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1.
Int J Mol Sci ; 25(7)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38612650

RESUMO

Chagas disease (CD) is a vector-borne Neglected Zoonotic Disease (NZD) caused by a flagellate protozoan, Trypanosoma cruzi, that affects various mammalian species across America, including humans and domestic animals. However, due to an increase in population movements and new routes of transmission, T. cruzi infection is presently considered a worldwide health concern, no longer restricted to endemic countries. Dogs play a major role in the domestic cycle by acting very efficiently as reservoirs and allowing the perpetuation of parasite transmission in endemic areas. Despite the significant progress made in recent years, still there is no vaccine against human and animal disease, there are few drugs available for the treatment of human CD, and there is no standard protocol for the treatment of canine CD. In this review, we highlight human and canine Chagas Disease in its different dimensions and interconnections. Dogs, which are considered to be the most important peridomestic reservoir and sentinel for the transmission of T. cruzi infection in a community, develop CD that is clinically similar to human CD. Therefore, an integrative approach, based on the One Health concept, bringing together the advances in genomics, immunology, and epidemiology can lead to the effective development of vaccines, new treatments, and innovative control strategies to tackle CD.


Assuntos
Doenças dos Animais , Doença de Chagas , Doenças do Cão , Trypanosoma cruzi , Humanos , Cães , Animais , Doença de Chagas/epidemiologia , Doença de Chagas/veterinária , Animais Domésticos , Doenças do Cão/epidemiologia , Mamíferos
2.
Vet Parasitol Reg Stud Reports ; 47: 100964, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38199683

RESUMO

Cryptosporidium is a protozoan parasite with worldwide distribution, infecting a wide range of hosts with some zoonotic species. Calves have been identified as one of the most common reservoirs of this parasite. However, little is known about the genetics of Cryptosporidium in calves in Portugal. This study aimed to molecularly characterize infections of Cryptosporidium in pre-weaned calves from the Lisbon and Tagus Valley (LTV) in Portugal. Fifty-two samples were collected from calves from eight dairy and two beef farms in LTV, Portugal. Cryptosporidium oocysts were detected by Modified Ziehl-Neelsen staining (MZN) and direct immunofluorescent assay (DFA). MZN and DFA revealed the presence of Cryptosporidium oocysts in 40.4% (21/52) and 67.3% (35/52) samples, respectively. Positive samples were analyzed by PCR-RFLP of the 18 s rRNA gene for species identification. DNA amplification of the 18S rRNA gene was successful for 88.6% (31/35) of samples. Cryptosporidium parvum was identified in 96.8% (30/31) of the samples, and from one sample Cryptosporidium bovis was identified. Cryptosporidium parvum positive samples were subtyped by sequencing the PCR product of a partial fragment of the 60 kDa glycoprotein (gp60) gene. Subtype analysis of the C. parvum isolates revealed that all isolates belonged to subtype family IIa. Four subtypes were recognized within this subtype family, including the hyper-transmissible IIaA15G2R1 subtype that is the most frequently reported worldwide (27/30), IIaA14G2R1 (1/30), IIaA16G2R1 (1/30) and IIaA19G2R1 (1/30). To our knowledge, this is the first report of C. bovis, and C. parvum subtypes IIaA14G2R1 and IIaA19G2R1 in cattle in LTV, Portugal. The presence of the zoonotic C. parvum subtype in this study suggests that pre-weaned calves are likely to be a significant reservoir of zoonotic C. parvum, highlighting the importance of animal-to-human infection transmission risk. Further molecular studies are required to better understand the epidemiology of cryptosporidiosis in Portugal.


