牛乳中の大腸菌群検出におけるSensiMedia法の有用性について評価を行い, 以下の結果を得た.
1) 大腸菌群を含む腸内細菌および一部の非発酵性グラム陰性菌を検出することが可能であった.また, 検出時間と菌数の間には相関があり, その相関係数は0.98～0.99と高い値を示した.
2) 37℃培養で, 腸内細菌5菌株は15時間以内, 2菌株は21時間以内に検出することができ, デソキシコーレイト寒天培養法と同等, あるいはより迅速に検査結果を得ることができた.
3) 37℃, 6時間の増菌培養法と組合せることで, 10^-2cfu/mlの汚染菌を23時間以内に検出することができた.
以上の結果から, SensiMedia法は簡便かつ迅速な検査法であり, さらに低レベルの汚染菌を迅速に検出するためには増菌培養法との組合せが有効であることが確認された.

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An outbreak of food-borne infection with enterotoxigenic Escherichia coli (ETEC) O6: H16 producing heat-labile enterotoxin and heat-stable enterotoxin occurred in Miyazaki Prefecture, Japan, in September 1999. During this outbreak, 211 out of 1, 439 people examined (14.7%) were affected. The major clinical symptoms were diarrhea and abdominal pain. However, data from epidemiological surveillance of infectious diseases in Miyazaki Prefecture showed that ten sporadic diarrhea cases caused by ETEC O6: H16 occurred diffusely in the prefecture for some weeks before and after this outbreak. In order to clarify the relationship between the outbreak and the sporadic cases, the isolates from each case were analyzed genetically by pulsed-field gel electrophoresis method (PFGE). As a result, the PFGE patterns of these isolates, except for one sample from a sporadic case, were observed to be the same, after cleavage of DNA with restriction enzymes Xbal, Notl and ApaI. These results suggest that the outbreak and the sporadic cases may have represented a diffuse outbreak initiated by contaminated foods appearing on the market in Miyazaki Prefecture.

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