Abstract
The LAS medium shown in Table 1 was prepared as a selective enrichment-medium for Clostridium perfringens by modifying the TSN agar. Then the LAS medium was applied to isolating Cl. perfringens from the 171 samples of fish and the 22 samples of the other sea-foods The results obtained from the experiments are as follows.
1) In the selective enrichment-culture of Cl. perfringens with the LAS medium, the presence of Cl. perfringens was judged by both blackening the medium and producing gas in the medium. Consequently this judgement in the LAS medium was more available than the judgement by only blackening in the TSN agar (Table 1).
2) Cl. perfringens identified by Benoki's criterion was isolated in the high percentage of 93 from the 213 cultures with the LAS medium in which the judgement of the presence of Cl. perfringens was positive. Likewise, as for the criteria in Bergey fs manual (key to the species of genus Clostridium) and of Strong et al., the isolation rates were 83 and 67 per cent respectively (Table 2).
3) There was a little difference between the specimens of the body surface and those of the alimentary canal, in selecting Cl. perfringens in the LAS 46°C-cultures, when the isolates from the cultures were identified by Benoki's criterion (Table 3).
