Induction of crossover by introduction of aro554:Tn10 into Salmonella chromosome.

One of the ancient methods for the generation of bacterial mutants was to insert the composite transposable elements (e.g. Tn10) flanked by desired gene sequences, into the bacterial chromosome.

Pre-existing immunity against vaccine vectors--friend or foe?

Over the last century, the successful attenuation of multiple bacterial and viral pathogens has led to an effective, robust and safe form of vaccination. Recently, these vaccines have been evaluated as delivery vectors for heterologous antigens, as a means of simultaneous vaccination against two pathogens. The general consensus from published studies is that these vaccine vectors have the potential to be both safe and efficacious.

Influence of promoter, gene copy number, and preexisting immunity on humoral and cellular responses to a vectored antigen delivered by a Salmonella enterica vaccine.

Attenuated Salmonella strains are currently in production as vaccines for protection of animals against salmonellosis. Such commercial strains offer the potential to deliver heterologous antigen to protect animals against other diseases. One vaccine strain, attenuated Salmonella enterica serovar Typhimurium (STM-1), was tested for the ability to deliver ovalbumin and to induce immune responses in mice.