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1.
Vet Parasitol ; 277: 108967, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31812121

RESUMO

Neospora caninum infection is regarded as one of the most important infectious causes of abortion in dairy cattle. To intervene in its spread, four potential controls including test-and-cull, medication, vaccination, and selective breeding are considered and assessed in this study. The cost of each control, together with the inevitable annual loss due to population dynamics, is adopted as an assessment criterion from an economic point of view. By performing simulation and sensitivity analysis, our results demonstrate that compared with each single control, combined controls are worthwhile with better financial outcomes. For farm affected with significant prevalence (equal to or greater than 30%), vaccine treatment is the most effective and economical option among all control strategies. On the other hand, for farm where prevalence is relatively low (around 10%), combined control, by applying vaccination followed with test-and-cull, medication or selective breeding, could be alternative treatment to provide better financial outcome against single control in an observed period.


Assuntos
Doenças dos Bovinos/prevenção & controle , Doenças dos Bovinos/terapia , Coccidiose/veterinária , Terapia Combinada/veterinária , Animais , Antiparasitários/uso terapêutico , Cruzamento , Bovinos , Doenças dos Bovinos/economia , Coccidiose/economia , Coccidiose/prevenção & controle , Coccidiose/terapia , Indústria de Laticínios/economia , Neospora/fisiologia , Dinâmica Populacional , Vacinas Protozoárias
2.
Exp Parasitol ; 208: 107790, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31697939

RESUMO

Neospora caninum is a protozoan that has tropism for the central nervous system. The aim of this study was to determine whether experimental infection of gerbils would interfere with activity of enzymes associated with energy metabolism. We randomized 20 gerbils into two groups (ten animals per group): the control group (healthy animals; uninfected) and the infected group (experimentally infected with dose 7.8 × 102 tachyzoites of N. caninum per gerbil). On day six and twelve post-infection (PI), brain and spleen tissues were collected for biochemical and histopathological analyses. No histopathological lesions were observed in the brains of infected animals; however, inflammatory infiltrates were found in the spleen. Significantly greater levels of reactive oxygen species (ROS) were observed in the brain and spleen of infected gerbils than in the control group at 12 days PI. Cytosolic creatine kinase (CK-CYT), mitochondrial creatine kinase (CK-MIT), and pyruvate kinase (PK) activities were lower in the brains of infected gerbils than in those of the control group on day 12 PI. There was significantly less CK-CYT activity in the spleens of infected gerbils on day 6 and 12 PI. Finally, there was significantly less sodium-potassium ion pump (Na+/K+ ATPase) activity in the brains and spleens of infected gerbils on day 12 PI. These data suggest that experimental infection with N. caninum interfered with energy metabolism associated with ATP homeostasis in the brain and spleen, directly or indirectly, apparently mediated by ROS overproduction, contributing to inhibition of Na+/K+ ATPase activity.


Assuntos
Encéfalo/enzimologia , Coccidiose/enzimologia , Metabolismo Energético , Neospora , Baço/enzimologia , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Coccidiose/metabolismo , Creatina Quinase/metabolismo , Citosol/enzimologia , Gerbillinae , Masculino , Mitocôndrias/enzimologia , Piruvato Quinase/metabolismo , Distribuição Aleatória , Espécies Reativas de Oxigênio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Baço/química , Baço/patologia
3.
An Acad Bras Cienc ; 91(4): e20190439, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31800709

RESUMO

This study aimed to evaluate the frequency of Neospora caninum antibodies in rodents from the Island of Fernando de Noronha, Brazil, and to contribute to epidemiological data on neosporosis in this region. Blood samples were collected from 154 black-rats (Rattus rattus) and 12 rock-cavies (Kerodon rupestris). The search for anti-N. caninum antibodies was made using the NAT technique, with a cut-off of 1:20. The frequency of positive mice was 5.19% (8/154 - 1:20 titer) and all rock-cavies were negative. The low frequency of antibodies against N. caninum in rodents found in the Island shows the low contamination of the environment where these animals live.


