New Approaches to the Treatment of Drug-Resistant Bacteria

Today, the treatment of infectious diseases is getting more difficult every day due to increasing drug resistance against microorganisms. In order to overcome the increasing drug resistance globally, a wide variety of studies are carried out on probiotic microorganisms. In this study, we aimed to investigate the synergistic activities of the bioactive components of L. casei and S. thermophilus probiotic microorganisms against ESBL-positive E. coli and K. pneumoniae strains against these two microorganisms. The non-toxic concentrations of L. casei and S. thermophilus bioactive components in Vero cell culture were determined. Antibacterial activities against ESBL-positive E. coli and K. pneumoniae at determined non-toxic concentrations were evaluated by studying MIC and MBC concentrations. Firstly, non-cytotoxic concentrations of bioactive metabolites of S. thermophilus and L. casei were determined on Vero cells. It has been determined that the bioactive metabolites of both S. thermophilus and L. casei cause toxicity of <32 µg/ml. For this reason, studies have been studied at levels lower than this concentration for antimicrobial efficacy studies. Antimicrobial activities of L. casei and S. thermophilus alone and in combination against E. coli were given. Here, it was determined that the activities of probiotic microorganisms created a synergistic effect when used in combination. It was determined that the activities of L. casei and S. thermophilus, when used in combination, had a synergistic effect against K. pneumoniae. In this study, where we aimed to produce a new and effective drug/solution in the treatment of wounds infected with drug-resistant bacteria (E. coli and K. pneumoniae), which are very difficult to treat, our findings may be hopeful.