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Modulación de la virulencia dentro de una isla de patogenicidad en el Enterococcus faecalis resistente a la
Nathan Shankar1, Arto S Baghdayan, Michael S Gilmore
1nathan-shankar@ouhsc.eduDepartment of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, PO Box 26901, Oklahoma City, Oklahoma 73190, USA.
Nature
|June 18, 2002
Resumen
Los investigadores descubrieron una gran isla de patogenicidad en Enterococcus faecalis, una bacteria intestinal común. Este elemento genético, que varía sutilmente entre las cepas, ayuda a modular la virulencia e identifica nuevos objetivos de enfermedades que no son esenciales para la función intestinal normal.
Área de la Ciencia:
- Microbiología Microbiología.
- La genómica es la genómica.
- Enfermedades infecciosas Enfermedades infecciosas.
Sus antecedentes:
- Los enterococos son parte de la flora intestinal normal del hombre.
- También son una causa importante de infecciones adquiridas en el hospital, a menudo resistentes a los antibióticos.
- Investigaciones anteriores no habían identificado islas de patogenicidad en este género.
Objetivo del estudio:
- Para investigar la base genética de la virulencia en Enterococcus faecalis.
- Identificar nuevos factores de virulencia y posibles objetivos terapéuticos.
Principales métodos:
- Secuenciación del genoma de dos cepas distintas de Enterococcus faecalis (cepa de brote hospitalario y primer aislamiento resistente a la vancomicina de los Estados Unidos).
- Análisis genómico comparativo para identificar elementos genéticos únicos.
- Análisis de la estructura y la variación dentro de la isla de patogenicidad identificada.
Principales resultados:
- Un gran (aprox. 150 kb) se identificó una isla de patogenicidad en ambas cepas, previamente desconocida en Enterococci.
- Esta isla tiene un menor contenido de G + C y está flanqueada por repeticiones terminales.
- Las variaciones sutiles y de alta frecuencia dentro de la isla modulan la virulencia bacteriana.
- La isla contiene factores de virulencia conocidos y nuevos genes raros en aislamientos no patógenos.
Conclusiones:
- La isla de patogenicidad enterocócica es un factor clave en la virulencia.
- Las variaciones en esta isla permiten que las cepas se adapten y causen infecciones.
- Los nuevos genes en la isla representan objetivos potenciales para nuevas terapias antimicrobianas.
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