Assuntos
Anticorpos Antiprotozoários/sangue , Neospora/imunologia , Roedores/parasitologia , Animais , Brasil , Ratos , Roedores/classificação
4.
Vet Parasitol ; 276: 108994, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31778941

RESUMO

Neospora caninum is a protozoan parasite (Phylum Apicomplexa) that has been recently suggested as a relevant cause of reproductive disorders in small ruminants. The aim of the present study is to develop and validate a new serological test based on time resolved fluorescency using N. caninum GRA7 recombinant antigen (GRA7-TRFIA) for the detection of N. caninum antibodies in sheep. A total of 346 serum samples (208 from experimentally infected sheep, 117 from a dairy farm with a previous history of Neospora-associated abortion, and 21 negative sera) were used. The validation of the new assay was performed by the evaluation of assay precision, analytical sensitivity (Se), accuracy and cross reactivity. In the experimentally infected sheep, antibody kinetics was compared between GRA7-TRFIA and an in house N. caninum tachyzoite soluble extract-based ELISA (NcSALUVET ELISA) by Wilcoxon matched-pairs signed rank test. The cut-off and diagnostic Se and specificity (Sp) of GRA7-TRFIA was estimated by ROC analysis with field samples. In addition, concordance and correlation between GRA7-TRFIA and a commercial ELISA and NcSALUVET ELISA were assessed by kappa value and Spearman correlation coefficient, respectively. Overall, GRA7-TRFIA showed an adequate precision, analytical Se and accuracy to detect anti-N. caninum antibodies in ovine serum, and no cross reactivity with the closely related protozoan Toxoplasma gondii. In naturally infected sheep, 100% Se and 95.35% Sp were obtained for a cut-off point of 62.68 Units of Fluorometry for N. caninum (UFN). Moreover, GRA7-TRFIA allowed earlier detection of N. caninum infection than NcSALUVET ELISA in experimentally infected sheep.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Coccidiose/veterinária , Neospora/imunologia , Doenças dos Ovinos/imunologia , Animais , Coccidiose/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Imunoensaio de Fluorescência por Polarização , Fluorometria/veterinária , Imunoglobulina G/sangue , Sensibilidade e Especificidade , Ovinos , Doenças dos Ovinos/parasitologia
5.
Vet Parasitol ; 276: 108990, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31775103

RESUMO

Neospora caninum infection is an important cause of neuromuscular disease in dogs and abortion in cattle, leading to significant economic losses in beef and dairy industries. The protective immunity against apicomplexan parasites, specifically Toxoplasma gondii and N. caninum, is typically achieved by inducing an IL-12-driven Th1 immune response. IL-12 stimulates IFN-γ production, which activates Inducible Nitric Oxide Synthase (iNOS) and promotes consequent Nitric Oxide (NO) synthesis, classically described as one of the main effector mechanisms for parasite elimination. Here, we aimed to evaluate the role played by iNOS during N. caninum infection. Our results show that N. caninum infection in C57BL/6 wild type (WT) mice induce NO production in vivo and in vitro. In agreement, iNOS deficient mice, as well as WT mice treated with iNOS inhibitor aminoguanidine, succumbed during acute infection with a dose lethal to 50 % of the WT mice, and presented significant increase in parasite load when submitted to sub-lethal infection protocols. Interestingly, the lack of control of parasite proliferation observed in iNOS-/- mice was associated with notable CNS inflammation and increased production of the main systemic proinflammatory cytokines (IL-12, IFN-γ, IL-6, TNF and IL-17A). Taken together, our findings show that iNOS plays an important role in restricting N. caninum replication, while also modulates the inflammatory process induced by the infection.


Assuntos
Coccidiose/enzimologia , Neospora/imunologia , Óxido Nítrico Sintase Tipo II/fisiologia , Animais , Coccidiose/parasitologia , Coccidiose/patologia , Interferon gama/análise , Subunidade p40 da Interleucina-12/análise , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/deficiência
6.
Parasitol Res ; 118(12): 3535-3542, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31701296

RESUMO

Neospora caninum causes neosporosis, a leading cause of bovine abortion worldwide. Uruguay is a developing economy in South America that produces milk to feed seven times its population annually. Naturally, dairy production is paramount to the country's economy, and bovine reproductive failure impacts it profoundly. Recent studies demonstrated that the vast majority of infectious abortions in dairy cows are caused by N. caninum. To delve into the local situation and contextualize it within the international standing, we set out to characterize the Uruguayan N. caninum strains. For this, we isolated four distinct strains and determined by microsatellite typing that these represent three unique genetic lineages, distinct from those reported previously in the region or elsewhere. An unbiased analysis of the current worldwide genetic diversity of N. caninum strains known, whereby six typing clusters can be resolved, revealed that three of the four Uruguayan strains group closely with regional strains from Argentina and Brazil. The remaining strain groups in an unrelated genetic cluster, suggesting multiple origins of the local strains. Microsatellite typing of N. caninum DNA from fetuses opportunistically collected from local dairy farms correlated more often with one of the isolates. Overall, our results contribute to further understanding of genetic diversity among strains of N. caninum both regionally and worldwide.


