FDA's Compliance Program Guideline Criteria for Non-toxigenic Escherichia coli: Impacts on Domestic and Imported Cheeses

Introduction: The U.S. Food and Drug Administration’s 2015 Domestic and Imported Cheese and Cheese Products Compliance Program Guidelines (CPG) consider cheeses to be adulterated if non-toxigenic Escherichia coli (E. coli) levels exceeding 10 MPN/g but less than 100 MPN/g are found in 3 or more of 5 subsamples.  It is unknown whether these standards impact food safety, and the extent to which these standards will impact domestic and imported cheeses.

Purpose: To determine E. coli levels and compliance with 1998, 2009, and 2015 FDA CPG non-toxigenic E. coli criteria in tested cheese samples.  

Methods: FDA’s Compliance Program results from January 1, 2004 to December 31, 2006 were analyzed to determine E. coli levels and compliance with 1998, 2009, and 2015 FDA CPG non-toxigenic E. coli criteria. Data was also analyzed to determine correlations between Listeria monocytogenes (L. m.) and non-toxigenic E. coli levels in cheese samples.  

Results: Out of 3,413 cheese samples tested for non-toxigenic E. coli during FY 04, 05, and 06, 2,584 (75.7%) samples contained E. coli levels that exceeded 10 E. coli/g.  Of these samples, 2,287 (67.0%) exceeded 2009 regulatory guidelines of 100 E. coli/g.  In comparison, out of 3,413 cheese samples tested, only 333 (9.8%) of tested cheese samples exceeded EU standards (<1,000 E. coli/g).  Of these samples, only 242 (7.1%) exceeded 1998 CPG criteria (<10,000 E. coli/g). Mexican-style soft, semi-soft, and soft ripened cheeses were most impacted by the 2015 non-toxigenic E. coli standards. Cheese samples that tested positive for L. m. showed poor correlation to non-toxigenic E. coli levels.  Samples that tested positive for high levels of L. m. had associated non-toxigenic E. coli levels as low as <3 E. coli/g. 

Significance: Based upon this analysis, FDA’s 2015 CPG non-toxigenic E. coli standards will have major impacts on domestic and imported cheeses without concomitant food safety benefits.