Antimicrobial Activity of Thai-herbal Plants against Food-borne Pathogens E. Coli, S. Aureus and C. Jejuni

Abstract

Food-borne pathogens, including Escherichia coli, Staphylococcus aureus and Campylobacter jejuni, are prophylactically prevented in livestock by using commercially available antibiotics. The European Union has recently banned the use of prophylaxis use of antibiotics in animals since 2006 while urgently considers ways to reduce food-borne pathogens. The objective of this study was to propose a screening method for identifying natural compounds with anti-bacteria activity from twenty-six Thai-herbal plants. Antimicrobial activity was evaluated by an agar diffusion method, which allowed for the determination of the minimum inhibitory concentration (MIC). The results indicated that Thai-herbs have potent antimicrobial activity against E. coli, S. aureus and C. jejuni at bacteria suspensions of 2.0-3.0x109 CFU/ml. Interestingly, C. formosum had the highest antimicrobial activity against the three food-borne pathogens of E. coli, S. aureus and C. jejuni, which were isolated from the chicken-caecum. MIC values of C. formosum against E. coli, S. aureus and C. jejuni were 3.0 mg/ml, 3.0 mg/ml and 0.3 mg/ml, respectively. Other herbal plants also had antimicrobial activity against the three food-borne pathogens in this study. The herbal plants provide not only a natural source of anti-bacterial activity, but also anti-oxidant activity and anticancer properties. The application of using Thai-herbal plants compounds by adding them in animal feed is proposed. This may be a safe means of enhancing health and production of livestock and thus benefits humans and animals. Consequently, the selection of herbal plants, for use in preventing food-borne bacterial infection, is both interesting and worthwhile for food safety.