METHOD FOR SEARCHING DYSENTERY BACCILLUS INFECTION-PREVENTING AGENT AND THE SAME AGENT

摘要

PURPOSE:To safely and readily obtain a dysentery baccillus by searching infection preventing ability using an infection ratio obtained by infecting HeLa cell with a specific microbial cell in the presence of a specimen as an index. CONSTITUTION:A cell-intrusive plasmid which D type dysentery baccillus is introduced into Escherichia coli to afford a cell-intrusive Escherichia coli (CIEC) (A). Then intrusion test of the bacterium A to a cultured cell is carried out to afford HeLa S3 (human cervical carcinoma-derived cell) cell (B) having high sensitivity. Then the bacterium a is added to the cell B and the cell is cultured and then dyed by Giemsa staining method and observed under microscope and ratio of infected cell is calculated to provide infection ratio (C). Then the above-mentioned infection ratio C obtained by bringing the bacterium A into contact with the cell B in the presence of a desired sample is selected as an index and dysentery baccillus infection-preventing agent containing an osmotic pressure-protecting substance such as an amino acid betaine or a substance having <=10000 molecular weight in fectal calf serium or a heat-resistant substance having >=10000 molecular weight in fetal calf serum as an active ingredient is prepared.