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1.
Exp Parasitol ; 207: 107781, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31626796

RESUMO

The paradigm that Toxoplasma gondii infection generates sterilizing protective immunity was broken by case studies in which reinfections were observed in immunocompetent pregnant women in the chronic phase of toxoplasmosis. Since then, several murine models have suggested that immunoprotection against a previous T. gondii infection may be violated after reinfection with strains of different genotypes. This study aimed to evaluate the dissemination of the parasite after reinfection with the virulent TgCTBr9 and EGS strains in BALB/c mice chronically infected with the avirulent TgCTBr5 strain. Three mice were euthanized at 2, 4, 8, 12, 24 and 48 h post challenge (p.c.) and at 7, 14 and 30 days p.c. Intestines, mesenteric lymph nodes, lungs and brains were collected for PCR-RFLP. Blood samples were collected to measure total IgG, IgG1 and IgG2a by ELISA. The reinfected animals survived and presented reduced morbidity after challenge with the virulent strains. Mice challenged with the TgCTBr9 strain showed a slight increase in anti-T. gondii IgG1. The spread of the TgCTBr5 strain was observed to occur earlier than the dissemination of the virulent TgCTBr9 or EGS strains. The TgCTBr9 strain was observed in the mesenteric lymph node at 7 days post challenge (d.p.c.); in the intestine and lungs at 14 d.p.c.; and in the brain at 30 d.p.c. EGS strain was demonstrated in the mesenteric lymph node and lung at 7 d.p.c and in the intestine and brain at a later time point. The immune response promoted by the primary infection with the avirulent strain (TgCTBr5) protected the animals from death after challenge with the virulent strains (TgCTBr9 or EGS).


Assuntos
Anticorpos Antiprotozoários/sangue , Toxoplasma/fisiologia , Toxoplasmose Congênita/parasitologia , Animais , Peso Corporal , Encéfalo/parasitologia , Brasil , Feminino , Genótipo , Humanos , Imunoglobulina G/sangue , Intestinos/parasitologia , Pulmão/parasitologia , Linfonodos/parasitologia , Mesentério , Camundongos , Camundongos Endogâmicos BALB C , Morbidade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Recidiva , Toxoplasma/genética , Toxoplasma/imunologia , Toxoplasma/patogenicidade , Toxoplasmose Congênita/imunologia , Virulência
2.
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
3.
Exp Parasitol ; 206: 107756, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31494217

RESUMO

Toxoplasma gondii is a widely distributed protozoan parasite, which affects worm-blooded animals including human. The commonest chemotherapeutics used for treatment of symptomatic toxoplasmosis have numerous adverse effects. Thus there is an eminent need to develop new therapeutic agents. Here we described the therapeutic efficacy of 4-(2-chloroquinolin-3-yl)-6-(2,5-dimethoxyphenyl)-2-oxo-1,2-dihydropyridine-3-carbonitrile (PPQ-8); a quinoline-related compound in a mouse model of acute and chronic toxoplasmosis. In acute infection, PPQ-8 decreased the parasite load in liver and spleen with amelioration of the hepatic and splenic pathology. In addition, recovered tachyzoites showed distorted shapes, reduced sizes, irregularities, surface protrusions, erosions and peeling besides apical region distortion when seen by scanning electron microscopy. In chronic toxoplasmosis, PPQ-8 produced degeneration and reduction of the brain cysts without stimulating a damaging inflammatory response within the brain. In both models acute and chronic, PPQ-8 prolonged the survival time of mice. These findings hold promise for the development of a novel anti-toxoplasmosis drug using PPQ-8, but further in vivo studies should be carried out to elucidate PPQ-8 mechanism of action and to report its efficacy in combination with other anti-toxoplasmosis agents.


Assuntos
Quinolinas/uso terapêutico , Toxoplasma/patogenicidade , Toxoplasmose Animal/tratamento farmacológico , Doença Aguda , Análise de Variância , Animais , Líquido Ascítico/parasitologia , Encéfalo/parasitologia , Encéfalo/patologia , Doença Crônica , Feminino , Estimativa de Kaplan-Meier , Fígado/parasitologia , Fígado/patologia , Camundongos , Microscopia Eletrônica de Varredura , Distribuição Normal , Quinolinas/síntese química , Quinolinas/química , Quinolinas/toxicidade , Distribuição Aleatória , Baço/parasitologia , Baço/patologia , Toxoplasma/efeitos dos fármacos , Toxoplasma/ultraestrutura , Toxoplasmose Animal/parasitologia
4.
Exp Parasitol ; 205: 107733, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31408623

