Hygienic Indicator Organisms. A Comparison of Survival and Enumeration of the Group D Streptococci and 'Escherichia coli'Following Freezing and Frozen Storage,

摘要

The Group D streptococci and Escherichia coli were compared as to their ability to survive freezing and frozen storage as well as the capability for enumeration on selective bacteriologic media. The non-enterococcal portion of the Group D streptococci, including Streptococcus bovis and Streptococcus equinus, exhibited marked sensitivity to all parameters measured. Escherichia coli was able to survive freezing and frozen storage, however cellular injury to frozen cells prevented enumeration on selective media. The enterococcal portion of the Group D streptococci demonstrated resistance to effects of freezing and frozen storage. Enumeration of the enterococci with the use of selective media was not affected by either freezing or frozen storage. Results of this study have implications in the hygienic analysis of frozen food products. (Author)