Bacterial Gene Expression Technologies

Random integration of the IVET vector into the pathogen chromosome is performed by insertion–duplication mutagenesis to create a pool of recombinant pathogens (this means that the gene in which the vector has inserted by homologous recombination is not disrupted). Recombinants can be selected using antibiotic resistance as an additional marker is also on the integrated IVET construct. Pooled clones are then inoculated into the mouse. The two main types of IVET promoter trap strategies are (a) the complementation of auxotrophic mutation and (b) the expression of antibiotic resistance. Only those bacteria that contain the selective marker fused to a gene that is transcriptionally active in the host are able to survive. After a suitable infection period bacteria that express the marker are isolated from lung liver spleen and mesenteric tissue.