amplified and sequenced. Comparison between sequences from females and eggs showed 99-99.6% identity to rDNA and 99.5-96.1% to the cox1 gene fragments, confirming egg morphological assignment. A higher divergence between sequences was observed in the cox1 fragment, with a maximum variation of 3.9%. The examination of eggs found in guanaco feces from southeastern Argentina and their specific molecular identification represent the first record for this host in Argentine Patagonia and contribute to improving the diagnosis of gastrointestinal nematodes in SACs, mainly in wild camelids.
Assuntos
Camelídeos Americanos/parasitologia , DNA Mitocondrial/genética , Fezes/parasitologia , Molineoidae/genética , Proteínas Nucleares/genética , Infecções por Strongylida/veterinária , Animais , Animais Domésticos , Argentina/epidemiologia , DNA de Helmintos , Feminino , Genoma Helmíntico , Molineoidae/isolamento & purificação , Contagem de Ovos de Parasitas , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Infecções por Strongylida/epidemiologia , Infecções por Strongylida/parasitologiaRESUMO
Attacks by adult stages of the soft tick Argas (Argas) neghmei (Acari:Argasidae) on inhabitants of the High Andean plateau of Argentina are reported . This is the first local report of this species, which was previously found in the north of Chile. Taxonomic differences between A (A.) neghmei and other neotropical and exotic species of the genus are underlined. The status of the knowledge about the Argentine argasid fauna is briefly described.
Assuntos
Animais , Carrapatos/classificação , Carrapatos/patogenicidade , ArgentinaRESUMO
Attacks by adult stages of the soft tick Argas (Argas) neghmei (Acari:Argasidae) on inhabitants of the High Andean plateau of Argentina are reported . This is the first local report of this species, which was previously found in the north of Chile. Taxonomic differences between A (A.) neghmei and other neotropical and exotic species of the genus are underlined. The status of the knowledge about the Argentine argasid fauna is briefly described. (AU)