Ligands affecting silver antimicrobial efficacy on Listeria monocytogenes and Salmonella enterica

► Silver speciation is crucial to understand its antimicrobial potential. ► Silver ions active at the nanomolar level in optimum conditions. ► Threefold differences between results in different environments. ► Thiol groups completely inactivate silver. ► Silver chloride complexes do not exert an antimicrobial effect.