RESUMO

Toxoplasma gondii is a ubiquitous protozoan of major medical and veterinary importance. Its treatment is difficult since the available drugs have severe side effects and reactivation may occur anytime. Vaccination with irradiated parasites exhibits ideal characteristics for vaccine development. In our experimental mice model, the protection against challenge with the virulent RH strain was assessed, using 255Gy irradiated tachyzoites. Eighty mice were allocated into 3 groups: naive control group, challenged with virulent RH tachyzoites group and a third group which is challenged with 1 × 106 irradiated tachyzoites, administered as two biweekly doses intraperitoneally. Protection was tested by challenging vaccinated mice with the virulent type RH tachyzoites 30 days after the 2nd vaccination dose. The assessment was built on qualitative clinical, quantitative parasitological, histopathological parameters and measurement of serum Nitric Oxide (NO). The results showed prolonged survival rate, absence of tachyzoites in the peritoneal aspirate by counting, absence of tachyzoites in all examined organs by impression smears, amelioration of histopathological changes in the liver, spleen, brain and lung specimens and increase of the serum NO level in the vaccinated group. Therefore, we propose that irradiated Toxoplasma tachyzoites confer protection for challenged mice and could be an alternative immunization schedule for vaccine development especially for who are at risk of severe immunosuppression.


Assuntos
Toxoplasma/imunologia , Toxoplasma/efeitos da radiação , Toxoplasmose Animal/prevenção & controle , Toxoplasmose Animal/parasitologia , Vacinação/métodos , Animais , Líquido Ascítico/parasitologia , Encéfalo/parasitologia , Encéfalo/patologia , Colorimetria , Feminino , Raios gama , Fígado/parasitologia , Fígado/patologia , Pulmão/parasitologia , Pulmão/patologia , Camundongos , Óxido Nítrico/análise , Baço/parasitologia , Baço/patologia , Taxa de Sobrevida , Toxoplasmose Animal/imunologia , Toxoplasmose Animal/mortalidade
5.
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 , Cercopithecus aethiops , 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
6.
Parasitol Res ; 118(9): 2591-2600, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31350619

RESUMO

Infective larvae of Toxocara canis and T. cati, the common roundworms of dogs and cats, may invade the central nervous system of paratenic hosts, including humans, causing neurotoxocarosis (NT). Previous studies on NT in the model organism "mouse" have indicated distinct differences between T. canis and T. cati regarding larval migration patterns as well as the severity of clinical symptoms and behavioural alterations. The objective of the present study was to provide an extensive characterization of the underlying histopathological alterations, comparing T. canis- and T. cati-induced changes in different brain areas over the course of murine infection. Four histological sections of five brains each of T. canis- and T. cati-infected as well as uninfected C57Bl/6 mice were investigated 7, 14, 28, 42, 70 and 98 days post infection (dpi), while brains of T. cati-infected and control mice were also available 120 and 150 dpi. In addition to haematoxylin-eosin and luxol fast blue-cresyl violet staining, immunohistochemistry was employed to study microglia/macrophage cell morphology and to detect accumulation of ß-amyloid precursor protein (ß-APP) as an indicator of axonal damage. Haemorrhages, eosinophilic vasculitis and activated microglia/macrophages were detected in both infection groups starting 7 dpi, followed by eosinophilic meningitis in cerebra as from 14 dpi. Overall, little differences in the proportion of animals affected by these alterations were found between the two infection groups. In contrast, the proportion of animals displaying ß-APP accumulation was significantly higher in the T. canis than T. cati group as from 28 dpi regarding the cerebrum as well as at 98 dpi regarding the cerebellum. In T. canis-infected mice, myelinophagic microglia/macrophages ("gitter cells") appeared as from 14 dpi, whereas these were first observed at 70 dpi in T. cati-infected animals. The proportion of animals displaying demyelination and/or gitter cells in the cerebrum was significantly higher in the T. canis than T. cati group as from 28 dpi, and at 28 and 42 dpi regarding the cerebellum. Earlier and more severe neurodegeneration during T. canis- than T. cati-induced NT, especially in the cerebrum, may explain the differences in behavioural alterations observed in previous studies. In addition to differences in larval migration preferences, immunological processes may contribute to these patterns, which warrant further investigation.


