The use of plant extracts and bacteriophages as an alternative therapy approach in combating bacterial infections: the study of lytic phages and Stevia rebaudiana

Introduction In the light of the problem of antibiotic-resistance, the use of alternative combined therapies in combating bacterial-related issues has gained popularity. Therefore, using up-to-date laboratory techniques, possible interactions of lytic bacteriophages (MS2, T4 and Phi6), acetone and methanol S. rebaudiana extracts (SRa and SRm) in the bacterial environment have been examined. Material and Methods Using a microdilution method, phages-extracts coincubation assay, static interactions synographies and dynamic growth profile experiments in a bioreactor, it was found that the interactions in a static environment differ from interactions in a dynamic environment. Results Dynamic conditions alter the influence of extracts in a concentration-dependent manner. The effects of the SRa and SRm extracts on bacterial growth in a dynamic environment depend on the species of the phage and bacterial host. The greatest differences were observed for E. coli strains and their phages, whereas P. syringae and Phi6 phage reacted very similar to both extracts. The differences also emerged for single extracts within E. coli strains and their phages. Conclusions Every extract type should be tested on a case-by-case basis and experiments outcomes should not be generalized before gathering data. Moreover, many varied experiments should be performed, especially when examining such multifactorial mixtures. Tested mixtures could be potentially used in multi-drug resistant bacterial infections treatments.