Distribution of Clostridium botulinum.

The distribution of Clostridium botulinum in the natural environments of Denmark, The Faroe Islands, Iceland, Greenland, and Bangladesh was examined. A total of 684 samples were tested. Type E was found in 90% of samples from the aquatic environment of Denmark, including sediments from young artificial lakes, and in 86% of samples from the marine environment of Greenland. Type E was not found in Danish cultivated soil and woodlands, including cultivated soil from reclaimed sea beds, but type B was frequently demonstrated in these environments. C. botulinum types A, B, or E were found in 2.6% of samples from the environments of the Faroe Islands and Iceland, whereas types C or D were demonstrated in 42% of samples from Bangladesh. The incidence of type E in aquatic sediments was not related to general industrial pollution or a high content of rotting vegetation. Fish or a rich aquatic fauna, on the other hand, appeared to contribute to a high incidence of type E. Based on these findings, it is suggested that type E is a true aquatic organism, because this environment offers the best conditions for survival of the spore in nature. It is further suggested that its presence in aquatic bottom deposits is based on sedimentation after proliferation in the carrion of the aquatic fauna and dissemination by water currents and migrating fish.