RESUMEN
This study investigated the prevalence of caprine toxoplasmosis in goat herds from Southern Brazil by the indirect immunofluorescence assay (IFA), and compared these results with the enzyme-linked immunosorbent assay (ELISA) and the modified agglutination test (MAT). In addition, possible risk factors associated with infection due to Toxoplasma gondii were determined. The serum samples evaluated were from 1,058 goats derived from 94 goat herds within the state of Paraná, Southern Brazil. Seropositivity by IFA was 30.0%, 33.3% by ELISA, and 25.3% by MAT. The risk factors associated with infection by T. gondii in goats were pasture rental, female goats, the presence of cats, and pastures shared with several goat herds. Using IFA as a standard, ELISA and MAT showed substantial concordance (kappa = 0.74 and 0.61), with sensitivities of 87 and 66.2% and specificities of 89.7 and 92.2%, respectively. These results demonstrate that caprine toxoplasmosis is endemic within the state of Paraná, Southern Brazil. In addition, the results from the three assays were relevant, without any significant differences as demonstrated due to the substantial concordance based on the kappa index.
Asunto(s)
Cabras , Toxoplasma/inmunología , Toxoplasmosis Animal/epidemiología , Pruebas de Aglutinación/veterinaria , Animales , Anticuerpos Antiprotozoarios/sangre , Brasil/epidemiología , Gatos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Masculino , Prevalencia , Factores de Riesgo , Sensibilidad y Especificidad , Estudios SeroepidemiológicosRESUMEN
The aim of this study was to evaluate an enzyme-linked immunoassay with recombinant rhoptry protein 2 (ELISA-rROP2) for its ability to detect Toxoplasma gondii ROP2-specific IgG in samples from pregnant women. The study included 236 samples that were divided into groups according to serological screening profiles for toxoplasmosis: unexposed (n = 65), probable acute infection (n = 48), possible acute infection (n = 58) and exposed to the parasite (n = 65). When an indirect immunofluorescence assay forT. gondii-specific IgG was considered as a reference test, the ELISA-rROP2 had a sensitivity of 61.8%, specificity of 62.8%, predictive positive value of 76.6% and predictive negative value of 45.4% (p = 0.0002). The ELISA-rROP2 reacted with 62.5% of the samples from pregnant women with probable acute infection and 40% of the samples from pregnant women with previous exposure (p = 0.0180). Seropositivity was observed in 50/57 (87.7%) pregnant women with possible infection. The results underscored that T. gondii rROP2 is recognised by specific IgG antibodies in both the acute and chronic phases of toxoplasmosis acquired during pregnancy. However, the sensitivity of the ELISA-rROP2 was higher in the pregnant women with probable and possible acute infections and IgM reactivity.
Asunto(s)
Antígenos de Protozoos/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoglobulina G/sangre , Proteínas de la Membrana/inmunología , Complicaciones Parasitarias del Embarazo/diagnóstico , Proteínas Protozoarias/inmunología , Toxoplasmosis/diagnóstico , Antígenos de Protozoos/sangre , Intervalos de Confianza , Ensayo de Inmunoadsorción Enzimática/normas , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Inmunoglobulina G/aislamiento & purificación , Inmunoglobulina M/sangre , Inmunoglobulina M/aislamiento & purificación , Invenciones/normas , Proteínas de la Membrana/genética , Valor Predictivo de las Pruebas , Embarazo , Complicaciones Parasitarias del Embarazo/sangre , Complicaciones Parasitarias del Embarazo/inmunología , Proteínas Protozoarias/genética , Proteínas Recombinantes , Estándares de Referencia , Sensibilidad y Especificidad , Toxoplasma/inmunología , Toxoplasmosis/sangre , Toxoplasmosis/inmunologíaRESUMEN
The history of DNA vaccine began as early as the 1960s with the discovery that naked DNA can transfect mammalian cells in vivo. In 1992, the evidence that such transfection could lead to the generation of antigen-specific antibody responses was obtained and supported the development of this technology as a novel vaccine platform. The technology then attracted immense interest and high hopes in vaccinology, as evidence of high immunogenicity and protection against virulent challenges accumulated from several animal models for several diseases. In particular, the capacity to induce T-cell responses was unprecedented in non-live vaccines. However, the technology suffered its major knock when the success in animals failed to translate to humans, where DNA vaccine candidates were shown to be safe but remained poorly immunogenic, or not associated with clinical benefit. Thanks to a thorough exploration of the molecular mechanisms of action of these vaccines, an impressive range of approaches have been and are currently being explored to overcome this major challenge. Despite limited success so far in humans as compared with later genetic vaccine technologies such as viral vectors and mRNA, DNA vaccines are not yet optimised for human use and may still realise their potential.
