ABSTRACT
Sarcoptic mange or scabies is a contagious parasitic skin disease that affects a wide range of domestic and wildlife species. A cross-sectional study was carried out to determine the prevalence, molecular identification, and characteristics of sarcoptic mange in vicuñas. A total of 3,274 vicuñas were examined. Following ritual harvesting events ("chaccus") in 13 Andean communities. The presence of mange mites was determined by the skin scraping technique and confirmed by PCR analysis using specific primers for the ITS2 gene of Sarcoptes scabiei. The presence of mange mites was also confirmed by microscopy using samples taken from wallows. A data collection form was used to register the characteristics of the vicuñas sampled. The prevalence of sarcoptic mange was 4.9% (95% CI: 4.1 - 5.6%). All samples from wallows tested positive (9/9). Importantly, the presence of the species S. scabiei was molecularly confirmed. Adult females with regular body condition were more susceptible to sarcoptic mange, although the lesions were mild. This study confirms the presence of S. scabiei in semi-captive vicuñas and points to the possible role of wallows in the dissemination of Sarcoptes mites.
Subject(s)
Sarcoptes scabiei , Scabies , Scabies/epidemiology , Scabies/veterinary , Cross-Sectional Studies , Animals , Peru/epidemiology , Female , Male , Prevalence , Sarcoptes scabiei/geneticsABSTRACT
Abstract Sarcoptic mange or scabies is a contagious parasitic skin disease that affects a wide range of domestic and wildlife species. A cross-sectional study was carried out to determine the prevalence, molecular identification, and characteristics of sarcoptic mange in vicuñas. A total of 3,274 vicuñas were examined. Following ritual harvesting events ("chaccus") in 13 Andean communities. The presence of mange mites was determined by the skin scraping technique and confirmed by PCR analysis using specific primers for the ITS2 gene of Sarcoptes scabiei. The presence of mange mites was also confirmed by microscopy using samples taken from wallows. A data collection form was used to register the characteristics of the vicuñas sampled. The prevalence of sarcoptic mange was 4.9% (95% CI: 4.1 - 5.6%). All samples from wallows tested positive (9/9). Importantly, the presence of the species S. scabiei was molecularly confirmed. Adult females with regular body condition were more susceptible to sarcoptic mange, although the lesions were mild. This study confirms the presence of S. scabiei in semi-captive vicuñas and points to the possible role of wallows in the dissemination of Sarcoptes mites.
Resumo A sarna sarcóptica é uma doença parasitária contagiosa da pele que afeta uma ampla gama de espécies domésticas e selvagens. Um estudo transversal foi realizado para determinar a prevalência, identificação molecular e características da sarna sarcóptica em vicunhas. Foram avaliadas 3.274 vicunhas, capturadas durante o "Chaccus", em 13 comunidades rurais alto andinas do Peru. A presença do ácaro da sarna foi determinada pelo raspado de pele e confirmada pela técnica de PCR, com iniciadores específicos para o gene ITS2 de Sarcoptes scabiei e por microscopia nos chafurdeiros. Foi preenchida uma ficha de coleta de dados com as características das vicunhas analisadas. A prevalência de sarna sarcóptica em vicunhas foi de 4,9% (95% IC: 4,1 - 5,6%). Todas as amostras de chafurda testadas (9/9) foram positivas, e a presença de S. scabiei foi confirmada molecularmente. Fêmeas adultas com condições corporais regulares foram mais suscetíveis à sarna sarcóptica, embora as lesões fossem leves. O estudo confirma a presença de S. scabiei em vicunhas em semicativeiro de comunidades camponesas alto andinas do Peru que sofrem de sarna. Destaca-se, ainda, o papel das chafurdas das vicunhas na disseminação da sarna.
ABSTRACT
Late blight (LB) caused by the oomycete Phytophthora infestans is one of the most important biotic constraints for potato production worldwide. This study assessed 508 accessions (79 wild potato species and 429 landraces from a cultivated core collection) held at the International Potato Center genebank for resistance to LB. One P. infestans isolate belonging to the EC-1 lineage, which is currently the predominant type of P. infestans in Peru, Ecuador, and Colombia, was used in whole plant assays under greenhouse conditions. Novel sources of resistance to LB were found in accessions of Solanum albornozii, S. andreanum, S. lesteri, S. longiconicum, S. morelliforme, S. stenophyllidium, S. mochiquense, S. cajamarquense, and S. huancabambense. All of these species are endemic to South America and thus could provide novel sources of resistance for potato breeding programs. We found that the level of resistance to LB in wild species and potato landraces cannot be predicted from altitude and bioclimatic variables of the locations where the accessions were collected. The high percentage (73%) of potato landraces susceptible to LB in our study suggests the importance of implementing disease control measures, including planting susceptible genotypes in less humid areas and seasons or switching to genotypes identified as resistant. In addition, this study points out a high risk of genetic erosion in potato biodiversity at high altitudes of the Andes due to susceptibility to LB in the native landraces, which has been exacerbated by climatic change that favors the development of LB in those regions.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Subject(s)
Phytophthora infestans , Solanum tuberosum , Solanum , Phytophthora infestans/genetics , Plant Breeding , Plant Diseases/genetics , Solanum tuberosum/geneticsABSTRACT
Crop wild relatives have a long history of use in potato breeding, particularly for pest and disease resistance, and are expected to be increasingly used in the search for tolerance to biotic and abiotic stresses. Their current and future use in crop improvement depends on their availability in ex situ germplasm collections. As these plants are impacted in the wild by habitat destruction and climate change, actions to ensure their conservation ex situ become ever more urgent. We analyzed the state of ex situ conservation of 73 of the closest wild relatives of potato (Solanum section Petota) with the aim of establishing priorities for further collecting to fill important gaps in germplasm collections. A total of 32 species (43.8%), were assigned high priority for further collecting due to severe gaps in their ex situ collections. Such gaps are most pronounced in the geographic center of diversity of the wild relatives in Peru. A total of 20 and 18 species were assessed as medium and low priority for further collecting, respectively, with only three species determined to be sufficiently represented currently. Priorities for further collecting include: (i) species completely lacking representation in germplasm collections; (ii) other high priority taxa, with geographic emphasis on the center of species diversity; (iii) medium priority species. Such collecting efforts combined with further emphasis on improving ex situ conservation technologies and methods, performing genotypic and phenotypic characterization of wild relative diversity, monitoring wild populations in situ, and making conserved wild relatives and their associated data accessible to the global research community, represent key steps in ensuring the long-term availability of the wild genetic resources of this important crop.