Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.844
Filtrar
1.
J Parasitol ; 106(1): 71-81, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31995717

RESUMO

An unusual coccidian parasite was described previously from the prostate of a male Antechinus flavipes (family: Dasyuridae; common name: yellow-footed antechinus). Morphometrics and a partial nuclear 18S small subunit rDNA (18S rDNA) sequence were used to assign this parasite to the genus Eimeria; it was named Eimeria taggarti. We generated full nuclear 18S rDNA and mitochondrial genome sequences from this parasite and used the newly completed 18S rDNA and mitochondrial cytochrome c oxidase subunit I (COI) sequences to perform a more in-depth phylogenetic analysis. The parasite clustered closely with Choleoeimeria spp. and Acroeimeria spp. infecting herptiles in a well-supported clade that was the sister lineage to the Eimeriidae sensu stricto. The mitochondrial genome of this parasite contained 2 inverted segments compared to mitochondrial genomes from parasites in the Eimeriidae sensu stricto (i.e., Stieda body-possessing coccidia with 4 dizoic sporocysts); this mitochondrial genome arrangement was shared with the only Choleoeimeria species for which sequence data were available publicly. Examination of histological preparations and TEM images uncovered bivalvate sporocysts and otherwise confirmed previously described morphological features of the parasite. Based on our phylogenetic analyses and histological observations, we propose the generic reclassification of E. taggarti to Choleoeimeria taggarti n. comb.


Assuntos
Coccidiose/veterinária , Eimeriidae/genética , Genoma Mitocondrial/genética , Marsupiais/parasitologia , Próstata/parasitologia , Animais , Coccidiose/parasitologia , DNA de Protozoário/química , DNA Ribossômico/química , Eimeriidae/classificação , Eimeriidae/isolamento & purificação , Eimeriidae/ultraestrutura , Complexo IV da Cadeia de Transporte de Elétrons/genética , Masculino , Anotação de Sequência Molecular , Oocistos/ultraestrutura , Filogenia , Reação em Cadeia da Polimerase , RNA de Protozoário/genética , RNA Ribossômico 18S/genética , Alinhamento de Sequência
2.
Ann Agric Environ Med ; 26(4): 538-543, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31885225

RESUMO

INTRODUCTION AND OBJECTIVE: It is easier and non-invasive to obtain faecal samples compared with blood samples. Molecular techniques may enable detection of parasites even in tiny amounts of blood-containing faeces. We aimed to compare the sensitivity of detection of three Babesia species and Hepatozoon canis in blood and faecal samples, including samples derived from naturally infected hosts. MATERIAL AND METHODS: Three groups were involved: 1) Nine BALB/c mice infected with Babesia microti sampled during acute (n=3), post-acute (n=3) and chronic phases of infection (n=3); 2) Eight dogs with symptoms of babesiosis; 3) Six red foxes infected with B. vulpes, one fox infected with B. canis, four foxes infected with H. canis. Genomic DNA was extracted from blood and faeces by use of commercial kits and amplified with genus-specific primers in one-step or nested PCR reactions. Selected PCR products were sequenced. RESULTS: No positive results for faecal samples were obtained from H. canis-positive foxes in contrast to Babesia spp. infections. Positive results from PCRs were obtained for all BALB/c mice (100%), five dogs (62.5%) and four of seven foxes (57.1%). Successful sequencing was obtained for six selected murine samples (B. microti), four canine samples (B. canis) and for one fox sample (B. vulpes). The success of B. microti detection in murine faecal samples from acute, post-acute and chronic phases was identical (100%). CONCLUSIONS: Detectability of Babesia spp. infections was lower in naturally infected dogs and foxes, compared to experimentally infected mice. Detection of DNA in faecal samples can be useful in the detection of Babesia infection in populations from which blood samples are hard to obtain, but due regard must be given to the possibility that prevalence of infection may be severely underestimated.


