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1.
Rev Chilena Infectol ; 37(3): 316-321, 2020 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-32853326

RESUMO

Congenital toxoplasmosis in twin pregnancies is infrequent. We present the case of a monozygotic and monocorial twin pregnancy with maternal toxoplasmosis infection diagnosed at 33 weeks gestation by detecting reactive IgM and IgG and low avidity test for IgG. The detection of the parasite in amniotic fluid could not be performed because the amniocentesis was not done. The term newborns presented cerebral calcifications and bilateral active chorioretinitis without other associated clinical manifestations. They had IgG and IgM reactive for toxoplasmosis. The detection of Toxoplasma gondii was not performed by placental PCR or cord blood. They received treatment during the first year of life with pyrimethamine, sulfadiazine and folinic acid. They had no adverse events associated with the therapy. The diagnostic assessment and treatment does not differ from pregnancies with a single fetus. One or both newborns may be compromised. Multidisciplinary monitoring is essential for the early detection of reactivations or progression of lesions.


Assuntos
Complicações Infecciosas na Gravidez , Complicações Parasitárias na Gravidez , Toxoplasma , Toxoplasmose Congênita , Anticorpos Antiprotozoários , Feminino , Humanos , Recém-Nascido , Gravidez
2.
Mem Inst Oswaldo Cruz ; 115: e200214, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32725060

RESUMO

BACKGROUND Chagas disease, resulting from Trypanosoma cruzi infections, continues to be a health concern mainly in Latin American countries where the parasite is endemic. The laboratory diagnosis of a chronic infection is determined through serological assays for antibodies against T. cruzi and several tests are available that differ in key components, formats and methodologies. To date, no single test meets the criteria of a gold standard. The situation is further complicated by the difficulties associated with performance comparisons between different immunoassays or methodologies executed at different times and geographical areas. OBJECTIVE To improve the diagnosis of Chagas disease, the WHO coordinated the development of two International Biological Reference Standards for antibodies against anti-T. cruzi: NIBSC 09/186 and NIBSC 09/188 that respectively represent geographical regions with the highest prevalence of TcII and TcI lineages of the parasite. METHODS The principle goal of this study was to verify the behavior of these standards when assayed by several commercially available serological tests that employ different methods to capture and detect human anti-T. cruzi antibodies. FINDINGS AND MAIN CONCLUSIONS The results reinforce the recommendation that these standards be considered for performance evaluations of commercialised immunoassays and should be an integral step in the development of new test components or assay paradigms.


Assuntos
Doença de Chagas/diagnóstico , Testes Sorológicos/normas , Trypanosoma cruzi/isolamento & purificação , Anticorpos Antiprotozoários/sangue , Doença de Chagas/parasitologia , Humanos , Imunoensaio/métodos , Padrões de Referência , Testes Sorológicos/métodos , Trypanosoma cruzi/imunologia , Organização Mundial da Saúde
3.
PLoS Negl Trop Dis ; 14(7): e0008202, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32645098

RESUMO

Plasmodium vivax is the most widespread and difficult to treat cause of human malaria. The development of vaccines against the blood stages of P. vivax remains a key objective for the control and elimination of vivax malaria. Erythrocyte binding-like (EBL) protein family members such as Duffy binding protein (PvDBP) are of critical importance to erythrocyte invasion and have been the major target for vivax malaria vaccine development. In this study, we focus on another member of EBL protein family, P. vivax erythrocyte binding protein (PvEBP). PvEBP was first identified in Cambodian (C127) field isolates and has subsequently been showed its preferences for binding reticulocytes which is directly inhibited by antibodies. We analysed PvEBP sequence from 316 vivax clinical isolates from eight countries including China (n = 4), Ethiopia (n = 24), Malaysia (n = 53), Myanmar (n = 10), Papua New Guinea (n = 16), Republic of Korea (n = 10), Thailand (n = 174), and Vietnam (n = 25). PvEBP gene exhibited four different phenotypic clusters based on the insertion/deletion (indels) variation. PvEBP-RII (179-479 aa.) showed highest polymorphism similar to other EBL family proteins in various Plasmodium species. Whereas even though PvEBP-RIII-V (480-690 aa.) was the most conserved domain, that showed strong neutral selection pressure for gene purifying with significant population expansion. Antigenicity of both of PvEBP-RII (16.1%) and PvEBP-RIII-V (21.5%) domains were comparatively lower than other P. vivax antigen which expected antigens associated with merozoite invasion. Total IgG recognition level of PvEBP-RII was stronger than PvEBP-RIII-V domain, whereas total IgG inducing level was stronger in PvEBP-RIII-V domain. These results suggest that PvEBP-RII is mainly recognized by natural IgG for innate protection, whereas PvEBP-RIII-V stimulates IgG production activity by B-cell for acquired immunity. Overall, the low antigenicity of both regions in patients with vivax malaria likely reflects genetic polymorphism for strong positive selection in PvEBP-RII and purifying selection in PvEBP-RIII-V domain. These observations pose challenging questions to the selection of EBP and point out the importance of immune pressure and polymorphism required for inclusion of PvEBP as a vaccine candidate.


