Chromosomal Complementation Using Tn 7 Transposon Vectors in Enterobacteriaceae

Abstract

Genetic complementation in many bacteria is commonly achieved by reintroducing functional copies of the mutated or deleted genes on a recombinant plasmid. Chromosomal integration systems using the Tn 7 transposon have the advantage of providing a stable single-copy integration that does not require selective pressure. Previous Tn 7 systems have been developed, although none have been shown to work effectively in a variety of enterobacteria. We have developed several mini-Tn 7 and transposase vectors to provide a more versatile system. Transposition of Tn 7 at the chromosomal att Tn 7 site was achieved by a classical conjugation approach, wherein the donor strain harbored the mini-Tn 7 vector and the recipient strain possessed the transposase vector. This approach was efficient for five different pathogenic enterobacterial species. Thus, this system provides a useful tool for single-copy complementation at an episomal site for research in bacterial genetics and microbial pathogenesis. Furthermore, these vectors could also be used for the introduction of foreign genes for use in biotechnology applications, vaccine development, or gene expression and gene fusion constructs.