<![CDATA[The increasing incidence of antibiotic resistance in Escherichia coli poses a significant challenge to public health, as the effectiveness of conventional antibiotics such as ciprofloxacin continues to decline due to the emergence of resistant E. coli strains. This study aims to evaluate red ginger extract's in vitro antibacterial activity against Escherichia coli and determine the optimal concentration for bacterial inhibition. This research aims to determine the effectiveness of red ginger extract with concentrations of 60%, 80% and 100% on the growth of Escherichia coli. Research method using a laboratory-based experimental study was conducted using red ginger extract prepared via ethanol maceration at concentrations of 60%, 80%, and 100%. The extract's antibacterial activity against E. coli was evaluated using the disc diffusion method following CLSI guidelines, with ciprofloxacin (500 mg) as a positive control and 95% ethanol as a negative control. Each treatment was replicated five times. Inhibition zones were measured after 24 hours of incubation at 37°C. The results of the study show that red ginger extract demonstrated significant antibacterial activity against E. coli, with mean inhibition zones of 6.08 ± 0.98 mm, 6.48 ± 1.21 mm, and 5.20 ± 1.89 mm for 60%, 80%, and 100% concentrations, respectively. The 80% concentration showed optimal inhibition activity, while the higher concentration (100%) demonstrated reduced effectiveness. Statistical analysis confirmed significant treatment differences (p < .001, η² = 0.967). The positive control produced significantly larger inhibition zones (23.16 ± 1.67 mm, p < .05). This study concludes that red ginger extract exhibits moderate antibacterial activity against E. coli in vitro, with 80% concentration showing optimal efficacy. These findings suggest potential applications in developing natural antimicrobial agents, although further research is needed to elucidate mechanisms of action and evaluate clinical applications.]]>
