DEVELOPMENT OF ANTI-BACTERIAL CERAMICS
The historically and sequentially huge outbreaks of food poisoning caused by enterohaemorrhagic E. coli O157:H7 had occurred in Japan 1996, and a number of patients was estimated over 12,000 including 12 death cases. Under these situations, we initiated the work of development of the anti-bacteria ceramics, and attained our initial purpose. The core portion of ceramics, which was constituted with complex of Al, Ti and Si, was coated with silver by firing, and the final product developed was a porous material. After repeating experiments by changing mixing amount of compounds, and firing conditions, the effective ceramics against bacteria was obtained. The ceramics at 1-2% (w/v) showed the bacteria killing activity against O157 at 106-107 cfu/ml in water within 1hr treatment at 37°C. Similar activity was demonstrated against other types of pathogenic bacteria such as MRSA, Vibrio spp., Legionella spp. and Salmonella spp. under the same treatment conditions. The amount of heavy metals solubilized into the ceramics water was measured, however Pb was not detectable, and Zn, Cu, Ag and organic compounds were at legally allowed levels respectively. Additionally the ceramics water at 20% (w/v) solution was orally administered into rats to examine the acute toxicity, and no toxicity was convinced in animal test. From these results it is conclusively speculated that the anti-bacteria ceramics developed is the effective agent to eradicate pathogenic bacteria caused food poisonings.
