In aFederal RegisterNotice published Sept. 20, 2011, the Food Safety and Inspection Service (FSIS) announced that six shiga toxin producingE. coliserogroups — O26, O45, O103, O111, O121, and O145 (hereinafter STEC) — are adulterants on raw, non-intact beef product or components in the same manner asE. coliO157:H7.

The effective date

FSIS will apply its adulteration decision when the agency initiates its verification sampling plan, expected March 5, 2012. The initial focus will be on beef trim, but once sampling has begun, STEC will be deemed adulterants on any raw, non-intact beef product or component.

FSIS is providing establishments the opportunity to reassess their HACCP programs to address the STEC and to implement any changes to the plan and implement a test program, if desired.

In the interim, FSIS “will generally not regard [STEC positive products] as adulterated.” The only exception identified in the notice is outbreak situations. That said, an establishment could have serious product liability exposure if it knowingly distributes a STEC positive product.

Laboratory method and sampling

Sampling: When implemented, FSIS will draw two 325-gram samples, one for E. coli O157:H7 analysis, the second for the STEC.

Analytical sample: FSIS has moved to a single 325-gram analytical sample for E. coli O157:H7 and for future STEC samples. Although FSIS determined that the 325g is not quite as sensitive as the previous 5-65g samples, the difference was not statistically significant.

Method: FSIS will use its new enrichment for E. coli O157 and STEC. The updated methods themselves have not yet been posted in the Microbiology Laboratory Guidebook.

Sample results: Potential, Presumptive, Confirmed

Potential Positives — Under a two-stage PCR test, samples will be analyzed for stx and eae (stage one); if positive, screened for the presence of one of the target 6 “O” serogroups (stage 2). A sample is “potential” if positive for stx, eae, and one or more of the target O-group genes. According to the agency, results would be available for stage 1 within two days and for stage 2 on the third day of analysis.

Please note, if a sample is positive for stx and eae, but not for one of the target O group, FSIS would nonetheless be concerned that the sample may contain a pathogenic STEC, other than the top 6. Accordingly, FSIS will use these sample results as part of the overall HACCP verification activities. Additionally, the agency expects that an establishment will reassess its HACCP plan following such results.

Presumptive Positive — Samples reported as potential are further analyzed using immunomagnetic beads and inoculated on Rainbow agar. Plates are observed for typical colonies which are tested with latex agglutination reagents. If one colony tests positive, the sample is deemed “presumptive positive.” This will be available on the fourth day.

Confirmed Positives — Samples are “confirmed positive” if the sample has been biochemically confirmed as E. coli. This will be available on the fifth day.

Other provisions

Imports — Imports will be subject to STEC sampling with FSIS initially focusing on raw ground components. In an apparentdifference with domestic sampling, if the FSIS sample “tests positive at the second stage” (which we take to mean a “potential positive”), product will be refused entry or, if not held, recalled.

Baseline — FSIS will perform a national baseline on beef carcasses later this year; STEC will be included in the baseline.

Checklist — In the coming months, FSIS will conduct a new “checklist” survey for STEC controls, similar to the survey conducted in 2007 for E. coli O157:H7.

Other materials — In conjunction with the Notice, FSIS also published a Risk Profile for STEC and Validation Guidance for Pathogen Test Kits.

Comments on Notice — The issue of whether the STEC are adulterants is not open for comment. FSIS is soliciting comments on implementation, outreach and cost-benefit estimates. Comments are due by Nov. 21, 2011.