Assuntos
Doenças dos Bovinos , Criptosporidiose , Cryptosporidium parvum , Cryptosporidium , Humanos , Animais , Bovinos , Cryptosporidium/genética , Portugal/epidemiologia , Criptosporidiose/epidemiologia , Cryptosporidium parvum/genética , Meio Ambiente , Oocistos , Doenças dos Bovinos/epidemiologia
3.
Parasit Vectors ; 16(1): 384, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37880680

RESUMO

BACKGROUND: The ticks Ixodes ricinus and Dermacentor reticulatus are two of the most important vectors in Europe. Climate niche modelling has been used in many studies to attempt to explain their distribution and to predict changes under a range of climate change scenarios. The aim of this study was to assess the ability of different climate niche modelling approaches to explain the known distribution of I. ricinus and D. reticulatus in Europe. METHODS: A series of climate niche models, using different combinations of input data, were constructed and assessed. Species occurrence records obtained from systematic literature searches and Global Biodiversity Information Facility data were thinned to different degrees to remove sampling spatial bias. Four sources of climate data were used: bioclimatic variables, WorldClim, TerraClimate and MODIS satellite-derived data. Eight different model training extents were examined and three modelling frameworks were used: maximum entropy, generalised additive models and random forest models. The results were validated through internal cross-validation, comparison with an external independent dataset and expert opinion. RESULTS: The performance metrics and predictive ability of the different modelling approaches varied significantly within and between each species. Different combinations were better able to define the distribution of each of the two species. However, no single approach was considered fully able to capture the known distribution of the species. When considering the mean of the performance metrics of internal and external validation, 24 models for I. ricinus and 11 models for D. reticulatus of the 96 constructed were considered adequate according to the following criteria: area under the receiver-operating characteristic curve > 0.7; true skill statistic > 0.4; Miller's calibration slope 0.25 above or below 1; Boyce index > 0.9; omission rate < 0.15. CONCLUSIONS: This comprehensive analysis suggests that there is no single 'best practice' climate modelling approach to account for the distribution of these tick species. This has important implications for attempts to predict climate-mediated impacts on future tick distribution. It is suggested here that climate variables alone are not sufficient; habitat type, host availability and anthropogenic impacts, not included in current modelling approaches, could contribute to determining tick presence or absence at the local or regional scale.


Assuntos
Dermacentor , Ixodes , Animais , Biodiversidade , Ecossistema , Europa (Continente)
4.
Cells ; 12(8)2023 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-37190011

RESUMO

Leishmaniasis is a parasitic disease caused by different species of Leishmania and transmitted through the bite of sand flies vector. Macrophages (MΦ), the target cells of Leishmania parasites, are phagocytes that play a crucial role in the innate immune microbial defense and are antigen-presenting cells driving the activation of the acquired immune response. Exploring parasite-host communication may be key in restraining parasite dissemination in the host. Extracellular vesicles (EVs) constitute a group of heterogenous cell-derived membranous structures, naturally produced by all cells and with immunomodulatory potential over target cells. This study examined the immunogenic potential of EVs shed by L. shawi and L. guyanensis in MΦ activation by analyzing the dynamics of major histocompatibility complex (MHC), innate immune receptors, and cytokine generation. L. shawi and L. guyanensis EVs were incorporated by MΦ and modulated innate immune receptors, indicating that EVs cargo can be recognized by MΦ sensors. Moreover, EVs induced MΦ to generate a mix of pro- and anti-inflammatory cytokines and favored the expression of MHCI molecules, suggesting that EVs antigens can be present to T cells, activating the acquired immune response of the host. Since nano-sized vesicles can be used as vehicles of immune mediators or immunomodulatory drugs, parasitic EVs can be exploited by bioengineering approaches for the development of efficient prophylactic or therapeutic tools for leishmaniasis.


