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Un pilus inducible formador de haces de Escherichia coli enteropatogénico
J A Girón1, A S Ho, G K Schoolnik
1Department of Microbiology and Immunology, Beckman Center, Howard Hughes Medical Institute, Stanford University, CA 94305.
Science (New York, N.Y.)
|November 1, 1991
Resumen
Los pili formadores de haces (BFP) son cruciales para que la Escherichia coli enteropatogénica (EPEC) se adhiera al intestino delgado y cause diarrea infantil. Estos pili, codificados en un plásmido de virulencia, son esenciales para la colonización EPEC y la infección.
Área de la Ciencia:
- Microbiología Microbiología.
- La patogénesis y la patogénesis.
- Adherencia bacteriana La adherencia bacteriana es la adherencia bacteriana.
Sus antecedentes:
- El Escherichia coli enteropatogénico (EPEC) es una causa importante de diarrea infantil.
- EPEC coloniza el intestino delgado formando colonias bacterianas adherentes en las células epiteliales.
- Se está investigando el papel de estructuras bacterianas específicas en la virulencia EPEC.
Objetivo del estudio:
- Investigar el papel del pili formador de haces (BFP) en la adherencia y virulencia del EPEC.
- Para caracterizar la expresión y la composición de BFP en EPEC.
- Para determinar la base genética para la expresión de BFP.
Principales métodos:
- Cultivo de EPEC en medios sólidos y células HEp-2.
- Experimentos de curación con plásmido para evaluar la expresión de BFP.
- Producción de antiserum y pruebas contra la infección EPEC.
- Análisis de subunidades de proteínas y secuenciación amino-terminal.
Principales resultados:
- EPEC expresa haces de filamentos similares a cuerdas, denominados BFP, cuando se cultivan en agar sanguíneo o células HEp-2.
- La expresión de BFP se observó en cinco serogrupos EPEC, todos con un plásmido de virulencia de ~ 92 kilobases.
- Las cepas curadas del plásmido perdieron la expresión de BFP y el crecimiento adherente.
- El antiserum contra BFP inhibió la capacidad de EPEC para infectar las células epiteliales cultivadas.
- La subunidad BFP (19.500 daltones) muestra homología amino-terminal con la toxina corregida de Vibrio cholerae pilin.
Conclusiones:
- Los pili formadores de haces (BFP) son factores esenciales de virulencia para la Escherichia coli enteropatógena (EPEC).
- BFP media la adherencia bacteriana a las células epiteliales del huésped, contribuyendo a la patogénesis EPEC.
- La expresión de BFP depende de un plásmido de virulencia específico, destacando su base genética.
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