This study investigated the antibacterial effects of Galla rhois extract (GRE) against Campylobacter jejuni and Campylobacter coli. The minimum inhibitory concentrations (MICs) of GRE against C. jejuni and C. coli were 0.28 and 0.55 mg/mL, respectively, and the corresponding minimum bactericidal concentrations (MBCs) were 4.4 and 5.5 mg/mL. C. jejuni treated with the MIC, MBC or 2×MBC of GRE showed significant inhibition of growth compared with that of the control group during the incubation period, and no viable bacteria were detected at 24 h after incubation. C. coli treated with MIC, MBC or 2×MBC of GRE also showed inhibition of growth compared with that of the control group during the incubation period, and in the C. coli cultures treated with MBC and 2×MBC of GRE, no viable bacteria were detected at 24 h after incubation. In conclusion, GRE is a candidate antibacterial agent against C. jejuni and C. coli, and may have applications for the control of Campylobacter infection in poultry.

Abstract
 INTRODUCTION
 MATERIALS AND METHODS
  Bacterial strains and culture
  Preparation of herbal extract
  Determination of MIC and MBC
  Time-kill assay
  Statistical analyses
 RESULTS
  Time-kill assay
 DISCUSSION
 REFERENCES

• Soo-Mi Lee(Department of Environmental Health, Graduate School of Public Health, Gyeongsang National University)
• Byung-Wook Cho(Department of Animal Science, College of Life Sciences, Pusan National University)
• Mee-Jeong Kim(Department of Environmental Health, Graduate School of Public Health, Gyeongsang National University, Centralized Scientific Instrumentation Facility, Gyeongsang National University)
• Ju-Yeon Park(Department of Environmental Health, Graduate School of Public Health, Gyeongsang National University, Division of Gastroenterology, Gyeongsang National University Hospital)
• Chun-Nam Cha(Engineering Research Institute, Department of Industrial Systems Engineering, Gyeongsang National University)
• Chang-Yeol Yoo(Department of Computer Information, Gyeongnam Provincial Namhae College)
• Suk Kim(Research Institute of Life Sciences, College of Veterinary Medicine, Gyeongsang National University)
• Hu Jang Lee(Department of Environmental Health, Graduate School of Public Health, Gyeongsang National University, Research Institute of Life Sciences, College of Veterinary Medicine, Gyeongsang National University) Corresponding Author