Assuntos
Aborto Animal/parasitologia , Doenças dos Bovinos/parasitologia , Coccidiose/veterinária , Neospora/genética , Neospora/isolamento & purificação , Animais , Argentina , Brasil , Bovinos , Doenças dos Bovinos/epidemiologia , Coccidiose/parasitologia , Feminino , Repetições de Microssatélites , Neospora/classificação , Neospora/imunologia , Filogenia , Gravidez , Uruguai
7.
Rev Bras Parasitol Vet ; 28(4): 816-820, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31618304

RESUMO

Toxoplasma gondii and Neospora caninum are Apicomplexan intracellular protozoan parasites that affect numerous animal species, thus leading to severe diseases and economic losses, depending on the vertebrate species involved. The role of the avian species in maintaining and transmission of these coccidia has been studied for several years as they tend to serve as a potential source of infection for mammals and humans. The present study aimed to assess the serological exposure of Orinoco goose (Neochen jubata) to T. gondii and N. caninum. Between 2010 and 2013, 41 free-ranging Orinoco geese were captured in the Araguaia River, Brazil. The presence and titration of IgY antibodies to both coccidia were assayed via indirect immunofluorescent antibody test (IFAT). While IgY antibodies for N. caninum were present in 5 animals, with titers of 20, the antibodies for T. gondii were found in 35 animals, with titers ranging from 20 to 640. Considering that the Orinoco goose's meat is consumed by the local population in the studied area, it may represent an important source of T. gondii infection for humans. Due to its migratory behavior, this goose may play a pivotal role in the natural dispersion of both parasites. Furthermore, molecular studies are required for genotyping the isolates of T. gondii that occurs in this avian species.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças das Aves/diagnóstico , Coccidiose/veterinária , Gansos/parasitologia , Neospora/imunologia , Toxoplasma/imunologia , Toxoplasmose Animal/diagnóstico , Animais , Doenças das Aves/epidemiologia , Doenças das Aves/parasitologia , Brasil/epidemiologia , Coccidiose/diagnóstico , Coccidiose/epidemiologia , Coccidiose/parasitologia , Técnica Indireta de Fluorescência para Anticorpo , Toxoplasmose Animal/epidemiologia , Toxoplasmose Animal/parasitologia
8.
Vet Res ; 50(1): 68, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31547877

RESUMO

Parameters such as pathogen dose and inoculation route are paramount in animal models when studying disease pathogenesis. Here, clinical findings, including foetal mortality, parasite transmission rates and lesion severity, and immune responses were evaluated in Asturiana pregnant heifers at day 110 of gestation challenged with a virulent (Nc-Spain7) Neospora caninum isolate. Four different doses of parasite tachyzoites were inoculated intravenously (IV1, 107 parasites, n = 6; IV2, 105, n = 6; IV3, 103, n = 6; and IV4, 102, n = 5), and the subcutaneous (SC) inoculation route was also assessed for the dose of 105 tachyzoites (SC, n = 6). In addition, a control group (n = 4 pregnant heifers) was evaluated. Foetal death was observed in all infected groups from 25 to 62 days post-infection, varying with the dose (IV1:4/6, IV2:3/6; IV4:2/5, IV3:1/6), and was three times less frequently associated with the SC route than IV inoculation (1/6 vs. 3/6). A dose-dependent effect for parasite loads in placental and foetal brain tissues was also detected. After SC challenge, a reduced number of tachyzoites were able to reach foetal brain tissues, and no lesions were observed. In calves, specific IgG responses in precolostral sera were mainly associated with high-dose groups (IV1 [100.0%] and IV2 [66.7%]), and cerebral parasite DNA detection was scarce (3/18). In dams, IFN-γ production and the dynamics of anti-N. caninum IgG antibodies varied with the dose, and the cell-mediated immune response was also found to be route-dependent. Our results confirm the influence of parasite dose and inoculation route on the outcome and dynamics of bovine neosporosis at mid-gestation.


