USE OF BACTERIOPHAGES TO CONTROL Salmonella Enteritidis IN FECAL FERMENTATION

Salmonella Enteritidis (SE) is one of the main serovar of Salmonella enterica involved in foodborne infections. When intestinal infection by SE requires treatments using antimicrobial, cases can be aggravated if the cause bacteria are resistant to the drugs used. A possible alternative to control these antimicrobial resistant bacteria is phagotherapy, which is characterized by the use of bacteriophages that will lead to the lysis of the target bacteria. The objective was to evaluate the in vitro efficacy of a bacteriophage cocktail for the inactivation of  SE in fecal fermentation. Fecal samples were collected from healthy donors and the fecal fermentation preparation was carried out. For the tests, a pool with three different SE isolates was used, and the bacteriophage cocktail was elaborated with the phages UPF_BP1, UPF_BP2 and UPF_BP3. Four different treatments were evaluated: the group called ASF, where the action of the bacteriophage cocktail against a pool of SE in fecal fermentation was tested; the CP1 group (positive control 1), in which only SE was inoculated in fecal fermentation; the CP2 group (positive control 2), in which the bacteriophage cocktail was inoculated in the fecal fermentation; and the CN group (negative control), containing only fecal fermentation. In all treatments the quantification of SE was performed, and in the ASF group, the quantification of phages was also performed. In the CP1 group there was a growth of 3,76 log10 UFC/mL, while in the ASF group there was a decrease in Salmonella showing 0,77 log10 UFC/mL. The results showed that the use of the bacteriophage cocktail against SE in fecal fermentation was able to reduce the amount of Salmonella in the sample. Despite not showing a significant difference (p=0.059), this in vitro sudy demonstrates the ability of phages to act against Salmonella in fecal fermentation, bringing positive evidence that corroborates the continuity of the study for future uses of phage therapy.