Molecular identification of Sarcocystis aucheniae in the wild South American camelid Vicugna vicugna.

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.

First mitochondrial and nuclear DNA sequences of Lamanema chavezi (Nematoda: Molineidae): Novel findings to improve its identification in feces from South American camelids.

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.

The Amblyomma maculatum Koch, 1844 (Acari: Ixodidae: Amblyomminae) tick group: diagnostic characters, description of the larva of A. parvitarsum Neumann, 1901, 16S rDNA sequences, distribution and hosts.

A review of the largely confused Amblyomma maculatum Koch, 1844 tick group of the subgenus Anastosiella Santos Dias, 1963 (A. neumanni Ribaga, 1902, A. maculatum, A. parvitarsum Neumann, 1901, A. tigrinum Koch, 1844 and A. triste Koch, 1844) is presented together with a discussion of the diagnostic characters used for the determination of adults, nymphs and, to a lesser extent, larvae. A key for this tick group is produced, including the description of the larva of A. parvitarsum, 1901. Sequences of 16S rDNA are obtained and compared with other Amblyomma spp., including two other species currently in Anastosiella but in the ovaletick group, A. ovale Koch, 1844 and A. aureolatum (Pallas, 1772). According to the morphology and the rDNA sequences, the maculatum group is reduced to A. maculatum (Neotropical-Nearctic), A. tigrinum (Neotropical) and A. triste (Neotropical) A. neumanni and A. parvitarsum are excluded from the subgenus. The distribution is sympatric in northern South America from where A. maculatumreaches the southern Nearctic and the range of A. tigrinum extends to the southern Neotropics. These species have been found on several domestic and wild vertebrates. A. triste and A. tigrinum have been also found on man. Their role as vectors of pathogens deserves further investigation.

First detection of Argas (Argas) neghmei (Acari: Argasidae) in Argentina

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)

First detection of Argas (Argas) neghmei (Acari: Argasidae) in Argentina

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.