Assuntos
Variação Genética , Malária Vivax/imunologia , Plasmodium vivax/genética , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Sequência de Aminoácidos , Anticorpos Antiprotozoários/imunologia , Ásia , Humanos , Imunidade Humoral , Malária Vivax/parasitologia , Plasmodium vivax/química , Plasmodium vivax/imunologia , Polimorfismo Genético , Proteínas de Protozoários/química , Seleção Genética , Alinhamento de Sequência
4.
Rev Bras Parasitol Vet ; 29(2): e022719, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32609246

RESUMO

We evaluated the prevalence of anti-Toxoplasma gondii antibodies in the serum samples collected from domestic cats in Belém, Pará, Brazil. We also correlated the presence of T. gondii antibodies with environmental variables and cat-owner habits. Four-hundred and forty-seven serum samples from domestic cats were analyzed. The sera were tested using an indirect immunofluorescence assay. Among the animals analyzed, 21.92% (98/447) were seropositive. A statistically significant association was found in relation to age and serology among the animals over 1 year old (p<0.01): in the group up to 1 year old, 12.82% (20/156) of the animals were positive, and in the group over 1 year old, 26.80% (78/291) were positive. Our results show that the cats in Belém, Pará region have anti-T. gondii antibodies, and their owners are not aware of toxoplasmosis or how to prevent its transmission.


Assuntos
Anticorpos Antiprotozoários , Doenças do Gato , Toxoplasma , Toxoplasmose Animal , Animais , Anticorpos Antiprotozoários/sangue , Brasil/epidemiologia , Doenças do Gato/epidemiologia , Doenças do Gato/parasitologia , Gatos , Prevalência , Estudos Soroepidemiológicos , Toxoplasmose Animal/epidemiologia
5.
Artigo em Inglês | MEDLINE | ID: mdl-32667393

RESUMO

Infection by the protozoan Toxoplasma gondii during pregnancy demands greater attention from the health authorities due to the risk of placental transmission, which can have devastating consequences to the foetus and newborn. This study was conducted in a high-risk prenatal care outpatient clinic of a university teaching hospital. Pregnant women screened for specific IgM and IgG anti -T. gondii, attended from January 2009 to August 2018 were included. From 530 suspected patients, 218 were followed up and they presented positive IgM and IgG anti- T. gondii. From these patients, 83 (38.0%) had low IgG avidity, 39 (18%) seroconverted in the second or third trimester of pregnancy, 19 (8.7%) had no avidity test, 69 (31.6%) had high IgG avidity after 16 weeks of gestation, five had recurrent chorioretinitis (2.2%) and three (1.3%) were seropositive to HIV. Complementary diagnoses were made in 30/48 (62.5%) of the patients revealing the presence of specific IgA antibodies raised to T. gondii; 3/63 (4.8%) peripheral blood samples and 1/57 (1.8%) amniotic fluid sample. There were eight foetal deaths, one case of neonatal hepatomegaly and one case of T. gondii DNA detected in a peripheral blood sample. Of the 139 newborn deliveries at the teaching hospital, there was a 38% loss of follow-up. The prevalence of congenital toxoplasmosis was 1.2 cases/1,000 live births in this study area, according to the retrospective survey of cases. Prenatal treatment may have helped to reduce the risk of vertical transmission.


Assuntos
Complicações Parasitárias na Gravidez/diagnóstico , Toxoplasma/isolamento & purificação , Toxoplasmose/diagnóstico , Instituições de Assistência Ambulatorial , Anticorpos Antiprotozoários/sangue , Brasil , Feminino , Hospitais de Ensino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Recém-Nascido , Gravidez , Complicações Parasitárias na Gravidez/tratamento farmacológico , Cuidado Pré-Natal , Estudos Prospectivos , Toxoplasma/genética , Toxoplasmose/sangue , Toxoplasmose/tratamento farmacológico
6.
Ann Parasitol ; 66(2): 183-192, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32592457

