Testing institution: Japan Food Research Laboratories
Test result issue date: July 21, 2011
Test result issue number: No. 11061508001-01
Calcinated shell calcium (Okhotsk Calcium F)
To test sterilization effect of the specimen on E. coli (serotype O157: H7)
The specimen solution was inoculated with a bacterial liquid containing E. coli (serotype O157: H7, verotoxin-producing strains I and II) (hereinafter called “test liquid”). The test liquid was stored at room temperature, and the viable bacteria count in the test liquid was measured 5 minutes and 10 minutes later. A pre-test had been conducted to determine the method of measuring the viable bacteria count.
The test results are shown in Table-1. It was also confirmed by the pre-test that the viable bacteria count could be measured without being affected by the specimen by diluting the test liquid 10 times on a SCDLP medium.
Table-1 Measurement of viable bacteria count per 1 ml of test liquid
Tested bacteria | Test object | Viable bacteria count (/ml) | ||
---|---|---|---|---|
Initial count*1 | 5 min. later | 10 min. later | ||
E. coli (O157:H7) |
Specimen*2 | 4.0 x 105 | <10 | <10 |
Control object | 4.0 x 105 | ー | 4.8 x 105 |
<10:Not detected
Control object: Purified water
Storage temperature: Room temperature
-: Not performed
*1: The initial count is the measured viable bacteria count in the control immediately after inoculation with the bacterial liquid.
*2: Supernatant 0.15 % solution of the specimen prepared with purified water and stirred for about 5 minutes.
Escherichia coli ATCC 43895 (E. coli, serotype O157: H7, verotoxin-producing strains I and II)
SCDLP agar medium [Nihon Pharmaceutical Co., Ltd.], pour plate cultural method, 35 ºC±1 ºC, for 2 days
Test strains were cultured on an ordinary agar medium [Eiken Chemical Co., Ltd.] at 35 ºC±1 ºC for 18 to 24 hours, floated in saline, and prepared so that bacterial count would be 107 to 108/ml to be used as the test bacteria liquid.
10 ml of specimen liquid (supernatant 0.15% solution of specimen prepared with purified water and stirred for about 5 minutes) was inoculated with 0.1 ml of test bacterial liquid to make a test liquid. The test liquid was stored at room temperature, and diluted 10 times on a SCDLP medium [Japan Pharmaceutical Co., Ltd.] immediately, and after 5 and 10 minutes. The viable bacteria count of the test liquid was measured with a medium for measurement of bacterial count.
At the same time, purified water was used as a control to be tested in the same way. The viable bacteria count was measured initially, and 10 minutes later.
End