Jpn. I. Oral Biol., 37: 152-161, 1995. Antimicrobial effects of high oxidation potential water on various microorganisms and an evaluation of mutagenicity of the water Shojiro Asai, Masatsugu Yamamura, Mitsuhiro Noda, Ichio Takase, Kenichi Hirata*, Eiichi Taki*, Shinsuke Minami*, Masao Aono*, Masahiko Isogai** and Isamu Namikawa Department of Oral Microbiology, School of Dentistry, Asahi University *Department of Operative Dentistry (Chief: Prof. Isamu Namikawa), School of Dentistry, Asahi University (Chief: Prof. Masao Aono) **Department of Oral and Maxillofacial Surgery (Chief: Prof. Nobutake Kanematsu), School of Dentistry, Asahi University 1851 Hozumi, Hozumi-cho, Motosu-gun, Gifu Prefecture 501-02, Japan Received on November 30, 1994; Accepted on January 30, 1995 l k Key words: high oxidation potential water/killing effect/saliva/disinfectants/mutagenicity Abstract: The purpose of this study was to examine the germicidal effect of the high oxidationpotential water (HOPW) on oral microorganisms, including pathogenic fungi, and the inhibitory effect of other factors such as whole saliva on this killing action of HOPW. In addition, we also evaluated the germicidal effect of HOPW on oral bacteria that had adhered to the impression material from a full mouth impression, and the mutagenicity of HOPW. Of the 12 bacterial species tested including MRSA, S. mutans, and T. rubrum, all microorganisms were killed by HOPW in 15 sec, except B. subtilis. B. subtilis, which is a sporeforming bacteria, was not affected by HOPW until 30 min. The killing potency of HOPW was similar level to that of other disinfectants, such as chlorhexidine gluconate (0.1%), sodium hydrochlorite (4%) and ethyl alcohol (70%). The killing action of HOPW was inhibited by adding yeast extract at a concentration of greater than 1% or whole saliva. HOPW had no significant germicidal effect on oral microorganisms that had adhered to impression material. This result may be due to the inhibitory effect of organic substances found in oral fluid. HOPW exhibited non-mutagenicity by the umu-test. These results indicate that HOPW may be a very useful disinfectant in dental clinics due to its strong killing action.
B. subtilis mutans, T. rubrum aureus 209P, 23266, 23295; S. haemolyticus JCM 2416; Pseudomonas aeruginosa CZT-1, ATCC 7700; Strepto- coccus mutans LM-7, OMZ-175, ATCC 25175; Escherichia coli ATCC 25922: Candida tropicalis ATCC 750, C. albicans ATCC 18804, C. glabrata ATCC 2001; Epidermophyton floccosum TIMM 0343, Tricho- phyton mentagrophytes TIMM 1189, T. rubrum TIMM Bacillus subtilis Staphylococcus aureus
E.floccosum,T. mentagrophytes,t. rubrum Salmonella typhimurium TA P.aeruginosa aureus 209P coli
Table 1 Germicidal effect of high oxidation potential water on microorganisms a MRSA, methicillin-resistant S. aureus; b MSSA, methicillin-susceptible S. aureus; c -, absence of growt; d+, growth; e Cont., without HOPW S. aureus 209P, S. aureus G86 P. aeruginosa
Table 2 Bactericidal effects of high oxidation potential water and other disinfectants on microorganisms a HOPW, high oxidation potential water; b-, absence of growth; c+, growth.; d Cont., without HOPW. Table 3 Inhibitory effect of yeast extract on the killing action by high oxidation potential water a Exposure time, 15 sec; b-,absence of growth; c+, growth.; d Cont., without HOPW. Table 4 Inhibitory effect of saliva on the killing action by high oxidation potential water a ~1 C+, original saliva; b ~5, five-fold dilution of saliva;, growth: d-, absence of growth.; e Cont., without HOPW
Table 5 Germicidal effect of high oxidation potential water on the oral microorganisms adhered to impression materials from the full dental mouth of individuals *Exposure time: 5 min. **Note: After taking dental impression from the lower jaw of the two individuals, the impression materials were immersed in 400 ml of high oxidation potential water or glutaraldehyde (2%) for 5 min, respectively. The organisms were harvested from the impression materials of the area per 5 mm2 by the sterile cottons and suspended in 10 ml of sterile physiological saline. The bacterial suspension (0.1 ml) was used for examining the number of bacterial colonies in Petri dish. Table 6 Bactericidal effect of high oxidation potential water on microorganisms in conditions of preservation a-, absence of growth; b +, growth. c, Cont., without HOPW. *Note: After creating high oxidation potential water, the water was divided into the four parts and kept in vessel with or without stopper at different temperatures. The bactericidal effect of the water were examined at exposure time of 15 sec. P. aeruginosa ATCC 7700, S.
Table 7 Germicidal effect of the high oxidation potential water adjusted at different ph ranges on microorganism a- absence of growth; b,+, growth. aurreus 209P E. coli ATCC 25922 P. aeruginosa P. aeruginosa ATCC 7700, S. aureus 209P, E. coli ATCC 25922, C. albicans ATCC 18804, S. mutans LM-7 P. aeruginosa, E. coli, C. albicans, S. mutans P. aerugi- nosa, E. coli, C. albicans, S. mutans S. aureus
Fig. 1 Ĉ-galactosidase activity of furylframide (A), 2- aminoanthracene (B), and high oxidation potential water (C).
umu - in vitro S. aureus P. aeruginosa, E. coli, C. albicans, S. mutans aeruginosa, Serratia marcescens B. subtilis B. subtilis ƒe ƒx ƒg Í,umu C umu - umu- P.aeruginosa ATCC 7700, S. aureus 209P E. coil ATCC 25922
10) Kitagawa, Y., Akaboshi, E., Shinagawa, H., Horii, T., Ogawa, H. and Kato, T.: Structural analysis of the umu operon required for inducible mutagenesis in Escherichia coli. Proc. Natl. Acad. Sci. USA 82: 4336-4340, 1985. 1) Muder, R. R., Brennen, C. M., Wagener, M., Vickers, R. M., Rihs, J. D., Hancock, G. A., Yee, Y. C., Miller, J. M. and Yu, L.: Methicillin-resistant staphylococcal colonization and infection in a longterm facility. Ann. Intern. Med. 114: 107 111, 1991. 18) Oda, Y., Nakamura, S., Oki, I., Kato, T. and Shinagawa, H.: Evaluation of the new system (umu-test) for the detection of environmental mutagens and carcinogens. Mutation Res. 147: 219-229, 1985.