Implicitly, parasite molecular studies assume temporal genetic stability. In this study we tested, for the first time to our knowledge, the extent of changes in genetic diversity and structure of Sarcoptes mite populations from Pyrenean chamois (Rupicapra pyrenaica) in Asturias (Spain), using one multiplex of 9 microsatellite markers and Sarcoptes samples from sympatric Pyrenean chamois, red deer (Cervus elaphus), roe deer (Capreolus capreolus) and red fox (Vulpes vulpes).
The mite Sarcoptes scabiei has a known host-range of over 100 mammal species including humans. One of the prime objectives of the Sarcoptes-World Molecular Network (WMN) is to design and develop universal Sarcoptes PCR-based diagnosis methods. We describe here for the first time two universal mitochondrial-based diagnosis methods: (i) conventional end-point PCR and (ii) TaqMan real-time PCR. The design of both of these universal diagnosis methods was based on Sarcoptes samples collected from 23 host species in 14 countries. These methods, based on skin scrapings, were successfully used to etiologically confirm the diagnosis of different clinical degrees of sarcoptic mange in 48 animals belonging to six species. These universal PCR-based diagnosis methods are highly specific, technically sensitive and simple, and are based on the amplification of 135 bp from the Mitochondrial 16S rDNA. The method based on TaqMan real-time qPCR was more sensitive than the conventional end-point PCR. Two universal PCR-based diagnosis methods for S. scabiei were successfully designed and applied; one based on conventional end-point PCR and the other on TaqMan real-time PCR. We recommend further testing and the application of these new universal methods worldwide.
Microsporum canis is a dermatophyte fungus of which cats and dogs are recognized as the natural hosts. M. canis is also easily transmitted to humans, causing lesions to the glabrous skin (tinea corporis) and to the head (tinea capitis). The present study describes some cases of infection with M. canis in children from a veterinary perspective, highlighting some important features of this clinical entity (e.g., the necessity to identify the animal source of infection with appropriate diagnostic tests; the fact that infected cats may present with no or atypical dermatological signs; and the importance of the environment as a fungal reserve).
30 April 2017 in The Journal of Infection in Developing Countries
Introduction: Trichophyton verrucosum belongs to the dermatophyte fungi, closely related organisms that cause skin infections in animals and humans. T. verrucosum infection has been reported in livestock and people in different countries from all continents. Human cases have been reported in different areas of Pakistan, but there is little information about the animal source of the fungus. Methodology: Dermatological specimens collected in the Chitral district of Pakistan for a study on mange in livestock were retrospectively analyzed for the presence of T. verrucosum. In total, 5,873 animals (1,087 cows, 2,033 goats, and 2,753 sheep) were screened for evidence of dermatological lesions during two surveys performed in the summer and winter seasons. Skin scrapings collected from animals with lesions were analyzed by direct microscopic examination after digestion in sodium hydroxide and a real-time polymerase chain reaction (PCR) targeting pathogenic Trichophyton species. Results: At microscopy, samples from 18 cows (1.6%), 3 sheep (0.1%), and 4 goats (0.2%) were positive for fungal elements consistent with T. verrucosum. PCR confirmed the microscopy results. The prevalence was lower than that reported in other countries in intensive breeding farms. Results agree with the literature regarding factors affecting T. verrucosum diffusion, i.e., infection was more prevalent in cattle, especially in younger animals during the winter season. Conclusions: This study reports, for the first time, the presence of T. verrucosum in livestock in Pakistan. A better knowledge of the animal role in the spread of this fungus may allow the adoption of more efficient control measures and prophylaxis.
Background: Sarcoptic mange is a globally distributed parasitic disease caused by the burrowing mite Sarcoptes scabiei. This mite has a certain degree of host specificity, although interspecific transmission can occur among phylogenetically related species or through prey–predator mediated exposure. In 2018, a wild boar (Sus scrofa) with lesions compatible with sarcoptic mange was hunted in Ports de Tortosa i Beseit Natural Park (PTB, north-eastern Spain), where an active epizootic outbreak of sarcoptic mange is affecting Iberian ibexes (Capra pyrenaica) since 2014. Methods: A complete necropsy, skin scrapings and skin digestions with hydroxide potassium were performed to confirm the diagnosis. Routine histopathological analysis, toluidine blue staining and immunohistochemistry were used to characterize the lesions and the inflammatory infiltrate. Finally, 10 specific S. scabiei microsatellites were molecularly genotyped through polymerase chain reactions in mites obtained from the affected wild boar. For phylogenetic comparison, mites obtained from sympatric Iberian ibexes and allopatric wild boars and Iberian ibexes from southern Spain were analysed. Results: Sarcoptes scabiei was visually and molecularly identified in the infested wild boar from PTB, causing skin lesions with dermal inflammatory infiltrate rich in T and B cells, which indicate an adaptive immune response. Three S. scabiei genetic clusters were identified: one included mites from southern Iberian ibexes, another included mites from southern wild boars, and a third one distinctively grouped the wild boar from PTB with the sympatric ibexes. Conclusions: To the authors’ knowledge, this is the first reported case of sarcoptic mange in wild boar in Spain and the first documented case of S. scabiei cross-transmission from a wild ruminant host to a wild boar. The wild boar presented an ordinary scabies type reaction, which is typical of the self-limiting infestations reported in other cases of interspecific transmission. Graphical
Defining hidden genetic diversity within species is of great significance when attempting to maintain the evolutionary potential of natural populations and conduct appropriate management. Our hypothesis is that isolated (and eventually small) wild animal populations hide unexpected genetic diversity due to their maintenance of ancient polymorphisms or introgressions. We tested this hypothesis using the Iberian ibex (Capra pyrenaica) as an example. Previous studies based on large sample sizes taken from its principal populations have revealed that the Iberian ibex has a remarkably small MHC DRB1 diversity (only six remnant alleles) as a result of recent population bottlenecks and a marked demographic decline that has led to the extinction of two recognized subspecies. Extending on the geographic range to include non-studied isolated Iberian ibex populations, we sequenced a new MHC DRB1 in what seemed three small isolated populations in Southern Spain (n = 132). The findings indicate a higher genetic diversity than previously reported in this important gene. The newly discovered allele, MHC DRB1*7, is identical to one reported in the domestic goat C. aegagrus hircus. Whether or not this is the result of ancient polymorphisms maintained by balancing selection or, alternatively, introgressions from domestic goats through hybridization needs to be clarified in future studies. However, hybridization between Iberian ibex and domestic goats has been reported in Spain and the fact that the newly discovered allele is only present in one of the small isolated populations and not in the others suggests introgression. The new discovered allele is not expected to increase fitness in C. pyrenaica since it generates the same protein as the existing MHC DRB1*6. Analysis of a microsatellite locus (OLADRB1) near the new MHC DRB1*7 gene reveals a linkage disequilibrium between these two loci. The allele OLADRB1, 187 bp in length, was unambiguously linked to the MHC DRB1*7 allele. This enabled us to perform a DRB-STR matching method for the recently discovered MHC allele. This finding is critical for the conservation of the Iberian ibex since it directly affects the identification of the units of this species that should be managed and conserved separately (Evolutionarily Significant Units).