Assuntos
Babesia/isolamento & purificação , Babesiose/parasitologia , Sangue/parasitologia , Coccídios/isolamento & purificação , Coccidiose/parasitologia , DNA de Protozoário/genética , Fezes/parasitologia , Animais , Babesia/genética , Coccídios/genética , DNA de Protozoário/sangue , Cães/parasitologia , Raposas/parasitologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Reação em Cadeia da Polimerase
3.
Vet Parasitol ; 276: 108991, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31770701

RESUMO

Eimeria tenella, an obligate intracellular parasite, can actively invade the cecal epithelial cells of chickens and cause severe enteric disease. Eukaryotic elongation factor 2 (eEF2) plays a major role in protein synthesis and cell survival. This study aims to explore the exact mechanisms underlying diclazuril inhibition in second-generation merozoites of E. tenella. The eEF2 cDNA of the second-generation merozoites of E. tenella (EtEF2) was cloned by reverse transcriptase polymerase chain reaction and rapid amplification of cDNA ends. Diclazuril-induced expression profiles of EtEF2 were also analyzed. The cloned full-length cDNA (2893 bp) of the EtEF2 nucleotide sequence encompassed a 2499 bp open reading frame (ORF) that encoded a polypeptide of 832 residues with an estimated molecular mass of 93.12 kDa and a theoretical isoelectric point of 5.99. The EtEF2 nucleotide sequence was submitted to the GenBank database with the accession number KF188423. The EtEF2 protein sequence shared 99 % homology with the eEF2 sequence of Toxoplasma gondii (GenBank XP_002367778.1). The GTPase activity domain and ADP-ribosylation domain were conserved signature sequences of the eEF2 gene family. The changes in the transcriptional and translational levels of EtEF2 were detected through quantitative real-time PCR and Western blot analyses. The mRNA expression level of EtEF2 was 2.706 fold increases and the protein level of EtEF2 was increased 67.31 % under diclazuril treatment. In addition, the localization of EtEF2 was investigated through immunofluorescence assay. Experimental results demonstrated that EtEF2 was distributed primarily in the cytoplasm of second-generation merozoites, and its fluorescence intensity was enhanced after diclazuril treatment. These findings indicated that EtEF2 may have an important role in understanding the signaling mechanism underlying the anticoccidial action of diclazuril and could be a promising target for novel drug exploration.


Assuntos
Galinhas/parasitologia , Coccidiose/veterinária , Coccidiostáticos/farmacologia , Eimeria tenella/efeitos dos fármacos , Quinase do Fator 2 de Elongação/metabolismo , Doenças das Aves Domésticas/tratamento farmacológico , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , Coccidiose/tratamento farmacológico , Coccidiose/parasitologia , Eimeria tenella/genética , Quinase do Fator 2 de Elongação/genética , Feminino , Imunofluorescência , Masculino , Merozoítos/efeitos dos fármacos , Merozoítos/genética , Camundongos , Camundongos Endogâmicos BALB C , Nitrilos/farmacologia , Filogenia , Doenças das Aves Domésticas/parasitologia , Reação em Cadeia da Polimerase em Tempo Real , Alinhamento de Sequência , Triazinas/farmacologia
4.
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
5.
Parasit Vectors ; 12(1): 517, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31685001

RESUMO

BACKGROUND: Bovine besnoitiosis, caused by the cyst-forming apicomplexan parasite Besnoitia besnoiti, is a chronic and debilitating cattle disease that continues to spread in Europe in the absence of control tools. In this scenario, in vitro culture systems are valuable tools to carry out drug screenings and to unravel host-parasite interactions. However, studies performed in bovine target cells are scarce. METHODS: The objective of the present study was to obtain primary bovine aortic endothelial cells (BAECs) and fibroblast cell cultures, target cells during the acute and the chronic stage of the disease, respectively, from healthy bovine donors. Afterwards, expression of surface (CD31, CD34 and CD44) and intracellular markers (vimentin and cytokeratin) was studied to characterize cell populations by flow cytometry. Next, the lytic cycle of B. besnoiti tachyzoites was studied in both target cells. Invasion rates (IRs) were determined by immunofluorescence at several time points post-infection, and proliferation kinetics were studied by quantitative PCR (qPCR). Finally, the influence of bovine viral diarrhea virus (BVDV) co-infection on the host cell machinery, and consequently on B. besnoiti invasion and proliferation, was investigated in BAECs. RESULTS: Morphology and cytometry results confirmed the endothelial and fibroblast origins. CD31 was the surface marker that best discriminated between BAECs and fibroblasts, since fibroblasts lacked CD31 labelling. Expression of CD34 was weak in low-passage BAECs and absent in high-passage BAECs and fibroblasts. Positive labelling for CD44, vimentin and cytokeratin was observed in both BAECs and fibroblasts. Regarding the lytic cycle of the parasite, although low invasion rates (approximately 3-4%) were found in both cell culture systems, more invasion was observed in BAECs at 24 and 72 hpi. The proliferation kinetics did not differ between BAECs and fibroblasts. BVDV infection favoured early Besnoitia invasion but there was no difference in tachyzoite yields observed in BVDV-BAECs compared to BAECs. CONCLUSIONS: We have generated and characterized two novel standardized in vitro models for Besnoitia besnoiti infection based on bovine primary target BAECs and fibroblasts, and have shown the relevance of BVDV coinfections, which should be considered in further studies with other cattle pathogens.