Assuntos
Toxocara canis/fisiologia , Toxocaríase/parasitologia , Toxoplasmose Cerebral/parasitologia , Peptídeos beta-Amiloides/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/parasitologia , Encéfalo/patologia , Modelos Animais de Doenças , Feminino , Humanos , Larva/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Toxocara canis/imunologia , Toxocaríase/metabolismo , Toxocaríase/patologia , Toxoplasmose Cerebral/metabolismo , Toxoplasmose Cerebral/patologia
7.
Turkiye Parazitol Derg ; 43(2): 99-101, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31204466

RESUMO

Hydatid disease is a parasitic disease. Although the disease causes many organ involvement, intracranial involvement is rarely seen. Clinical findings vary according to the number, size, localization of the cyst and the immune status of the patient. We aimed to present a rare case with intracranial hydatid cyst. A 8-year-old male patient presented with headache and vomiting. Physical examination revealed papillary edema. Brain computerized tomography imaging revealed a 13x13 cm cystic formation in the brain. The patient's echinococcal indirect hemagglutination test result was positive. The patient was started on oral albendazole therapy for intracranial hydatid cyst and was operated by brain surgery. Pathologic examination of the cyst was compatible with hydatid cyst. Although cysts are detected in the liver and lungs, cysts may be seen in atypically located areas. It should be kept in mind in clinically suspected patients that the disease can develop in rare organs, especially in patients with endemic areas. In patients with hydatid disease, advanced radiological examinations such as lung X-ray, abdominal ultrasonography and brain magnetic resonance imaging and echocardiographic examination should be performed for other organ involvement.


Assuntos
Encéfalo/parasitologia , Equinococose/diagnóstico , Administração Oral , Albendazol/administração & dosagem , Albendazol/uso terapêutico , Animais , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/uso terapêutico , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Encéfalo/cirurgia , Criança , Equinococose/tratamento farmacológico , Equinococose/cirurgia , Echinococcus/isolamento & purificação , Cefaleia , Testes de Hemaglutinação , Humanos , Masculino , Tomografia Computadorizada por Raios X , Vômito
8.
Parasitol Res ; 118(7): 2149-2157, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31165238

RESUMO

There is uncertainty in the identification of Myxobolus drjagini, the causative agent of silver carp twist disease, in the literature. An investigation of fish parasites in Lake Taihu, China, revealed several Myxobolus drjagini-like myxosporeans infecting the subcutaneous tissue of the head skin, the olfactory and oculomotor nerves in the cranial cavity, and the intrafilamental epithelium of the gills of silver carp Hypophthalmichthys molitrix (Valenciennes, 1844). Myxospores from the head skin and the nerves were identified as conspecific to M. drjagini based on morphological and molecular data; although the spores from each of the two organs presented morphological variations. SSU rDNA sequence analysis revealed that the sequence of M. drjagini previously deposited in GenBank (AF085179) was invalid. Myxospores from the gills were identified as Myxobolus paratypicus n. sp. The spores were oval, asymmetric in frontal view, 13.8 (12.9-14.9) µm long, 9.9 (9.2-11.1) µm wide, and 7.0 µm thick. Two pyriform polar capsules were unequal in size (ratio above 4:1) with slightly converging anterior ends, and the posterior end of the large polar capsule extended beyond the middle of the spore. The large polar capsule was 7.5 (6.2-8.2) µm long and 5.0 (4.2-5.6) µm wide; the small polar capsule was 2.7 (2.1-3.6) µm long and 1.4 (1.1-1.9) µm wide. Polar filaments were coiled with 7-8 turns in the large polar capsule. The SSU rDNA sequence of M. paratypicus n. sp. was not identical to that of any myxozoan available in GenBank and showed highest similarity with M. drjagini (96%) and Myxobolus pavlovskii (95%) collected from bighead carp and silver carp, respectively.