Assuntos
Doenças dos Bovinos/mortalidade , Coccidiose/veterinária , Imunidade Celular , Neospora/imunologia , Complicações Parasitárias na Gravidez/veterinária , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Coccidiose/mortalidade , Coccidiose/parasitologia , Feminino , Feto/parasitologia , Injeções Intravenosas/veterinária , Gravidez , Complicações Parasitárias na Gravidez/mortalidade , Complicações Parasitárias na Gravidez/parasitologia , Distribuição Aleatória , Vacinação/veterinária
9.
Vet Res ; 50(1): 72, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31551079

RESUMO

Early Neospora caninum infection dynamics were investigated in pregnant heifers intravenously inoculated with PBS (G-Control) or 107 tachyzoites of high (G-NcSpain7)- or low (G-NcSpain1H)-virulence isolates at 110 days of gestation. Serial culling at 10 and 20 days post-infection (dpi) was performed. Fever was detected at 1 dpi in both infected groups (P < 0.0001), and a second peak was detected at 3 dpi only in G-NcSpain7 (P < 0.0001). At 10 dpi, Nc-Spain7 was detected in placental samples from one animal related to focal necrosis, and Nc-Spain7 transmission was observed, although no foetal lesions were associated with this finding. The presence of Nc-Spain1H in the placenta or foetuses, as well as lesions, were not detected at 10 dpi. At 20 dpi, G-NcSpain7 animals showed almost 100% positive placental tissues and severe focal necrosis as well as 100% transmission. Remarkably, foetal mortality was detected in two G-NcSpain7 heifers. Only one animal from G-NcSpain1H presented positive placental samples. No foetal mortality was detected, and lesions and parasite transmission to the foetus were not observed in this group. Finally, 100% of G-NcSpain7 heifers at 20 dpi presented specific antibodies, while only 60% of G-NcSpain1H animals presented specific antibodies at 20 dpi. In addition, earlier seroconversion in G-Nc-Spain7 was observed. In conclusion, tachyzoites from Nc-Spain7 reached the placenta earlier and multiplied, leading to lesion development, transmission to the foetus and foetal mortality, whereas Nc-Spain1H showed delayed infection of the placenta and no lesional development or transmission during early infection.


Assuntos
Doenças dos Bovinos/imunologia , Coccidiose/veterinária , Feto/parasitologia , Neospora/patogenicidade , Placenta/parasitologia , Complicações Parasitárias na Gravidez/veterinária , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Coccidiose/imunologia , Coccidiose/parasitologia , Feminino , Idade Gestacional , Neospora/fisiologia , Gravidez , Complicações Parasitárias na Gravidez/imunologia , Complicações Parasitárias na Gravidez/parasitologia , Vacinação/veterinária , Virulência/genética
10.
Parasitol Res ; 118(10): 3001-3010, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31486947

RESUMO

Neospora caninum is an apicomplexan parasite considered one of the main causes of abortion in cattle worldwide; thus, there is an urgent need to develop novel therapeutic agents to control the neosporosis. Enoyl acyl carrier protein reductase (ENR) is a key enzyme of the type II fatty acid synthesis pathway (FAS II), which is essential for apicomplexan parasite survival. The antimicrobial agent triclosan has been shown to be a very potent inhibitor of ENR. In this study, we identified an E. coli ENR-like protein in N. caninum. Multiple sequence alignment showed all the requisite features of ENR existed in this protein, so we named this protein NcENR. Swiss-Model analysis showed NcENR interacts with triclosan. We observed that ENR is localized in the apicoplast, a plastid-like organelle. Similar to the potent inhibition of triclosan on other apicomplexa parasites, this compound markedly inhibits the growth of N. caninum at low concentrations. Further research showed that triclosan attenuated the invasion ability and proliferation ability of N. caninum at low concentrations. The results from in vivo studies in the mouse showed that triclosan attenuated the virulence of N. caninum in mice mildly and reduced the parasite burden in the brain significantly. Taken together, triclosan inhibits the growth of N. caninum both in vitro and in vivo at low concentrations.


Assuntos
Coccidiose/parasitologia , Coccidiostáticos/farmacologia , Neospora/efeitos dos fármacos , Triclosan/farmacologia , Animais , Encéfalo/parasitologia , Coccidiose/tratamento farmacológico , Coccidiostáticos/metabolismo , Coccidiostáticos/uso terapêutico , Modelos Animais de Doenças , Enoil-(Proteína de Transporte de Acila) Redutase (NADH)/genética , Enoil-(Proteína de Transporte de Acila) Redutase (NADH)/metabolismo , Camundongos , Neospora/crescimento & desenvolvimento , Neospora/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Triclosan/metabolismo , Triclosan/uso terapêutico
11.
Parasitol Res ; 118(10): 2945-2955, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31485864