Assuntos
Doenças dos Bovinos/parasitologia , Coccidiose/veterinária , Células Endoteliais/parasitologia , Fibroblastos/parasitologia , Sarcocystidae/crescimento & desenvolvimento , Animais , Antígenos CD34/metabolismo , Bovinos , Coccidiose/parasitologia , Receptores de Hialuronatos/metabolismo , Estágios do Ciclo de Vida , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Fatores de Tempo
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.
Parasitol Res ; 118(12): 3443-3447, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31720843

RESUMO

Galápagos giant tortoises are an essential component of their ecosystem and evaluation of parasites in their populations is essential for the management of conservation processes. Coccidiosis is the most common intestinal infection in free-living and captive reptiles. The aim of this study was to characterize molecularly the presence of Eimeria sp. in captive reared giant tortoises from Santa Cruz, Santiago, Española, and Pinzon Islands hatched and housed at the tortoise rearing center on Santa Cruz Island, Galápagos, by sequencing of the 18S rRNA gene. Galápagos. All samples were previously analyzed by coproparasitoscopic flotation technique and PCR for molecular identification. The results obtained by microscopy examination showed oocysts in all samples. PCR and sequencing indicated the presence Eimeria sp., showing a similarity percentage of 98% with Eimeria environmental. In conclusion, we identified a group of coccidia of the genus Eimeria sp. (MK909931) in Galápagos tortoises.


Assuntos
Coccidiose/veterinária , Eimeria/isolamento & purificação , Tartarugas/parasitologia , Animais , Coccidiose/parasitologia , Ecossistema , Eimeria/classificação , Eimeria/genética , Ilhas
8.
Rev Bras Parasitol Vet ; 28(4): 605-612, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31721926

RESUMO

Eimeriosis is a global poultry health problem. In the current study, we investigated the role of Salvadora persica leaf extracts (SE) against murine eimeriosis induced by Eimeria papillata. The infection induced an oocyst output of 6242 ± 731 oocysts/g feces. After treatment with 300 mg/kg SE, the oocysts expelled in feces decreased by approximately 3-fold. In addition, the total number of E. papillata in the parasitic stage decreased in the jejunum of mice after treatment with SE. In addition, SE significantly reduced the number of apoptotic cells by approximately 2-fold in the infected jejunum. SE ameliorated the changes in glutathione, malondialdehyde, and catalase due to E. papillata infection. Finally, SE regulated the cytokine genes, interleukin (IL)-1ß, IL-6, interferon-γ, and tumor necrosis factor-α, and the apoptotic genes, B-cell lymphoma-2, Bax, and Caspase-3. SE protects the jejunum from E. papillata induced injury and may have potential therapeutic value as a food additive during eimeriosis.


Assuntos
Antiprotozoários/farmacologia , Coccidiose/parasitologia , Eimeria/efeitos dos fármacos , Fezes/parasitologia , Extratos Vegetais/farmacologia , Salvadoraceae/química , Animais , Antiprotozoários/isolamento & purificação , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Contagem de Ovos de Parasitas
9.
Parasitol Res ; 118(12): 3459-3468, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31659452

