This study investigated the antibacterial effects of GR ethanol extracts (GRE), sodium chlorate (SC) and a combination of GRE and SC (GS) on Brucella abortus (B. abortus). The antibacterial activities of GRE, SC and GS towards B. abortus were evaluated by incubating B. abortus with GRE, SC and GS. Following treatment with GRE, SC and GS, B. abortus survival and intracellular proliferation in macrophages were monitored. In the cellular cytotoxicity assay, GRE, SC and GS are not cytotoxic at concentrations less than 400 μg/ml, 15 mM and 0.6GS (1 of GS, GRE 1,000 μg/ml + SC 30 mM), respectively. The viability of B. abortus was markedly decreased in a dosedependent manner in all treatment groups. In addition, B. abortus intracellular proliferation within macrophages was significantly reduced in cells treated with GRE (400 μg/mL), SC (15 mM) and 0.5GS (GRE 500 μg/mL + SC 15 mM) after 48 hr-incubation (GRE, p < 0.01; SC and 0.5GS, p < 0.001). Especially, in the treatment of GS, the synergistic effect of GRE and SC treatment on B. abortus in macrophage was observed. In conclusion, GS is useful as an antibacterial candidate against B. abortus, and can be applied in the field of meat and milk hygiene.

ABSTRACT
 Introduction
 Materials and Methods
  Cells and culture conditions
  Bacterial culture
  GRE and SC solution preparation
  Cytotoxicity assay
  Bactericidal analysis
  Inhibitory effects for intracellular proliferation of B.abortus
  Statistical analysis
 Results
  Cytotoxic effects on murine macrophage
  Bactericidal effects of GRE and GS on B. abortus
  Inhibitory effects of GRE, SC and GS on bacterialintracellular proliferation
 Discussion
 요 약
 References

• Gyeong-Hwan Kim(Engineering Research Institute, Department of Industrial Systems Engineering, Gyeongsang National University)
• Il-Hwa Hong(Gyeongsang Research Institute of Life Sciences, College of Veterinary Medicine, Gyeongsang National University)
• Eun-Ah Yu(Tongyeong National Quarantine Station, Ministry of Health & Welfare)
• Eun-Kee Park(Medical Humanities and Social Medicine, College of Medicine, Kosin University)
• Chang-Yeol Yoo(Department of Computer Information, Gyeongnam Provincial Namhae College)
• Suk Kim(Gyeongsang Research Institute of Life Sciences, College of Veterinary Medicine, Gyeongsang National University)
• Hu Jang Lee(Gyeongsang Research Institute of Life Sciences, College of Veterinary Medicine, Gyeongsang National University) Correspondence to