Assuntos
Micropartículas Derivadas de Células , Exossomos , Interações Hospedeiro-Patógeno , Imunomodulação , Leishmania guyanensis , Leishmania , Ativação de Macrófagos , Macrófagos , Leishmania guyanensis/imunologia , Interações Hospedeiro-Patógeno/imunologia , Leishmania/imunologia , Animais , Camundongos , Linhagem Celular , Macrófagos/imunologia , Macrófagos/parasitologia , Micropartículas Derivadas de Células/imunologia , Micropartículas Derivadas de Células/parasitologia , Exossomos/imunologia , Exossomos/parasitologia , Peptídeo Hidrolases/metabolismo , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Citocinas/metabolismo , Imunidade Inata
5.
Virol J ; 20(1): 103, 2023 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-37237382

RESUMO

The European rabbit (Oryctolagus cuniculus) populations of the Iberian Peninsula have been severely affected by the emergence of the rabbit haemorrhagic disease virus (RHDV) Lagovirus europaeus/GI.2 (RHDV2/b). Bushflies and blowflies (Muscidae and Calliphoridae families, respectively) are important RHDV vectors in Oceania, but their epidemiological role is unknown in the native range of the European rabbit. In this study, scavenging flies were collected between June 2018 and February 2019 in baited traps at one site in southern Portugal, alongside a longitudinal capture-mark-recapture study of a wild European rabbit population, aiming to provide evidence of mechanical transmission of GI.2 by flies. Fly abundance, particularly from Calliphoridae and Muscidae families, peaked in October 2018 and in February 2019. By employing molecular tools, we were able to detect the presence of GI.2 in flies belonging to the families Calliphoridae, Muscidae, Fanniidae and Drosophilidae. The positive samples were detected during an RHD outbreak and absent in samples collected when no evidence of viral circulation in the local rabbit population was found. We were able to sequence a short viral genomic fragment, confirming its identity as RHDV GI.2. The results suggest that scavenging flies may act as mechanical vectors of GI.2 in the native range of the southwestern Iberian subspecies O. cuniculus algirus. Future studies should better assess their potential in the epidemiology of RHD and as a tool for monitoring viral circulation in the field.


Assuntos
Infecções por Caliciviridae , Dípteros , Vírus da Doença Hemorrágica de Coelhos , Lagovirus , Animais , Coelhos , Lagovirus/genética , Infecções por Caliciviridae/epidemiologia , Filogenia , Vírus da Doença Hemorrágica de Coelhos/genética
6.
Acta Trop ; 235: 106662, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35998679

RESUMO

Blowflies have forensic, sanitary and veterinary importance, as well as being pollinators, parasitoids and ecological bioindicators. There is still little work with real data and from experiments assessing the relationship between blowflies' morphologic features and environmental and demographic factors. The present work tests whether the variation, in the shape and size, of Chrysomya albiceps (Wiedemann, 1819) wings is influenced by the following factors: 1) time; 2) temperature; 3) sex and; 4) different types of carcasses (pig, dog/cat and whale). Male and female wings from four different sites collected in six different years were used to obtain wing size and shape of C. albiceps. Analyses between wing shape and the variables tested had low explanatory power, even though they had statistical support. However, it was possible to identify differences in wing shape between males and females, with good returns in sex identification. The comparison between wing size and the variables tested showed that wing size has a negative relationship with temperature, significant differences between sexes, slight variation over time and no influence by carcass types. Furthermore, wing size influenced wing shape. Understanding population-specific characteristics of C. albiceps provide important insights about how the species reacts under specific conditions.


Assuntos
Calliphoridae , Asas de Animais , Animais , Cadáver , Calliphoridae/anatomia & histologia , Feminino , Medicina Legal , Masculino , Temperatura , Asas de Animais/anatomia & histologia
7.
BMC Vet Res ; 17(1): 21, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413330

RESUMO

BACKGROUND: The black stork (Ciconia nigra Linnaeus, 1758) is a recognized endangered species in Europe and most of the specimens from the Western Palearctic region breed in the Iberian Peninsula. Available works regarding parasites in black storks are scarce. This work reports the presence one ecto- and two endoparasite species from a black stork in Portugal. CASE PRESENTATION: A black stork was found in southern Portugal after colliding against electric cables. The specimen did not survive its sustained injuries and a post-mortem exam was performed. During the procedure, several ecto- and endoparasite specimens were found. The collected parasites were lice (Neophilopterus tricolor), nematodes (Desportesius sagittatus) and trematodes (Cathaemasia hians). CONCLUSIONS: Three different species of parasites are reported from a black stork in Portugal. Ecto- and endoparasites of C. nigra have not frequently been described in the literature, and this case report is a contribution to the field. Additional studies will be important to better understand the impact that parasites can have on C. nigra health and survival.