RESUMO

Schizophrenia and bipolar disorder are serious neuropsychiatric disorders. Studies have found a high seroprevalence of Toxoplasma gondii in psychiatric patients. This study aimed to estimate the seroprevalence of T. gondii infection among schizophrenia and bipolar disorder patients. A case-control study was conducted in Assiut University Hospitals on 53 patients with schizophrenia, 57 patients with bipolar disorder, and 50 healthy volunteers. The psychiatric patients were recruited from the psychiatry department and the controls from their relatives. Both groups were subjected to socio-demographic assessment. Neither of them was immunodeficient nor with any other psychiatric disorders. Anti-Toxoplasma IgG antibodies were detected by indirect-ELISA to find the relationship between T. gondii infection and psychiatric disorders. Data were analysed using Chi-square test. The seropositivity rate, among patients with schizophrenia (50.9%) and patients with bipolar disorders (52.6%), was significantly higher than control group (30%) (P = 0.031 and 0.018 respectively). We found no statistically significant difference among all groups regarding environmental risk factors associated with T. gondii infection, except cat contact which was higher in schizophrenia and bipolar disorder patients (P = 0.011 and 0.007 respectively). The results of our study confirm that T. gondii infection is significantly correlated with schizophrenia and bipolar disorder and significantly associated with cat contact rather than beef consumption.


Assuntos
Anticorpos Antiprotozoários , Transtorno Bipolar , Esquizofrenia , Toxoplasma , Toxoplasmose , Animais , Anticorpos Antiprotozoários/sangue , Transtorno Bipolar/complicações , Estudos de Casos e Controles , Gatos , Grupos Controle , Egito/epidemiologia , Humanos , Fatores de Risco , Esquizofrenia/complicações , Estudos Soroepidemiológicos , Toxoplasmose/sangue , Toxoplasmose/complicações , Toxoplasmose/epidemiologia
7.
Ann Parasitol ; 66(2): 193-199, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32592458

RESUMO

Toxoplasmosis is a disease caused by the protozoan parasite Toxoplasma gondii. Infection with T. gondii is one of the most common parasitic diseases in humans and other warm-blooded animals with global distribution and generally, one-third of human populations are estimated to be contaminated with this parasite. The prevalence of infection varies according to age, geographical location and dietary habits. The socioeconomic losses caused by the disease can be costly for the community. Acquired toxoplasmosis is potentially associated with schizophrenia, Alzheimer's disease, driving accidents, self-injury and suicide. Also, unusual strains of parasite that are genetically different from the rest (atypical strains) are responsible for several cases of lethal acquired parasites in people with safe immunity, which highlights the potential danger of this parasite in public health. As there is no comprehensive study on the association between toxoplasmosis and cardiovascular diseases in Iran, therefore, current study aimed at assessing the relationship between cardiovascular disease and toxoplasmosis among cardiac patients at the Seyyed al-Shohada specialist Cardiology Centre, Urmia, Iran. This study investigated the seropositivity rate for anti-Toxoplasma IgG antibodies by ELISA in patients with cardiovascular diseases. So, 375 patients with cardiovascular diseases and 336 healthy volunteers were selected for this investigation. The seropositivity rate of anti-Toxoplasma IgG antibodies was significantly higher in cardiovascular patients (63.73%) than in healthy volunteers (37.64%) (P<0.001). Also, a positive association was observed between anti-T. gondii IgG antibody seropositivity and cat contact (P≤0.001, OR: 5.178; 95% CI: 1.97-13.57), consumption of raw or undercooked meat (P≤0.001, OR: 0.3; 95% CI: 0.15-0.61), and consumption of not boiled milk (P≤0.001, OR: 0.26, 95% CI: 0.12-0.54). Our results indicate that T. gondii infection is associated with heart disease and suggest that heart disease might be related with a chronic infection. Risk factors associated with T. gondii exposure found in the present study may help design future prevention strategies against T. gondii infection.


Assuntos
Doenças Cardiovasculares , Insuficiência Cardíaca , Toxoplasmose , Animais , Anticorpos Antiprotozoários/sangue , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/epidemiologia , Gatos , Estudos Transversais , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/epidemiologia , Humanos , Irã (Geográfico)/epidemiologia , Fatores de Risco , Estudos Soroepidemiológicos , Toxoplasma , Toxoplasmose/complicações , Toxoplasmose/epidemiologia
8.
Rev Bras Parasitol Vet ; 29(2): e000820, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32490893

RESUMO

Toxoplasma gondii is one of the most important protozoa parasites worldwide. Although many seroprevalence studies have been performed in domestic and wild species, data on the cumulative incidence and the spatial distribution of T. gondii in animals are extremely scarce. In the present study, dogs from Botucatu municipality, São Paulo state, were followed for one year and their blood samples were collected on three moments: days 1, 180, and 360. The sera were submitted to the immunofluorescence antibody test (IFAT) to detect IgG antibodies to T. gondii. Age and sex were compared with IFAT results through statistical tests. Spatial analysis was used to detect clusters of seropositive dogs. Among the 350 dogs that were seronegative on day 1, 53 became seropositive in subsequent samplings; thus, cumulative incidence was 15.1% exposed dogs/year. Age and sex were not associated with serological results. The spatial analysis revealed that seropositive dogs were distributed in all the studied areas, with a significant cluster in a zone with poor sanitary conditions and low socioeconomic status. T. gondii is frequent and widely distributed in the urban area of Botucatu, and impoverished areas are possibly associated with high levels of environmental contamination by this parasite.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças do Cão/epidemiologia , Toxoplasmose Animal/epidemiologia , Animais , Brasil/epidemiologia , Doenças do Cão/diagnóstico , Doenças do Cão/parasitologia , Cães , Feminino , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Incidência , Estudos Longitudinais , Masculino , Estudos Soroepidemiológicos , Análise Espacial , Toxoplasmose Animal/diagnóstico
9.
Rev Bras Parasitol Vet ; 29(2): e001120, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32490894

