aStrains (JS846-848) contain a sulA+-lac+ transcriptional fusion. bMid-log LB cultures were split and 10 µg/ml nalidixic acid (Nal) was added to one half. β-galactosidase activity was determined after
aThe nucleotides incorporated to generate restriction sites are indicated in lower case. bPrimers designed based on R. typhi str. Wilmington genome sequence (NCBI acc. no. NC_006142).
