Antibacterial Activity Test of Ketul Leaf Essential Oil (Bidens Pilosa L.) Against Shigella Dysentriae and Salmonella Typhi Bacteria

Diarrhea is a condition of defecating three or more times in one day and the stool that comes out is a watery liquid or slightly frothy. This disease is caused by the bacteria Shigella dysenteriae and Salmonella typhi. This study aims to determine the antibacterial activity of the essential oil of ketul leaves (Bidens pilosa L.) against Shigella dysenteriae and Salmonella typhi, and to analyze the composition of chemical compounds in the essential oil. The essential oil was isolated using steam-water distillation. The characterization test of the essential oil was carried out by determining the specific gravity, refractive index, and GC-MS analysis. The antibacterial activity test used the disc diffusion method with concentrations of 20%, 40%, 60%, positive control ciprofloxacin 5 µg/disc and negative control DMSO. The results of the characterization test showed the yield of essential oil was 0.002% (v/w), specific gravity 0.8886 g/ml, and refractive index 1.388. GC-MS analysis identified 51 chemical compounds dominated by sesquiterpenes and benzene. The results of the antibacterial activity test showed that the average inhibitory diameter of essential oils at concentrations of 20%, 40%, and 60% against Shigella dysenteriae bacteria was 8.70 mm; 10.48mm; 11.39 mm, while against Salmonella typhi bacteria it was 8.96 mm; 11.52 mm; 13.25 mm. Ketul leaf essential oil has the potential as a natural antibacterial.