Mycobacterium-E. coli shuttle vectors pSHKLx1 (encoding a promoted luxAB [V. harveyi] cassette) (A) and pSHKGluc1 (encoding a promoted Gluc luciferase gene from G. princeps) (B). trpA term, terminator sequence; Hygr, hygromycin resistance gene; Kmr, kanamycin resistance gene; ori myc, mycobacterial origin of replication (pAL5000); ori coli, E. coli origin of replication (pUC); Phsp60, promoter from M. tuberculosis hsp60 gene.