This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Pace, P. J. Articles by Wisniewski, H. J. Search for Related Content PubMed Articles by Pace, P. J. Articles by Wisniewski, H. J. Agricola Articles by Pace, P. J. Articles by Wisniewski, H. J.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1967 July; 15(4): 877-884
Copyright © 1967 American Society for Microbiology. All Rights Reserved.

Demonstration and Isolation of Clostridium botulinum Types from Whitefish Chubs Collected at Fish Smoking Plants of the Milwaukee Area

City Health Department, Milwaukee, Wisconsin 53202
National Center for Urban and Industrial Health, U.S. Public Health Service, Cincinnati, Ohio

ABSTRACT

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.