Assuntos
Doenças das Aves/parasitologia , Infestações por Piolhos/veterinária , Infecções por Rhabditida/veterinária , Infecções por Trematódeos/veterinária , Animais , Aves , Echinostomatidae/isolamento & purificação , Ftirápteros , Portugal , Rabditídios/isolamento & purificação
9.
Front Vet Sci ; 6: 362, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31681815

RESUMO

Canine leishmaniosis (CanL) caused by Leishmania infantum is a zoonotic disease of global concern. Antileishmanial drug therapies commonly used to treat sick dogs improve their clinical condition, although when discontinued relapses can occur. Thus, the current study aims to evaluate the effect of CanL treatments in peripheral blood, lymph node, and bone marrow cytokine profile associated with clinical recovery. Two groups of six dogs diagnosed with CanL were treated with miltefosine combined with allopurinol and meglumine antimoniate combined with allopurinol (MT+A and MG+A), respectively. At diagnosis and after treatment, during a 3-month follow-up, clinical signs, hematological and biochemical parameters, urinalysis results and antileishmanial antibody titers were registered. Furthermore, peripheral blood, popliteal lymph node, and bone marrow samples were collected to assess the gene expression of IL-2, IL-4, IL-5, IL-10, IL-12, TNF-α, TGF-ß, and IFN-γ by qPCR. In parallel, were also evaluated samples obtained from five healthy dogs. Both treatment protocols promoted the remission of clinical signs as well as normalization of hematological and biochemical parameters and urinalysis values. Antileishmanial antibodies returned to non-significant titers in all dogs. Sick dogs showed a generalized upregulation of IFN-γ and downregulation of IL-2, IL-4, and TGF-ß, while gene expression of IL-12, TNF-α, IL-5, and IL-10 varied between groups and according to evaluated tissue. A trend to the normalization of cytokine gene expression was induced by both miltefosine and meglumine antimoniate combined therapies. However, IFN-γ gene expression was still up-regulated in the three evaluated tissues. Furthermore, the effect of treatment in the gene expression of cytokines that were not significantly changed by infection, indicates that miltefosine and meglumine antimoniate combined therapy directly affects cytokine generation. Both combined therapies are effective in CanL treatment, leading to sustained pro-inflammatory immune environments that can compromise parasite survival and favor dogs' clinical cure. In the current study, anti-inflammatory and regulatory cytokines do not seem to play a prominent role in CanL or during clinical recovery.

10.
J Forensic Sci ; 64(5): 1304-1311, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30801721

RESUMO

Most emerging or re-emerging infections are vector-borne or zoonotic and can be disseminated worldwide by infected humans or animals. They are a major public health problem and cause a great impact on economy. Zoonotic outbreaks began to be characterized in the 90s, after the creation of Europol and the FBI. Such investigations are carried by forensic pathologists and other specialists to determine whether an outbreak is natural or deliberate. This review will discuss ten zoonotic outbreaks nonrelated to wars focusing on forensic management. In conclusion, some points should be highlighted in the management of a zoonotic outbreak: (i) its diagnosis and detection by forensic pathologists and the coordination of efforts between other specialists are key factors; (ii) communication guidelines and an efficient healthcare system are crucial for any emergency response; (iii) biosafety of all specialists involved must be guaranteed.


