Category Archives: O45

USA – USDA Starts Testing Ground Beef For Big Six E. coli Strains, O157

Food Poisoning Bulletin

The USDA’s Food Safety and Inspection Service (FSIS) has started testing ground beef, bench trim, and other raw ground beef components for Shiga toxin-producing E. coli strains (STEC) that are adulterants. They include the “Big Six” O26, O45, O103, O111, O121, and O145 as well as O157. The testing started on February 1, 2023. This new program was announced in the Federal Register on June 4, 2020.

USDA Methods Update – Detection, Isolation, and Identification of Top Seven Shiga Toxin-Producing Escherichia coli (STEC) from Meat Products, Carcass, and Environmental Sponges


This method describes the laboratory procedure for analysis of raw and ready-to-eat meat products, and laboratory environmental sponge samples for the seven targeted STEC serogroups (O157, O26, O45, O103, O111, O121 and O145).

Research – Attachment of Shiga Toxin-Producing Escherichia coli (STEC) to Pre-Chill and Post-Chill Beef Brisket Tissue


Shiga toxin-producing Escherichia coli (STEC) has caused numerous foodborne illness outbreaks where beef was implicated as the contaminated food source. Understanding how STEC attach to beef surfaces may inform effective intervention applications at the abattoir. This simulated meat processing conditions to measure STEC attachment to adipose and lean beef tissue. Beef brisket samples were warmed to a surface temperature of 30 °C (warm carcass), while the remaining samples were maintained at 4 °C (cold carcass), prior to surface inoculation with an STEC cocktail (O26, O45, O103, O111, O121, O145, and O157:H7). Cocktails were grown in either tryptic soy broth (TSB) or M9 minimal nutrient medium. Loosely and firmly attached cells were measured at 0, 3, 5, and 20 min and 1, 3, 8, 12, 24 and 48 h. TSB-grown STEC cells became more firmly attached throughout storage and a difference in loosely versus firmly attached populations on lean and adipose tissues was observed. M9-grown STEC demonstrated a 0.2 log10 CFU/cm2 difference in attachment to lean versus adipose tissue and variability in populations was recorded throughout sampling. Future research should investigate whether a decrease in intervention efficacy correlates to an increase in firmly attached STEC cells on chilled carcasses and/or subprimals, which has been reported. View Full-Text

Research – Fate of Salmonella and Enterohemorrhagic Escherichia coli on Wheat Grain

Journal of Food Protection

Wheat flour has been connected to outbreaks of foodborne illnesses with increased frequency in recent years, specifically, outbreaks involving Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC). However, there is little information regarding the survival of these pathogens on wheat grain during long-term storage in a low-moisture environment. This study aims to evaluate the long-term survival of these enteric pathogens on wheat grain over the course of a year. Hard red spring wheat was inoculated with strains of four serovars of Salmonella enterica (Enteritidis , Agona, Tennessee, and Montevideo) and six serotypes of EHEC (O157:H7, O26:H11, O121:H19, O45:NM, O111:H8, and O103:H2) in triplicate, sealed in Mylar bags to maintain the water activity, and stored at room temperature (22 ± 1°C). The survival of each pathogen was evaluated by plating onto differential media . Viable counts of strains from all four serovars of Salmonella (Enteritidis , Agona, Tennessee, and Montevideo) were detected on wheat grain stored at room temperature (22 ± 1°C) for the duration of the study (52 weeks). Viable counts of strains from EHEC serotypes O45:NM, O111:H8, and O26:H11 were only detected for 44 weeks and strains from serotypes O157:H7, O121:H19, and O103:H2 were only detected for 40 weeks until they passed below the limit of detection (2.0 log CFU/g). D -values were found to be significantly different between Salmonella and EHEC (adj. p ≤ 0.05) with Salmonella D -values ranging from 22.9 ± 2.2 to 25.2 ± 1.0 weeks and EHEC D -values ranging from 11.4 ± 0.6 to 13.1 ± 1.8 weeks. There were no significant differences amongst the four Salmonella strains or amongst the six EHEC strains (adj. p > 0.05). These observations highlight the wide range of survival capabilities of enteric pathogens in a low-moisture environment and confirm these pathogens are a food safety concern when considering the long shelf life of wheat grain and its products.

USA – Florida company recalls 3 tons of ground beef for E. coli risk

Food Safety News

Operators of institutional kitchens in Florida are being urged to check their refrigerators and freezers for fresh and frozen raw ground beef products because the producer found E. coli in the meat.

Win Opportunity Knocks, doing business as Ottomanelli Wholesale Meats Inc. in St. Petersburg, FL, reported the ground beef products could be contaminated with three different E. coli serotypes, O45, O130 and O145, according to a recall notice posted July 18.

The notice on the USDA’s Food Safety and Inspection Service (FSIS website, did not indicate what type of institutions received the recalled beef. The notice also did not say whether there have been any reported or confirmed illnesses in relation to the recalled products.