Assuntos
Encéfalo/parasitologia , Carpas/parasitologia , Brânquias/parasitologia , Myxobolus/classificação , Doenças Parasitárias em Animais/parasitologia , Esporos de Protozoários/classificação , Animais , China , DNA de Protozoário/genética , DNA Ribossômico/genética , Doenças dos Peixes/parasitologia , Myxobolus/genética , Myxobolus/isolamento & purificação , Filogenia , Esporos , Esporos de Protozoários/isolamento & purificação
9.
Parasite ; 26: 36, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31198175

RESUMO

Currently, information on the occurrence and genetic characterization of Toxoplasma gondii and Neospora caninum in tissues of rabbits in China is lacking. In this study, brain and heart samples from 470 slaughtered domestic rabbits were collected in Henan Province, Central China. The occurrence rate of T. gondii and N. caninum DNA detected by nested PCR was 2.8% and 2.1%, respectively. There were no significant differences (p > 0.05) in the frequency of the two parasite infections in relation to sex, breed, and region. Three out of 13 T. gondii-positive samples were completely or partially genotyped at 11 genetic markers using PCR-RFLP, and one was identified as ToxoDB genotype #9. For N. caninum, three different sequences at the ITS1 region and two genotypes at the MS5 microsatellite locus were identified. To our knowledge, this is the first genetic characterization of N. caninum isolates from rabbits.


Assuntos
Animais Domésticos/parasitologia , Coccidiose/veterinária , Carne/parasitologia , Neospora/genética , Toxoplasma/genética , Toxoplasmose Animal/epidemiologia , Animais , Encéfalo/parasitologia , China/epidemiologia , Coccidiose/epidemiologia , DNA de Protozoário/genética , DNA de Protozoário/isolamento & purificação , Feminino , Genótipo , Coração/parasitologia , Masculino , Repetições de Microssatélites , Neospora/isolamento & purificação , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Coelhos/parasitologia , Toxoplasma/isolamento & purificação
10.
Infect Immun ; 87(8)2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31182619

RESUMO

Toxoplasma gondii, a common neurotropic parasite, is increasingly being linked to neuropsychiatric disorders, including schizophrenia, Alzheimer's disease, and Parkinson's disease. However, the pathogenic mechanisms underlying these associations are not clear. Toxoplasma can reside in the brain for extensive periods in the form of tissue cysts, and this process requires a continuous immune response to prevent the parasite's reactivation. Because neuroinflammation may promote the onset and progression of neurodegenerative diseases, we investigated neurodegeneration-associated pathological changes in a mouse model of chronic Toxoplasma infection. Under conditions of high-grade chronic infection, we documented the presence of neurodegeneration in specific regions of the prefrontal cortex, namely, the anterior cingulate cortex (ACC) and somatomotor cortex (SC). Neurodegeneration occurred in both glutamatergic and GABAergic neurons. Neurons that showed signs of degeneration expressed high levels of CX3CL1, were marked by profoundly upregulated complement proteins (e.g., C1q and C3), and were surrounded by activated microglia. Our findings suggest that chronic Toxoplasma infection leads to cortical neurodegeneration and results in CX3CL1, complement, and microglial interactions, which are known to mediate the phagocytic clearance of degenerating neurons. Our study provides a mechanistic explanation for the link between Toxoplasma infection and psychiatric disorders.


Assuntos
Encéfalo/parasitologia , Ativação do Complemento/fisiologia , Microglia/fisiologia , Doenças Neurodegenerativas/etiologia , Toxoplasmose/complicações , Animais , Quimiocina CX3CL1/fisiologia , Doença Crônica , Modelos Animais de Doenças , Feminino , Camundongos , Ácido gama-Aminobutírico/fisiologia
11.
Exp Parasitol ; 204: 107717, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31228418

RESUMO

Spiramycin-metronidazole and spiramycin-loaded chitosan (CS) nanoparticles (NPs) were tested in comparison with the current spiramycin treatment of T.gondii concerning tissue penetration and blood brain barrier (BBB) passage. Swiss Albino mice were inoculated intraperitoneally with 2500 T. gondii tachyzoites RH strain and were divided into experimental and control groups. The experimental groups orally received CS NPs, spiramycin, spiramycin-metronidazole, spiramycin-loaded CS NPs 400 mg/kg and spiramycin-loaded CS NPs 100 mg/kg. Drug efficacy was assessed by mice survival time, mortality rate, parasite load in different organs and morphological study of the tachyzoites movement by light microscope and the ultra-structure by SEM. The results revealed that the maximum survival time of more than 200 days with no mortality on the sacrifice day (8th) was observed in mice receiving spiramycin-loaded NPs. Spiramycin-loaded NPs showed the highest significant percent reduction of tachyzoites (about 90% reduction) in liver, spleen and brain as compared to the other used drugs denoting successful bypass of BBB. Light microscopy of the treated peritoneal tachyzoites showed sluggish tachyzoites movement while the NPs caused loss of their movement. SEM of the treated tachyzoites were more mutilated and some of them appeared rupturing in those receiving CS NPs and spiramycin-loaded NPs. In conclusion, spiramycin-loaded NPs showed the highest efficiency in the treatment of acute toxoplasmosis. The non-toxic nature and the anti-parasitic effect of both CS and spiramycin make the use of spiramycin-loaded CS NPs a potential material for treatment of human toxoplasmosis.


