RESUMO
Entamoeba histolytica is a rare but feared pathogen owing to its related morbidity and mortality. Physicians in an ambulatory clinic in Cusco noted frequent reports of E. histolytica diagnosed by microscopy. Other non-pathogenic species of Entamoeba have an identical microscopic appearance. To determine whether the organisms were actually E. histolytica, faecal specimens from children aged six months to three years with diarrhoea were tested by a species-specific ELISA for E. histolytica antigen. Although 19/73 patients (26.0%) were presumptively diagnosed with amoebiasis based on microscopy, none were confirmed by ELISA. Most cases diagnosed as E. histolytic by microscopy in Peru are not infected by the pathogenic species and are probably colonised by non-pathogenic amoeba such as Entamoeba dispar.
Assuntos
Diarreia/diagnóstico , Entamoeba histolytica/isolamento & purificação , Entamebíase/diagnóstico , Instituições de Assistência Ambulatorial , Animais , Pré-Escolar , Erros de Diagnóstico , Diarreia/parasitologia , Entamoeba/citologia , Entamoeba/imunologia , Entamoeba/isolamento & purificação , Entamoeba histolytica/citologia , Entamoeba histolytica/imunologia , Entamebíase/parasitologia , Ensaio de Imunoadsorção Enzimática , Fezes/parasitologia , Humanos , Lactente , Microscopia , Peru/epidemiologiaRESUMO
Intestinal protozoans found in ancient human samples have been studied primarily by microscopy and immunodiagnostic assays. However, such methods are not suitable for the detection of zoonotic genotypes. The objectives of the present study were to utilize immunoenzimatic assays for coproantigen detection of Cryptosporidium sp., Giardia duodenalis, and Entamoeba histolytica/Entamoeba dispar in sixty ancient human and animal samples collected from 14 archaeological sites in South America, and to carry out a critical analysis of G. duodenalis according to results obtained from three diagnostic methodologies: microscopy, immunodiagnostic tests (immunoenzymatic and immunofluorescence), and molecular biology (PCR and sequencing). More than half (31/60) of the samples analyzed using immunoenzymatic tests were positive for at least one of the intestinal protozoans, with 46.6% (28/60) corresponding to G. duodenalis, 26.6% (16/60) to Cryptosporidium sp., and 5% (3/60) to E. histolytica/E. dispar. Cryptosporidium sp. and G. duodenalis coinfection was observed in 15% (9/60) of the samples, whereas all three protozoans were found in 5% (3/60) of samples. In the Northeast Region of Brazil, by immunoenzymatic tests there is evidence that G. duodenlais and Cryptosporidium sp. have infected humans and rodents for at least 7150 years. However, for G. duodenalis, the results from the three diagnostic tests were discordant. Specifically, despite the efficiency of the molecular biology assay in the experimental models, G. duodenalis DNA could not be amplified from the ancient samples. These results raise the following question: Are all ancient samples positive for coproantigen of G. duodenalis by immunoenzymatic tests truly positive? This scenario highlights the importance of further studies to evaluate the sensitivity and specificity of the immunoenzymatic method in the archaeological context.
Assuntos
Arqueologia/métodos , Cryptosporidium/isolamento & purificação , Entamoeba/isolamento & purificação , Fezes/parasitologia , Giardia lamblia/isolamento & purificação , Técnicas Imunoenzimáticas/normas , Animais , Antígenos de Protozoários/análise , Antígenos de Protozoários/genética , Cryptosporidium/genética , Cryptosporidium/imunologia , Entamoeba/genética , Entamoeba/imunologia , Entamoeba histolytica/genética , Entamoeba histolytica/imunologia , Entamoeba histolytica/isolamento & purificação , Giardia lamblia/genética , Giardia lamblia/imunologia , Humanos , Enteropatias Parasitárias/parasitologia , Roedores , Sensibilidade e Especificidade , América do SulRESUMO
The use of oxygen as the final electron acceptor in aerobic organisms results in an improvement in the energy metabolism. However, as a byproduct of the aerobic metabolism, reactive oxygen species are produced, leaving to the potential risk of an oxidative stress. To contend with such harmful compounds, living organisms have evolved antioxidant strategies. In this sense, the thiol-dependent antioxidant defense systems play a central role. In all cases, cysteine constitutes the major building block on which such systems are constructed, being present in redox substrates such as glutathione, thioredoxin, and trypanothione, as well as at the catalytic site of a variety of reductases and peroxidases. In some cases, the related selenocysteine was incorporated at selected proteins. In invertebrate parasites, antioxidant systems have evolved in a diversity of both substrates and enzymes, representing a potential area in the design of anti-parasite strategies. The present review focus on the organization of the thiol-based antioxidant systems in invertebrate parasites. Differences between these taxa and its final mammal host is stressed. An understanding of the antioxidant defense mechanisms in this kind of parasites, as well as their interactions with the specific host is crucial in the design of drugs targeting these organisms.
Assuntos
Antioxidantes/metabolismo , Infecções por Protozoários/parasitologia , Compostos de Sulfidrila/metabolismo , Animais , Entamoeba/imunologia , Entamoeba/metabolismo , Interações Hospedeiro-Parasita , Humanos , Imunidade Inata , Plasmodium/imunologia , Plasmodium/metabolismo , Infecções por Protozoários/imunologia , Schistosoma/imunologia , Schistosoma/metabolismo , Taenia/imunologia , Taenia/metabolismoRESUMO
There is a clear need to perform epidemiological studies to find the true prevalence of Entamoeba histolytica around the world. The evaluation of this prevalence has been hindered by the existence of two different species which are morphologically identical, but genetically different, namely E. histolytica, which causes amebiasis, and E. dispar, which is non-pathogenic. In Brazil, the E. dispar has been detected in communities in the Southeastern (SE) and Northeastern (NE) regions with poor sanitation. However, individuals infected with E. histolytica have been identified in other regions. There is an absence of reports on the prevalence of these parasites in the state of Paraíba, which also has areas with poor sanitary conditions where a high prevalence of the E. histolytica/E. dispar complex has been detected in children from urban slums. The present study evaluated the prevalence of E. histolytica and E. dispar in 1,195 asymptomatic children between two and 10 years of age, living in a sprawling urban slum in Campina Grande, in the state of Paraíba, in Northeastern Brazil. These children were examined and their feces samples were analyzed microscopically. A total of 553 children tested positive for the E. histolytica/E. dispar complex, and 456 of the positive samples were tested with the E. histolytica II® ELISA kit. All 456 samples were negative for the presence of the adhesin E. histolytica specific antigen. The evidence suggests that in this community E. histolytica is absent and E. dispar is the dominant species.
Assuntos
Antígenos de Protozoários/sangue , Entamoeba histolytica/imunologia , Entamebíase/epidemiologia , Brasil/epidemiologia , Criança , Pré-Escolar , Entamoeba/imunologia , Entamebíase/diagnóstico , Ensaio de Imunoadsorção Enzimática , Fezes/parasitologia , Humanos , Lactente , Áreas de Pobreza , Prevalência , Especificidade da Espécie , População UrbanaRESUMO
There is a clear need to perform epidemiological studies to find the true prevalence of Entamoeba histolytica around the world. The evaluation of this prevalence has been hindered by the existence of two different species which are morphologically identical, but genetically different, namely E. histolytica, which causes amebiasis, and E. dispar, which is non-pathogenic. In Brazil, the E. dispar has been detected in communities in the Southeastern (SE) and Northeastern (NE) regions with poor sanitation. However, individuals infected with E. histolytica have been identified in other regions. There is an absence of reports on the prevalence of these parasites in the state of Paraíba, which also has areas with poor sanitary conditions where a high prevalence of the E. histolytica/E. dispar complex has been detected in children from urban slums. The present study evaluated the prevalence of E. histolytica and E. dispar in 1,195 asymptomatic children between two and 10 years of age, living in a sprawling urban slum in Campina Grande, in the state of Paraíba, in Northeastern Brazil. These children were examined and their feces samples were analyzed microscopically. A total of 553 children tested positive for the E. histolytica/E. dispar complex, and 456 of the positive samples were tested with the E. histolytica II® ELISA kit. All 456 samples were negative for the presence of the adhesin E. histolytica specific antigen. The evidence suggests that in this community E. histolytica is absent and E. dispar is the dominant species.
A prevalência mundial de Entamoeba histolytica não está bem estabelecida. Este fato deve-se à complicação derivada da existência de duas espécies morfologicamente idênticas, mas geneticamente diferentes: a E. histolytica que causa amebíases e a E. dispar descrita como não patogênica. No Brasil, em comunidades com precárias condições sanitárias e endêmicas para várias parasitoses, localizadas nas regiões Sudeste (SE) e Nordeste (NE), somente E. dispar tem sido encontrada, porém outras regiões, apresentam indivíduos infectados por E. histolytica. Na região agreste do Estado da Paraíba (NE) que apresenta as mesmas precárias condições sanitárias, não tem sido reportada prevalência específica destes parasitos, embora fosse encontrada alta prevalência do complexo E. dispar/E. histolytica em crianças em favela urbana. O presente estudo foi realizado em favela da cidade de Campina Grande, Estado da Paraíba, onde 1.195 crianças de dois a 10 anos sem sintomatologia foram examinadas. Amostras de fezes destas crianças foram analisadas microscopicamente, encontrando-se 553 positivas para o complexo E. dispar/E. histolytica. Do total de amostras positivas, 456 foram submetidas à pesquisa do antígeno especifico para E. histolytica pelo teste ELISA E. histolytica II®,obtendose resultado negativo para a presença do antígeno adesina específico de E. histolytica, em todas as amostras testadas. Os resultados sugerem que nesta comunidade não há infecção por E. histolytica, e que E. dispar é a espécie dominante na região.
Assuntos
Criança , Pré-Escolar , Humanos , Lactente , Antígenos de Protozoários/sangue , Entamoeba histolytica/imunologia , Entamebíase/epidemiologia , Brasil/epidemiologia , Ensaio de Imunoadsorção Enzimática , Entamoeba/imunologia , Entamebíase/diagnóstico , Fezes/parasitologia , Áreas de Pobreza , Prevalência , Especificidade da Espécie , População UrbanaRESUMO
INTRODUCTION: This study evaluated the frequency of intestinal parasites, emphasizing the identification and differentiation of Entamoeba spp. METHODS: Multiplex polymerase chain reaction (PCR), coproantigen tests and morphometric analysis were performed for Entamoeba spp. differentiation. RESULTS: The overall frequency of intestinal parasites was 65%. Entamoeba histolytica was detected by the coproantigen test, and the PCR showed that Entamoeba dispar predominated in the population. In contrast, morphometric analysis was important for identifying Entamoeba hartmanni. CONCLUSIONS: It is possible to identify the causative agent of amoebiasis and to differentiate this agent from other species by combining techniques.
Assuntos
Entamoeba/classificação , Entamebíase/epidemiologia , Fezes/parasitologia , Adolescente , Adulto , Brasil/epidemiologia , Criança , Pré-Escolar , DNA de Protozoário/análise , Entamoeba/genética , Entamoeba/imunologia , Entamebíase/diagnóstico , Entamebíase/parasitologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex , Adulto JovemRESUMO
Introduction: This study evaluated the frequency of intestinal parasites, emphasizing the identification and differentiation of Entamoeba spp. Methods: Multiplex polymerase chain reaction (PCR), coproantigen tests and morphometric analysis were performed for Entamoeba spp. differentiation. Results: The overall frequency of intestinal parasites was 65%. Entamoeba histolytica was detected by the coproantigen test, and the PCR showed that Entamoeba dispar predominated in the population. In contrast, morphometric analysis was important for identifying Entamoeba hartmanni. Conclusions: It is possible to identify the causative agent of amoebiasis and to differentiate this agent from other species by combining techniques. .
Assuntos
Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Entamoeba/classificação , Entamebíase/epidemiologia , Fezes/parasitologia , Brasil/epidemiologia , DNA de Protozoário/análise , Ensaio de Imunoadsorção Enzimática , Entamoeba/genética , Entamoeba/imunologia , Entamebíase/diagnóstico , Entamebíase/parasitologia , Reação em Cadeia da Polimerase MultiplexRESUMO
The influence of inflammation on the number of trophozoites and on the murine amoebic liver abscess area following infection with Entamoeba histolytica and E. dispar was evaluated. Immunohistochemistry and digital morphometry were used to identify and quantify the trophozoites, neutrophils, macrophages, and lesions. Positive correlation was observed between the number of trophozoites and inflammatory cells. A significant decrease in parasitism and inflammation in groups treated with dexamethasone was observed. The scarceness or absence of trophozoites in the treated groups suggest the importance of the inflammatory response in the production of amoebic hepatic abscesses in spite of the inherent virulence of the parasite being decisive in the establishment of the lesion.
Assuntos
Entamoeba/imunologia , Entamoeba/patogenicidade , Interações Hospedeiro-Parasita , Inflamação/patologia , Abscesso Hepático Amebiano/imunologia , Abscesso Hepático Amebiano/patologia , Fígado/patologia , Animais , Anti-Inflamatórios/administração & dosagem , Biometria , Dexametasona/administração & dosagem , Imuno-Histoquímica , Inflamação/imunologia , Fígado/parasitologia , Camundongos , MicroscopiaRESUMO
The reptilian parasite Entamoeba invadens is accepted as a model for the study of the Entamoeba encystation process. Here we describe the production and characterization of a mAb (B4F2), generated against a component of the E. invadens cyst wall. This mAb specifically recognizes a 48-kDa protein present in cytoplasmic vesicles of cells encysting for 24 h. In mature cysts (96 h), the antigen was detected on the cyst surface. By two-dimensional electrophoresis and mass spectrometry analysis, the B4F2 specific antigen was identified as enolase. Levels of enolase mRNA were increased in encysting cells and the B4F2 mAb was found to inhibit cyst formation. Therefore, these results strongly suggest a new role for enolase in E. invadens encystation, and the B4F2 mAb will be useful tool to study its role in the differentiation process.
Assuntos
Entamoeba/fisiologia , Fosfopiruvato Hidratase/fisiologia , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/imunologia , Western Blotting , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Entamoeba/enzimologia , Entamoeba/crescimento & desenvolvimento , Entamoeba/imunologia , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Hibridomas , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos BALB C , Fosfopiruvato Hidratase/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Trofozoítos/imunologia , Trofozoítos/fisiologiaRESUMO
Amebiasis is an infection caused by Entamoeba histolytica. However, differentiation between E. histolytica and Entamoeba dispar, which are morphologically identical species, is essential for treatment decision, precaution of the invasive disease and public health. The purpose of the present study was to evaluate a Multiplex -PCR for detection and differentiation of E. histolytica from E. dispar from fresh stool samples in comparison with the coproantigen commercial ELISA. Microscopic examination of stools using the Coprotest method, detection of stool antigen by enzyme-linked immunosorbent assay kit and a home made Multiplex-PCR, were used for the diagnosis of amoebiasis infection. Analysis of the 127 stools samples by microscopy examination demonstrated that only 27 (21%) samples were positive for E. histolytica/E. dispar complex. Among these stool samples, 11 were positive by Multiplex-PCR, with nine presenting the diagnostic fragment characteristic of E. dispar (96 bp) and two presenting diagnostic fragment of E. histolytica (132 bp). Among negative samples detected by microscopic examination, three positive samples for E. dispar and one positive for E. histolytica by Multiplex-PCR was observed. This denotes a low sensibility of microscopic examination when a single stool sample is analyzed. Assay for detection of E. histolytica antigen was concordant with multiplex-PCR in relation to E. histolytica. Statistical analysis comparing the sensibility tests was not done because of the low number of E. histolytica cases. The results demonstrate the importance of the specific techniques use for the differentiation between E. histolytica and E. dispar.
Assuntos
DNA de Protozoário/análise , Entamoeba histolytica/genética , Entamebíase/diagnóstico , Fezes/parasitologia , Reação em Cadeia da Polimerase/métodos , Animais , Antígenos de Protozoários/análise , DNA de Protozoário/genética , Diagnóstico Diferencial , Entamoeba/genética , Entamoeba/imunologia , Entamoeba/isolamento & purificação , Entamoeba histolytica/imunologia , Entamoeba histolytica/isolamento & purificação , Entamebíase/parasitologia , Humanos , Técnicas Imunoenzimáticas , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Amebiasis is an infection caused by Entamoeba histolytica. However, differentiation between E. histolytica and Entamoeba dispar, which are morphologically identical species, is essential for treatment decision, precaution of the invasive disease and public health. The purpose of the present study was to evaluate a Multiplex -PCR for detection and differentiation of E. histolytica from E. dispar from fresh stool samples in comparison with the coproantigen commercial ELISA. Microscopic examination of stools using the Coprotest method, detection of stool antigen by enzyme-linked immunosorbent assay kit and a home made Multiplex-PCR, were used for the diagnosis of amoebiasis infection. Analysis of the 127 stools samples by microscopy examination demonstrated that only 27 (21 percent) samples were positive for E. histolytica/E. dispar complex. Among these stool samples, 11 were positive by Multiplex-PCR, with nine presenting the diagnostic fragment characteristic of E. dispar (96 bp) and two presenting diagnostic fragment of E. histolytica (132 bp). Among negative samples detected by microscopic examination, three positive samples for E. dispar and one positive for E. histolytica by Multiplex-PCR was observed. This denotes a low sensibility of microscopic examination when a single stool sample is analyzed. Assay for detection of E. histolytica antigen was concordant with multiplex-PCR in relation to E. histolytica. Statistical analysis comparing the sensibility tests was not done because of the low number of E. histolytica cases. The results demonstrate the importance of the specific techniques use for the differentiation between E. histolytica and E. dispar.
Assuntos
Animais , Humanos , DNA de Protozoário/análise , Entamoeba histolytica/genética , Entamebíase/diagnóstico , Fezes/parasitologia , Reação em Cadeia da Polimerase/métodos , Antígenos de Protozoários/análise , Diagnóstico Diferencial , DNA de Protozoário/genética , Entamoeba histolytica/imunologia , Entamoeba histolytica/isolamento & purificação , Entamoeba/genética , Entamoeba/imunologia , Entamoeba/isolamento & purificação , Entamebíase/parasitologia , Técnicas Imunoenzimáticas , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Este trabalho teve como objetivo determinar a ocorrência das espécies Entamoeba histolytica/Entamoeba dispar em amostras clínicas de pacientes ambulatoriais de Pernambuco. Neste estudo, foi utilizado o teste imunoenzimático específico para Entamoeba histolytica, que entre os 213 pacientes não identificou nenhuma amostra fecal positiva. Estes resultados confirmam Entamoeba dispar é a espécie dominante nesta região.
The objective this study was to determine the occurrence of the species Entamoeba histolytica/Entamoeba díspar in clinical samples of ambulatory patients in Pernambuco. A specific assay for Entamoeba histolytica was used in this study, which identified no positive fecal samples among the 213 patients. These results confirm that E. dispar is the dominant species in Pernambuco State.
Assuntos
Humanos , Animais , Entamoeba/isolamento & purificação , Entamebíase/diagnóstico , Brasil/epidemiologia , Ensaio de Imunoadsorção Enzimática , Entamoeba histolytica/classificação , Entamoeba histolytica/imunologia , Entamoeba histolytica/isolamento & purificação , Entamoeba/classificação , Entamoeba/imunologia , Entamebíase/epidemiologia , Entamebíase/parasitologia , Fezes/parasitologiaRESUMO
We analyzed the expression and location of EhRabB in clone L-6, a phagocytosis-deficient mutant of Entamoeba histolytica, in comparison with the wild-type clone A. Intriguingly, trophozoites of clone L-6 express more EhRabB than those of clone A. However, the majority of EhRabB-containing vesicles remained in the cytoplasm of clone L-6 during phagocytosis. To investigate molecular alterations in EhRabB of clone L-6 we compared the EhrabB gene sequences from clones L-6 and A. We also isolated, sequenced and compared the RabB protein of Entamoeba dispar. Results showed that EhrabB gene of clone L-6 is 98.2 and 94.1% identical to rabB genes of E. dispar and clone A, respectively. The rabB genes from clone A and E. dispar have 92.2% identity. Four out of five amino acids changes in RabB proteins of clone L-6 and E. dispar are shared. These changes may alter the binding of effector proteins and the specific subcellular location of EhRabB.
Assuntos
Entamoeba histolytica/química , Fagocitose/fisiologia , Proteínas rab de Ligação ao GTP/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , DNA Complementar/química , DNA de Protozoário/química , Densitometria , Eletroforese em Gel de Poliacrilamida , Entamoeba/química , Entamoeba/genética , Entamoeba/imunologia , Entamoeba histolytica/genética , Entamoeba histolytica/imunologia , Dados de Sequência Molecular , Mutação , Fagocitose/genética , RNA Mensageiro/genética , RNA Mensageiro/isolamento & purificação , RNA de Protozoário/genética , RNA de Protozoário/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas rab de Ligação ao GTP/química , Proteínas rab de Ligação ao GTP/fisiologiaRESUMO
Previous studies using methods varying from traditional serologic tests to molecular biology techniques have shown that in northeastern Brazil, Entamoeba dispar was more prevalent than E. histolytica. In this study, the prevalence was established by using E. histolytica stool antigen detection kits and a polymerase chain reaction (PCR) with genomic DNA extracted from cultured trophozoites in all four-nuclei, amoeba-positive samples from a population living in Macaparana in northeastern Brazil. Among 1,437 stool samples analyzed, only 59 (4.1%) were positive for four nuclei amoeba. However, all of these samples were negative in an immunoenzymatic assay for the presence of E. histolytica-specific galactose adhesin. Of 59 cultivated samples, only 31 showed trophozoites. Extraction of DNA from these 31 samples, followed by the PCR, showed that 23 samples (74.19%) were positive for E. dispar and no amplification was observed for pathogenic E. histolytica. The remaining eight samples were negative for both species. These findings are consistent with those previously reported.
Assuntos
DNA de Protozoário/análise , Entamoeba histolytica/isolamento & purificação , Entamoeba/isolamento & purificação , Entamebíase/epidemiologia , Fezes/parasitologia , Animais , Antígenos de Protozoários/análise , Brasil/epidemiologia , Entamoeba/genética , Entamoeba/imunologia , Entamoeba histolytica/genética , Entamoeba histolytica/imunologia , Entamebíase/parasitologia , Humanos , Reação em Cadeia da Polimerase , PrevalênciaRESUMO
To correlate a particular state of immunity with Entamoeba spp., we used colorimetric PCR to differentiate E. histolytica from E. dispar in individuals with amoebiasis and to associate its presence with the clinical profile, including humoral and cellular immune responses to E. histolytica. Our results showed high levels of antibody in acute amoebiasis and elevation of IL-4 production, a cytokine related to Th2 profile, associated with E. histolytica. In chronic amoebiasis, even with anti-E. histolytica seropositivity, intestinal symptoms were associated with E. dispar in all the cases, without differences in level of antibodies, BTI, CD4+/CD8+ ratio, INF-gamma, and IL-4. Among asymptomatic carriers, E. dispar was more frequently found; however, identification of E. histolytica in two asymptomatic carriers associated with high levels of INF-gamma, a cytokine related to Th1 profile, demonstrate the importance of making specific diagnosis of Entamoeba spp., to establish the clinical and epidemiological behavior in both intestinal and extra-intestinal amoebiasis.
Assuntos
Entamoeba histolytica/classificação , Entamoeba/classificação , Entamebíase/imunologia , Doença Aguda , Animais , Anticorpos Antiprotozoários/sangue , Formação de Anticorpos , Relação CD4-CD8 , Doença Crônica , Citocinas/sangue , Disenteria Amebiana/imunologia , Disenteria Amebiana/fisiopatologia , Entamoeba/genética , Entamoeba/imunologia , Entamoeba histolytica/genética , Entamoeba histolytica/imunologia , Entamebíase/diagnóstico , Ensaio de Imunoadsorção Enzimática , Humanos , Imunidade Celular , Interferon gama/sangue , Interleucina-4/sangue , México , Reação em Cadeia da Polimerase/métodos , Linfócitos T/imunologia , Fatores de TempoRESUMO
In this study the authors used the Elisa-based antigen detection tests that distinguish E. histolytica from E. dispar to examine the prevalence of E. histolytica infection in individuals from an urban slum in Fortaleza, Northeastern, Brazil. This test has a sensitivity and specificity that is comparable to PCR and isoenzyme analysis, which is the gold standard. Single stools samples were obtained from 735 individuals. The prevalence of E. histolytica infection was 14.9% (110/735) and 25.4%(187/735) for E. dispar-E. histolytica complex. The most affected age group for E. histolytica /E. histolytica-E. dispar infection was the 1-5 year olds but there was no remarkable decrease with age. There was no significant difference in colonization rates between males and females. The results from this survey demonstrate that E. histolytica is highly prevalent in the Community studied. Furthermore, it offers promise for the antigen detection test as a sensitive and technically simple tool for detecting E. histolytica infection in the field.
Assuntos
Anticorpos Monoclonais , Anticorpos Antiprotozoários/imunologia , Disenteria Amebiana/diagnóstico , Entamoeba/imunologia , Entamebíase/diagnóstico , Adolescente , Adulto , Animais , Brasil , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Áreas de Pobreza , População UrbanaAssuntos
Antígenos de Protozoários/imunologia , Portador Sadio/imunologia , Entamoeba histolytica/imunologia , Entamoeba/imunologia , Antígenos HLA/análise , Adolescente , Adulto , Animais , Portador Sadio/parasitologia , Estudos de Casos e Controles , Entamoeba/crescimento & desenvolvimento , Entamoeba histolytica/crescimento & desenvolvimento , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
A quantitative study on digestion of erythrocytes by Entamoeba invadens was attempted. Trophozoites of the IP-1 strain were fed red blood cells for 30 min, and subsequently phagocytosis was stopped by means of osmotic shock; post-phagocytosis incubations for up to 15 h were made in order to evaluate intracellular digestion, after staining the red blood cells with benzidine. Eighty-two per cent of trophozoites were capable of phagocytosing erythrocytes, containing an average of 5.5 erythrocytes per amoeba. Erythrocyte digestion within amoebae was shown by loss of benzidine-stainable material and proceeded with a first-order kinetics, with a t1/2 approximately 7 h. Within 15 h there were no amoebae containing erythrocytes. The procedure described may be useful for the evaluation of intracellular digestion in other Entamoeba species.