Vector construction and triclosan selection. (A) The bla gene in pUC19, which confers ampicillin resistance, was replaced with fabI and its promoter region (pFab). The pUC19 multiple cloning site (MCS) is retained, however HincII, HindIII and PstI are not unique in pFab. The fabI cassette in pFab can be transferred to other pUC-derived plasmids using the AatII and AlwNI restriction sites. The fabI cassette was also inserted into the MCS of pUC19 to obtain pUCFA. All plasmids are available from the authors. (B) Growth of pFab and pUCFA clones on LBT and LBA plates. (C) Plasmids propagated in different E. coli hosts were digested with BamHI and analyzed by gel electrophoresis.