Salmonellosis continues to be an important health problem for humans and animals, worldwide. In fact, infections due to Salmonella spp. account for the most common foodborne zoonoses in Europe and North America and remain a prominent cause of invasive infections in different farm animals.
It is beyond any reasonable doubt that the elective strategy to control and eradicate salmonellosis in farm animals relies on high standard of hygienic practices accompanied by testing and removal of positive animals. Nevertheless, it is important to highlight that these measures require high costs and an integrated approach to be really effective. Therefore, it is possible to hypothesize ancillary approaches to improve such strategy. On that account, vaccination can represent a valuable strategy.
In the past years, we performed several experiments to assess safety and efficacy of an attenuated strain of Salmonella enterica serovar Typhimurium devoid of the operon ZnuABC (S.Typhimurium ΔZnuABC). Our results provided scientific evidence that S.Typhimurium ΔZnuABC is attenuated, safe and protective either in mouse or pig models of salmonella infections. More lately, we tested the protective effect of S.Typhimurium ΔZnuABC versus a pig model of salmonellosis due to S.Choleraesuis. We found that S.Typhimurium ΔZnuABC reduces clinical signs of S.Choleraesuis and the colonization of virulent strain in different organs.
As a whole, these findings suggest that S.Typhimurium ΔZnuABC is a very promising vaccine strain to be used in the field under different conditions (oral and/or parenteral delivery) to tackle pig salmonellosis induced by homologous or heterologous serovars.