RESUMEN

Bacille Calmette-Guérin (BCG) vaccines are live attenuated strains of Mycobacterium bovis administered to prevent tuberculosis. To better understand the differences between M. tuberculosis, M. bovis, and the various BCG daughter strains, their genomic compositions were studied by performing comparative hybridization experiments on a DNA microarray. Regions deleted from BCG vaccines relative to the virulent M. tuberculosis H37Rv reference strain were confirmed by sequencing across the missing segment of the H37Rv genome. Eleven regions (encompassing 91 open reading frames) of H37Rv were found that were absent from one or more virulent strains of M. bovis. Five additional regions representing 38 open reading frames were present in M. bovis but absent from some or all BCG strains; this is evidence for the ongoing evolution of BCG strains since their original derivation. A precise understanding of the genetic differences between closely related Mycobacteria suggests rational approaches to the design of improved diagnostics and vaccines.

Asunto(s)

Vacuna BCG/genética , Eliminación de Gen , Genoma Bacteriano , Mycobacterium bovis/genética , Mycobacterium tuberculosis/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Vacuna BCG/inmunología , ADN Bacteriano/genética , Evolución Molecular , Variación Genética , Humanos , Mycobacterium bovis/inmunología , Mycobacterium bovis/patogenicidad , Mycobacterium tuberculosis/inmunología , Mycobacterium tuberculosis/patogenicidad , Hibridación de Ácido Nucleico , Sistemas de Lectura Abierta , Reacción en Cadena de la Polimerasa , Vacunas Atenuadas , Virulencia