Assuntos
Coccidiostáticos/administração & dosagem , Metronidazol/administração & dosagem , Espiramicina/administração & dosagem , Toxoplasmose Animal/tratamento farmacológico , Doença Aguda , Animais , Líquido Ascítico/parasitologia , Materiais Biocompatíveis , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Encéfalo/parasitologia , Quitosana , Combinação de Medicamentos , Sistemas de Liberação de Medicamentos , Estimativa de Kaplan-Meier , Fígado/parasitologia , Masculino , Camundongos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanopartículas , Tamanho da Partícula , Projetos Piloto , Baço/parasitologia , Taxa de Sobrevida , Comprimidos , Toxoplasma/efeitos dos fármacos , Toxoplasma/ultraestrutura , Toxoplasmose Animal/mortalidade
12.
Vet Parasitol ; 269: 2-6, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31079823

RESUMO

Neospora caninum is an apicomplexan protozoan parasite that is a leading cause of abortion in cattle. Detection of parasite-specific DNA by PCR is a highly sensitive method for identifying the presence of N. caninum in a variety of tissues. We developed and validated a probe-based real-time PCR assay targeting the conserved Nc5 gene of N. caninum. Using N. caninum strain Nc-1 genomic DNA and a synthetic gene fragment as amplification standards, we determined the PCR amplification efficiency and the limit of detection to be 95.60% and 3 copies, respectively. Five pathogens frequently associated with bovine abortions, namely bovine viral diarrhea virus types I and II, bovine alphaherpesvirus-1, Chlamydia, and Leptospira, were tested to ensure analytical exclusivity. A total of 103 clinical samples from aborted fetuses were tested concurrently with a standard conventional PCR and the new probe-based real-time PCR assay. All tested samples showed 100% agreement between these two assays. In conclusion, the probe-based real-time PCR assay facilitates accurate and rapid detection of N. caninum from abortions in cattle.


Assuntos
Aborto Animal/diagnóstico , Doenças dos Bovinos/diagnóstico , Coccidiose/veterinária , Neospora/isolamento & purificação , Complicações Parasitárias na Gravidez/veterinária , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Feto Abortado/parasitologia , Aborto Animal/parasitologia , Animais , Encéfalo/parasitologia , Bovinos , Doenças dos Bovinos/parasitologia , Coccidiose/diagnóstico , Coccidiose/parasitologia , Primers do DNA/genética , Sondas de DNA/genética , Feminino , Coração/parasitologia , Neospora/genética , Gravidez , Complicações Parasitárias na Gravidez/diagnóstico , Complicações Parasitárias na Gravidez/parasitologia
13.
Parasite ; 26: 27, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31041898

RESUMO

To assess the prevalence of Toxoplasma gondii infection in native and commensal rodents as indicators of environmental pollution, we analyzed brain tissue from small mammals collected on legal and illegal waste sites in the Slovenian and Croatian parts of Istria. A total of 136 animals and five species of the family Muridae were analyzed: black rat (Rattus rattus), domestic mouse (Mus musculus), wood mouse (Apodemus sylvaticus), striped field mouse (Apodemus agrarius), and yellow-necked mouse (Apodemus flavicollis). Using quantitative Polymerase Chain Reaction (qPCR), T. gondii DNA was detected in four homogenized brain tissue samples (2.94%), from all of the analyzed species, except black rat. Out of these, two samples, domestic mouse (Mus musculus) and wood mouse (Apodemus sylvaticus) had sufficient DNA for genotyping of T. gondii isolates in which we demonstrated the presence of clonal type II using RFLP PCR with four markers (SAG1, SAG2, GRA6 and GRA7). Three of four infected animals (75%) were collected on dumpsites.