RESUMO

The aim of the present study was to characterize the specific immune response in prepubertal female calves inoculated with Neospora caninum. Forty-eight N. caninum-seronegative 6-month-old Angus female calves were randomly allocated into two groups: group A calves were inoculated subcutaneously (sc) with 1 × 106 tachyzoites of the low virulence NC-Argentina LP1 isolate in sterile phosphate-buffered saline (PBS); group B calves were mock inoculated sc with sterile PBS. Calves from group A developed a specific immune response characterized by the production of IgG antibodies and the expression of IFN-γ and TNF-α cytokines. Animals did not present any febrile reaction or reactions at the site of inoculation. Although chronic N. caninum infection was developed in 50% of calves of group A after inoculation, according to the presence of antibodies against rNc-SAG4, antigen characteristic of bradyzoites, N. caninum antibodies dropped below the cut-off of ELISA from day 210 post-inoculation onwards. Future trials using the same group of inoculated animals will allow the characterization of the evolution of the immune response during pregnancy and to determine whether the immunization with the local isolate is able to prevent congenital transmission and to protect against heterologous challenges.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Doenças dos Bovinos/imunologia , Coccidiose/veterinária , Neospora/imunologia , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Coccidiose/imunologia , Coccidiose/parasitologia , Citocinas/metabolismo , Feminino , Imunização/veterinária , Neospora/patogenicidade , Distribuição Aleatória
12.
Exp Parasitol ; 205: 107736, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31442455

RESUMO

Goats are frequently described as an intermediate host for the protozoan Neospora caninum, manifesting the disease mainly by recurrent abortions with placentitis and encephalitis in fetuses. Several reports of natural and experimental infections in cattle and mice show differences in the immune response, and the outcome of the infection can be variable depending on the species affected and by the behavior of the infective strain. This study describes for the first time two Neospora caninum strains isolated from naturally infected goats from the state of Minas Gerais, Brazil. One placenta and one brain from different goats were processed for a first bioassay in gerbils (Meriones unguiculatus). Subsequently, a second bioassay was performed by inoculating the processed brain samples from gerbils into Interferon gamma (IFN-γ) knockout mice (KO mice). Tachyzoites collected from the peritoneal fluid of the KO mice were inoculated into VERO cell monolayers, where they presented a very slow growth rate. The tachyzoites were also inoculated into BALB/c mice with a dose of 106 tachyzoites per animal. After a 5-week follow up, the animals infected with both of the strains developed a strong polarized Th1 response with increased serum and spleen gene expression levels of pro-inflammatory cytokines (mainly IFN-γ and TNF-α) in the first week. Tissue lesions were mild in the animals infected with both strains. Despite the strong immune response preventing an infection in the visceral organs, the parasite was able to reach the brain, causing progressive brain lesions from the second to fifth week post infection. The NC-goat1-infected mice presented with severe meningoencephalitis, but the NC-goat2-infected animals had considerable histological brain lesions only at week 5. Immunohistochemical analysis of the mouse brains revealed a different pattern of inflammatory cells compared to the naturally infected goats. A severe inflammatory infiltrate of CD3+ T lymphocytes was found in the NC-goat1-infected mice. A more discrete infiltrate of CD3+ T cells was found in the NC-goat2-infected animals. Additionally, IBA1 IHC revealed an intense microglial reaction and monocyte perivascular cuffs in the NC-goat1-infected animals and lower microglia/monocyte infiltrates in the NC-goat2-infected mice. This work contributes knowledge on the pathogenicity of new Neospora caninum strains in mice, comparable with other well-established mouse models of the disease, and demonstrates the importance of studying goats as an intermediate host of this parasite.


Assuntos
Coccidiose/veterinária , Doenças das Cabras/parasitologia , Neospora/patogenicidade , Animais , Bioensaio/veterinária , Encéfalo/parasitologia , Encéfalo/patologia , Coccidiose/parasitologia , Coccidiose/patologia , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Gerbillinae , Doenças das Cabras/patologia , Cabras , Imuno-Histoquímica/veterinária , Interferon gama/genética , Interferon gama/metabolismo , Fígado/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neospora/isolamento & purificação , Pâncreas/patologia , Placenta/patologia , Gravidez , Baço/metabolismo , Baço/patologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Células Vero
13.
Vet Parasitol ; 273: 5-10, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31442893

RESUMO

Neospora caninum is a major pathogen of cattle and dogs, and neosporosis is widespread in five continents. In this study effect of experimental neosporosis on sperm quality of C57BL/6 mice in different days was investigated. Based on the results sperm concentration was not changed in infected groups but neosporosis induced a significant decrease in epididymis sperm motility at 60 days post infection. A significant increase in the number of abnormal sperms at five, 15, 30 and 60 days post infection was found. At days 15, 30 and 60 post infection testosterone concentrations were significantly low in infected groups and FSH level was significantly high in infected groups at five and 30 days post infection. LH level was decreased in infected groups, but the difference was significant at five, 15 and 30 days post infection. Comparison of TSH and T4 levels between groups revealed a significant decrease in infected groups at five, 15, 30 and 60 days post infection. Except 15 days post infection T3 levels decreased significantly in infected groups. GPX activity, MDA and TAC level was significantly increased in infected mice at five days post infection. In this study neosporosis is associated with hypogonadotrophic gonadal insufficiency in infected C57BL/6 male mice.