RESUMO

This study aimed to determine the seroprevalence, factors associated with seropositivity to Leishmania infection in dogs and spatial analysis in six municipalities in the semiarid region of Pernambuco, Brazil. Blood samples were collected from 462 dogs, 77 in each municipality, and used for serological analysis [dual path platform (DPP®) and enzyme-linked immunosorbent assay (ELISA)]. Clinical signs of dogs were evaluated and associated factors for Leishmania infection were analyzed using robust Poisson regression model. A seroprevalence of 42.8% (198/462, IC: 95% = 38.6%-47.6%) was detected in dogs that tested positive in both tests, ranging from 29.8% to 55.8%, with higher prevalence in the municipality of Cabrobó (55.8%; P = 0.006). About 67% (132/198) of the seropositive dogs showed one or more clinical signs suggestive of canine leishmaniasis (CanL), such as lymphadenomegaly, skin lesions and conjunctivitis, which were associated with seropositivity. High seroprevalence levels were identified in urban and rural areas in all the municipalities, and the buffer for sand flies around cases covered almost these entire areas. Spatial analysis revealed a significant cluster, showing a relative risk of 1.88 in the urban area of Cabrobó. The higher density of seropositive dogs in urban areas indicates the need effective control measures against CanL to prevent the emergence of canine and human diseases.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças do Cão/epidemiologia , Leishmania infantum/imunologia , Leishmaniose Visceral/veterinária , Animais , Brasil/epidemiologia , Doenças do Cão/diagnóstico , Cães , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Masculino , Prevalência , Fatores de Risco , Estudos Soroepidemiológicos , Análise Espacial
10.
Rev Bras Parasitol Vet ; 29(2): e003520, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32520088

RESUMO

Blood samples and swabs from ocular conjunctiva and mouth were obtained from 64 cats. Of 64 serum samples, 19 were positive for Leishmania antibodies by ELISA (29.80%). Eight cats were positive by PCR (12.5%) in swab samples from mouth and/or ocular mucosa. Poor kappa agreement between serological and molecular results (k = 0.16) was obtained. From five positive PCR samples one was L. braziliensis and four were L. infantum. Phylogenetic analysis performed with the five isolates of Leishmania, showed that samples of L. infantum isolated from the cats were phylogenetically close to those isolated from domestic dogs in Brazil, while the L. braziliensis is very similar to the one described in humans in Venezuela. The study demonstrated that, despite high seropositivity for Leishmania in cats living in the study region, poor agreement between serological and molecular results indicate that positive serology is not indicative of Leishmania infection in cats. Parasite DNA can be detected in ocular conjunctiva and oral swabs from cats, indicating that such samples could be used for diagnosis. Results of phylogenetic analyzes show that L. infantum circulating in Brazil is capable of infecting different hosts, demonstrating the parasite's ability to overcome the interspecies barrier.


Assuntos
Doenças do Gato/parasitologia , Leishmania braziliensis/isolamento & purificação , Leishmania infantum/isolamento & purificação , Leishmaniose/parasitologia , Animais , Anticorpos Antiprotozoários/sangue , Doenças do Gato/diagnóstico , Gatos , DNA de Protozoário/análise , Ensaio de Imunoadsorção Enzimática/veterinária , Leishmania braziliensis/genética , Leishmania braziliensis/imunologia , Leishmania infantum/genética , Leishmania infantum/imunologia , Leishmaniose/diagnóstico , Filogenia , Reação em Cadeia da Polimerase/veterinária
11.
Rev Bras Parasitol Vet ; 29(2): e016019, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32520089

RESUMO

A cross-sectional study was carried out on a sample of 379 horses to determine the seroprevalence of Neospora spp. in Jordan using the indirect fluorescent antibody test. Five variables, namely locality (n=10), climatic zone (n=4), age group (n=3), gender, and breed were tested as risk factors for Neospora-immunoglobulin (Ig)G seropositivity at four cutoff titers (1:50, 1:200, 1:400, and 1:800) using univariate and multivariate logistic regression analyses. A total of 122 (32%; 95% CI: 28, 37) sera samples had anti-Neospora-IgG at a cutoff titer of 1:50. Increased Neospora-IgG seropositivity was found in horses in three localities (Madaba, Zarka, and Petra) and was associated with the following variables: cool temperate climate; age >14 years; and female gender. Seropositivity was found among horses from Madaba at all cutoff titers, Zarka at titers >1:200, and Petra at titers <1:200. Cool temperate climate was associated with titers <1:400. Horses aged >14 years were found to be associated with seropositivity at titers ≥1:200. Female gender was associated with high seropositivity at >1:800.


