Peste porcina africana, una epidemia que recorre Europa. Un repaso a los orígenes, la epidemiología, los signos clínicos y el futuro de la enfermedad más preocupante para el sector en la actualidad

La peste porcina africana (PPA) es una enfermedad vírica hemorrágica que afecta al cerdo doméstico y al jabalí de declaración obligatoria a la Organización Mundial de Sanidad Animal (OIE). Su agente etiológico, el virus de la PPA (VPPA), es el único miembro del género Asfivirus, que es a su vez el único miembro de la familia Asfarviridae. Se trata de un virus con envoltura, cuyo material genético consiste en una única cadena doble de ADN (bicatenario), de aproximadamente 170-193 Kb, que codifica más de 150 proteínas. El VPPA es sin duda alguna el virus más complejo (desde el punto de vista estructural) con el que se trabaja en medicina veterinaria. Dicha complejidad ha propiciado que a día de hoy, lamentablemente, no existan ni tratamiento ni vacuna eficaces contra la PPA. Así pues, la única estrategia actualmente disponible para controlar la enfermedad consiste en la combinación de un diagnóstico rápido con el vaciado de las granjas afectadas y unos óptimos niveles de bioseguridad

Peste suína africana, uma epidemia que percorre a Europa

Faremos neste artigo uma revisão às origens, epidemiologia, sinais clínicos e o futuro desta doença, que ainda hoje tem um impacto significativo e é tão preocupante para este setor de atividade

Differential expression of porcine microRNAs in African swine fever virus infected pigs : a proof-of-concept study

African swine fever (ASF) is a re-expanding devastating viral disease currently threatening the pig industry worldwide. MicroRNAs are a class of 17-25 nucleotide non- coding RNAs that have been shown to have critical functions in a wide variety of biological processes, such as cell differentiation, cell cycle regulation, carcinogenesis, apoptosis, regulation of immunity as well as in viral infections by cleavage or translational repression of mRNAs. Nevertheless, there is no information about miRNA expression in an ASFV infection. In this proof-of-concept study, we have analyzed miRNAs expressed in spleen and submandibular lymph node of experimentally infected pigs with a virulent (E75) or its derived attenuated (E75CV1) ASFV strain, as well as, at different times post-infection with the virulent strain, by high throughput sequencing of small RNA libraries. Spleen presented a more differential expression pattern than lymph nodes in an ASFV infection. Of the most abundant miRNAs, 12 were differentially expressed in both tissues at two different times in infected animals with the virulent strain. Of these, miR-451, miR-145-5p, miR-181a and miR-122 presented up-regulation at late times post-infection while miR-92a, miR-23a, miR-92b-3p, miR-126-5p, miR-126-3p, miR-30d, miR-23b and miR-92c showed down-regulation. Of the 8 differentially expressed miRNAs identified at the same time post-infection in infected animals with the virulent strain compared with animals infected with its attenuated strain, miR-126-5p, miR-92c, miR-92a, miR-30e-5p and miR-500a-5p presented up-regulation whereas miR-125b, miR-451 and miR-125a were down-regulated. All these miRNAs have been shown to be associated with cellular genes involved in pathways related to the immune response, virus-host interactions as well as with several viral genes. The study of miRNA expression will contribute to a better understanding of African swine fever virus pathogenesis, essential in the development of any disease control strategy. The online version of this article (10.1186/s12985-017-0864-8) contains supplementary material, which is available to authorized users

Identification of African Swine Fever Virus Transcription within Peripheral Blood Mononuclear Cells of Acutely Infected Pigs