Assuntos
Genótipo , Roedores/parasitologia , Toxoplasma/genética , Toxoplasmose Animal/parasitologia , Animais , Encéfalo/parasitologia , Croácia/epidemiologia , DNA de Protozoário/genética , Reação em Cadeia da Polimerase , Prevalência , Eslovênia/epidemiologia , Toxoplasmose Animal/epidemiologia , Instalações de Eliminação de Resíduos
14.
Korean J Parasitol ; 57(2): 93-99, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31104401

RESUMO

Both Plasmodium spp. and Toxoplasma gondii are important apicomplexan parasites, which infect humans worldwide. Genetic analyses have revealed that 33% of amino acid sequences of inner membrane complex from the malaria parasite Plasmodium berghei is similar to that of Toxoplasma gondii. Inner membrane complex is known to be involved in cell invasion and replication. In this study, we investigated the resistance against T. gondii (ME49) infection induced by previously infected P. berghei (ANKA) in mice. Levels of T. gondii-specific IgG, IgG1, IgG2a, and IgG2b antibody responses, CD4+ and CD8+ T cell populations were found higher in the mice infected with P. berghei (ANKA) and challenged with T. gondii (ME49) compared to that in control mice infected with T. gondii alone (ME49). P. berghei (ANKA) + T. gondii (ME49) group showed significantly reduced the number and size of T. gondii (ME49) cysts in the brains of mice, resulting in lower body weight loss compared to ME49 control group. These results indicate that previous exposure to P. berghei (ANKA) induce resistance to subsequent T. gondii (ME49) infection.


Assuntos
Plasmodium berghei/imunologia , Toxoplasma/imunologia , Toxoplasmose Animal/imunologia , Toxoplasmose Animal/prevenção & controle , Animais , Anticorpos Antiprotozoários/sangue , Peso Corporal , Encéfalo/parasitologia , Encéfalo/patologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Feminino , Imunoglobulina G/sangue , Camundongos Endogâmicos BALB C , Toxoplasmose Animal/parasitologia , Toxoplasmose Animal/patologia
15.
Malar J ; 18(1): 174, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31113429

RESUMO

BACKGROUND: Avian malaria parasites (genus Plasmodium) are cosmopolitan and some species cause severe pathologies or even mortality in birds, yet their virulence remains fragmentally investigated. Understanding mechanisms and patterns of virulence during avian Plasmodium infections is crucial as these pathogens can severely affect bird populations in the wild and cause mortality in captive individuals. The goal of this study was to investigate the pathologies caused by the recently discovered malaria parasite Plasmodium homocircumflexum (lineage pCOLL4) in four species of European passeriform birds. METHODS: One cryopreserved P. homocircumflexum strain was multiplied and used for experimental infections. House sparrows (Passer domesticus), common chaffinches (Fringilla coelebs), common crossbills (Loxia curvirostra) and common starlings (Sturnus vulgaris) were exposed by subinoculation of infected blood. Experimental and control groups (8 individuals in each) were observed for over 1 month. Parasitaemia, haematocrit value and body mass were monitored. At the end of the experiment, samples of internal organs were collected and examined using histological and chromogenic in situ hybridization methods. RESULTS: All exposed birds were susceptible, with similar average prepatent period and maximum parasitaemia, yet virulence was different in different bird species. Mortality due to malaria was reported in chaffinches, house sparrows and crossbills (7, 5 and 3 individuals died respectively), but not in starlings. Exoerythrocytic meronts (phanerozoites) were observed in the brain of all dead experimental birds. Blockage of blood vessels in the brain led to cerebral ischaemia, invariably causing brain damage, which is likely the main reason of mortality. Phanerozoites were observed in parenchymal organs, heart and muscles of all infected individuals, except starlings. CONCLUSION: This study shows that P. homocircumflexum is generalist and the same lineage caused similar parasitaemia-related pathologies in different host species. Additionally, the mode of exo-erythrocytic development is different in different birds, resulting in different mortality rates. This should be taken into consideration in studies addressing pathology during avian malaria infections.