Assuntos
Anticorpos Antiprotozoários/sangue , Coccidiose/veterinária , Doenças dos Cavalos/epidemiologia , Neospora/imunologia , Fatores Etários , Animais , Coccidiose/diagnóstico , Coccidiose/epidemiologia , Estudos Transversais , Feminino , Doenças dos Cavalos/diagnóstico , Cavalos , Jordânia/epidemiologia , Masculino , Fatores de Risco , Estudos Soroepidemiológicos , Fatores Sexuais
12.
PLoS Negl Trop Dis ; 14(6): e0008358, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32589656

RESUMO

Antibody-mediated parasite killing is considered the most effective host immune response against extracellular trypanosome parasites. However, due to host-parasite co-evolution pressure, these parasites have "learned" how to hijack the host immune system via the development of immune evasion strategies. Hereby they prevent elimination and promote transmission. In the past, our group has shown that African trypanosome parasites are able to "shut down" the host B cell compartment, via the abolishment of the homeostatic B cell compartment. In line with this, we have reported that trypanosome infections result in detrimental outcomes on auto-reactive and cancer B cells. To unravel the immune mechanisms involved in these processes we adopted here a well-defined B cell vaccine model, i.e. the thymo-dependent hapten-carrier NP-CGG (4-Hydroxy-3-nitrophenylacetyl-Chicken Gamma Globulin) emulsified in Alum adjuvant. Results show that T. brucei infections abrogate the circulating titres of vaccine-induced CGG-specific as well as NP-specific IgG1+ antibodies, a hallmark of memory B cell responses in this model. This happens independently of their affinity and IFNÉ£ signalling. Next, we demonstrate that T. brucei infections also induce a decrease of anti-NP IgG3+ antibodies induced by the administration of NP coupled to Ficoll, a thymo-independent antigen. Confirming the non-specificity of the infection-associated immunopathology, this report also shows that trypanosome infections abolish vaccine-induced memory response against malaria parasite in BALB/c mice. Together, these data indicates that T. brucei infections impair every stages of B cell development, including effector plasma B cells, independently of their specificity and affinity as well as the host genetic background.


Assuntos
Subpopulações de Linfócitos B/imunologia , Plasmócitos/imunologia , Tripanossomíase Africana/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Linfócitos B/imunologia , Modelos Animais de Doenças , Feminino , Patrimônio Genético , Interações Hospedeiro-Parasita/imunologia , Evasão da Resposta Imune , Imunidade Humoral , Imunoglobulina G , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Vacinas Protozoárias/imunologia , Trypanosoma brucei brucei
13.
Exp Parasitol ; 216: 107942, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32598889

RESUMO

The intracellular protozoan parasite Neospora caninum is incriminated to induce drastic economic losses in both livestock and pet animal industries. Neosporosis is primarily characterized by abortion in cattle and paralytic symptoms in dogs. Because there are no effective treatments or vaccines, diagnosis is critical for Neospora control. Thus, diversification of laboratory tests and specimens used for diagnosis of N. caninum is an essential scientific endeavor to judge and select the most appropriate diagnostic tool. Herein, we provide the first evidence for the utility of urine samples for demonstration of specific antibodies against N. caninum employing an experimentally infected murine model. Specific antibodies to recombinant N. caninum dense granule 7, surface antigen 1, and lysate antigen were assayed using different antibodies-based ELISAs. Urine based IgG ELISA efficiently discriminated between infected mice (acute or chronic infection), and those of non-infected mice. This effect was also noticed for IgG1 and IgG2a suggesting the utility of urine for assessment of T-helper 2- and T-helper 1-mediated immunities, respectively. In addition, reactivity of specific antibody in urine was also confirmed against parasites when indirect fluorescent antibody test was employed. Usefulness of urine as an additional clinical sample for Neospora diagnosis was confirmed via comparison with the relevant control non-infected and infected mouse sera as reference samples. Because of minimum invasiveness and ease of urine collection, this approach might offer new diagnostic opportunities for N. caninum either for the field or research purposes. However, further studies are required to extrapolate this preliminary study and results in the animal species of interest particularly in dogs.