African swine fever virus (ASFV) has become widespread in Europe, Asia and elsewhere, thereby causing extensive economic losses. The viral genome includes nearly 200 genes, but their expression within infected pigs has not been well characterized previously. In this study, four pigs were infected with a genotype II strain (ASFV POL/2015/Podlaskie); blood samples were collected before inoculation and at both 3 and 6 days later. During this period, a range of clinical signs of infection became apparent in the pigs. From the blood, peripheral blood mononuclear cells (PBMCs) were isolated. The transcription of the ASFV genes was determined using RNAseq on poly(A)+ mRNAs isolated from these cells. Only very low levels of virus transcription were detected in the PBMCs at 3 days post-inoculation (dpi) but, at 6 dpi, extensive transcription was apparent. This was co-incident with a large increase in the level of ASFV DNA within these cells. The pattern of the virus gene expression was very reproducible between the individual pigs. Many highly expressed genes have undefined roles. Surprisingly, some genes with key roles in virus replication were expressed at only low levels. As the functions of individual genes are identified, information about their expression becomes important for understanding their contribution to virus biology

Fecal microbiota transplantation from warthog to pig confirms the influence of the gut microbiota on African swine fever susceptibility

African swine fever virus (ASFV) is the causative agent of a devastating hemorrhagic disease (ASF) that affects both domestic pigs and wild boars. Conversely, ASFV circulates in a subclinical manner in African wild pigs, including warthogs, the natural reservoir for ASFV. Together with genetic differences, other factors might be involved in the differential susceptibility to ASF observed among Eurasian suids (Sus scrofa) and African warthogs (Phacochoerus africanus). Preliminary evidence obtained in our laboratory and others, seems to confirm the effect that environmental factors might have on ASF infection. Thus, domestic pigs raised in specific pathogen-free (SPF) facilities were extremely susceptible to highly attenuated ASFV strains that were innocuous to genetically identical domestic pigs grown on conventional farms. Since gut microbiota plays important roles in maintaining intestinal homeostasis, regulating immune system maturation and the functionality of the innate/adaptive immune responses, we decided to examine whether warthog fecal microbiota transplantation (FMT) to domestic pigs affects host susceptibility to ASFV. The present work demonstrates that warthog FMT is not harmful for domestic weaned piglets, while it modifies their gut microbiota; and that FMT from warthogs to pigs confers partial protection against attenuated ASFV strains. Future work is needed to elucidate the protective mechanisms exerted by warthog FMT

DNA Vaccination Partially Protects against African Swine Fever Virus Lethal Challenge in the Absence of Antibodies

The lack of available vaccines against African swine fever virus (ASFV) means that the evaluation of new immunization strategies is required. Here we show that fusion of the extracellular domain of the ASFV Hemagglutinin (sHA) to p54 and p30, two immunodominant structural viral antigens, exponentially improved both the humoral and the cellular responses induced in pigs after DNA immunization. However, immunization with the resulting plasmid (pCMV-sHAPQ) did not confer protection against lethal challenge with the virulent E75 ASFV-strain. Due to the fact that CD8+ T-cell responses are emerging as key components for ASFV protection, we designed a new plasmid construct, pCMV-UbsHAPQ, encoding the three viral determinants above mentioned (sHA, p54 and p30) fused to ubiquitin, aiming to improve Class I antigen presentation and to enhance the CTL responses induced. As expected, immunization with pCMV-UbsHAPQ induced specific T-cell responses in the absence of antibodies and, more important, protected a proportion of immunized-pigs from lethal challenge with ASFV. In contrast with control pigs, survivor animals showed a peak of CD8+ T-cells at day 3 post-infection, coinciding with the absence of viremia at this time point. Finally, an in silico prediction of CTL peptides has allowed the identification of two SLA I-restricted 9-mer peptides within the hemagglutinin of the virus, capable of in vitro stimulating the specific secretion of IFNγ when using PBMCs from survivor pigs. Our results confirm the relevance of T-cell responses in protection against ASF and open new expectations for the future development of more efficient recombinant vaccines against this disease

Deletion Mutants of the Attenuated Recombinant ASF Virus, BA71ΔCD2, Show Decreased Vaccine Efficacy

