RESUMO
ABSTRACT We developed a loop-mediated isothermal amplification (LAMP) assay for the detection of Y. pestis by targeting the 3a sequence on chromosome. All 11 species of the genus Yersinia were used to evaluate the specificity of LAMP and PCR, demonstrating that the primers had a high level of specificity. The sensitivity of LAMP or PCR was 2.3 or 23 CFU for pure culture, whereas 2.3 × 104 or 2.3 × 106 CFU for simulated spleen and lung samples. For simulated liver samples, the sensitivity of LAMP was 2.3 × 106 CFU, but PCR was negative at the level of 2.3 × 107 CFU. After simulated spleen and lung samples were treated with magnetic beads, the sensitivity of LAMP or PCR was 2.3 × 103 or 2.3 × 106 CFU, whereas 2.3 × 105 or 2.3 × 107 CFU for magnetic bead-treated liver samples. These results indicated that some components in the tissues could inhibit LAMP and PCR, and liver tissue samples had a stronger inhibition to LAMP and PCR than spleen and lung tissue samples. LAMP has a higher sensitivity than PCR, and magnetic bead capture of DNAs could remarkably increase the sensitivity of LAMP. LAMP is a simple, rapid and sensitive assay suitable for application in the field or poverty areas.
Assuntos
Humanos , Peste/microbiologia , DNA Bacteriano/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Magnetismo/métodos , Yersinia pestis/isolamento & purificação , Yersinia pestis/classificação , Yersinia pestis/genética , DNA Bacteriano/isolamento & purificação , DNA Bacteriano/química , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Separação Imunomagnética , Primers do DNA/genética , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Magnetismo/instrumentaçãoRESUMO
Accidental ingestion of foreign bodies in childhood is an increasing problem. Although many of them can be treated with an expectant approach, allowing their passage through the gastrointestinal tract, magnets must be extracted, due to their high rate of complications, such as perforation. We report three patients that ingested magnets. A five year-old male was operated with an extensive ulceration of the jejunum, where a cylindrical magnet was extracted. A four year-old female was operated with a perforation of the anterior wall of the stomach and three magnets were extracted from the peritoneal cavity. A four year-old female, was transferred from a hospital where she had been operated for a magnet ingestion that provoked three perforations in the small bowel.