Assuntos
Anticorpos Antiprotozoários/urina , Coccidiose/diagnóstico , Neospora/imunologia , Análise de Variância , Animais , Anticorpos Antiprotozoários/sangue , Chlorocebus aethiops , Coccidiose/imunologia , Coccidiose/parasitologia , Ensaio de Imunoadsorção Enzimática , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Imunoglobulina G/sangue , Imunoglobulina G/urina , Imunoglobulina M/sangue , Imunoglobulina M/urina , Camundongos , Camundongos Endogâmicos BALB C , Neospora/isolamento & purificação , Células Vero
14.
Mol Immunol ; 124: 161-171, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32585510

RESUMO

Leishmania infantum pyridoxal kinase (PK) protein was characterized after an immunoproteomics screening performed with the sera from patients suffering visceral leishmaniasis (VL). Since it was recognized by sera of mammalian hosts infected by a viscerotropic Leishmania species, PK could emerge as a new vaccine candidate against disease, due to its antigenicity and immunogenicity. In this context, in the present study, the effects of the immunization using PK were evaluated when administered as a DNA plasmid (pDNAA3/PK) or recombinant protein (rPK) plus saponin. The immune response elicited by both vaccination regimens reduced in significant levels the parasite load in spleen, liver, draining lymph nodes and bone marrow, being associated with the development of Th1-type immune response, which was characterized by high levels of IFN-γ, IL-12, GM-CSF, and specific IgG2a antibody, besides low production of IL-4, IL-10, and protein and parasite-specific IgG1 antibodies. CD8+ T cells were more important in the IFN-γ production in the pDNAA3/PK group, while CD4+ T cells contributed more significantly to production of this cytokine in the rPK/Saponin group. In addition, increased IFN-γ secretion, along with low levels of IL-10, were found when PBMCs from VL patients after treatment and healthy individuals were stimulated with the protein. In conclusion, when administered either as a DNA plasmid or recombinant protein plus adjuvant, PK can direct the immune response towards a Th1-type immune profile, protecting mice against L. infantum challenge; therefore, it can be seen as a promising immunogen against human VL.


Assuntos
Antígenos de Protozoários/imunologia , Vacinas contra Leishmaniose/imunologia , Leishmaniose Visceral/imunologia , Piridoxal Quinase/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , Humanos , Leishmania infantum/imunologia , Camundongos , Proteínas Recombinantes/imunologia , Vacinas de DNA/imunologia
15.
PLoS Negl Trop Dis ; 14(6): e0008272, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32555598

RESUMO

INTRODUCTION: Presence of asymptomatic individuals in endemic areas is common. The possible biomarkers in asymptomatic individuals once they get exposed to infection as well as following conversion to symptomatic disease are yet to be identified.We identified asymptomatic Visceral leishmaniasis (VL) infection amongst rK39+sorted direct agglutination test positive (DAT+) endemic healthy population and confirmed it by quantitative PCR(qPCR).The immunological determinants such as Adenosine deaminase (ADA), Interferon gamma (IFN-γ), Tumour Necrosis Factor alpha (TNF-α) and Interleukin 10 (IL-10)were examined to predict probable biomarkers for conversion to symptomatic VL. METHODS: Sample size was 5794 healthy individuals from VL endemic region. Antibody tests(DAT &rK39) were performed and later a qPCR assay was employed using kDNA specific primers and probes. Immunological biomarkers examined were ADA level by ADA-MTP kit and quantitative cytokines(IFN-γ, IL-10 and TNF-α) by ELISA. RESULTS: 120 asymptomatic individuals of 308 rK39 sero-positives were DAT positive comprising of 56 with previous history and 64 with no history of VL. RT-PCR confirmed asymptomatic VL in 42 sero-positives. These were followed up through repeated qPCR and evaluation of immunological determinants. We observed10 symptomatic cases converted from a total of 42 asymptomatic individuals identified at base-line. The level of ADA, IL-10 and IFN-γ remained consistently high in asymptomatic cases and amongst these, ADA and IL-10 but not IFN-γ remained higher at the development of clinical symptoms into active VL. On the contrary, there was no significant change in the mean concentration of TNF-α at both stages of the disease. DISCUSSION: We surmise from our data that considerable proportion of asymptomatic cases can be a reservoir and may play a crucial role in transmission of visceral leishmaniasis in endemic areas. The data also suggests that ADA and IL-10 can serve as a potential biomarker during the conversion of asymptomatic into symptomatic VL.


