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Carmona J.,University of Minho | Carmona J.,ICVS 3Bs PT Government Associate Laboratory | Cruz A.,University of Minho | Cruz A.,ICVS 3Bs PT Government Associate Laboratory | And 19 more authors.
PLoS ONE | Year: 2013

Tuberculosis associates with a wide spectrum of disease outcomes. The Beijing (Bj) lineage of Mycobacterium tuberculosis (Mtb) is suggested to be more virulent than other Mtb lineages and prone to elicit non-protective immune responses. However, highly heterogeneous immune responses were reported upon infection of innate immune cells with Bj strains or stimulation with their glycolipids. Using both in vitro and in vivo mouse models of infection, we here report that the molecular mechanism for this heterogeneity may be related to distinct TLR activations. Among this Mtb lineage, we found strains that preferentially activate TLR2, and others that also activate TLR4. Recognition of Mtb strains by TLR4 resulted in a distinct cytokine profile in vitro and in vivo, with specific production of type I IFN. We also uncover a novel protective role for TLR4 activation in vivo. Thus, our findings contribute to the knowledge of the molecular basis underlying how host innate immune cells handle different Mtb strains, in particular the intricate host-pathogen interaction with strains of the Mtb Bj lineage. © 2013 Carmona et al.

Couto M.,CIISA | Santos A.S.,Escola Universitaria Vasco da Gama | Laborda J.,Associacao para o Estudo e Protecao do Gado Asinino | Novoa M.,Associacao para o Estudo e Protecao do Gado Asinino | And 2 more authors.
Livestock Science | Year: 2016

The Miranda donkey (Equus asinus) has an important role in the maintenance of rural landscape and traditions in inland of Portugal. Breeding and keeping of these animals rely on mountain pasture areas, known for their characteristic botanical diversity. However, their grazing behaviour in these areas has not been described and this knowledge is important to set the best management practices that promote an efficient use of these particular feed resources that could be related with parasitic level of these animals. In this way, this study aimed to assess feeding behaviour, diet selection, and relate the total phenolic and tannin content of ingested plants with the parasite load in a group of Miranda donkeys under free ranging system in natural mountain pastures. For this purpose, eight adult non-pregnant Jennies from the Miranda donkey breed were managed under continuous grazing on a 1.6 ha natural mountain pasture from late May to late July. Body condition score (BCS) and grazing behaviour of the Jennies was assessed in two different occasions. Additionally, the level of gastrointestinal nematode infections of the herd was assessed throughout the study. Results showed that animals spent 75.6% of total observation time in search/prehension activities corresponding to an average of 16 h/day. Jennies showed a preference for herbaceous species, although they were able to incorporate in their diet up to 30% of shrubs, suggesting that they can be used as biological tool for controlling and reducing shrub encroachment in these mountain areas. Parasite level increased from 0% positive samples in June to a maximum of 25% in July. The increase of EPG may be related with the observed decrease in the shrub consumption throughout the observation period. Having in account the presence of phenolic and condensed tannins in shrubs, their potential as natural anti-parasitic compounds and the possibility of taking part in donkey diet, these preliminary results can be of the utmost importance regarding an integrated approach of Miranda donkey parasite control. © 2016 Elsevier B.V.

Menino J.F.,University of Minho | Menino J.F.,ICVS 3Bs PT Government Associate Laboratory | Saraiva M.,University of Minho | Saraiva M.,ICVS 3Bs PT Government Associate Laboratory | And 20 more authors.
PLoS Neglected Tropical Diseases | Year: 2013