Assuntos
Coccidiose/patologia , Espermatozoides/fisiologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neospora , Motilidade Espermática
14.
Exp Parasitol ; 204: 107731, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31374185

RESUMO

Neospora caninum is an obligate intracellular parasite related to cases of abortion and fertility impairment in cattle. The control of the parasite still lacks an effective protective strategy and the understanding of key mechanisms for host infection might be crucial for identification of specific targets. There are many proteins related to important mechanisms in the host cell infection cycle such as adhesion, invasion, proliferation and immune evasion. The surface proteins, especially SRS (Surface Antigen Glycoprotein - Related Sequences), have been demonstrated to have a pivotal role in the adhesion and invasion processes, making them potential anti-parasite targets. However, several predicted surface proteins were not described concerning their function and importance in the parasite life cycle. As such, a novel SRS protein, NcSRS57, was described. NcSRS57 antiserum was used to detect SRS proteins by immunofluorescence in parasites treated or not with phosphatidylinositol-specific phospholipase C (PI-PLC). The treatment with PI-PLC also allowed the identification of NcSRS29B and NcSRS29C, which were the most abundant SRS proteins in the soluble fraction. Our data indicated that SRS proteins in N. caninum shared a high level of sequence similarity and were susceptible to PI-PLC. In addition, the description of the SRS members, regarding abundance, function and immunogenicity will be useful in guiding specific methods to control the mechanism of adhesion and invasion mediated by these surface proteins.


Assuntos
Antígenos de Protozoários/metabolismo , Antígenos de Superfície/metabolismo , Neospora/química , Fosfoinositídeo Fosfolipase C/farmacologia , Proteínas de Protozoários/metabolismo , Animais , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Antígenos de Superfície/genética , Antígenos de Superfície/imunologia , Clonagem Molecular , DNA de Protozoário/isolamento & purificação , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Soros Imunes/imunologia , Soros Imunes/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal , Neospora/efeitos dos fármacos , Neospora/genética , Neospora/imunologia , Fosfoinositídeo Fosfolipase C/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Espectrometria de Massas em Tandem , Fosfolipases Tipo C/metabolismo , Fosfolipases Tipo C/farmacologia , Células Vero
15.
Rev Bras Parasitol Vet ; 28(3): 383-394, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31390432

RESUMO

This study evaluated the seroprevalence of Toxoplasma gondii, Neospora caninum and Leptospira spp. in dogs from Foz do Iguaçu, Paraná, Brazil. Indirect immunofluorescent antibody test was used to detect antibodies anti-T.gondii and anti-N. caninum. Immunoenzymatic assay and microscopic serum agglutination were used for screening antibodies anti-T.gondii and anti-Leptospira spp., respectively. The results were: 67.02% of the samples reactive for T.gondii and 1.38% for N. caninum, both without statistically significant variables. For Leptospira spp. the results indicated seroprevalence of 23.11%. The analysis of the variables without distinction of serovar showed association for intrinsic characteristics as breed, age, nutritional status and dog category. The extrinsic variables as city region and access to the street presented association (p<0.05). The most prevalent serovars were: Canicola 59.47%; Bratislava 13.07% and Butembo 15.68%. Variables that make up the adjusted multiple analysis model using Leptospira spp. were: age, breed and nutritional status; serovar Canicola, sex, nutritional status and area (p<0.05); serovar Bratislava, lymphadenomegaly and presence of fleas (p<0.05). Given the results obtained, dogs can be used as sentinels for toxoplasmosis and leptospirosis in Foz do Iguaçu and other cities with similar outcomes. In addition, preventive measures should be taken by health authorities because they are zoonoses and humans are also at risk.