Assuntos
Anticorpos Antiprotozoários/sangue , Citocinas/sangue , Leishmaniose Visceral/epidemiologia , Adolescente , Adulto , Idoso , Testes de Aglutinação , Infecções Assintomáticas/epidemiologia , Biomarcadores/sangue , Criança , Progressão da Doença , Doenças Endêmicas , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Índia/epidemiologia , Leishmania donovani , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/imunologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Soroconversão , Adulto Jovem
16.
PLoS Negl Trop Dis ; 14(6): e0008323, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32559186

RESUMO

Malaria is caused by multiple different species of protozoan parasites, and interventions in the pre-elimination phase can lead to drastic changes in the proportion of each species causing malaria. In endemic areas, cross-reactivity may play an important role in the protection and blocking transmission. Thus, successful control of one species could lead to an increase in other parasite species. A few studies have reported cross-reactivity producing cross-immunity, but the extent of cross-reactive, particularly between closely related species, is poorly understood. P. vivax and P. knowlesi are particularly closely related species causing malaria infections in SE Asia, and whilst P. vivax cases are in decline, zoonotic P. knowlesi infections are rising in some areas. In this study, the cross-species reactivity and growth inhibition activity of P. vivax blood-stage antigen-specific antibodies against P. knowlesi parasites were investigated. Bioinformatics analysis, immunofluorescence assay, western blotting, protein microarray, and growth inhibition assay were performed to investigate the cross-reactivity. P. vivax blood-stage antigen-specific antibodies recognized the molecules located on the surface or released from apical organelles of P. knowlesi merozoites. Recombinant P. vivax and P. knowlesi proteins were also recognized by P. knowlesi- and P. vivax-infected patient antibodies, respectively. Immunoglobulin G against P. vivax antigens from both immune animals and human malaria patients inhibited the erythrocyte invasion by P. knowlesi. This study demonstrates that there is extensive cross-reactivity between antibodies against P. vivax to P. knowlesi in the blood stage, and these antibodies can potently inhibit in vitro invasion, highlighting the potential cross-protective immunity in endemic areas.


Assuntos
Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Reações Cruzadas , Malária/imunologia , Plasmodium knowlesi/imunologia , Plasmodium vivax/imunologia , Animais , Humanos , Camundongos , Análise de Sequência de Proteína
17.
Ann Parasitol ; 66(2): 143-156, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32531102

RESUMO

Recently, Leishmania infantum has increasingly been detected in stray cats in endemic regions of the world. Cats have been considered playing a role in the epidemiology of visceral leishmaniosis, an endemic zoonosis in Iran. The studies concerning feline leishmaniosis (FeL) allow the hypothesis that cats can be considered as potential reservoirs. The investigations on Leishmania infection in cats are very few in Iran and therefore we aimed to assess the L. infantum infection in stray cats and its possible role in transmission of the disease to human by direct agglutination test (DAT), ELISA, nested-PCR and confirmation via sequencing and phylogenetic analysis in Fars province, Iran. Whole blood samples were obtained from 174 stray cats. Anti-Leishmania antibodies were detected in the sera using DAT and ELISA. DNA was extracted from the buffy coat of each subject and PCR amplified, targeting Leishmania kDNA gene. PCR results were confirmed by sequence analysis. Prevalence of clinical signs in positive cats was 19.0%. Anti-Leishmania antibodies with different titers were detected in 48 (27.59%) and leishmanial DNA in 36 (20.69%) of the cats. The sequencing of PCR-positive cats revealed the parasite as L. infantum. A high seroprevalence of L. infantum was revealed, with higher levels in males, adult cats, and those living in rural districts and southern zones. Despite the reservoir task of cats in nature is still ambiguous, the high serological and molecular detection of L. infantum in stray cats indicates that cats are regularly bitten by infected sand flies in Fars province, southern Iran, and may have a potential reservoir role in the maintenance of L. infantum in the endemic areas of zoonotic visceral leishmaniosis in Iran. Anyway, Leishmania infection must be appraised in the differential diagnosis of cutaneous or systemic clinical signs in cats.


Assuntos
Anticorpos Antiprotozoários/sangue , Leishmania infantum , Leishmaniose Visceral/veterinária , Animais , Gatos , DNA de Protozoário/sangue , Feminino , Humanos , Irã (Geográfico)/epidemiologia , Leishmaniose Visceral/sangue , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/transmissão , Masculino , Filogenia , Reação em Cadeia da Polimerase , Prevalência , Estudos Soroepidemiológicos
18.
PLoS Negl Trop Dis ; 14(6): e0008400, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32530918

RESUMO

Recent outbreaks of enterically transmitted infections, including acute hepatitis A and shigellosis, have raised the concerns of increasing Entamoeba histolytica infection (EHI) among people living with HIV (PLWH) in Taiwan. This study investigated the prevalence of EHI, its temporal trends, and associated factors among newly diagnosed PLWH in Taiwan. Medical records of newly diagnosed PLWH at six medical centers in Taiwan between 2009 and 2018 were reviewed. The annual prevalence of invasive amoebiasis and seroprevalence of E. histolytica were determined and examined by the Cochran-Armitage test. The clinical characteristics associated with invasive amoebiasis and seropositivity for E. histolytica were analyzed in multivariable regression models. Among 5362 patients seeking HIV care at six medical centers in Taiwan during the 10-year study period, 119 (2.2%) had invasive amoebiasis at the time or within six months of their HIV diagnosis. Among 3499 who had indirect hemagglutination antibody (IHA) determined, 284 (8.1%) had positive IHA (≥1:32) and 205 (5.9%) had high-titre IHA (≥1:128). The prevalence of invasive amoebiasis increased from 1.3% in 2012 to 3.3% in 2018 (p = 0.024). Invasive amoebiasis was independently associated with a greater age, men who have sex with men, rapid plasma reagin titre ≥1:4, and concurrent shigellosis and giardiasis. Increasing prevalence of invasive amoebiasis among newly diagnosed PLWH in Taiwan calls for strategies to prevent ongoing transmission in this population. Routine screening of EHI for early diagnosis and treatment is recommended, especially among men who have sex with men and those who present with other sexually or enterically transmitted infections.


