RESUMO
Sarcocystis is a genus of intracellular parasitic protozoa that infects various species of mammals, birds, and reptiles worldwide. At least 46 Sarcocystis species naturally infect rodents as intermediate hosts producing tissue cysts. This study aimed to provide the first report and molecular characterisation of Sarcocystis spp. in muscles from plains viscacha (Lagostomus maximus) in Argentina. Muscle samples of 53 plains viscachas from three provinces of Argentina were processed by homogenisation and optical microscopy to detect tissue cysts. Positive samples were analysed by PCR-sequencing, using the following markers: 18S rRNA, ITS1, and coxI. The 18S rRNA and coxI consensus sequences were aligned with other sequences from Sarcocystis spp., and phylogenetic trees were constructed. Of all animals processed, 13.2% (7/53) harboured Sarcocystis sp. cysts. 18S rRNA consensus sequences were obtained from four muscle samples and one individual cyst, and they showed 99.88-100% similarity, except for the cyst sequence, which showed 97.11% homology. Similarities of only 96-97% were recorded in the 18S rRNA fragment with other Sarcocystis spp. whose sequences are available in the GenBank. The five coxI fragment sequences obtained were 100% identical and showed an identity of 99.41-99.48% with S. canis. For ITS1 only short and low-quality sequences were obtained. In the phylogenetic trees, all the sequences from plains viscachas were positioned together in a branch separated from other Sarcocystis spp. These results could be related to new Sarcocystis spp. producing sarcocysts in plains viscachas. Besides, comprehensive cyst morphological analysis using TEM from the new Sarcocystis species will allow a description of the cyst wall ultrastructure. In this sense, further studies are needed to deepen these findings and elucidate other potential intermediate and possible definitive hosts.
RESUMO
NTRODUCCIÓN: Los roedores sinantrópicos, representados por el ratón doméstico (Mus musculus), la rata parda (Rattus norvegicus) y la rata negra (Rattus rattus), representan un riesgo importante para la salud. En Sudamérica, la fragmentación socioeconómica se refleja en marcadas diferencias entre centros urbanos y áreas periféricas, y se asocia a un registro heterogéneo. El objetivo fue relevar datos por encuestas a los habitantes de dos barrios del Gran La Plata con características contrastantes para explorar, describir y evaluar la percepción en relación con la presencia de roedores en domicilio, peridomicilio y barrio como vehículos de transmisión de enfermedades. MÉTODOS: A partir de un diseño descriptivo exploratorio, se confeccionaron y realizaron encuestas siguiendo la técnica de muestreo estratificado. Se consideraron las variables género y grupo, de tal manera que la muestra tuviese la misma distribución. La información se transfirió a una base de datos y se analizó a través de IBM SPSS Statistics V25. RESULTADOS: Existe una preocupación común respecto al rol de los roedores urbanos como reservorios y fuentes de infección de patologías zoonóticas. En el barrio más vulnerable, la presencia de roedores fue más frecuente que en el centro de la ciudad. DISCUSIÓN: Este estudio provee un abordaje diferente en relación con roedores y patologías asociadas, considerando la percepción social y revelando su importancia para los programas de manejo y control.
Assuntos
Parasitos , Roedores , Percepção Social , Zoonoses , NoxasRESUMO
Wellcomia species (Oxyuridae, Syphaciinae) parasitise several families of rodents from Africa, Asia and America with diverse ecological characteristics. A new species of Wellcomia is described based on specimens obtained from the plains viscacha Lagostomus maximus (Chinchillidae) from Argentina. The description includes morphometric and ecological aspects and an emended diagnosis of the genus Wellcomia. In addition, a molecular characterisation (18S rRNA) and an exploratory analysis of the genetic distances of the species included in this genus are provided. The new species, Wellcomia hugoti n. sp., differs from other species of the genus in the morphology of the cephalic plate, the ventral rugose area in males and the vulva in females. The new species showed a low prevalence (7.7%) and a high mean abundance (73.8). The genetic distances detected do not allow a comprehensive assessment of the monophyly of the genus. This is the seventh record of this genus in rodents from the Americas, the second in rodents from Argentina and the first record for the family Chinchillidae.
