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A total of 1,071 whitefish chub samples were examined at eight stages of processing, including sampling aboard ship, various processing steps in the smoking plant, and display in retail cases. The frequency of Clostridium botulinum contamination of freshly caught and eviscerated chubs was approximately 13 to 14%. The highest percentage of contamination (20%) was noted among chubs sampled at the brining step of processing. The prevalence of contamination among chubs sampled at other processing stages prior to the smoking operation ranged from 6 to 14%. Of 858 freshly smoked chubs that had been processed at 180 F for 30 min (internal temperature of loin muscle), 10 were contaminated with C. botulinum (1 Type B and 9 Type E). The use of heat-shocked (60 C for 15 min) and nonheat-shocked enrichment cultures in combination yielded a greater number of positive samples than either method yielded when used alone. Each toxic enrichment culture obtained was subcultured to obtain isolation of the toxigenic organism. Toxigenic pure cultures of C. botulinum were obtained from 80% of the fish samples observed to produce toxic enrichment cultures.

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Identification of Salmonella enteritidis serotype Havana, isolated from a 2½-month old female, engendered efforts to trace the source of infection. The inquiry led to examination of commercially prepared dehydrated dog foods. Twenty-five samples, representing four different manufacturers plus two retail store brands, were examined. Each of 11 samples, produced by one manufacturer, contained one or more Salmonella serotypes. Eight of them contained S. enteritidis serotype Havana. Isolates of serotype Havana from the index case and her mother had antibiotic susceptibility patterns essentially identical to those of nine of 10 serotype Havana isolates recovered from one sample of dog food. The possibility that the human isolates were related to the dog food isolates could not be eliminated.