Assuntos
Malária Aviária/parasitologia , Passeriformes/parasitologia , Plasmodium/patogenicidade , Animais , Encéfalo/parasitologia , Encéfalo/patologia , Coração/parasitologia , Fígado/parasitologia , Fígado/patologia , Parasitemia , Filogenia , Plasmodium/genética , Reação em Cadeia da Polimerase , Virulência
16.
Acta Trop ; 196: 1-6, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31059707

RESUMO

Toxoplasmosis is a disease caused by Toxoplasma gondii, an intracellular protozoan able to infect a wide range of hosts. The infection is particularly severe in immunocompromised patients or during pregnancy, circumstances in which the parasite could find a more favorable microenvironment to replicate and invade host tissues. The current treatment consists in toxic drugs for the patients, being not appropriate for the fetuses and immunodeficient patients. So far, there is a lack of available vaccine to prevent the disease. The present study aimed to evaluate the immune response induced by peptides derived from parasite immunodominant proteins from key components, as surface, rhoptry, microneme and dense granule antigens. A panel of eleven peptides was selected considering the highest scores for B cell epitope prediction by in silico analyses. The peptides were divided in groups, according to the parasite organelle locations, and used to immunize C57BL/6 mice. The animals were submitted to three doses of immunization and infected by 10 cysts of T. gondii ME49 strain. Blood samples were collected and used to measure the production of antibodies and cytokines, while the brains were collected to determine the parasite burden by quantitative polymerase chain reaction (qPCR). It was found that synthetic peptides from all targets were able to induce IgG synthesis in immunized mice, as well as to modulate the Th1/Th2 cytokine production, particularly the MIC and SRS groups, which presented the IFN-γ/IL-10 and TNF-α/IL-10 ratios 30 and 10 times higher, respectively, when compared with non-immunized group. Interestingly, the animals from MIC and SRS groups had significantly lower levels of T. gondii DNA in their brains. In summary, it can be concluded that peptides mainly from SRS and MIC parasite components constitute relevant targets to design vaccine candidates against parasite burden observed during chronic toxoplasmosis.


Assuntos
Encéfalo/parasitologia , Epitopos Imunodominantes/imunologia , Vacinas Protozoárias/imunologia , Toxoplasma/imunologia , Toxoplasmose Animal/prevenção & controle , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Encéfalo/imunologia , Citocinas/metabolismo , Epitopos de Linfócito B/imunologia , Feminino , Imunização , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos/imunologia , Proteínas de Protozoários/genética
17.
Exp Parasitol ; 202: 15-21, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31078550

RESUMO

Toxoplasma gondii is an opportunistic zoonotic protozoan that exceeds neurological and congenital impact sequence to reactivating latent toxoplasmosis especially under immunosuppression. Sex-associated hormones influence the severity of Toxoplasma infection. Thus, our study aimed to compare toxoplasmosis associated morbidity in both male and female mice and to monitor the response to anti-Toxoplasma therapeutics fortified with sex hormones in comparison to presently used drugs. Twenty male and 20 female mice were infected with ME49 Toxoplasma strain. The morbidity was assessed in the chronic stage in both sexes by estimating brain cyst burden, brain histopathological examination and monitoring serum anti-Toxoplasma IL-12 using ELISA method. Another 40 male and 40 female mice were infected with ME49 Toxoplasma strain then after 6 weeks received different treatment regimens including Atovaquone, Spiramycin, Metronidazole, Estradiol benzoate and Testoserone propionate either as a monotherapy or as a combination. Treatment response was monitored by scoring mice activity and brain cyst burden. This study showed that female mice demonstrated higher cyst burden and manifested more pathological reactions than male mice. While, the IL-12 serum level was significantly higher in male than female mice. Also, it is proved that the Toxoplasma cyst number was reduced significantly when used testosterone/atovaquone, or testosterone/spiramycin/metronidazole combined regimen in female mice groups. While for male mice, the combined therapy of spiramycin/metronidazole was the superior one. Accordingly, combined therapy with sex hormones is a promising strategy for discovering new therapeutic regimens for treating latent toxoplasmosis especially in female.


Assuntos
Coccidiostáticos/uso terapêutico , Toxoplasmose Animal/epidemiologia , Animais , Anticorpos Antiprotozoários/sangue , Atovaquona/uso terapêutico , Encéfalo/parasitologia , Encéfalo/patologia , Doença Crônica , Quimioterapia Combinada , Ensaio de Imunoadsorção Enzimática , Estradiol/análogos & derivados , Estradiol/uso terapêutico , Feminino , Imunoglobulina G/sangue , Interleucina-12/sangue , Masculino , Metronidazol/uso terapêutico , Camundongos , Morbidade , Fatores Sexuais , Espiramicina/uso terapêutico , Propionato de Testosterona/uso terapêutico , Toxoplasma/fisiologia , Toxoplasmose Animal/tratamento farmacológico
18.
Infect Immun ; 87(8)2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31109947