RESUMO

Bovine besnoitiosis (Besnoitia besnoiti) is an emerging parasitic disease of cattle in Europe. This study reports a case of bovine besnoitiosis in a dairy farm housing 217 cattle in Italy. A serological screening was performed on the whole herd using the recommended approach of ELISA and confirmatory Western Blot. Seropositive animals were clinically examined to reveal symptoms and lesions of besnoitiosis. Risk factors and the effects of the parasite infection on reproductive and productive performances were evaluated. Histopathology and molecular analyses on tissues from a slaughtered cow affected by the chronic phase of the disease were carried out. An overall seroprevalence of 23.5%, which increased up to 43.5% considering only cows, was recorded. Clinical examination of 33 of the seropositive cows evidenced the presence of tissue cysts in at least one of the typical localizations (sclera, vulva, or skin) in 25 animals. Statistical analysis did not evidence any significative impact of the parasite infection on herd efficiency; however, a decrease of productive parameters was recorded in cows showing cutaneous cysts. Concerning the chronically affected cow, histopathology revealed B. besnoiti tissue cysts in the skin of the neck, rump, hind legs, eyelid and vulva, in the muzzle, in mucosal membranes of the upper respiratory tract, and in the lungs. Parasite DNA was detected also in masseter muscles, tonsils, mediastinal lymph nodes, liver, cardiac muscle, aorta wall, ovaries, uterus, and vulva. Bovine besnoitiosis continues to spread in the Italian cattle population. Breeders and veterinarians should be aware of this parasitic disease, and control programs should be developed based on surveillance through a diagnostic procedure including both clinical examination and laboratory tests.


Assuntos
Doenças dos Bovinos/parasitologia , Coccidiose/veterinária , Animais , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/fisiopatologia , Coccidiose/epidemiologia , Coccidiose/parasitologia , Coccidiose/fisiopatologia , Testes Diagnósticos de Rotina , Europa (Continente) , Feminino , Itália/epidemiologia , Estudos Longitudinais , Reprodução , Sistema Respiratório/parasitologia , Sistema Respiratório/patologia , Fatores de Risco , Sarcocystidae/genética , Sarcocystidae/imunologia , Sarcocystidae/isolamento & purificação , Sarcocystidae/fisiologia , Estudos Soroepidemiológicos , Pele/parasitologia , Pele/patologia , Útero/parasitologia , Útero/patologia
10.
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
11.
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
12.
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
13.
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
14.
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
15.
Vet Parasitol ; 273: 105-111, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31473449

RESUMO

Diclazuril, which is widely used for the prevention of coccidiosis in chickens, has a lethal effect on asexual and sexual stages of Eimeria spp. However, little is known about its effect on the exogenous stages of Eimeria spp. In this study, we evaluated the effect of in vitro treatment with 0.2% diclazuril on unsporulated and sporulated oocysts of Eimeria spp. For this purpose, a total of 180 male layer chicks aged one day were randomly divided into 5 experimental groups. Each group was divided into 3 replicates of 12 chicks each. Group 1 (G1) and Group 2 (G2) were negative (non-immunized and non-challenged) and positive (non-immunized and challenged) controls, respectively. Group 3 (G3) was immunized per os with 1.0 × 104 non-diclazuril treated-sporulated oocysts. Groups 4 (G4) was immunized per os with 0.2% diclazuril treated-unsporulated oocysts (1.0 × 104) in which diclazzuril didn't affect sporulation. Group 5 (G5) was immunized per os with 0.2% diclazuril treated-sporulated oocysts (1.0 × 104). Chicks of G2, G3, G4, and G5 were challenged with 7.5 × 104 untreated sporulated oocysts at the age of 21 days, while the group 1 chicks remained unchallenged. G4 and G5 animals immunized with 0.2% diclazuril-treated oocysts showed a significant decrease in bloody diarrhea severity, lesion scores, and oocyst counts in comparison to those immunized with untreated oocysts. Furthermore, histopathologic findings showed a low number of parasitic stages in cecal tissues in G4 and G5. A significant increased body weight gain was observed in Gs 4 and 5 in comparison to G2. In addition, expression levels of IL-2, IL-12, and IFN-γ were significantly increased in G4 and G5. In conclusion, diclazuril is effective in attenuating Eimeria oocysts and thus provides an alternative approach for using diclazuril-treated oocysts to protect chicks against Eimeria challenge.