Asunto(s)
Vacunas de ADN , Animales , Humanos , Vectores Genéticos , Linfocitos T/inmunología , Vacunas de ADN/historia , Vacunas de ADN/inmunologíaRESUMEN
Paracoccidioidomycosis (PCM) is an infectious disease endemic to South America, caused by the thermally dimorphic fungi Paracoccidioides. Currently, there is no effective human vaccine that can be used in prophylactic or therapeutic regimes. We tested the hypothesis that the immunogenicity of the immunodominant CD4+ T-cell epitope (P10) of Paracoccidioides brasiliensis gp43 antigen might be significantly enhanced by using a hepatitis B virus-derived particle (VLP) as an antigen carrier. This chimera was administered to mice as a (His)6-purified protein (rPbT) or a replication-deficient human type 5 adenoviral vector (rAdPbT) in an immunoprophylaxis assay. The highly virulent Pb18 yeast strain was used to challenge our vaccine candidates. Fungal challenge evoked robust P10-specific memory CD4+ T cells secreting protective Th-1 cytokines in most groups of immunized mice. Furthermore, the highest level of fungal burden control was achieved when rAdPbT was inoculated in a homologous prime-boost regimen, with 10-fold less CFU recovering than in non-vaccinated mice. Systemic Pb18 spreading was only prevented when rAdPbT was previously inoculated. In summary, we present here VLP/P10 formulations as vaccine candidates against PCM, some of which have demonstrated for the first time their ability to prevent progression of this pernicious fungal disease, which represents a significant social burden in developing countries.
Asunto(s)
Antígenos Fúngicos/inmunología , Linfocitos T CD4-Positivos/inmunología , Epítopos de Linfocito T/inmunología , Proteínas Fúngicas/inmunología , Vacunas Fúngicas/administración & dosificación , Glicoproteínas/inmunología , Paracoccidioides/crecimiento & desarrollo , Paracoccidioides/inmunología , Paracoccidioidomicosis/prevención & control , Animales , Citocinas/inmunología , Citocinas/metabolismo , Epítopos de Linfocito T/genética , Vacunas Fúngicas/inmunología , Virus de la Hepatitis B/genética , Inmunización , Epítopos Inmunodominantes/inmunología , Inmunogenicidad Vacunal , Memoria Inmunológica , Hígado/microbiología , Pulmón/microbiología , Ratones Endogámicos BALB C , Paracoccidioidomicosis/inmunología , Paracoccidioidomicosis/microbiología , Bazo/microbiología , Células TH1/inmunología , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología , Vacunas de Partículas Similares a Virus/administración & dosificación , Vacunas de Partículas Similares a Virus/genética , Vacunas de Partículas Similares a Virus/inmunologíaRESUMEN
This study describes the characteristics of 31 children with congenital toxoplasmosis children admitted to the University Hospital of Londrina, Southern Brazil, from 2000 to 2010. In total, 23 (85.2%) of the mothers received prenatal care but only four (13.0%) were treated for toxoplasmosis. Birth weight was <2500g in 37.9% of the infants. During the first month of life, physical examination was normal in 34.5%, and for those with clinical signs and symptoms, the main manifestations were hepatomegaly and/or splenomegaly (62.1%), jaundice (13.8%), and microcephaly (6.9%). During ophthalmic examination, 74.2% of the children exhibited injuries, 58.1% chorioretinitis, 32.3% strabismus, 19.4% microphthalmia, and 16.2% vitreitis. Anti-Toxoplasma gondii IgM antibodies were detected in 48.3% of the children. Imaging brain evaluation was normal in 44.8%; brain calcifications, hydrocephaly, or both conditions were observed in 27.6%, 10.3%, and 17.2%, respectively, of the patients. Patients with cerebrospinal fluid protein≥200mg/dL presented more brain calcifications (p=0.0325). Other sequelae were visual impairment (55.2% of the cases), developmental delay (31.0%), motor deficit (13.8%), convulsion (27.5%), and attention deficit (10.3%). All patients were treated with sulfadiazine, pyrimethamine, and folinic acid, and 55.2% of them exhibited adverse effects. The results demonstrate the significance of the early diagnosis and treatment of toxoplasmosis during pregnancy to reduce congenital toxoplasmosis and its consequences.
Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Toxoplasma/inmunología , Toxoplasmosis Congénita/complicaciones , Toxoplasmosis Congénita/diagnóstico , Adolescente , Adulto , Brasil , Niño , Femenino , Humanos , Recién Nacido , Masculino , Tamizaje Neonatal , Embarazo , Complicaciones Infecciosas del Embarazo/terapia , Estudios Retrospectivos , Adulto JovenRESUMEN
This study aimed to investigate anti-Toxoplasma gondii antibodies and to isolate the parasite from the brains of horses processed at slaughterhouses in Brazil. We collected brain and blood samples from 398 horses of various ages, from six Brazilian states. Serum samples were evaluated by indirect fluorescent antibody test (IFAT cut-off titre ≥ 1:64), and brains were submitted to mouse bioassay. Among the 398 horses, positivity for T. gondii was identified in 46 (11.6%) by IFAT and in 14 (3.5%) by mouse bioassay. In 12 of those 14 bioassays, mice were positive only by IFAT (cut-off titre ≥ 1:16), T. gondii being isolated in the remaining two. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of 18S rDNA to differentiate among T. gondii, Neospora caninum, and Sarcocystis neurona, we found that two of the 14 brains were positive for T. gondii only. For genotyping of the two isolates and the PCR-positive brain, we performed PCR-RFLP based on 13 markers, and SAG2 all samples were Toxoplasma gondii type I. Collectively, IFAT of horse sera and mouse bioassay identified positivity in 60 (15%) of the samples. Our results show that some horses sent to slaughter in Brazil have been exposed to T. gondii.
Asunto(s)
Enfermedades de los Caballos/diagnóstico , Enfermedades de los Caballos/parasitología , Toxoplasma/aislamiento & purificación , Toxoplasmosis Animal/diagnóstico , Mataderos , Animales , Anticuerpos Antiprotozoarios/sangre , Brasil , Enfermedades de los Caballos/sangre , Caballos , Toxoplasma/inmunología , Toxoplasmosis Animal/sangreRESUMEN
The aim of this study was to evaluate an enzyme-linked immunoassay with recombinant rhoptry protein 2 (ELISA-rROP2) for its ability to detectToxoplasma gondii ROP2-specific IgG in samples from pregnant women. The study included 236 samples that were divided into groups according to serological screening profiles for toxoplasmosis: unexposed (n = 65), probable acute infection (n = 48), possible acute infection (n = 58) and exposed to the parasite (n = 65). When an indirect immunofluorescence assay forT. gondii-specific IgG was considered as a reference test, the ELISA-rROP2 had a sensitivity of 61.8%, specificity of 62.8%, predictive positive value of 76.6% and predictive negative value of 45.4% (p = 0.0002). The ELISA-rROP2 reacted with 62.5% of the samples from pregnant women with probable acute infection and 40% of the samples from pregnant women with previous exposure (p = 0.0180). Seropositivity was observed in 50/57 (87.7%) pregnant women with possible infection. The results underscored that T. gondii rROP2 is recognised by specific IgG antibodies in both the acute and chronic phases of toxoplasmosis acquired during pregnancy. However, the sensitivity of the ELISA-rROP2 was higher in the pregnant women with probable and possible acute infections and IgM reactivity.
