RESUMO
A polymerase chain reaction (PCR) assay was evaluated for detection of Opisthorchis viverrini eggs in the stool specimens of light and heavily infected individuals in Khon Kaen province of Thailand. A total of 75 fecal specimens were analyzed by PCR following DNA extraction. All the microscopically positive samples were positive by PCR, while 23 of 30 (76.6%) microscopically negative samples were also PCR positive. The sensitivity of the assay was 5 eggs/g of stool. This method is potentially useful in the diagnosis of human opisthorchiasis in endemic areas for treatment and in epidemiological investigations.
Assuntos
DNA de Helmintos/isolamento & purificação , Fezes/parasitologia , Opistorquíase/diagnóstico , Opisthorchis/isolamento & purificação , Reação em Cadeia da Polimerase , Animais , Feminino , Humanos , Masculino , Opistorquíase/parasitologia , Opisthorchis/genética , Óvulo , Contagem de Ovos de Parasitas , Sensibilidade e EspecificidadeRESUMO
Human opisthorchiais caused by the liver fluke Opisthorchis viverrini is a major fish-borne trematode infection endemic in the Southeast Asian countries. The infection is acquired through consumption of raw fish harboring metacercariae of O. viverrini. Owing to potential risk of transmission of opisthorchiasis through fish trade, rapid and reliable detection methods have gained importance to ensure food safety. In the study described here, we report successful development and evaluation of a polymerase chain reaction (PCR) assay for the detection of O. viverrini, based on the nucleotide sequence derived in this study. The assay is specific with no cross-reaction with other trematodes commonly found in fish including the closely related species, Clonorchis sinensis. The sensitivity of the assay was determined to be 10(-12)ng of O. viverrini DNA while in artificially spiked fish meat, 3 metacercariae could be detected. The results suggest that the PCR method described here is specific to O. viverrini with potential application in fish quarantining.
Assuntos
Doenças dos Peixes/diagnóstico , Doenças dos Peixes/parasitologia , Opistorquíase/veterinária , Opisthorchis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Animais , Sequência de Bases , Primers do DNA/genética , DNA de Helmintos/química , DNA de Helmintos/genética , Eletroforese em Gel de Ágar , Peixes , Dados de Sequência Molecular , Opistorquíase/diagnóstico , Opistorquíase/parasitologia , Opisthorchis/genética , Sensibilidade e Especificidade , Análise de Sequência de DNARESUMO
The prevalence of human enteric viruses in bivalve molluscan shellfish and shrimp collected off the south west coast of India was studied to assess the extent of fecal pollution of coastal environment. Out of 194 samples analyzed, 37% of oyster, 46% of clam and 15% of shrimp samples were positive for enteroviruses (EV). Adenoviruses (ADV) were detected in 17% of oyster and 27% of clam samples. However, other enteric viruses such as noroviruses (NoV) and hepatitis A virus (HAV) were not detected in any of the samples. High prevalence of EV and ADV was noticed between May to December. Thirty four percent of oyster and 49% of clam samples showed fecal coliform values higher than the limit. MS-2 phage was detected in 57% of oyster and 73% of clam samples. The presence of MS-2 phage and human enteric viruses showed association while fecal coliforms and enteric viruses showed no association. However, 17 samples, which were positive for enteric viruses (EV and ADV), were negative for MS-2 phage.