Assuntos
Coccidiose/veterinária , Eimeria/efeitos dos fármacos , Nitrilos/farmacologia , Oocistos/efeitos dos fármacos , Doenças das Aves Domésticas , Triazinas/farmacologia , Animais , Ceco/parasitologia , Galinhas , Coccidiose/parasitologia , Coccidiose/prevenção & controle , Eimeria/patogenicidade , Masculino , Doenças das Aves Domésticas/parasitologia , Doenças das Aves Domésticas/prevenção & controle , Distribuição Aleatória , Virulência/efeitos dos fármacos
16.
Parasitol Res ; 118(10): 2989-2999, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31473858

RESUMO

Chicken coccidiosis is caused by the apicomplexan parasite Eimeria spp. At present, drug resistance of Eimeria is common because of the indiscriminate use of anticoccidial drugs. The gene encoding surface antigen 10 of Eimeria tenella (EtSAG10) is differentially expressed between drug-resistant and drug-sensitive strains. RNA-seq analysis indicated that this gene was downregulated in strains resistant to maduramicin and diclazuril compared to susceptible strains. EtSAG10 DNA sequence alignment revealed that they contained one and ten mutations in MRR and DZR, compared with DS, respectively. A full-length EtSAG10 cDNA was successfully cloned and expressed, and the polyclonal antibody was prepared. The transcription and translation levels of EtSAG10 were analyzed by quantitative real-time PCR (qPCR) and Western blotting. The localization of EtSAG10 in Spz, Mrz, and parasites in the first asexual stage was determined by indirect immunofluorescence. The potential association of EtSAG10 with sporozoite invasion of host cells was assessed by invasion inhibition assays. The results showed that EtSAG10 had a predicted transmembrane domain at the C-terminal end and a predicted signal peptide at the N-terminal end. EtSAG10 was downregulated in drug-resistant strains, which is consistent with the RNA-seq results. The EtSAG10 protein was localized to the parasite surface and parasitophorous vacuole membrane. This protein was shown to play a role in the infection of chicken intestine by sporozoites.


Assuntos
Antígenos de Protozoários/genética , Antígenos de Superfície/genética , Galinhas/parasitologia , Coccidiose/veterinária , Eimeria tenella/imunologia , Doenças das Aves Domésticas/parasitologia , Animais , Antígenos de Protozoários/metabolismo , Antígenos de Superfície/metabolismo , Coccidiose/parasitologia , Coccidiostáticos/farmacologia , Resistência a Medicamentos/genética , Eimeria tenella/efeitos dos fármacos , Eimeria tenella/genética , Eimeria tenella/crescimento & desenvolvimento , Regulação da Expressão Gênica , Mutação , Esporozoítos/genética , Esporozoítos/imunologia
17.
Parasitol Res ; 118(10): 3033-3041, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31407118

RESUMO

Coccidiosis, caused by the infection of Eimeria parasites, is one of the most common diseases in domestic rabbits. Live anticoccidial vaccine formulated with attenuated precocious lines of pathogenic eimerian parasites is expected to be valuable for the control of rabbit coccidiosis as a similar strategy to produce anticoccidial vaccines against chicken coccidiosis has being used for several decades. Eimeria media, moderate pathogenic, is widespread in China. Therefore, attenuated anticoccidial vaccines against rabbit coccidiosis should contain vaccine strain(s) of E. media. In this study, a precocious line of E. media (Empre) was selected by collecting and propagating the early excreted oocysts with 16 successive generations. The prepatent period of Empre reduced from 108 h of its parental strain (Emwt) to 70 h. The fecundity of Empre was about 1/10 to 1/3 lower than that of Emwt. Each sporocyst of Empre sporulated oocyst contained only one large refractile body instead of two smaller ones seen in the parental strain. When vaccinated with 1 × 103 or 1 × 104 precocious line oocysts, the rabbits were completely protected against homologous challenge with the parental strain 14 days post challenge by terms of body weight gain and oocyst output counting, indicating the efficacy of Empre. Meanwhile, all immunized rabbits showed no clinical sign post immunization, indicating the safety of Empre. For co-immunization, 1 × 103Empre oocysts and 5 × 102 oocysts of a precocious line of E. intestinalis (EIP8) were inoculated to each rabbit in a trial. No diarrhea or mortality was found after vaccination, and the weight gains of the vaccinated group were similar to that of unvaccinated-unchallenged control (UUC) group, while the weight gains of the vaccinated group were similar to that of unvaccinated-unchallenged control (UUC) group (P > 0.05), but significantly higher than that of UCC group (P < 0.01) after challenge, indicating it is safe and effective when using co-immunization. These results together show that Empre, as a precocious line, is a good candidate of precocious line of E. media for anticoccidial vaccine development.