RESUMO

Little is known about whether pathogen invasion of neural tissue is affected by immune-based mechanisms in endothelial cells. We examined the effects of endothelial cell CD40 on Toxoplasma gondii invasion of the retina and brain, organs seeded hematogenously. T. gondii circulates in the bloodstream within infected leukocytes (including monocytes and dendritic cells) and as extracellular tachyzoites. After T. gondii infection, mice that expressed CD40 restricted to endothelial cells exhibited diminished parasite loads and histopathology in the retina and brain. These mice also had lower parasite loads in the retina and brain after intravenous (i.v.) injection of infected monocytes or dendritic cells. The protective effect of endothelial cell CD40 was not explained by changes in cellular or humoral immunity, reduced transmigration of leukocytes into neural tissue, or reduced invasion by extracellular parasites. Circulating T. gondii-infected leukocytes (dendritic cells used as a model) led to infection of neural endothelial cells. The number of foci of infection in these cells were reduced if endothelial cells expressed CD40. Infected dendritic cells and macrophages expressed membrane-associated inducible Hsp70. Infected leukocytes triggered Hsp70-dependent autophagy in CD40+ endothelial cells and anti-T. gondii activity dependent on ULK1 and beclin 1. Reduced parasite load in the retina and brain not only required CD40 expression in endothelial cells but was also dependent on beclin 1 and the expression of inducible Hsp70 in dendritic cells. These studies suggest that during endothelial cell-leukocyte interaction, CD40 restricts T. gondii invasion of neural tissue through a mechanism that appears mediated by endothelial cell anti-parasitic activity stimulated by Hsp70.


Assuntos
Encéfalo/parasitologia , Antígenos CD40/fisiologia , Células Endoteliais/imunologia , Retina/parasitologia , Toxoplasma/patogenicidade , Animais , Autofagia , Movimento Celular , Proteínas de Choque Térmico HSP70/fisiologia , Leucócitos/fisiologia , Camundongos , Camundongos Endogâmicos C57BL
19.
Vet Parasitol Reg Stud Reports ; 15: 100266, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30929943

RESUMO

Coenurus cerebralis is the larval stage of Taenia multiceps, which infects the muscles and brain of goats and, to a lesser extent, sheep. The resulting cerebral and non-cerebral infections caused by the larval form (metacestode) of this cestode are commonly known as coenurosis. A weak emaciated carcass of five months old female goat, on necropsy, revealed numerous parasitic cysts (n = 56, grossly visible) in the visceral cavity including heart, diaphragm, thoracic cavity, abdominal cavity and pelvic inlet. A large number of variable sized parasitic cysts were also observed embedded in the pericardium and myocardium causing functional damage to the heart. The parasite caused extensive tissue damage at gross and microscopic levels in the heart including traumatic destruction of the myocardium with degenerative and necrotic changes and infiltration of mononuclear cells. On parasitological examination, the cysts were identified as Coenurus cerebralis, as the scolices had characteristic four suckers and a rostellum with a double crown of hooks. Further confirmation was done using polymerase chain reaction targeting specific ND1 and CO1 genes. Phylogenetic analysis of CO1 and ND1 genes showed a major branch comprising two clades of T. multiceps grouped as separate entities with the first clade showing T. multiceps/Coenurus cerebralis native CIRG strain (cerebral) being placed in proximity to T. multiceps/Coenurus cerebralis CIRG strain (non-cerebral/visceral) compared to the Chinese strains of T. multiceps. The phylogenetic analysis of ND1 and CO1 genes of C. cerebralis of cerebral and non-cerebral isolates revealed close proximity but expressed in two different disease forms (i.e., visceral coenurosis and neural coenurosis) which indicated that they were very close divergent from a common ancestor. On the basis of the observations it was concluded that goat died due to cardiac dysfunction resulting from severe systemic infection of metacestode of T. multiceps was closely related to isolate that caused neural coenurosis in another goat. Based on the sequencing analysis and phylogenetic information, the possible differences in the clinical manifestation (neural or visceral) could be attributed to the pathogenesis.


Assuntos
Encéfalo/parasitologia , Infecções por Cestoides/veterinária , Doenças das Cabras/epidemiologia , Coração/parasitologia , Filogenia , Taenia/classificação , Animais , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Variação Genética , Doenças das Cabras/parasitologia , Cabras/parasitologia , Índia/epidemiologia , Miocárdio/patologia , Reação em Cadeia da Polimerase , Taenia/patogenicidade
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