PCR-based quantitation of transfected luciferase DNA: evaluation using an Entamoeba histolytica reporter construct.

pseudomallei. In conclusion, we have constructed a Tp resistance cassette vector termed p34E-Tp. The Tp resistance cassette is small (ca. 600 bp) and may be useful as an alternative selective marker for cassette mutagenesis of cloned genes and gene replacement experiments. This cassette was used to construct the small (5.3-kb) broad-host-range plasmid pBBR1Tp. This plasmid contains all the characteristics of pBBR1MCS (medium copy number, mobilizable, 15 unique cloning sites, blue/white screening for recombinants and compatibility with multiple plasmid replicons) with the advantage of having the Tp resistance marker for use in bacteria that are naturally resistant to antibiotics commonly used as selective pressure for plasmid acquisition and maintenance. Third generation cephalosporins are the preferred treatment for individuals with B. cepacia or B. pseudomallei infections and Tp is no longer the first choice in the treatment of these bacterial infections. However, as with other broad-host-range recombinant plasmids conferring resistance to antibiotics, strains containing pBBR1MCS should be properly disposed of by autoclaving after use.