Antimicrobial activity of essential oils and structurally related synthetic food additives towards Clostridium perfringens

Aims: To assess the potential of essential oils and structurally related synthetic food additives in inhibiting the growth of Clostridium perfringens for the control of necrotic enteritis in chickens. Methods and Results: The antimicrobial activity of essential oils/compounds was measured by determining the inhibition of bacterial growth. Thirty-three of 66 oils/compounds exhibited ≥80% inhibition. Seven with the highest potency were further studied. The oils/compounds had MIC95 values between 167 and 425 μg ml -1. Most of them were tolerant to low pH (2.0) and exhibited minor or no inhibition of Lactobacillus isolates from the chicken intestine. When mixed with chicken ileal digesta, the oils/compounds retained their efficacy against C. perfringens, but had little effect on the total number of lactobacilli and anaerobic bacteria in the digesta. Conclusions: Some essential oils/compounds demonstrated good potential in controlling C. perfringens. Significance and Impact of the Study: This study has identified candidates of essential oils/compounds for in vivo studies for the control of necrotic enteritis in chickens. © 2008 The Authors.