Assuntos
Surtos de Doenças , Zoonoses/epidemiologia , Animais , Antraz/epidemiologia , Antraz/transmissão , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/transmissão , Febre Aftosa/epidemiologia , Febre Aftosa/transmissão , Medicina Legal , Gastroenterite/epidemiologia , Gastroenterite/microbiologia , Síndrome Pulmonar por Hantavirus/epidemiologia , Síndrome Pulmonar por Hantavirus/transmissão , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/transmissão , História do Século XX , História do Século XXI , Humanos , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/transmissão , Escherichia coli Shiga Toxigênica , Tularemia/epidemiologia , Tularemia/transmissão , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/transmissão
11.
Vet Parasitol ; 248: 10-20, 2017 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-29173534

RESUMO

Canine leishmaniosis caused by L. infantum is a severe zoonotic disease. Although macrophages are the definitive host cells, neutrophils are the first cells to encounter the parasite soon after its inoculation in the dermis by the phlebotomine vector. To study the interaction of dog neutrophils and L. infantum promastigotes, blood neutrophils were isolated from healthy donors and the infection was established in vitro. In the majority of the dogs, L. infantum was efficiently phagocytized by neutrophils, and oxidative (superoxide production) and non-oxidative (neutrophil elastase exocytosis) intracellular effector mechanisms were activated, but the release of neutrophil extracellular traps was minimized. Furthermore, promastigotes and culture supernatants induced neutrophil migration, but the prior contact with Leishmania inhibits chemotaxis, which might contribute to neutrophil retention at the inoculation site. Neutrophil-parasite interaction resulted in a decrease in parasite viability, although some intracellular promastigotes survive and maintain their proliferative capacity. These findings indicate that dog neutrophils are competent effector cells able to control the initial L. infantum infection. However, some parasites evade intracellular effector mechanisms and can be transferred to the definitive host cell, the macrophage, contributing to the development of canine leishmaniosis.


Assuntos
Doenças do Cão/imunologia , Imunidade Inata , Leishmania infantum/fisiologia , Leishmaniose Visceral/veterinária , Neutrófilos/imunologia , Animais , Doenças do Cão/parasitologia , Cães , Feminino , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/parasitologia , Masculino , Neutrófilos/parasitologia
12.
PLoS One ; 12(7): e0180606, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28683145

RESUMO

Vector-borne diseases are not only accounted responsible for their burden on human health-care systems, but also known to cause economic constraints to livestock and animal production. Animals are affected directly by the transmitted pathogens and indirectly when animal movement is restricted. Distribution of such diseases depends on climatic and social factors, namely, environmental changes, globalization, trade and unplanned urbanization. Culicoides biting midges are responsible for the transmission of several pathogenic agents with relevant economic impact. Due to a fragmentary knowledge of their ecology, occurrence is difficult to predict consequently, limiting the control of these arthropod vectors. In order to understand the distribution of Culicoides species, in mainland Portugal, data collected during the National Entomologic Surveillance Program for Bluetongue disease (2005-2013), were used for statistical evaluation. Logistic regression analysis was preformed and prediction maps (per season) were obtained for vector and potentially vector species. The variables used at the present study were selected from WorldClim (two climatic variables) and CORINE databases (twenty-two land cover variables). This work points to an opposite distribution of C. imicola and species from the Obsoletus group within mainland Portugal. Such findings are evidenced in autumn, with the former appearing in Central and Southern regions. Although appearing northwards, on summer and autumn, C. newsteadi reveals a similar distribution to C. imicola. The species C. punctatus appears in all Portuguese territory throughout the year. Contrary, C. pulicaris is poorly caught in all areas of mainland Portugal, being paradoxical present near coastal areas and higher altitude regions.


