Constitutive and Inducible Expression of Green Fluorescent Protein in Brucella suis

A gene fusion system based on plasmid pBBR1MCS and the expression of green fluorescent protein was developed for Brucella suis, allowing isolation of constitutive and inducible genes. Bacteria containing promoter fusions of chromosomal DNA to gfp were visualized by fluorescence microscopy and examined by flow cytometry. Twelve clones containing gene fragments induced inside J774 murine macrophages were isolated and further characterized.