Assuntos
Coccidiose/veterinária , Doenças do Cão/epidemiologia , Leptospirose/veterinária , Toxoplasmose Animal/epidemiologia , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antiprotozoários/sangue , Brasil/epidemiologia , Coccidiose/diagnóstico , Coccidiose/epidemiologia , Doenças do Cão/diagnóstico , Cães , Ensaio de Imunoadsorção Enzimática , Técnica Indireta de Fluorescência para Anticorpo , Leptospira/imunologia , Leptospirose/diagnóstico , Leptospirose/epidemiologia , Neospora/imunologia , Fatores de Risco , Estudos Soroepidemiológicos , Toxoplasma/imunologia , Toxoplasmose Animal/diagnóstico
16.
Rev Bras Parasitol Vet ; 28(3): 403-409, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31390435

RESUMO

To estimate the seroprevalence of Toxoplasma gondii and Neospora caninum, using an indirect immunofluorescent assay (IFA), and identify the risk factors associated, serum samples were collected from 1,070 pigs from 320 backyard pig farming in the of Mato Grosso state. The animal-level seroprevalence of T. gondii and N. caninum was 32.48% and 13.49%, respectively, with a herd seroprevalence of 55.63% for T. gondii and 27.81% for N. caninum. Feeding the animals with leftovers increases the probability of the presence of anti-T. gondii antibodies in pigs by 1.09-fold. Unlike to T. gondii, feeding with leftovers was found to be negatively associated with N. caninum seropositivity in farm-level analysis and in the animal-level model, so decreasing the chances of positivity. Yet, age was considered a risk factor for N. caninum seropositivity. Further studies are necessary to evaluate the impact of T. gondii infection on backyard pig farming production, and its importance as a source of toxoplasmosis infection in humans in the Mato Grosso state, as well as, the role of domestic pigs in the epidemiology of neosporosis.


Assuntos
Anticorpos Antiprotozoários/sangue , Coccidiose/veterinária , Neospora/imunologia , Doenças dos Suínos/epidemiologia , Suínos/parasitologia , Toxoplasma/imunologia , Toxoplasmose Animal/epidemiologia , Animais , Brasil/epidemiologia , Coccidiose/diagnóstico , Coccidiose/epidemiologia , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Masculino , Fatores de Risco , Estudos Soroepidemiológicos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/parasitologia , Toxoplasmose Animal/diagnóstico
17.
Acta Trop ; 198: 105094, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31323195

RESUMO

Neospora caninum is the etiological agent of neosporosis, a worldwide infectious disease recognized as the major cause of abortions and reproductive failures in livestock, responsible for significant economic losses in cattle industries. Currently, there are not cost-effective control options for this pathology, and the development of a vaccine involving new and integrated approaches is highly recommended. In this study, we evaluated the immunogenic and protective efficacy, as well as the potential DIVA (Differentiation of Infected from Vaccinated Animals) character of a recombinant subunit vaccine composed by the major surface antigen from N. caninum (NcSAG1) and the carrier/adjuvant heat shock protein 81.2 from Arabidopsis thaliana (AtHsp81.2) in a mouse model of congenital neosporosis. BALB/c female mice were intraperitoneal (i.p.) immunized with a mixture of equimolar quantities of rNcSAG1 and rAtHSP81.2 or each protein alone (rNcSAG1 or rAtHsp81.2). The vaccine containing a mixture of rNcSAG1 and rAtHsp81.2 significantly enhanced the production of specific anti-rNcSAG1 total IgG (tIgG), IgG1 and IgG2a antibodies in immunized mice when compared to control groups (non-vaccinated and rAtHsp81.2 immunized mice) as well as to the group of mice immunized only with the antigen (rNcSAG1). In addition, partial protection against vertical transmission and improvement of the offspring survival time was observed in this group. On the other hand, rAtHsp81.2 induced the production of specific anti-rAtHsp81.2 tIgG, allowing us to differentiate vaccinated from infected mice. Despite further experiments have to be made in cattle to test the capability of this vaccine formulation to differentiate vaccinated from infected animals in the field, our results suggest that the formulation composed by rNcSAG1 and rAtHsp81.2 could serve as a basis for the development of a new vaccine approach against bovine neosporosis.


Assuntos
Antígenos de Protozoários/imunologia , Coccidiose/prevenção & controle , Transmissão Vertical de Doença Infecciosa/prevenção & controle , Complicações Parasitárias na Gravidez/prevenção & controle , Vacinas Protozoárias/imunologia , Animais , Anticorpos Antiprotozoários , Coccidiose/parasitologia , Feminino , Imunoglobulina G , Camundongos , Camundongos Endogâmicos BALB C , Neospora/imunologia , Gravidez , Vacinação , Vacinas Sintéticas/imunologia
18.
Rev Bras Parasitol Vet ; 28(2): 221-228, 2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31271639