Assuntos
Ceratopogonidae , Insetos Vetores , Animais , Geografia , Portugal
13.
Vet Parasitol Reg Stud Reports ; 8: 13-20, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-31014630

RESUMO

This study was carried out in southern Portugal to determine the prevalence of parasitic helminths infecting wild birds. Between September and December of 2013, adult parasites were collected from the gastrointestinal tract of 22 bird specimens (belonging to 12 species) that died in Wildlife Rehabilitation and Investigation Centre of the Ria Formosa. Identified gastrointestinal parasites include the nematodes (Contracaecum sp., Cosmocephalus obvelatus, Desportesius invaginatus, Dispharynx nasuta, Porrocaecum angusticolle and Synhimantus laticeps) and cestodes (Diplophallus sp., Neyraia intricata and Tetrabothrius sp.). The overall level of infection was 54.5% (12/22) and the most frequent helminths present were nematodes (40.9% - 9/22), followed by cestodes (13.6% - 3/22). Helminthic richness was similar in all birds (one species or genera per bird) and the helminth species, except Dispharynx nasuta, exhibited a clear relationship with host diet. Five helminth species (Cosmocephalus obvelatus, Desportesius invaginatus, Dispharynx nasuta, Porrocaecum angusticolle and Neyraia intricata) and two genera (Contracaecum sp. and Diplophallus sp.) were reported for the first time in Portugal and the presence of P. angusticolle in Bonelli's eagle was recorded for the first time across all researched literature.

14.
Parasitol Int ; 65(3): 295-301, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26899014

RESUMO

This study was carried out to determine chewing louse species of wild birds in the Ria Formosa Natural Park, located in southern Portugal. In addition, the hypothesis that bird age, avian migration and social behaviour have an impact on the louse prevalence was tested. Between September and December of 2013, 122 birds (belonging to 10 orders, 19 families, 31 genera and 35 species) captured in scientific ringing sessions and admitted to the Wildlife Rehabilitation and Investigation Centre of Ria Formosa were examined for lice. Twenty-six (21.3%) birds were found to be infested with at least one chewing louse species. The chewing lice identified include 18 species. Colonial birds (34.9%) and migratory birds (29.5%) had statistically significant higher prevalence than territorial birds (6.8%) and resident birds (13.1%), respectively. This paper records 17 louse species for the first time in southern Portugal: Laemobothrion maximum, Laemobothrion vulturis, Actornithophilus piceus lari, Actornithophilus umbrinus, Austromenopon lutescens, Colpocephalum heterosoma, Colpocephalum turbinatum, Eidmanniella pustulosa, Nosopon casteli, Pectinopygus bassani, Pseudomenopon pilosum, Trinoton femoratum, Trinoton querquedulae, Craspedorrhynchus platystomus, Degeeriella fulva, Falcolipeurus quadripustulatus, Lunaceps schismatus. Also a nymph of the genus Strigiphilus was collected from a Eurasian eagle-owl. These findings contribute to the knowledge of avian chewing lice from important birds areas in Portugal.


Assuntos
Doenças das Aves/parasitologia , Infestações por Piolhos/veterinária , Ftirápteros/classificação , Estrigiformes/parasitologia , Animais , Animais Selvagens , Doenças das Aves/epidemiologia , Feminino , Infestações por Piolhos/epidemiologia , Infestações por Piolhos/parasitologia , Masculino , Ftirápteros/anatomia & histologia , Portugal/epidemiologia
15.
Syst Parasitol ; 92(2): 171-9, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26358076

RESUMO

A new coccidian species (Protozoa: Apicomplexa: Eimeriidae) is described from a specimen of the Eurasian blackbird Turdus merula Linnaeus held for rehabilitation and reintroduction into the wild in a centre for research and recovery of wild animals in Quinta de Marim, Olhão, Portugal. Isospora lusitanensis n. sp. has subspherical to ovoidal oöcysts, measuring on average 26.4 × 23.4 µm, with smooth, bi-layered wall c.1.1 µm thick. Micropyle and oöcyst residuum are absent, but a polar granule is present. Sporocysts are ellipsoidal, measuring on average 16.0 × 10.9 µm. Stieda body is knob-like and sub-Stieda body is prominent and rounded. Sporocyst residuum is composed of scattered spherules. Sporozoites are vermiform, with one refractile body and a nucleus. The morphological and morphometric data for the new species were compared with those for species parasitising birds of the Muscicapidae, Turdidae, Timaliidae, Troglodytidae and Cinclidae, which are considered phylogenetically close. The original histograms of Isospora turdi Schwalbach, 1959 were redrawn for comparison with I. lusitanensis n. sp. and a linear regression of width against length of the oöcysts is presented for characterisation. This is the first isosporoid coccidian described from T. merula in mainland Portugal.


