Weakening of Virulence Factors and Biofilm in Salmonella Typhi by Medicinal Plants Extracts

Objective(s): Salmonella typhi, is a serious global health threat because it causes typhoid fever, a severe systemic infection. According to the World Health Organization, millions of cases of typhoid are recorded annually, and thousands of people die from it. To combat this pathogen, new medications are required. The current study aims to study the ability of medicinal plants (thyme and cinnamon) to modulate the properties of Salmonella typhi isolates instead of killing them. Materials and Methods: The plants were extracted with the help of solvents (ethanol and ethyl acetate) and to find out the minimum inhibitory concentration, the different concentrations were used. The biofilm and expression of genes (invA & fliC) of the bacterium were studied when exposed to sub-inhibitory concentrations of the plant extracts. Results: MIC values ranging between 20-25 mg/ml and 10-15 mg/ml for ethanol and ethyl acetate extracts of Thyme respectively. While the MIC values of cinnamon were 18-25 and 10-15 mg/ml for both ethanol and ethyl acetate extracts respectively. The examinations revealed a significant decrease in the composition of biofilms by isolates when treated with SICs from plant extracts. The transcription expression profile of invasion (invA) and flagellar (fliC) genes were downregulated when treated with the plant extracts. Conclusion: The findings indicate that both thyme and cinnamon extracts may have promising activity against the biofilm and virulence of S. typhi. Thus, they could be used as potential as an antibacterial drug.