E. coli O103 as an adulterant in Cheese and other foods.

According to Washington State Health, two Whatcom County residents are known to have been sickened by cheese tainted with E. coli O103, and test results showed a genetic link between their illness and Twin Sisters Creamery products. An additional case in Oregon has also been genetically linked. One is a child under five years old, and two are adults. One person was hospitalized. All illnesses occurred between September 5 and September 16, 2025.

It reminded me of the history of deeming additional Shiga-tozin producing E. coli as adulterants – including E. coli O103.

The history of deeming non-O157:H7 adulterants

E. coli strains as adulterants is a direct result of aggressive and persistent advocacy and litigation by the food safety law firm Marler Clark, following years of foodborne illness outbreaks. The effort was a critical expansion of food safety policy, building on the initial success of having E. coli O157:H7 declared an adulterant after the deadly 1993 Jack in the Box outbreak. 

The precedent: E. coli O157:H7 is deemed an adulterant

The pivotal moment in U.S. food safety occurred in 1994, after the Jack in the Box outbreak sickened hundreds and killed four children. 

• Trigger event: The outbreak was linked to undercooked hamburgers, with litigation handled by attorney Bill Marler.
• Legal precedent: As a direct result of this crisis and the ensuing litigation, the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS) declared E. coliO157:H7 an “adulterant” in raw ground beef.
• Major policy shift: This declaration was a dramatic shift from the prior stance that pathogens in raw meat were not adulterants. It established a zero-tolerance policy, making it illegal to sell ground beef contaminated with O157:H7. 

The push for non-O157:H7 STEC adulterants

After 1994, public health experts, including Marler Clark, recognized that other Shiga toxin-producing E. coli (STEC) strains posed similar public health risks.

• Persistent outbreaks: Several high-profile outbreaks tied to non-O157 STECs occurred in the 2000s, including an O111 outbreak in Oklahoma in 2008 and O26 illnesses linked to Cargill ground beef in 2010.
• Marler Clark’s campaign: Bill Marler and his law firm, Marler Clark, took a leading role in advocating for regulatory change. Citing the ongoing illnesses and deaths, they repeatedly petitioned the USDA and FSIS to expand the adulterant classification to other dangerous STECs.
• Strategic actions: As part of their campaign, Marler Clark funded independent lab tests on ground beef to demonstrate the prevalence of non-O157 STECs. They published articles and gave presentations to press for action and public awareness. 

The official regulatory change

The collective pressure from Marler Clark, other food safety advocates, and federal agencies culminated in a major regulatory announcement in 2011 and implementation in 2012.

• Final determination (2011): The FSIS officially determined that six additional STEC strains—O26, O45, O103, O111, O121, and O145—would be classified as adulterants in raw ground beef. This decision was announced in September 2011 and followed years of deliberation and public comment.
• Implementation (2012): FSIS began implementing a zero-tolerance policy for these six non-O157 STECs in raw beef trim in 2012.
• Expanded testing (2013): Over time, testing for these adulterants was expanded to include ground beef, bench trim, and other raw ground beef components. 

The impact of the change

Deeming these non-O157 STECs as adulterants had a profound effect on the meat industry and public health.

• Legal accountability: It provided a new basis for legal action against companies whose products caused illness, aligning liability with the broader range of dangerous STEC pathogens, not just O157:H7.
• Industry innovation: The adulterant classification spurred the meat industry to develop new and improved testing methods, sanitation protocols, and risk-management strategies to prevent contamination.
• Public health improvement: The expanded testing and industry changes resulted in a significant reduction of illnesses from both O157:H7 and non-O157 STECs. 

Republished with permission from Bill Marler and Marler Clark. Copyright (c) Marler Clark LLP, PS. All rights reserved.

Source: https://www.marlerblog.com/case-news/e-coli-o103-as-an-adulterant-in-cheese-and-other-foods/