Antibacterial Activity of Pyrogallol, a Polyphenol Compound against Vibrio parahaemolyticus Isolated from The Central Region of Thailand

Vibrio parahaemolyticus is a notorious marine bacterium that causes disease to human and marine animal. Polyphenols are plant-derived products that are commonly found in fruits and plants. These products are well-known for their antioxidant properties due to the ability to scavenge free radicals. In addition, many polyphenols have been proved to possess bactericidal effects against both Gram-negative, and Gram-positive bacteria. In this work, a total of 30 isolates of V. parahaemolyticus including pathogenic (n = 9) and non-pathogenic (n = 21) strains were isolated from Pacific White shrimps obtained from the central area of Thailand. Susceptibility of V. parahaemolyticus to pyrogallol, a polyphenol compound commonly found in mango and many citrus plants, was compared to antibiotics. Antibacterial activity of V. parahaemolyticus to pyrogallol was between 32-64 μg/ml for both MIC and MBC. However, susceptibility to enrofloxacin, oxolinic acid, and oxytetracycline was in acceptable range (MIC, MBC < 2 μg/ml). All isolates resisted to ampicillin and amoxicillin (MIC, MBC > 128 μg/ml). This result indicates that pyrogallol may be an alternative compound for combating V. parahaemolyticus.