INHIBITORY EFFECT OF STEVIA AND ROSA EXTRACTS AGAINST BACTERIAL QUORUM SENSING

Quorum Sensing is a mechanism by which orchestrate the expression of many genes in bacteria. Therefore, any interference with the system will inhibit bacterial infections. The principal purpose of the research was to evaluate the potential of anti-quorum sensing of Rosa damascena and Stevia rebaudiana against Staphylococcus aureus.

Ten isolates of Staphylococcus aureus were collected and identified. Plant species were collected from gardens of Fars province and extracted using 96% ethanol. The effect of anti-QS properties of the plant extracts was evaluated using Chromobacterium Violaceum CV026 biosensor. Furthermore, Biofilm production of the strains was investigated through the microtiter plate. In addition, the phytocompounds of Rosa and Stevia were identified by GC-MASS.

The results showed that Rosa damascene (19±0.5) and Stevia rebaudiana (17±0.5) extracts significantly (P<0.05) possess anti-QS activities. Moreover, both extracts had antimicrobial activity and anti-biofilm properties. The results of the GC-MASS analysis also disclosed that the extract of rosa contains compounds such as Geraniol, β-Citronellol and Linalool, and also the extract of Stevia has compounds similar to Furfural, Terpinen-4-ol, Linalool, and α-Pinenem which could interfere with bacterial QS.

According to the anti-biofilm and anti-QS properties of Rosa and Stevia extracts, the active compounds of the extracts, with an accurate evaluation, could be considered as an appropriate approach for bacterial treatment.