Assuntos
Isospora/classificação , Aves Canoras/parasitologia , Animais , Isospora/citologia , Oocistos/citologia , Portugal , Especificidade da Espécie
16.
Parasit Vectors ; 6: 88, 2013 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-23566789

RESUMO

BACKGROUND: Canine leishmaniosis caused by Leishmania infantum is a parasitic zoonotic disease transmitted by phlebotomine sandflies (Diptera: Psychodidae). Genus Phlebotomus is the biological vector in the Old World and Lutzomyia in the New World. The dog is the domestic reservoir host but other animals like the fox (Vulpes vulpes) and rodents are known to maintain the infection in both sylvatic and domestic cycles. METHODS: To identify the role of synanthropic rodents Mus musculus and Rattus norvegicus as reservoir hosts for Leishmania infantum natural infection, 30 rodents were captured under a trap rodent control program in two private dog shelters from Sintra and Sesimbra, located in the Lisbon Metropolitan Area, known to be endemic for canine leishmaniosis in Portugal. Tissue samples were screened for the presence of Leishmania amastigotes by qPCR and parasitological analysis. RESULTS: A total of 33.3% (9/27) of Mus musculus rodents revealed the presence of Leishmania spp. DNA while 29.6% (8/27) were positive in the parasitological analysis. Concerning Rattus norvegicus (n=3), one animal revealed infection only by parasitological analysis. CONCLUSIONS: Our results identified for the first time in Portugal the presence of Leishmania infection in both rodent species. As susceptible hosts, infected Mus musculus and Rattus norvegicus may increase the risk for dog and human infection in households and surrounding areas, enhancing the need for efficient rodent control measures in shelters and risk zones to prevent transmission of the infection.


Assuntos
Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/veterinária , Doenças dos Roedores/epidemiologia , Estruturas Animais/parasitologia , Animais , Cães , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Camundongos , Parasitologia , Portugal/epidemiologia , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Doenças dos Roedores/parasitologia
17.
Vet Parasitol ; 189(2-4): 137-44, 2012 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-22698797

RESUMO

Canine leishmaniosis, caused by Leishmania infantum, is a systemic disease with variable clinical signs and a progressive evolution. This disease is characterized by impaired T cell-mediated immune response, which has been associated with disease chronicity and high mortality. Protective immunity against leishmaniosis is thought to be mediated by T cell and cytokine production. The T cell activation requires a primary signal delivered by the major histocompatibility complex (MHC) molecules present on the surface of antigen presenting cells, and a non-specific signal generated by co-stimulatory molecules. To characterize canine immune responses in the presence of L. infantum parasites or their antigens, in vitro cell cultures of canine macrophages and lymphocytes were established, and the macrophages presenting MHC class II molecules were evaluated as well as the expression of IL-12 and CD80-86 co-stimulatory molecules and nitric oxide production. The results showed for the first time the up-regulation of MHC class II molecules on the surface in canine peripheral blood monocyte-derived macrophages during L. infantum infection in the presence of lymphocytes. In addition, a lack of co-stimulatory expression and a reduced release of nitric oxide were observed, suggesting a loss of T cell function and consequently an inactivation of the macrophage oxidative burst which, in turn, favors the survival of Leishmania. These results constitute a new contribution for the understanding of the interactions between L. infantum and the canine immune system.