African swine fever (ASF) has become the major threat to the global swine industry. Lack of available commercial vaccines complicates the implementation of global control strategies. So far, only live attenuated ASF viruses (ASFV) have demonstrated solid protection efficacy at the experimental level. The implementation of molecular techniques has allowed the generation of a collection of deletion mutants lacking ASFV-specific virulence factors, some of them with promising potential as vaccine candidates against the pandemic genotype II ASFV strain currently circulating in Africa, Europe, Asia and Oceania. Despite promising results, there is room for improvement, mainly from the biosafety point of view. Aiming to improve the safety of BA71∆CD2, a cross-protective recombinant live attenuated virus (LAV) lacking the ASFV CD2v gene (encoding β-glucuronidase as a reporter gene) available in our laboratory, three new recombinants were generated using BA71∆CD2 as a template: the single mutant BA71∆CD2 f, this time containing the fluorescent mCherry reporter gene instead of CD2v, and two double recombinants lacking CD2v and either the lectin gene (EP153R) or the uridine kinase (UK) gene (DP96R). Comparative in vivo experiments using BA71∆CD2 f, BA71∆CD2DP96R and BA71∆CD2EP153R recombinant viruses as immunogens, demonstrated that deletion of either DP96R or EP153R from BA71∆CD2 f decreases vaccine efficacy and does not improve safety. Our results additionally confirm ASFV challenge as the only available method today to evaluate the protective efficacy of any experimental vaccine. We believe that understanding the fine equilibrium between attenuation and inducing protection in vivo deserves further study and might contribute to more rational vaccine designs in the future

Cross-protection against African swine fever virus upon intranasal vaccination is associated with an adaptive-innate immune crosstalk

African swine fever virus (ASFV) is causing a worldwide pandemic affecting the porcine industry and leading to important global economic consequences. The virus causes a highly lethal hemorrhagic disease in wild boars and domestic pigs. Lack of effective vaccines hampers the control of virus spread, thus increasing the pressure on the scientific community for urgent solutions. However, knowledge on the immune components associated with protection is very limited. Here we characterized the in vitro recall response induced by immune cells from pigs intranasally vaccinated with the BA71ΔCD2 deletion mutant virus. Vaccination conferred dose-dependent cross-protection associated with both ASFV-specific antibodies and IFNγ-secreting cells. Importantly, bulk and single-cell transcriptomics of blood and lymph node cells from vaccinated pigs revealed a positive feedback from adaptive to innate immunity. Indeed, activation of Th1 and cytotoxic T cells was concomitant with a rapid IFNγ-dependent triggering of an inflammatory response characterized by TNF-producing macrophages, as well as CXCL10-expressing lymphocytes and cross-presenting dendritic cells. Altogether, this study provides a detailed phenotypic characterization of the immune cell subsets involved in cross-protection against ASFV, and highlights key functional immune mechanisms to be considered for the development of an effective ASF vaccine. African swine fever (ASF) pandemic is currently the number one threat for the porcine industry worldwide. Lack of treatments hampers its control, and the insufficient knowledge regarding the immune effector mechanisms required for protection hinders rational vaccine design. Here we present the first comprehensive study characterizing the complex cellular immune response involved in cross-protection against ASF. We show that, upon in vitro reactivation, cells from immune pigs induce a Th1-biased recall response that in turn enhances the antiviral innate response. Our results suggest that this positive feedback regulation of innate immunity plays a key role in the early control of ASF virus infection. Altogether, this work represents a step forward in the understanding of ASF immunology and provide critical immune components that should be considered to more rationally design future ASF vaccines

Guia per desenvolupar la competència transversal. Comunicació escrita i oral

Les competències transversals són un aspecte clau en la formació dels estudiants de la Universitat. El Grup d'innovació docent de la Facultat de Veterinària ha desenvolupat unes guies amb l'objectiu d'estandarditzar l'ensenyament de les competències transversals al graus impartits a la Facultat, oferir eines i recursos a l'alumnat per ajudar-los a desenvolupar aquestes competències, i oferir eines i recursos al professorat per facilitar l'ensenyament i l'avaluació de les competències en el marc de les assignatures pròpies. La guia per desenvolupar la competència transversal de comunicació escrita i oral estableix tres nivells de domini i 7 indicadors d'aprenentatge que l'estudiant ha d'assolir de forma progressiva al llarg del grau. En acabar els estudis l'estudiant ha de demostrar que ha adquirit l'habilitat d'expressar-se oralment i per escrit en un registre científic

