|Abstract or Summary
- Comparatively little work has been done to determine the ecology
of Clostridium botulinum type E since its initial isolation in the
nineteen-thirties. This spore forming, anaerobic microorganism is
relatively heat labile and has been missed in ecological surveys in
which heat was used to selectively screen for spore formers. Use of
gentler methods has, however, facilitated its demonstration in marine
sediments throughout the Northern Hemisphere.
The type E organism elaborates a highly potent neurotoxin and
has been isolated as the causative agent in recent fatalities involving
the consumption of fish products. Until recently the organism
was not believed to be present in the United States south of the
The purpose of this investigation was to determine if the organism
could be demonstrated in shellfish, inland lake fish, and sediment
samples throughout the Northwest. Samples of coastal shellfish--
including various species of clams, crabs and oysters, varieties of
smoked fish products, species of inland lake fish and inland lake,
river and coastal sediment samples were examined for the presence of
the type E organism.
The organism was found, to some extent, in almost every type of
sample tested. Type E toxin was demonstrated in incubated samples
of shellfish and smoked fish products collected from eleven sites
along the Oregon and Washington coast. The organism was found in
shore sediments from the tidewater and freshwater areas of the Columbia,
Alsea, and Umpqua rivers but could not be demonstrated in sediments
taken from saltwater beaches at the mouths of these rivers.
The type E organism was also demonstrated in fish from inland lakes
in the Oregon Cascade Mountains, in sediments from the shores of these
lakes, and along the shores of a river and three reservoirs in this
area. These samples were collected between 95 and 120 linear miles
from the coast.
The isolation of the type E botulinum organism in fish and shellfish
products demonstrates that the organism does present a potential
hazard which should be recognized by Northwest processors and distributors
of these products. High concentrations of the spores of this
organism, such as those found in bottom sediments of some of the inland
lakes and reservoirs may serve to contaminate fish and other
wildlife. Much of the data collected supports a terrestial distribution
of the spores.