Objective: Urinary tract infections (UTIs) are among the most prevalent infectious diseases, frequently caused by Escherichia coli. The escalating antibiotic resistance of this bacterium, driven by widespread antibiotic use and the transfer of resistance genes, has intensified therapeutic challenges. Teucrium polium L. rich in bioactive compounds such as monoterpenes and polyphenols, has been valued in traditional medicine. This study aimed to evaluate the antibacterial efficacy of the hydroalcoholic extract of T. polium against standard and clinical E. coli strains and to compare its effects with commonly used antibiotics.
Materials and Methods: In this descriptive study, a hydroalcoholic extract of T. polium was prepared using the maceration method from samples collected in Yasuj, Iran. The standard E. coli strain (ATCC 25922) and clinical isolates from UTI patients were tested. The susceptibility of the strains to antibiotics, including nitrofurantoin, gentamicin, cotrimoxazole, cefepime, ceftriaxone, and ciprofloxacin, was assessed using the disk diffusion method. The antibacterial activity of the extract was evaluated by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) via the microdilution method, and the zone of inhibition (ZOI) diameter. Data were analyzed using SPSS version 16, employing the Kolmogorov-Smirnov and one-way ANOVA tests.
Results: Both standard and clinical E. coli strains were susceptible to the tested antibiotics. The MIC of the T. polium extract was 62.5 μg/mL for the standard strain and ranged from 31.25 to 62.5 μg/mL for clinical isolates. The MBC ranged from 125 to 250 μg/mL. No stastically significant differences were observed between the MIC and MBC of standard and clinical strains (P.value>0.05). The ZOI diameter was larger for the standard strain compared to clinical isolates, though this difference was not statistically significant (P.value>0.05). The T. polium extract exhibited considerable antibacterial activity, albeit less potent than some antibiotics.
Conclusions: The hydroalcoholic extract of T. polium demonstrates antibacterial potential against E. coli and could serve as a natural adjunct to address antibiotic resistance. Further studies are recommended to investigate its toxicity and identify active compounds. These findings underscore the significance of medicinal plants in developing novel therapeutic strategies.