Aportación al conocimiento de Aspergillus sección Nigri

Descripció del recurs: el 26 d'agost de 2008Consultable des del TDXTítol obtingut de la portada digitalitzadaLos integrantes de la sección Nigri sonunos de los más importantes del género Aspergillus. De distribución ubicua, algunas de sus especies se utilizan ampliamente en la industria alimentaria y poseen la categoria de GRAS("generally regarded as safe") de la FDA. Pese a ello, se ha descrito la capacidad de elaborar ocratoxina A(OA)por parte de los integrantes del agregado A.niger, lo que supone un riesgo inesperado para la salud humana y animal. Por otro lado, la taxonomia de la seccion Nigri es una de las más complejas del genero y esta basada fundamentalmente en criterios morfologicos. En una de las últimas revisiones se creó el agregado A.niger, constituido por dos especies, seis variedades y dos formas. En un intento de clarificar la taxonomía del agregado, se ha propuesto la división del agregado en dos especies, morfológicamente indistinguibles, denominadas A.niger y A.tubingensis atendiendo a patrones de RFLP obtenidos del DNA total. En el presente trabajo se determinó la frecuencia de aparición de las especies del genero Aspergillus y en especial de las especies de la sección Nigri en piensos y materias primas y se estudió la capacidad ocratoxigénica de las cepas de esta sección. Con el fin de estudiar la distribución de las dos especies propuestas en los substratos estudiados describimos una nueva tecnica de RFLP más sencilla y fácil de interpretar y que permite diferenciar de forma más clara estos grupos de cepas. Paralelamente, se realizó un estudio de las características morfológicas macroscopicas y microscópicas de las cepas y su comportamiento a distintas temperaturas y concentraciones de NaC1. De entre los resultados obtenidos, destacamos los siguientes: Las especies del género Aspergillus se aislaron frecuentemente en los substratos estudiados, en especial en piensos. Su recuento parcial en este tipo de muestras representó más del 50% del recuento fungico total. De las especies productoras de OA aisladas en el presente estudio, la frencuencia de aislamiento de A.niger fue superior a la de A.ochraceus. Las cepas tipo de las dos especies propuestas en el agregado A.niger, A.niger CBS 55.65 y A.tubingensis CBS 134.48 resultaron estar muy próximas en terminos filogenéticos, por lo que podría tratarse de una misma especie. La digestión con RsaI del fragmento 5.8S-ITS rDNA amplificado mediante PCR fue un sistema facil, practico y rapido para clasificar cepas del agregado a.niger en dos grupos llamados N y T que se corresponden con las dos especies propuestas. Las cepas de los dos grupos N y T fueron morfológicamente indistinguibles. Las pequeñas diferencias observadas no constituyeron una característica practica para diferenciar ambos grupos. La temperatura optima de crecimiento de las cepas del agregado A.niger fue de 35º C, no desarrollándose por debajo de 10ºC, ni por encima de los 50ºC. Al considerar la división del agregado en los grupos N y T, las cepas tipo T presentaron una temperatura optima de 35ºC y las tipo N de 30-35ºC. Las cepas tipo T se diferenciaron de las tipo N por desarrollase más rapidamente a la temperatura mas baja (10ºC) en la que se obtuvo el desarrollo de las especies del agregado. El crecimiento de las cepas del agregado. A.niger se vio favorecido a concentraciones bajas de cloruro sódico, observándose una mayor tolerancia a 25º C que a 35ºC. Los grupos de cepas N y T presentaron una respuesta similar al NaC1. Todas las cepas ocratoxigenicas del agregado A.niger con patron del RFLP conocido pertenecen al grupo N, por lo que los aislamientos del grupo T parecen no ser capaces de producir OA