Assuntos
Entamoeba histolytica , Entamebíase/epidemiologia , Entamebíase/transmissão , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Adulto , Fatores Etários , Anticorpos Antiprotozoários/sangue , Estudos Transversais , Entamebíase/diagnóstico , Feminino , Homossexualidade Masculina , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Soroepidemiológicos , Minorias Sexuais e de Gênero , Taiwan/epidemiologia , Adulto Jovem
19.
BMC Infect Dis ; 20(1): 415, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32539811

RESUMO

BACKGROUND: Mounting evidence suggested a complex correlation between host lipid metabolism and Toxoplasma gondii (T. gondii) infection. However, the inherent association between T. gondii infection and host lipid state remains elusive either in mice or in human hosts. METHODS: Through a study in a sample of 1045 healthy participants from eastern China, we determined the association of T. gondii infection and host lipid levels using serological methods. We then examined the host lipid levels in C57BL/6 J mice at both acute and chronic T. gondii infection stages (for a period up to 36 weeks post infection). RESULTS: In our case-control study, T. gondii seropositive individuals had higher low-density lipoproteins (LDL) (P = 0.0043) and total cholesterol (TC) (P = 0.0134) levels compared to seronegative individuals. Furthermore, individuals with LDL (OR = 3.25; 95% CI:1.60-6.61) and TC (OR = 2.10; 95% CI:1.22-3.63) levels above the upper limit of normal range had higher odds ratio to be T. gondii IgG positive. Consistently, in vivo data revealed that a significantly increased LDL level was first observed at early acute stage but plateaued to later time (chronic infection with T. gondii). CONCLUSIONS: In both healthy population and T. gondii-infected mice, seropositive individuals had higher LDL level. Individuals with positive T. gondii IgG had more odds of being with LDL and TC abnormality. Latent T. gondii infection is common worldwide, potential medical interventions to host lipid metabolism may be a breakthrough point to the prevention and control of this parasite infection.


Assuntos
Metabolismo dos Lipídeos , Toxoplasma/fisiologia , Toxoplasmose/metabolismo , Toxoplasmose/parasitologia , Adulto , Animais , Anticorpos Antiprotozoários/sangue , Estudos de Casos e Controles , China/epidemiologia , Feminino , Interações Hospedeiro-Patógeno , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Razão de Chances , Toxoplasma/imunologia , Toxoplasmose/sangue
20.
Rev Bras Parasitol Vet ; 29(2): e021019, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32428187

RESUMO

The midwest region of Brazil has witnessed an increase in the number of cases of human (HVL) and canine visceral leishmaniasis (CVL). The aim of the present study was to evaluate the population's perception of these diseases, factors associated with CVL, its spatial distribution, and the prevalence of anti-Leishmania spp. in 385 dogs, determined using a commercially available immunochromatographic rapid test and confirmed using enzyme-linked immunosorbent assay (ELISA). Of the 385 samples, 54 were positive for CVL and confirmed by ELISA, corresponding to a prevalence of 14%. Knowledge of signs of CVL by tutors (p = 0.038); previous occurrence of CVL in the vicinity (p = 0.022); symptomatic dog(s) (p = 0.014), splenomegaly (p = 0.055), and ear ulcer(s) (p = 0.059) were significantly associated with CVL. The results revealed a significant prevalence of CVL spatially distributed in rural and urban contexts. The association between environmentally related variables and perception and the occurrence of CVL underscores the importance of implementing control and prevention strategies primarily focused on environmental management and health education activities.


Assuntos
Doenças do Cão/parasitologia , Leishmaniose Visceral/epidemiologia , Fatores Etários , Distribuição Animal , Animais , Anticorpos Antiprotozoários/sangue , Brasil/epidemiologia , Cidades/epidemiologia , Estudos Transversais , Doenças do Cão/sangue , Doenças do Cão/epidemiologia , Cães , Características da Família , Feminino , Humanos , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/veterinária , Masculino , Percepção , Prevalência , Análise Espacial , Inquéritos e Questionários
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