ARS | Publication request: The effect of repeated sodium hypochlorite exposure on chlorine resistance development in Escherichia coli O157:H7

Submitted to: Food Science and Technology Critical Reviews
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 16, 2010
Publication Date: August 1, 2010
Citation: Inatsu, Y., Juneja, V.K., Bari, M.L., Kawasaki, S., Kitagawa, T., Kawamoto, S. 2010. The effect of repeated sodium hypochlorite exposure on chlorine resistance development in Escherichia coli O157:H7. Food Science and Technology Critical Reviews. 16:607-612.

Interpretive Summary: Chlorine water is widely used for sanitation of food facilities and disinfection of raw foods. We hypothesized that Escherichia coli O157:H7, a deadly bacterium, might acquire resistance to chlorine. Therefore, characteristics of the pathogen were assessed after repeated exposure to sodium hypochlorite solution. The results indicated that pathogens’ growth and viability, cellular activity and susceptibility to antibiotics were not altered. These findings will help the food service establishments to rely on the effectiveness of chlorine in decontaminating the surfaces and raw foods.

Technical Abstract: The emergence and spread of microorganisms with reduced susceptibility to antimicrobial agents is a major public health problem. Chlorine water has been widely used to reduce attached bacteria on the surface of food or for sanitizing the processing facilities. However, there are limited reports concerning the development of acquired resistance of the pathogen to chlorine. Therefore, this in vitro study was designed to evaluate the possibility of E. coli O157:H7 acquiring chlorine resistance. To simulate the occurrence of the spontaneous hypochlorous acid resistant mutants, chemical mutation was introduced. The 8 cycle spontaneous hypochlorous acid resistant strains and wild type strains of E. coli O157:H7 was compared for their growth and viability, cellular activity and susceptibility to antibiotics. There was no significant difference (p < 0.05) in the cellular activity and the susceptibility to antibiotics observed in the sodium hypochrorite (NaClO) treated samples as compared to the control. These findings suggested that E. coli O157:H7 cells will not acquire resistance to chlorine solution even though the bacteria were repeatedly grown and exposed to NaClO.