RESUMO

Geese, ducks, mallards, and swans are birds of the order Anseriformes, which are found in the wild, in zoos and parks, and raised for meat consumption. Toxoplasma gondii, Sarcocystis sp., and Neospora caninum are protozoans of several species of animals. Wild and domestic birds can serve as intermediate hosts, disseminators and potential sources of infection of these protozoa to humans through contaminated meat. The aims of this study were: (i) to perform a serological survey of T. gondii, Sarcocystis sp. and N. caninum in geese (Anser sp.) from public parks and from captivity and (ii) to compare seroprevalence between these two locations. Antibodies were detected by Immunofluorescence antibody test using the serum of 149 geese. Antibodies to Sarcocystis sp., T. gondii, and N. caninum were detected in 28.18%, 18% and 0.67% of geese, respectively; 57% of geese from urban parks and 26.53% of geese from captivity were seropositive for at least one protozoa. The results indicate environmental contamination, particularly for the occurrence of antibodies against T. gondii - a zoonosis that causes toxoplasmosis and is transmitted through oocyte ingestion. This is the first serological survey of T. gondii, Sarcocystis sp. and N. caninum in geese from urban parks in Curitiba, Brazil.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças das Aves/epidemiologia , Doenças das Aves/parasitologia , Gansos/parasitologia , Neospora/imunologia , Sarcocystis/imunologia , Toxoplasma/imunologia , Animais , Brasil/epidemiologia , Imunofluorescência , Estudos Soroepidemiológicos , População Urbana
19.
Vet Parasitol ; 270: 20-24, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31213237

RESUMO

Neosporosis is a common cause of abortion in cattle worldwide but is rare in horses. Here, the first case of histologically, ultrastructurally, immunohistochemically, and molecularly confirmed equine abortion caused by neosporosis is reported. Samples of lung, heart, liver, skeletal muscle, tongue, brain, and the placenta from a female fetus aborted at 280 days of gestation were fixed in formalin and submitted for diagnosis. Histologically, there was disseminated neosporosis with severe lesions in lungs, liver and the heart. Protozoal tachyzoites in all tissues reacted with polyclonal anti-Neospora caninum rabbit antibodies. Transmission electron microscopic observation on lung tissue revealed tachyzoites consistent with Neospora, including many rhoptries. Polymerase-chain reaction (PCR) using primers designed to amplify the rRNA gene internal transcribed spacer 1 (ITS1) of the Sarcocystidae was performed on DNA extracted from fetal tissues. Comparison of the ITS1 amplified from the foal tissue to sequences available in GenBank revealed 100% sequence identity to the ITS1 from three isolates of Neospora hughesi.


Assuntos
Feto Abortado/parasitologia , Aborto Animal/parasitologia , Coccidiose/veterinária , Doenças dos Cavalos/parasitologia , Feto Abortado/ultraestrutura , Animais , Anticorpos Antiprotozoários/metabolismo , Coccidiose/diagnóstico , Coccidiose/parasitologia , DNA Espaçador Ribossômico/genética , Feminino , Doenças dos Cavalos/diagnóstico , Cavalos , Imuno-Histoquímica , Microscopia Eletrônica de Transmissão , Neospora/genética , Neospora/ultraestrutura
20.
Acta Trop ; 197: 105044, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31173736

RESUMO

Neospora caninum is an intracellular protozoan infecting many domestic and wild animals. In the present study, the brain tissues of wild birds collected in Hunan province of China were examined by N. caninum specific nested PCR, targeting the Nc-5 gene and the internal transcribed spacer 1 (ITS-1) region of the nuclear ribosomal DNA. The prevalence of N. caninum was detected in 15.5% (37/239) of wild birds, including 20.5% (9/44) of the examined olive-backed pipit Anthus hodgsoni, 18.3% (24/131) of the examined tree sparrows Passer montanus, 7.9% (3/38) of the examined chestnut bunting Emberiza rutila and 3.8% (1/26) of the examined yellow-breasted bunting E. aureola. Phylogenetic analyses showed that N. caninum from different hosts and geographical origins are genetically diverse and can be further classified into two distinct groups. Our findings indicated that wild birds are potential source of N. caninum for other animals. To our knowledge, this is the first report of N. caninum infection in wild birds in China, which provides a foundation for the prevention and control of this parasite in China and elsewhere.


Assuntos
Animais Selvagens/parasitologia , Coccidiose/veterinária , Neospora/genética , Neospora/isolamento & purificação , Passeriformes/parasitologia , Animais , China/epidemiologia , Coccidiose/epidemiologia , Coccidiose/parasitologia , DNA de Protozoário/genética , Filogenia , Reação em Cadeia da Polimerase/veterinária
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