Distribution of Clostridium botulinum Type E Strains in Nunavik, Northern Quebec, Canada

ABSTRACTThe distribution and levels ofClostridium botulinumtype E were determined from field sites used by Inuit hunters for butchering seals along the coast of Nunavik. The incidence rates ofC. botulinumtype E in shoreline soil along the coast were 0, 50, and 87.5% among samples tested for the Hudson Strait, Hudson Bay, and Ungava Bay regions, respectively. Spores were detected in seawater or coastal rock surfaces from 17.6% of butchering sites, almost all of which were located in southern Ungava Bay. Concentrations ofC. botulinumtype E along the Ungava Bay coast were significantly higher than on the coasts of Hudson Strait and Hudson Bay, with the highest concentrations (270 to 1,800/kg of sample) found near butchering sites located along the mouths of large rivers. The Koksoak River contained high levels ofC. botulinumtype E, with the highest median concentration (270/kg) found in sediments of the marine portion of the river.C. botulinumtype E was found in the intestinal contents (4.4%) and skins (1.4%) of seals. A high genetic biodiversity ofC. botulinumtype E isolates was observed among the 21 butchering sites and their surroundings along the Nunavik coastline, with 83% of isolates (44/53) yielding distinct pulsed-field gel electrophoresis genotypes. Multiple sources ofC. botulinumtype E may be involved in the contamination of seal meat during butchering in this region, but the risk of contamination appears to be much higher from environmental sources along the shoreline of southern Ungava Bay and the sediments of the Koksoak River.