Assuntos
Coccidiose/veterinária , Eimeria/patogenicidade , Infecções Protozoárias em Animais/parasitologia , Animais , Coccidiose/parasitologia , Coccidiose/prevenção & controle , Eimeria/crescimento & desenvolvimento , Eimeria/imunologia , Eimeria/fisiologia , Imunização/veterinária , Oocistos/crescimento & desenvolvimento , Oocistos/imunologia , Oocistos/patogenicidade , Infecções Protozoárias em Animais/prevenção & controle , Vacinas Protozoárias/imunologia , Coelhos , Reprodução , Vacinas Atenuadas/imunologia
18.
Parasitol Res ; 118(10): 2773-2779, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31456045

RESUMO

Based on morphology and morphometry of gametocytes in blood and molecular phylogenetic analysis, we described a new species of hemoparasite from the genus Haemogregarina isolated from Lepidosiren paradoxa in the eastern Amazon region. Haemogregarina daviesensis sp. nov. is characterized by monomorphic gametocytes of varying maturity stage and their dimensions were 16 ± 0.12 µm (range 13-18) in length and 6 ± 0.97 µm (range 5-8) in width. The morphological and morphometric data were not identical with other haemogregarine species from fish. All specimens of L. paradoxa analyzed were infected by H. daviesensis sp. nov. and the parasitemia level was moderate (1-28/2000 blood erythrocytes). Two sequences were obtained from L. paradoxa, and these constituted a monophyletic sister clade to the Haemogregarina species. In addition, H. daviesensis sp. nov. detected here grouped with Haemogregarina sp. sequences isolated from chelonian Macrochelys temminckii, with 99% bootstrap support. This study provides the first data on the molecular phylogeny of an intraerythrocytic haemogregarine of freshwater fish and highlights the importance of obtaining additional information on aspects of the general biology of these hemoparasites in fish populations, in order to achieve correct taxonomic classification.


Assuntos
Coccidiose/veterinária , Eucoccidiida/isolamento & purificação , Doenças dos Peixes/parasitologia , Animais , Coccidiose/parasitologia , Eucoccidiida/classificação , Eucoccidiida/genética , Eucoccidiida/fisiologia , Feminino , Peixes/parasitologia , Água Doce/parasitologia , Masculino , Parasitemia/parasitologia , Parasitemia/veterinária , Filogenia
19.
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
20.
Parasitol Int ; 73: 101975, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31421267

RESUMO

This work reports the occurrence of coccidia of the genus Calyptospora in fishes from the eastern Amazon. Fish were collected on flood plains in the municipality of Macapá, State of Amapá, Brazil. Fresh squash preparations of liver, heart and gallbladder were examined under light microscope. Positive samples of Geophagus proximus and Hoplias malabaricus were used to detect parasites by PCR with Calyptospora-specific primers mRF and mrR, which amplify a region of the 18S rRNA gene. Oocysts were observed in 55% of 130 fishes examined. Parasite prevalence varied according to feeding habits, and was 100% in carnivores, 74% in omnivores (invertivores and detritivores) and 0% in herbivores. Variation in the frequency of parasitized organs showed 100% in the liver, 30% in the gallbladder, and 9% in the heart. The sequences obtained from G. proximus and H. malabaricus were identical and showed 99% similarity to Calyptospora serrasalmi. To our knowledge, this is the first report of the occurrence of Calyptospora in 10 new species of fish from the region of the eastern Brazilian Amazon. The results demonstrate the occurrence of C. serrasalmi in the region and the research provides new primers for the diagnosis of Calyptospora spp.


Assuntos
Coccidiose/veterinária , Eucoccidiida/isolamento & purificação , Doenças dos Peixes/epidemiologia , Peixes , Animais , Brasil , Caraciformes , Ciclídeos , Coccidiose/epidemiologia , Coccidiose/parasitologia , Dieta , Doenças dos Peixes/parasitologia , Reação em Cadeia da Polimerase/veterinária , Prevalência , RNA de Protozoário/análise , RNA Ribossômico 18S/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA