RESUMO
Cysticercosis is a worldwide parasitic disease of humans and pigs principally caused by infection with the larvae of the pork tapeworm Taenia solium. Through the use of the recently-made-available T. solium genome, we identified a gene within a novel 1448 bp ORF that theoretically encodes for a 433 amino acid-long protein and predicted to be an α-enolase closely related to enolases of other flatworms. Additional bioinformatic analyses revealed a putative plasminogen-binding region on this protein, suggesting a potential role for this protein in pathogenesis. On this basis, we isolated the mRNA encoding for this presumptive enolase from T. solium metacestodes and reverse-transcribed it into cDNA before subsequently cloning and expressing it in both E. coli (rEnoTs) and insect cells (rEnoTsBac), in a 6xHis tagged manner. The molecular weights of these two recombinant proteins were â¼48 and â¼50â¯kDa, respectively, with the differences likely attributable to differential glycosylation. We used spectrophotometric assays to confirm the enolase nature of rEnoTs as well as to measure its enzymatic activity. The resulting estimates of specific activity (60.000 U/mg) and Km (0.091â¯mM) are quite similar to the catalytic characteristics of enolases of other flatworms. rEnoTs also exhibited high immunogenicity, eliciting a strong polyclonal antibody response in immunized rabbits. We subsequently employed rEnoTsBac for use in an ELISA aimed at discriminating between healthy pigs and those infected with T. solium. This diagnostic assay exhibited a sensitivity of 88.4% (95% CI, 74.92%-96.11%) and a specificity of 83.7% (95% CI: 69.29%-93.19%). In conclusión, this study reports on and enzymatically characterizes a novel enolase from T. solium metacestode, and shows a potential use as an immunodiagnostic for porcine cysticercosis.
Assuntos
Antígenos de Helmintos/imunologia , Cisticercose/veterinária , Fosfopiruvato Hidratase/imunologia , Doenças dos Suínos/diagnóstico , Taenia solium/enzimologia , Sequência de Aminoácidos , Animais , Anticorpos Anti-Helmínticos/biossíntese , Antígenos de Helmintos/química , Antígenos de Helmintos/genética , Antígenos de Helmintos/metabolismo , Biologia Computacional , Intervalos de Confiança , Cisticercose/diagnóstico , DNA Complementar/genética , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Vetores Genéticos , Fosfopiruvato Hidratase/química , Fosfopiruvato Hidratase/genética , Fosfopiruvato Hidratase/metabolismo , Filogenia , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , RNA Mensageiro/genética , RNA Mensageiro/isolamento & purificação , Curva ROC , Coelhos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Sensibilidade e Especificidade , Alinhamento de Sequência , Células Sf9 , Espectrofotometria/veterinária , Suínos , Doenças dos Suínos/parasitologia , Taenia solium/classificação , Taenia solium/genética , Taenia solium/imunologiaRESUMO
BACKGROUND: The recent avian influenza epidemic in Asia and the H1N1 pandemic demonstrated that influenza A viruses pose a threat to global public health. The animal origins of the viruses confirmed the potential for interspecies transmission. Swine are hypothesized to be prime "mixing vessels" due to the dual receptivity of their trachea to human and avian strains. Additionally, avian and human influenza viruses have previously been isolated in swine. Therefore, understanding interspecies contact on smallholder swine farms and its potential role in the transmission of pathogens such as influenza virus is very important. METHODS: This qualitative study aimed to determine swine-associated interspecies contacts in two coastal areas of Peru. Direct observations were conducted at both small-scale confined and low-investment swine farms (n = 36) and in open areas where swine freely range during the day (n = 4). Interviews were also conducted with key stakeholders in swine farming. RESULTS: In both locations, the intermingling of swine and domestic birds was common. An unexpected contact with avian species was that swine were fed poultry mortality in 6/20 of the farms in Chancay. Human-swine contacts were common, with a higher frequency on the confined farms. Mixed farming of swine with chickens or ducks was observed in 36% of all farms. Human-avian interactions were less frequent overall. Use of adequate biosecurity and hygiene practices by farmers was suboptimal at both locations. CONCLUSIONS: Close human-animal interaction, frequent interspecies contacts and suboptimal biosecurity and hygiene practices pose significant risks of interspecies influenza virus transmission. Farmers in small-scale swine production systems constitute a high-risk population and need to be recognized as key in preventing interspecies pathogen transfer. A two-pronged prevention approach, which offers educational activities for swine farmers about sound hygiene and biosecurity practices and guidelines and education for poultry farmers about alternative approaches for processing poultry mortality, is recommended. Virological and serological surveillance for influenza viruses will also be critical for these human and animal populations.
Assuntos
Criação de Animais Domésticos/métodos , Vírus da Influenza A/crescimento & desenvolvimento , Vírus da Influenza A/genética , Recombinação Genética , Zoonoses/transmissão , Animais , Aves , Humanos , Peru , Medição de Risco , SuínosRESUMO
Cystic echinococcosis (CE) caused by the larval form of Echinococcus granulosus is a major public health problem in sheep-raising regions of the World. This study compared portable ultrasound with the enzyme-linked immunoelectrotransfer blot (EITB) assay as screening methods to estimate the prevalence of human CE in a remote village in the Peruvian Andes. Three hundred eighty-nine villagers were examined by portable ultrasound and blood samples were drawn by venipuncture. Sera were collected and tested for antibodies against CE using an EITB assay. Cystic lesions were classified based on their ultrasound morphologic characteristics. The prevalence of human CE using portable ultrasound and the EITB assay were 4.9% and 2.6%, respectively. Fifty-three percent of subjects with CE were EITB positive. Portable ultrasound was well received by the community, augmented CE detection and allowed a faster estimate of human infection than the EITB assay.
Assuntos
Equinococose/diagnóstico , Equinococose/epidemiologia , Echinococcus/isolamento & purificação , Programas de Rastreamento/métodos , Sistemas Automatizados de Assistência Junto ao Leito , Ultrassonografia/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Anti-Helmínticos/sangue , Criança , Equinococose/imunologia , Echinococcus/imunologia , Doenças Endêmicas/prevenção & controle , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peru/epidemiologia , Prevalência , Reprodutibilidade dos Testes , Estudos Soroepidemiológicos , Ultrassonografia/instrumentaçãoRESUMO
An epidemiological study was conducted in a highland rural community in Peru to determine risk factors for canine echinococcosis caused by Echinococcus granulosus. Dogs were diagnosed using a coproantigen enzyme-linked immunosorbent assay (ELISA). Dog owners were interviewed prior to stool collection and asked for attitudes, practices and beliefs likely to be associated with local patterns of E. granulosus transmission. Univariate and multivariate analysis were used to determine odds ratios (OR) and their 95% confidence intervals (CI). The main risk factors found to be significantly associated with canine echinococcosis by univariate analysis were dog age (3-25 months) (OR, 5.14; CI, 1.7-15.7), female sex (OR, 4.3; CI, 1.4-13.3) and having been fed hydatid infected offal (OR, 2.9; 95% CI, 1.0-8.6). There was complete lack of knowledge about echinococcosis transmission. In addition to periodic dog treatment, control programs need to emphasize education of the human population to increase knowledge of parasite transmission and to change human practices associated with high rates of infection.
Assuntos
Coccidiose/epidemiologia , Coccidiose/veterinária , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Echinococcus granulosus/isolamento & purificação , Doenças Endêmicas , Animais , Antígenos de Protozoários/análise , Coccidiose/parasitologia , Coccidiose/transmissão , Doenças do Cão/transmissão , Cães , Ensaio de Imunoadsorção Enzimática/veterinária , Fezes/parasitologia , Feminino , Humanos , Entrevistas como Assunto , Masculino , Análise Multivariada , Peru/epidemiologia , Fatores de Risco , Zoonoses/parasitologiaRESUMO
One hundred and six dogs (61 males and 45 females) were examined for Echinococcus granulosus infection in a farming cooperative in the central highlands of Peru during November 1998. Canine echinococcosis was diagnosed using direct microscopic examinations of purged feces following arecoline purging and a coproantigen-detection enzyme-linked immunosorbent assay (ELISA) for E. granulosus. Mean age was 2 years with a range of 3 months to 9 years. The overall prevalence of canine echinococcosis using the ELISA test was 79% (84/106). Seventy-four dogs were successfully purged with arecoline. The frequency of canine echinococcosis was 82 (61/74) and 34% (25/74) by the coproantigen ELISA test and arecoline purging, respectively. The sensitivity and specificity of the coproantigen ELISA test was 88 and 95%, respectively. We found this assay to be especially advantageous in remote geographical areas. In future control programs against echinococcosis in Peru and other areas where E. granulosus is endemic the coproantigen ELISA should be used for the surveillance of the dog population.
Assuntos
Antígenos de Helmintos/análise , Doenças do Cão/diagnóstico , Equinococose/veterinária , Echinococcus/isolamento & purificação , Ensaio de Imunoadsorção Enzimática/veterinária , Animais , Arecolina/uso terapêutico , Agonistas Colinérgicos/uso terapêutico , Doenças do Cão/tratamento farmacológico , Doenças do Cão/epidemiologia , Cães , Equinococose/diagnóstico , Equinococose/tratamento farmacológico , Equinococose/epidemiologia , Echinococcus/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Fezes/parasitologia , Feminino , Masculino , Peru/epidemiologia , Prevalência , Sensibilidade e EspecificidadeRESUMO
Immunity to Taenia solium infection was investigated using an experimental intramuscular oncosphere infection assay (IMOA) model in pigs. Three naturally infected pigs with cysticercosis were treated with oxfendazole (OFZ), a drug demonstrated to kill cysts in porcine muscle. These animals were then challenged with oncospheres but did not develop any cysts while three uninfected pigs that were similarly challenged, did develop intramuscular cysts. In another study, two groups of three pigs each were immunized with crude T. solium oncosphere and metacestode antigens, respectively, and tested with the IMOA. Immunization with crude oncosphere antigens (OAs) induced 100% protection, while metacestode antigens provided only partial protection. Immunoblots showed that pigs with complete immune protection to oncosphere intramuscular challenge had antibodies to two OAs at 31.3 and 22.5 kDa, respectively. Antibody to these two antigens was absent in pigs immunized with metacestodes or in uninfected control pigs. This study demonstrated the presence of two antigens that are unique to the oncosphere. Although, antibody to these two antigens is consistently present in pigs that are protected from an oncosphere intramuscular challenge their role in preventing infection by T. solium larval cysts is still hypothetical.
Assuntos
Antígenos de Helmintos/imunologia , Cisticercose/veterinária , Imunização/veterinária , Doenças dos Suínos/imunologia , Taenia solium/imunologia , Animais , Anti-Helmínticos/uso terapêutico , Antígenos de Helmintos/administração & dosagem , Benzimidazóis/uso terapêutico , Cisticercose/imunologia , Cisticercose/prevenção & controle , Modelos Animais de Doenças , Injeções Intramusculares/veterinária , Músculos/parasitologia , Suínos , Doenças dos Suínos/parasitologia , Doenças dos Suínos/prevenção & controleAssuntos
Humanos , Animais , Masculino , Feminino , Teníase , Teníase/terapia , Teníase/transmissão , Neurocisticercose/parasitologia , Fenômenos BiológicosRESUMO
Objetivo: describir la frecuencia de los quistes hepáticos no parasitarios y las características clínicas de los pacientes que los presentan. Antecedentes: los quistes hepáticos no parasitarios tienen una frecuencia baja comparados con el resto de la patología hepática y usualmente son asintomáticos. Sólo aquellos de gran tamaño o que se complican presentan manifestaciones clínicas. Material y método: se revisaron los expedientes con este diagnóstico de 1987 a 1997. Resultados: encontramos seis casos, cinco mujeres y un hombre, con edad promedio de 60.3 años, cuyo síntoma más común fue el dolor abdominal. Los signos más comunes fueron dolor a la palpación superficial y profunda, así como tumoración abdominal palpable. El diagnóstico se fundamentó además en ultrasonido, tomografía computarizada de abdomen y colangiografía retrógrada endoscópica. A dos pacientes que tenían comunicación a vía biliar se les realizó derivación interna y al resto drenaje y marsupialización. Conclusión: los quistes hepáticos no parasitarios son raros y evolucionan satisfactoriamente