Infection Prevention and Control

Salmonella enterica is a Gram-negative bacterium responsible of salmonellosis, a gastrointestinal infection that causes 550 million cases each year, from which 220 million are children less than 5 years. In fact, S. enterica is one of four major etiological agent of diarrhea; worldwide. To cause infection, this bacterium contains a lot of virulence factors such as capsule, lipopolysaccharide, enterotoxins, and the capacity to forms biofilms. It has been reported that biofilm structure protects Salmonella from immune system cells and antibiotics action. Therefore, the development of new antimicrobials and anti-biofilms agents to combat salmonellosis are needed. In this work, we investigated the bactericide and biofilmicide effect of bLF and the peptides Lactoferricin17-30, D-Lactoferricin17-30, Lactoferrampin265-284, D-Lactoferrampin265-284 and LFchimera on Salmonella enterica. Materials and Methods: Strains of Salmonella enterica were incubated with bLF, LFcin17-30, D-LFcin17-30, LFampin265-284, D- LFampin265-284, LFchimera and gentamicin in different concentrations during 2 h. Then, the viability of cultures was assessed by determination of colony forming unit/ml. To form biofilms, strains of Salmonella were incubated for 12 (mature) or 8 (immature), and then; biofilms were treated with bLF, LFcin17-30, D-LFcin17-30, LFampin265-284, D-LFampin265-284, and LFchimera, during 4 and 6 h. The effect of treatment on biofilms was assessed by colony counts (CFU/ ml) and by Live/dead biofilms vitality kit. In addition; biofilms were visualized by florescence microscopy and fluorescence was measured. Results: bLF and synthetic peptides shown bactericide effect on salmonella, but bLF and LFchimera presented a greater effect. On the other hand bLF and LFchimera affected immature biofilms, but only bLF disrupted mature and established biofilms. Based in our results LF and LFchimera are alternative approaches that could prevent Salmonella colonization of the human host and perhaps against salmonellosis.