Abstract
Background: Uropathogenic Escherichia coli (UPEC) is a significant contributor to urinary tract infections (UTIs). The inappropriate prescription and utilization of antibiotics in treating UTIs have resulted in a rise in antibiotic resistance. The aim of this study was to investigate the antibacterial properties of mint nanoemulsion against beta-lactam-resistant strains of UPEC.
Methods: Three hundred fifty urine samples were collected in sterile containers and cultured on eosin-methylene blue agar and blood agar media under sterile conditions. Microbial sensitivity testing was conducted using the standard disk diffusion method. Molecular analysis was performed to identify the blaTEM, blaSHV, and blaCTX genes in the samples. The mint nanoemulsion was produced using the low-energy method of spontaneous emulsion formation and characterized using scanning electron microscopy (SEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR). The antibacterial activity of the mint nanoemulsion against multidrug-resistant (MDR) isolates underwent assessment.
Results: One hundred UPEC strains were isolated and identified, showing differing levels of resistance and sensitivity to various antibiotics. Nitrofurantoin exhibited the highest resistance (22%), while amikacin had the lowest resistance (4%). The prevalence of the blaTEM, blaSHV, and blaCTX genes among the UPEC isolates was 93.33%, 100%, and 73.33%, respectively. The mint nanoemulsion demonstrated effective antibacterial activity against resistant isolates, with a minimum inhibitory concentration of 0.2 mg/µL and a minimum bactericidal concentration of 0.3 mg/µL.
Conclusion: The resistance of UPEC against conventional antibiotics commonly used to treat UTIs was consistently high and demonstrated an increasing trend over time. This escalating situation could potentially become more severe in the future if the rational consumption of antibiotics is not carefully managed. Nanoemulsions synthesized using mint revealed promising stability and robust antimicrobial properties against UPEC isolates. Consequently, it is evident that these synthesized nanoemulsions represent a viable candidate as effective antimicrobial agents in combating antibiotic resistance in UTI treatment.