Outgrowth of naturally occurring Clostridium botulinum in vacuum-packaged fresh fish.

A total of 1074 test samples of commercial, domestic, vacuum-packaged fresh fish were studied to determine whether spoilage occurs before the products become toxic from naturally occurring Clostridium botulinum spores. The products were incubated for 12 days at 12 degrees C (mild abuse). After incubation, they were tested for botulinal toxin and evaluated for organoleptic acceptability. Even when only marginally acceptable to laboratory personnel, none of the 1074 test samples were positive for C. botulinum toxin. Thus, the fish either contained no C. botulinum spores, or the spores were unable to grow out and produce toxin before spoilage made the product marginally unacceptable.