Genotipagem de polimorfismos no gene prnp em ovinos da raça Santa Inês no Estado de São Paulo

Santos, Caio Rodrigues dos; Mori, Ênio; Leão, Diego A.; Maiorka, Paulo César

doi:10.1590/s0100-736x2012000300007

Cited by 5 publications

(9 citation statements)

References 14 publications

(24 reference statements)

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“…Until now, no cases of scrapie have been reported in Dorper and White Dorper sheep. Additionally, although some work has characterized PRNP polymorphisms in Brazilian flocks, few studies report these polymorphisms in association with scrapie outbreaks (Andrade et al 2013;Ianella et al 2012;Lima et al 2007;Pacheco et al 2007;Passos et al 2008;Santos et al 2012;Sotomaior et al 2008). The present study describes three outbreaks of classical scrapie occurring in Dorper and White Dorper flocks on three different rural properties in Brazil.…”

Section: Introductionmentioning

confidence: 74%

Report of outbreaks of classical scrapie in Dorper sheep and associated prion protein gene polymorphisms in affected flocks

Andrade

Oliveira

Leal

et al. 2015

Trop Anim Health Prod

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Scrapie is an infectious neurodegenerative disease affecting sheep and goats, related with conformational alteration of an isoform of the prion protein that leads to deposition and aggregation in the host's central nervous system. Occurrence of the natural disease can be influenced by host genetic factors, such as a single nucleotide polymorphism of the prion protein gene. This study reports three scrapie-affected Dorper flocks located on three different farms in Brazil. The objective of this study was to analyze these three flocks using scrapie diagnostics, combining histology, immunohistochemistry, genotyping, and western blot assays. For immunohistochemistry, 192 sheep were selected and 308 sheep blood samples were taken for genotyping. A total of 22 sheep were scrapie positive by immunohistochemistry. Of these, four presented clinical signs and had scrapie immunoreactivity at the obex in western blot assays. The sheep without clinical signs were positive in lymphoid organs, such as the third eyelid and rectal mucosa. The major genotypes found on the flocks were ARQ/ARQ, ARQ/ARR, and ARQ/VRQ for codons 136, 154, and 171. Most of the sheep were considered to be at moderate to high risk, based on risk groups for developing scrapie. Some blood samples were sequenced, and polymorphisms were identified in other codons, such as 127, 142, and 143. Our data demonstrate the importance of preclinical scrapie diagnosis in Brazilian sheep, as most of the affected sheep showed no clinical signs, and emphasize the relevance of genotyping other Dorper sheep to determine the genotypic profile of the breed.

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Section: Introductionmentioning

confidence: 74%

Report of outbreaks of classical scrapie in Dorper sheep and associated prion protein gene polymorphisms in affected flocks

Andrade

Oliveira

Leal

et al. 2015

Trop Anim Health Prod

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“…To date, research with this breed has identified polymorphisms in the PRNP gene, which enables the identification of resistant or susceptible animals to the disease (Lima et al, 2007;Santos et al, 2012), but no case had been reported before the present study. These authors identified both resistant and susceptible genotypes in the Santa Inês breed.…”

Section: In All Prpmentioning

confidence: 86%

“…In Brazil, positive scrapie cases have been reported (Leal et al; and some research has investigated the susceptibility of ovine herds (Lima et al, 2007;Santos et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Scrapie diagnosis in a goat and four Santa Inês sheep from the same herd in Brazil

Leal

Correa

Boos

et al. 2015

Arq. Bras. Med. Vet. Zootec.

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Scrapie is a fatal and progressive transmissible spongiform encephalopathy (TSE) of natural occurrence in sheep and goats. The suspicion of scrapie may be based on clinical signs; however, the detection of pathological features of the prionic protein (PrP) in target tissues is necessary to diagnose the disease. The presence of an abnormal protein form (PrP Sc ) in lymphoreticular and nervous tissues is an important characteristic in diagnosis. This paper reports a case of scrapie in a flock of 55 Suffolk crossbred sheep, 19 Santa Inês sheep and 21 goats in the Mato Grosso state, midwestern Brazil. The animals were euthanized after the confirmation of a scrapie case with clinical signs in a Suffolk sheep in the same farm. Samples of brainstem at the level of the obex and lymphoid issues like palatine tonsils, mesenteric lymph nodes, third eyelid fixed in formalin 10% were processed for histological examination. Histological examination with hematoxylin and eosin did not show any microscopic changes in samples. Immunohistochemistry (IHC) examination to detect anti-prion PrPSc was performed in lymphoid tissues. Scrapie diagnosis was confirmed based on IHC positive results for PrP Sc in lymphoid tissues of a crossbreed goat and four Santa Inês sheep, without any clinical scrapie signs. IHC showed positive staining in at least three lymphoid germinal centers in goat mesenteric lymph node, palatine tonsil, and third eyelid samples. The mesenteric lymph node, and tonsil samples of all sheep showed positive immunostaining, and only one sheep showed positive staining in lymphoid follicles in the third eyelid. Scrapie diagnosis using IHC in fixed samples of lymphoreticular tissue is technically feasible to detect the disease in both goats and sheep, as a form of pre-clinical diagnosis. The results indicate that the herd was infected by a sheep coming from another herd where scrapie had been diagnosed before.Keywords: scrapie, prion, diseases of small ruminants, immunohistochemistry, lymphoid tissues RESUMO Scrapie é uma encefalopatia espongiforme transmissível (EET) progressiva e fatal de ocorrência natural em ovinos e caprinos. A suspeita de scrapie é baseada nos sinais clínicos, porém a manifestação patológica da proteína priônica (PrP) nos tecidos-alvo é necessária para a confirmação da doença. A presença de uma forma anormal da proteína (PrP

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“…Currently, data about PRNP polymorphisms in Brazil are being published (LIMA et al, 2007;PACHECO et al, 2007;SOTOMAIOR et al, 2008;PASSOS et al, 2008;ANDRADE et al, 2011;IANELLA et al, 2012;SANTOS et al, 2012). Further studies like these must be carried out in order to identify the resistant and susceptible genotypes in the different breeds, contributing to increase the value of rams and dams, which may be commercialized with the certification of scrapie resistance and will help control the disease.…”

Section: Discussionmentioning

confidence: 99%

“…In Brazil, although there is not yet a breeding program to control scrapie, some data on PRNP polymorphisms have been published (LIMA et al, 2007;PACHECO et al, 2007;SOTOMAIOR et al, 2008;PASSOS et al, 2008;ANDRADE et al, 2011;IANELLA et al, 2012;SANTOS et al, 2012). These articles mainly give the percentages of the different polymorphisms, but do not make any kind of association with the presence of the PrP Sc .…”

Section: Introductionmentioning

confidence: 99%

Prion protein gene polymorphisms and accumulation of pathogenic prion protein (PrPSc) in a herd with previously confirmed scrapie cases

Sotomaior¹,

Driemeier²,

Leal³

et al. 2015

Biosci. J.

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Genotipagem de polimorfismos no gene prnp em ovinos da raça Santa Inês no Estado de São Paulo

Cited by 5 publications

References 14 publications

Report of outbreaks of classical scrapie in Dorper sheep and associated prion protein gene polymorphisms in affected flocks

Report of outbreaks of classical scrapie in Dorper sheep and associated prion protein gene polymorphisms in affected flocks

Scrapie diagnosis in a goat and four Santa Inês sheep from the same herd in Brazil

Prion protein gene polymorphisms and accumulation of pathogenic prion protein (PrPSc) in a herd with previously confirmed scrapie cases

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