Asunto(s)
Femenino , Humanos , Embarazo , Antígenos de Protozoos/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoglobulina G/sangre , Proteínas de la Membrana/inmunología , Complicaciones Parasitarias del Embarazo/diagnóstico , Proteínas Protozoarias/inmunología , Toxoplasmosis/diagnóstico , Antígenos de Protozoos/sangre , Intervalos de Confianza , Ensayo de Inmunoadsorción Enzimática/normas , Técnica del Anticuerpo Fluorescente Indirecta , Inmunoglobulina G/aislamiento & purificación , Inmunoglobulina M/sangre , Inmunoglobulina M/aislamiento & purificación , Invenciones/normas , Proteínas de la Membrana/genética , Valor Predictivo de las Pruebas , Complicaciones Parasitarias del Embarazo/sangre , Complicaciones Parasitarias del Embarazo/inmunología , Proteínas Protozoarias/genética , Proteínas Recombinantes , Estándares de Referencia , Sensibilidad y Especificidad , Toxoplasma/inmunología , Toxoplasmosis/sangre , Toxoplasmosis/inmunologíaRESUMEN
This study describes the characteristics of 31 children with congenital toxoplasmosis children admitted to the University Hospital of Londrina, Southern Brazil, from 2000 to 2010. In total, 23 (85.2%) of the mothers received prenatal care but only four (13.0%) were treated for toxoplasmosis. Birth weight was <2500 g in 37.9% of the infants. During the first month of life, physical examination was normal in 34.5%, and for those with clinical signs and symptoms, the main manifestations were hepatomegaly and/or splenomegaly (62.1%), jaundice (13.8%), and microcephaly (6.9%). During ophthalmic examination, 74.2% of the children exhibited injuries, 58.1% chorioretinitis, 32.3% strabismus, 19.4% microphthalmia, and 16.2% vitreitis. Anti-Toxoplasma gondii IgM antibodies were detected in 48.3% of the children. Imaging brain evaluation was normal in 44.8%; brain calcifications, hydrocephaly, or both conditions were observed in 27.6%, 10.3%, and 17.2%, respectively, of the patients. Patients with cerebrospinal fluid protein > 200 mg/dL presented more brain calcifications (p = 0.0325). Other sequelae were visual impairment (55.2% of the cases), developmental delay (31.0%), motor deficit (13.8%), convulsion (27.5%), and attention deficit (10.3%). All patients were treated with sulfadiazine, pyrimethamine, and folinic acid, and 55.2% of them exhibited adverse effects. The results demonstrate the significance of the early diagnosis and treatment of toxoplasmosis during pregnancy to reduce congenital toxoplasmosis and its consequences.
Asunto(s)
Adolescente , Adulto , Niño , Femenino , Humanos , Recién Nacido , Masculino , Embarazo , Adulto Joven , Anticuerpos Antiprotozoarios/sangre , Toxoplasma/inmunología , Toxoplasmosis Congénita/complicaciones , Toxoplasmosis Congénita/diagnóstico , Brasil , Tamizaje Neonatal , Complicaciones Infecciosas del Embarazo/terapia , Estudios RetrospectivosRESUMEN
This study aimed to investigate anti-Toxoplasma gondii antibodies and to isolate the parasite from the brains of horses processed at slaughterhouses in Brazil. We collected brain and blood samples from 398 horses of various ages, from six Brazilian states. Serum samples were evaluated by indirect fluorescent antibody test (IFAT cut-off titre ≥ 1:64), and brains were submitted to mouse bioassay. Among the 398 horses, positivity for T. gondii was identified in 46 (11.6%) by IFAT and in 14 (3.5%) by mouse bioassay. In 12 of those 14 bioassays, mice were positive only by IFAT (cut-off titre ≥ 1:16), T. gondii being isolated in the remaining two. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of 18S rDNA to differentiate among T. gondii, Neospora caninum, and Sarcocystis neurona, we found that two of the 14 brains were positive for T. gondii only. For genotyping of the two isolates and the PCR-positive brain, we performed PCR-RFLP based on 13 markers, and SAG2 all samples were Toxoplasma gondii type I. Collectively, IFAT of horse sera and mouse bioassay identified positivity in 60 (15%) of the samples. Our results show that some horses sent to slaughter in Brazil have been exposed toT. gondii.
