Construction of a Plasmid that Increases the Level of ompA Gene Expression in Escherichia coli for the Study of its Effect on Bacterial Conjugation

Abstract

Conjugation, a mechanism by which bacteria exchange their genetic materials, is of great importance due to its implication in horizontal gene transfer and adaptation. The outer membrane protein A (OmpA) present on the conjugation recipient cell has previously been shown to be essential in transfer of F plasmid. The goal of this study was to construct a plasmid that could increase the level of ompA expression in the conjugation recipient χ strains, Escherichia coli 2320 and 478. This plasmid could be transformed into the recipient cells for the further investigaton of how ompA expression affects the conjugation efficiency. Primers were designed for the amplification of ompA by Polymerase Chain Reaction and for the subsequent cloning of ompA into pCR2.1-TOPO vector using TOPO TA Cloning system. The resulting plasmid was named pCCK06-1 and was successfully χ isolated and transformed into E. coli 2320 and 478 through electroporation. A control + conjugation between F donor E. coli JCFLOxK1200 strain and the wild-type recipient χ 2320 and 478 strains was shown to be successful. Further conjugation experiments between the donor and transformed recipients could yield results of the effect of increased ompA expression on conjugation efficiency.