Assuntos
Doenças do Cão/parasitologia , Leishmania infantum/fisiologia , Leishmaniose Visceral/veterinária , Macrófagos/parasitologia , Animais , Antígeno B7-1/genética , Antígeno B7-1/metabolismo , Antígeno B7-2/genética , Antígeno B7-2/metabolismo , Cães , Feminino , Regulação da Expressão Gênica , Genes MHC da Classe II/fisiologia , Interleucina-12/genética , Interleucina-12/metabolismo , Leishmaniose Visceral/parasitologia , Masculino , Óxido Nítrico/metabolismo , Explosão Respiratória/fisiologia
18.
Vet Immunol Immunopathol ; 137(3-4): 275-83, 2010 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-20615553

RESUMO

Canine visceral leishmaniasis (CanL) is an emerging disease, expanding in various parts of the world. The infection caused by Leishmania, an intracellular protozoan parasite, can show different clinical manifestations, from asymptomatic or subclinical to symptomatic dogs, in which a wide spectrum of clinical signs is evident. The fact that the parasite replicates in different organs raises the hypothesis that each organ may have a specific immune response. The local immune responses should be evaluated and taken into consideration when developing prophylactic tools. Therefore, phenotypic characterization of peripheral blood, lymph node and bone marrow lymphocyte populations and the expression of class II molecules of major histocompatibility complex (MHCII) were performed in asymptomatic and symptomatic dogs and in dogs that had been diagnosed and treated for leishmaniasis. Our findings showed that blood and bone marrow lymphocytes from symptomatic dogs were highly activated. In bone marrow of asymptomatic and treated dogs, a high frequency of MHCII(+) lymphocytes was observed, as well as MHCII(+) monocytes in the treated group. These results show increased expression of MHCII molecules giving evidence for antigenic presentation mainly by lymphocytes. The symptomatic and treated dogs showed an expansion of CD4(+) T cells subpopulations in lymph nodes, revealing an important contribution of these cells in controlling local parasite replication. This study also underlines the eventual importance of CD3(+)CD4(-)CD8(-) (double negative) and CD3(+)CD4(+)CD8(+) (double positive) T cell subsets in sensing and controlling latent infections and their possible function in the immune dynamics during CanL. The specific cellular immune responses raised in different compartments where the parasite replicates seem to have variable effects on local parasite control, highlighting the complexity of the cellular immune response developed by the dog infected by Leishmania infantum.


Assuntos
Doenças do Cão/imunologia , Leishmania infantum/imunologia , Leishmaniose Visceral/veterinária , Linfócitos T/imunologia , Animais , Anticorpos Antiprotozoários/sangue , Cães , Feminino , Antígenos de Histocompatibilidade Classe II/análise , Imunidade Humoral , Imunofenotipagem , Leishmaniose Visceral/imunologia , Masculino
20.
Vet Parasitol ; 123(1-2): 17-23, 2004 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-15265567

RESUMO

A survey was conducted during the months of April-June 2003 in the northeast Portugal (Bragança district) in order to characterize the hemoparasite population of an autochthonous Mirandesa breed of Bos taurus. The polymerase chain reaction (PCR) analysis of the bovine blood revealed that 3 out of 116 animals were infected with Theileria and/or Babesia parasites, while reverse line blot hybridisation (RLB) analysis showed that these animals were infected with Theileria buffeli/orientalis. Cloning and sequencing confirmed the RLB results. Database sequence searches combined with phylogenetic analysis of the partial 18S ribosomal RNA gene sequences obtained enabled us to place the parasites in question as members of the T. buffeli/orientalis group, confirming the PCR/RLB diagnosis.


Assuntos
Doenças dos Bovinos/parasitologia , Theileria/genética , Theileriose/parasitologia , Animais , Babesia/genética , Babesia/isolamento & purificação , Babesiose/sangue , Babesiose/parasitologia , Babesiose/veterinária , Sequência de Bases , Bovinos , Doenças dos Bovinos/sangue , DNA de Protozoário/química , DNA de Protozoário/genética , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Filogenia , Reação em Cadeia da Polimerase/veterinária , Portugal , RNA Ribossômico 18S/química , RNA Ribossômico 18S/genética , Alinhamento de Sequência , Theileria/isolamento & purificação , Theileriose/sangue
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