O objetivo do estudo foi investigar anticorpos anti-Toxoplasma gondii e isolar o parasita do cérebro de equídeos abatidos em matadouros-frigoríficos no Brasil. Colheram-se amostras de 398 cérebros e sangue de equídeos machos e fêmeas de idades variadas, provenientes de seis estados brasileiros. As amostras de soro foram avaliadas pelo teste de imunofluorescência indireta (IFI) para T. gondii (ponto de corte ≥ 64), e os fragmentos de cérebros foram submetidos ao bioensaio em camundongos. Por meio da IFI, 46 (11,6%) equídeos foram soropositivos. Pelo bioensaio em camundongos, 14 (3,5%) cérebros de equídeos testados foram positivos. Em doze dos bioensaios, os camundongos foram positivos somente pela IFI (ponto de corte ≥ 16) e T. gondii foi isolado nos outros dois bioensaios. A PCR-RFLP com base em 18S rDNA para diferenciar entre T. gondii, Neospora caninum, e Sarcocystis neurona foram feitas em todos os 14 cérebros e dois foram positivos apenas para T. gondii. De dois isolados positivos para T. gondii e do cérebro positivo à PCR em que realizou-se a PCR-RFLP, com base em 13 marcadores e SAG2, a genotipagem mostrou ser o T. gondii tipo I para todas as amostras. A IFI de soros de equídeos e do bioensaio em camundongos identificaram positividade em 60 (15%) amostras testadas. Os resultados mostram que alguns cavalos enviados para abate foram expostos ao T. gondii.
Asunto(s)
Animales , Prevalencia , Enfermedades de los Caballos/diagnóstico , Enfermedades de los Caballos/parasitología , Toxoplasma/aislamiento & purificación , Toxoplasmosis Animal/diagnóstico , Mataderos , Anticuerpos Antiprotozoarios/sangre , Brasil , Enfermedades de los Caballos/sangre , Caballos , Toxoplasma/inmunología , Toxoplasmosis Animal/sangreRESUMEN
This study aimed to investigate anti-Toxoplasma gondii antibodies and to isolate the parasite from the brains of horses processed at slaughterhouses in Brazil. We collected brain and blood samples from 398 horses of various ages, from six Brazilian states. Serum samples were evaluated by indirect fluorescent antibody test (IFAT cut-off titre 1:64), and brains were submitted to mouse bioassay. Among the 398 horses, positivity for T. gondii was identified in 46 (11.6%) by IFAT and in 14 (3.5%) by mouse bioassay. In 12 of those 14 bioassays, mice were positive only by IFAT (cut-off titre 1:16), T. gondii being isolated in the remaining two. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of 18S rDNA to differentiate among T. gondii, Neospora caninum, and Sarcocystis neurona, we found that two of the 14 brains were positive for T. gondii only. For genotyping of the two isolates and the PCR-positive brain, we performed PCR-RFLP based on 13 markers, and SAG2 all samples were Toxoplasma gondii type I. Collectively, IFAT of horse sera and mouse bioassay identified positivity in 60 (15%) of the samples. Our results show that some horses sent to slaughter in Brazil have been exposed toT. gondii.
O objetivo do estudo foi investigar anticorpos anti-Toxoplasma gondii e isolar o parasita do cérebro de equídeos abatidos em matadouros-frigoríficos no Brasil. Colheram-se amostras de 398 cérebros e sangue de equídeos machos e fêmeas de idades variadas, provenientes de seis estados brasileiros. As amostras de soro foram avaliadas pelo teste de imunofluorescência indireta (IFI) para T. gondii (ponto de corte 64), e os fragmentos de cérebros foram submetidos ao bioensaio em camundongos. Por meio da IFI, 46 (11,6%) equídeos foram soropositivos. Pelo bioensaio em camundongos, 14 (3,5%) cérebros de equídeos testados foram positivos. Em doze dos bioensaios, os camundongos foram positivos somente pela IFI (ponto de corte 16) e T. gondii foi isolado nos outros dois bioensaios. A PCR-RFLP com base em 18S rDNA para diferenciar entre T. gondii, Neospora caninum, e Sarcocystis neurona foram feitas em todos os 14 cérebros e dois foram positivos apenas para T. gondii. De dois isolados positivos para T. gondii e do cérebro positivo à PCR em que realizou-se a PCR-RFLP, com base em 13 marcadores e SAG2, a genotipagem mostrou ser o T. gondii tipo I para todas as amostras. A IFI de soros de equídeos e do bioensaio em camundongos identificaram positividade em 60 (15%) amostras testadas. Os resultados mostram que alguns cavalos enviados para abate foram expostos ao T. gondii.