This study evaluated the bactericidal efficacy of a disinfectant containing chlorine dioxide as its main ingredient against Paenibacillus larvae (P. larvae) that is the causative agent of American foulbrood. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to P. larvae for 30 min at 4°C. The disinfectant and test bacterium were diluted with low and high organic matter (OM) suspension according to treatment condition. On low and high OM conditions, the bactericidal activity of the disinfectant against P. larvae was 2.5 and 1.25 fold dilution, respectively. The recommended dilution time of the disinfectant in low and high OM was 2.0 and 1.0 fold dilution, respectively. As the disinfectant possesses bactericidal efficacy against P. larvae, the disinfectant can be used to prevent American foulbrood in larvae of honeybees.

• Chun-Nam Cha(Department of Industrial and Systems Engineering, Gyeongsang National University, Jinju 52828, Korea)
• Chang-Soo Cho(College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Korea)
• Suk Kim(College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Korea)
• Hu-Jang Lee(College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Korea) Corresponding author
• Jin-Kyung Kim(Department of Dental Hygiene, Daegu Health College, Daegu 41453, Korea) Corresponding author