Role of Antibacterial Compounds in Neem Leaf Extract (Azadirachta indica A. Juss) in Inhibiting the Growth of Vibrio parahaemolyticus Bacteria in the Vannamei Shrimp

Herbal plants are increasingly being used as alternatives to synthetic antibacterials due to their cost-effectiveness and minimal adverse effects. Among various plants, the neem leaves (Azadirachta indica A. Juss) have been extensively utilized in traditional medicine for their antiviral, antifungal, insecticidal, and antibacterial properties. This study aimed to identify antibacterial compounds extracted from neem leaves with potential activity against Vibrio parahaemolyticus in the vannamei shrimp (Penaeus vannamei). The antibacterial compounds were identified using GC-MS (Gas Chromatography-Mass Spectrometry), while the antibacterial activity was evaluated through disc diffusion tests with concentrations of 50, 75, and 100 mg/mL, followed by a minimum inhibitory concentration (MIC) test. The GC-MS analysis revealed 12 peak compounds in the neem leaf extract, detected as secondary metabolites from the mycosporin, phenol, alkaloid, triterpenoid, phytosterol, and steroid groups. The antibacterial activity test showed inhibition zone diameters of approximately 12.8, 11.5, and 10.1mm at concentrations of 100, 75, and 50mg/ mL, respectively, with minimum inhibitory concentrations of 25 and 12.5mg/ mL. Based on these results, the neem leaf extract shows promise as an alternative antibacterial agent.