Background: Paracoccidioides brasiliensis causes paracoccidioidomycosis, one of the most prevalent systemic mycosis in Latin America. Thus, understanding the characteristics of the protective immune response to P. brasiliensis is of interest, as it may reveal targets for disease control. The initiation of the immune response relies on the activation of pattern recognition receptors, among which are TLRs. Both TLR2 and TLR4 have been implicated in the recognition of P. brasiliensis and regulation of the immune response. However, the role of TLR9 during the infection by this fungus remains unclear. Methodology/Principal findings: We used in vitro and in vivo models of infection by P. brasiliensis, comparing wild type and TLR9 deficient (-/-) mice, to assess the contribution of TLR9 on cytokine induction, phagocytosis and outcome of infection. We show that TLR9 recognizes either the yeast form or DNA from P. brasiliensis by stimulating the expression/production of pro-inflammatory cytokines by bone marrow derived macrophages, also increasing their phagocytic ability. We further show that TLR9 plays a protective role early after intravenous infection with P. brasiliensis, as infected TLR9-/- mice died at higher rate during the first 48 hours post infection than wild type mice. Moreover, TLR9-/- mice presented tissue damage and increased expression of several cytokines, such as TNF-α and IL-6. The increased pattern of cytokine expression was also observed during intraperitoneal infection of TLR9-/- mice, with enhanced recruitment of neutrophils. The phenotype of TLR9-/- hosts observed during the early stages of P. brasiliensis infection was reverted upon a transient, 48 hours post-infection, neutrophil depletion. Conclusions/Significance: Our results suggest that TLR9 activation plays an early protective role against P. brasiliensis, by avoiding a deregulated type of inflammatory response associated to neutrophils that may lead to tissue damage. Thus modulation of TLR9 may be of interest to potentiate the host response against this pathogen. © 2013 Menino et al.

Vilhena H.,Escola Universitaria Vasco da Gama | Vilhena H.,Animal and Veterinary Research Center | Granada S.,Escola Universitaria Vasco da Gama | Oliveira A.C.,Clinica Casa Dos Animais | And 5 more authors.
Parasites and Vectors | Year: 2014

Background: Canine leishmaniosis (CanL) due to Leishmania infantum is a global zoonosis endemic in more than 70 countries in Europe, North Africa, Asia and America; however, data on this infection is scarce from southern Africa. The aim of this study was to survey dogs in Luanda, Angola, for Leishmania infection. Findings. One hundred-and-three dogs presented to a veterinary medical centre in Luanda were serologically and molecularly assessed for Leishmania with the direct agglutination test (DAT) and polymerase chain reaction (PCR). Two dogs were seropositive, with DAT titres of 800 and ≥6400; the latter was also found to be PCR-positive and confirmed to be infected with L. infantum by DNA sequence analysis. No other dog was found to be PCR-positive. The first dog had been imported from Portugal, but the latter had never left Angola (neither had its parents), strongly suggesting an autochthonous infection. Conclusions: Although other cases of CanL have previously been described in the country, this is the first reported study of canine Leishmania infection at the population level, as well as the first report on the molecular characterization of L. infantum in dogs from Angola. © 2014 Vilhena et al.; licensee BioMed Central Ltd.

Vilhena H.,Escola Universitaria Vasco da Gama | Martinez-Diaz V.L.,Autonomous University of Barcelona | Cardoso L.,University of Tras os Montes e Alto Douro | Cardoso L.,University of Porto | And 5 more authors.
Parasites and Vectors | Year: 2013

Background: In recent years, several clinical cases and epidemiological studies of feline vector-borne diseases (FVBD) have been reported worldwide. Nonetheless, information on FVBD agents and their prevalence in Portugal is scarce. Methods. Three-hundred and twenty domestic cats presented to 30 veterinary medical centres in the north and centre regions of Portugal were randomly sampled. Blood was assayed by real-time polymerase chain reaction (PCR) for genera Anaplasma/Ehrlichia, genus Babesia, Hepatozoon canis, Hepatozoon felis, Leishmania infantum and the genus Rickettsia. Babesia-positive samples were further tested for Babesia canis and Babesia vogeli. Results: Eighty (25.0%) out of the 320 cats were positive to at least one vector-borne agent, including seven (2.2%) cats co-infected with two agents. Two cats (0.6%) were infected with Anaplasma/Ehrlichia spp., four (1.3%) with B. canis, 26 (8.1%) with B. vogeli, 50 (15.6%) with H. felis, one (0.3%) with L. infantum and four (1.3%) with Rickettsia spp. No cat tested positive for H. canis. One cat (0.3%) was co-infected with B. canis and B. vogeli, three (0.9%) with B. vogeli and H. felis, one (0.3%) with H. felis and L. infantum, and two (0.6%) with H. felis and Rickettsia spp. Conclusions: A considerable prevalence of infection with vector-borne pathogens among the domestic feline population of the north and centre of Portugal has been revealed by the present study. Additionally, this is the first detection of B. vogeli in cats from Europe and of H. felis in cats from Portugal. © 2013 Vilhena et al.; licensee BioMed Central Ltd.

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