BACKGROUND: Agricultural water is known to be one of the major routes in bacterial contamination of fresh vegetable. However, there is a lack of fundamental data on the microbial safety of agricultural water in Korea.
METHODS AND RESULTS: We investigated the density of indicator bacteria in the surface water samples from 31 sites collected in April, July, and October 2018, while in the groundwater samples from 20 sites collected in April and July 2018 in Jeollabuk-do. In surface water, the mean density of coliform, fecal coliform, and Escherichia coli was 2.7±0.55, 1.9±0.71, and 1.4±0.58 log CFU/100 mL, respectively, showing the highest bacterial density in July. For groundwater, the mean density of coliform, fecal coliform, and E. coli was 1.9±0.58, 1.4±0.37, and 1.0±0.33 log CFU/ 100mL, respectively, showing no significant difference between sampling time. The survival of E. coli O157:H7 were prolonged in water with higher organic matter contents such as total nitrogen (TN), and nitrate-nitrogen (NO3-N). The reduction rates of E. coli O157:H7 in the water showed greater in order of 25, 35, 5, and 15℃.
CONCLUSION: These results can be utilized as fundamental data for prediction the microbiological contamination of agricultural water and the development of microbial prevention technology.