Abstract
The incidence of Clostridium perfringens was 100% in soil specimens collected from formerly developed areas, such as cultivated field, public park and playground. On the contrary, it was 10 to 90% in those collected from newly developed areas, such as soccer ground, baseball ground, tennis court, turf and the site of construction. A high incidence of the organism was observed in the soil of areas well cultivated, frequently utilized or trodden by people. The number of C. perfringens cells found in one gram of soil ranged from 7 to 900. The isolates from soil specimens were examined for survival in a sterilized 50% soil suspension. Some of them rapidly formed thermostabile cells resistant to heating at 75C for 15min. The others were not heat-resistant. Both types of the isolates survived for more than 4 weeks, although the heat-resistant cells survived relatively long with a slight decrease in number. The isolates from soil were examined for survival in a 50% soil suspension, α-toxigenicity and salt tolerance, in comparison with those from human feces, but no differences were observed between both groups of isolates. The finding of the present study suggests that no multiplication of C. perfringens may occur in soil.
