The effect of bacterial warfare on resistance in Salmonella. Towards a more optimal selection of Live Microbial Formulations.
Due to the over- and misuse of antibiotics over the past decades, resistant pathogens withstanding antibiotic treatments are on the rise. A trend of increasing drug resistance has also been observed for non-typhoidal Salmonella, which is one of the primary causes of foodborne disease and has the highest disease burden among enteropathogens. Since the prevalence of antibiotic (multi-)resistant Salmonella species is increasing, alternative strategies to combat Salmonella infections are urgently needed. It is generally believed that the intake of certain Live Microbial Formulations (LMF) (a term that comprises probiotics, next-generation probiotics and live biotherapeutic products) may prevent (and/or hamper) Salmonella infections, as well as other enteropathogenic infections. However, certain mechanisms through which LMF strains and antibiotics act, are in many ways resembling. This raises the concern that certain antibiotic-resistant mechanisms in Salmonella might provide cross-protection against the modes of action of LMF strains, rendering such reatments ineffective. Maybe even more problematic, continuous use of LMF strains may cause Salmonella to evolve resistance mechanisms against the LMF, that could potentially also cross-protect them against antibiotics. This study attempts to elucidate underlying mechanisms for resistance development in relation to the presence of different LMF strains. The ultimate goal is to select certain LMF strains that (i) have a high activity against antibiotic-resistant Salmonella strains and (ii) show a promising outlook on reducing the antibiotic resistance development in sensitive Salmonella strains.