Molecular study on the effect of Tea Tree Oil and its polymer on gene expression of serine protease autotransporter genes of uropathogenic Escherichia coli

Background: One of the major global challenges is the increasing rate of antimicrobial resistance; therefore, alternative therapies are required to cope with this growing problem. Objectives: Researchers are polymerizing tea tree oil to create new antimicrobial materials that not only kill or inhibit microbes but also suppress the virulence of uropathogenic E. coli. Methods: After isolation and identification of 100 strains of Uropathogenic E. coli using traditional and molecular methods, 60 MDR isolates were selected to determine the minimum inhibitory concentration (MIC) of both tea tree oil and its polymer using the agar dilution method. After exposure to 1/2 MIC, the gene expression was assessed using RT-qPCR. Results: The MIC of the essential oil was 10000 ppm for two isolates (3.3%), 5000 ppm for 51 isolates (85%), and 2500 ppm for seven isolates (11.7%), whereas the minimum inhibitory concentration of the polymer was 20000ppm for all tested isolates. In addition, tea tree oil decreased sat gene expression in most of the isolates in this study after treatment with tea tree oil, while the gene expression of all isolates decreased after treatment with the polymer. However, multiple comparisons revealed no significant differences between them. In contrast, more strains showed either an increase or no change in vat gene expression after treatment. Conclusion: Tea tree oil especially its polymer reduced sat expression more than vat, highlighting the polymer’s potential as an anti-virulence antibacterial to tackle resistance and pathogenicity.