Expression Variation of Serine Protease Autotransporters Genes of Uropathogenic E. coli in Response to Tea Tree Essential Oil (Melaleuca alternifolia) and its Polymer

Abstract

In this study, the antibacterial activity of tea tree essential oil and its polymer on Uropathogenic E. coli was determined. In addition to their effect on the gene expression of two serine protease autotransporter genes, sat and vat. Five hundred clinical urine samples have been collected from individuals aged between 15 and ≥65 years old with urinary tract infections in Babylon. One hundred E. coli isolates were collected and isolated using selective and differential culture media, then verified by polymerase chain reaction (PCR). The minimum inhibitory concentration (MIC) was determined using the agar dilution method to assess the antibacterial activity of tea tree essential oil and its polymer. The MIC values of tea tree essential oil was 10000 ppm for 2 strains (3.3%), 5000 ppm for 51 strains (85%), and 2500 ppm for 7 strains (11.7%), while MIC of the polymer was 20000 ppm for 58 strains (96.7%), and 10000 ppm for 2 strains (3.3%). Gene expression was measured using the RT-qPCR method. Tea tree essential oil and its polymer were highly effective antibacterial agents against E. coli bacteria, and their effect on decreasing gene expression of the sat gene was more pronounced than that of the vat gene. This effect indicates the potential of tea tree essential oil and its polymer as alternative antibacterial agents that target bacterial virulence, providing a strategy for combating antibiotic resistance and pathogenicity.