Tag Archives: flour

Martin Easter, Hygiena
In the Food Lab

The New Normal: Pinpointing Unusual Sources of Food Contamination

By Martin Easter, Ph.D.
No Comments
Martin Easter, Hygiena

Shiga toxin-producing E. coli in dry flour, and then romaine lettuce. E. coli O104 in fenugreek sprout seeds. Recent announcements of foodborne illness outbreaks have begun involving unusual combinations of bacteria and foods. These out-of-the-ordinary outbreaks and recalls are a small but growing part of the 600 million documented food poisonings that occur worldwide every year according to the World Health Organization. Preventing outbreaks from these new combinations of pathogen and food demand a range of accurate tests that can quickly identify these bacteria. Over the past several years, outbreaks from unusual sources included:

  • E. coli O121 (STEC) in flour: Last summer, at least 29 cases of a E. coli O121 infection were announced in six Canadian provinces. The source arose from uncooked flour, a rare source of such infections because typically flour is baked into final products. Eight people were hospitalized, and public health officials have now included raw, uncooked flour as well as raw batter and dough as a source of this type of infection.
  • E. coli O104:H4 in fenugreek sprouts: One of Europe’s biggest recent outbreaks (affecting more than 4,000 people in Germany in 2011, and killing more than 50 worldwide) was originally thought to be caused by a hemorrhagic (EHEC) E. coli strain that from cucumbers, but was but was later found to be from an enteroaggregative E. coli (EAEC) strain in imported fenugreek seeds—the strain had acquired the genes to produce Shiga toxins.
  • Mycoplasma in New Zealand dairy cows: While not unusual in cattle, the incident reported in August marks the pathogen’s first appearance in cows in New Zealand, a country known for strict standards on agricultural hygiene. The microorganism is not harmful to people, but can drastically impact livestock herds.
  • Listeria monocytogenes in food sources: Listeria monocytogenes causes fewer but more serious incidence of food poisoning due to a higher death rate compared to Salmonella and Campylobacter. Whereas Listeria has been historically associated with dairy and ready to eat cooked meat products, recent outbreaks have been associated with fruit, and the FDA, CDC and USDA are conducting a joint investigation of outbreaks in frozen as well as in fresh produce.
  • Listeria in cantaloupe: In 2011, one of the worst foodborne illnesses recorded in the United States killed 20 and sickened 147, from Listeria monocytogenes that was found in contaminated cantaloupes from a farm in Colorado. The outbreak bloomed when normal background levels of the bacteria grew to deadly concentrations in multiple locations, from transport trucks to a produce washer that was instead designed for potatoes.

The outbreaks underscore the fundamental need to have a robust food safety program. Bacteria can colonize many different locations and the opportunity is created by a change in processing methods and/or consumer use or misuse of products. So robust risk assessment and preventative QA procedures need to be frequently reviewed and supported by appropriate surveillance methods.

Food safety and public health agencies like the European Food Safety Authority (EFSA) or the CDC have employed a wide range of detection and identification tests, ranging from pulse field gel electrophoresis (PFGE), traditional cell culture, enzyme immunoassay, and the polymerase chain reaction (PCR). In the case of Germany’s fenugreek-based E. coli outbreak, the CDC and EFSA used all these techniques to verify the source of the contamination.

These tests have certain advantages and disadvantages. Cell culture can be very accurate, but it depends on good technique and usually takes a long time to present results. PFGE provides an accurate DNA fingerprint of a target bacteria, but cannot identify all strains of certain microorganisms. Enzyme immunoassays are precise, but can produce false-positive results in certain circumstances and require microbiological laboratory expertise. PCR is very quick and accurate, but doesn’t preserve an isolate for physicians to test further for pathogenic properties.

Identification of the pathogens behind foodborne contamination is crucial for determining treatment of victims of the outbreak, and helps public health officials decide what tools are necessary to pinpoint the outbreak’s cause and prevent a recurrence. Rapid methods such as the polymerase chain reaction (PCR), which can quickly and accurately amplify DNA from a pathogen and make specific detection easier, are powerful tools in our efforts to maintain a safe food supply.

Recently, scientists and a third-party laboratory showed that real-time PCR assays for STEC and E. coli O157:H7 could detect E. coli O121, O26 and O157:H7 in 25-g samples of flour at levels satisfying AOAC method validation requirements. The results of the study demonstrated that real-time PCR could accurately detect stx, eae and the appropriate E. coli serotype (O121, O26 or O157:H7) with no statistical difference from the FDA’s Bacteriological Analytical Manual (BAM) cell culture method.

Agencies like the World Health Organization and CDC have repeatedly stated that historical records of food poisoning represent a very small percentage of true incidents occurring every year worldwide. Many of today’s most common food pathogens, like Listeria monocytogenes, E. coli O157:H7 or Campylobacter jejuni, were unknown 30 years ago. It’s not clear yet if unusual sources of contamination arise from increasing vigilance and food safety testing, or from an increasingly interdependent, globally complex food supply. No matter the reason, food producers, processors, manufacturers, distributors and retailers need to keep their guard up, using the optimum combination of tools to protect the public and fend off food pathogens.

Recall

E. Coli Outbreak Investigation of Flour Ends, More Illnesses to Come

By Food Safety Tech Staff
No Comments
Recall

Last week the CDC announced the end of its investigation involving Shiga toxin-producing E. coli  (STEC) in General Mills flour and flour products. However, many consumers may still have these products in their homes, and thus the agency is warning that it expects to see more illnesses. As of September 26, 2016, the CDC recorded 63 infections with strains of STEC O121 or STEC O26 in 24 states, 17 of which resulted in hospitalizations, and no deaths. The agency continues to urge consumers to refrain from eating (this includes a simple “taste”) raw dough or batter. It is also advising against giving playdough made with raw flour to children.

CDC worked with FDA and used PulseNet to identify illnesses that were part of the outbreak. This investigation led General Mills to initiate several recalls of its branded flours (May 31, 2016, July 1, 2016 and July 25, 2016), affecting more than 10 million pounds of product.

“In an epidemiologic investigation, investigators compared the responses of ill people in this outbreak to those of people of similar age and gender reported to state health departments with other gastrointestinal illnesses. Results from this investigation indicated an association between getting sick with STEC and someone in the household using Gold Medal brand flour.

Federal, state, and local regulatory officials performed traceback investigations using package information collected from ill people’s homes and records collected from restaurants where ill people were exposed to raw dough. These initial investigations indicated that the flour used by ill people or used in the restaurants was produced during the same week in November 2015 at the General Mills facility in Kansas City, Missouri, where Gold Medal brand flour is produced,” according to the CDC’s outbreak summary.

Massive Flour Recall Expanded, Again

More E. Coli Illnesses, General Mills Expands Flour Recall

 

Recall

Massive Flour Recall Expanded, Again

By Food Safety Tech Staff
No Comments
Recall

As a result of four additional confirmed illnesses, General Mills has added four more production dates to its flour recall (production dates through February 10, 2016). The initial recall was announced May 31, with an expanded recall taking place earlier this month.

“At this time, it is unknown if we are experiencing a higher prevalence of E.coli in flour than normal, if this is an issue isolated to General Mills’ flour, or if this is an issue across the flour industry. The newer detection and genome sequencing tools are also possibly making a connection to flour that may have always existed at these levels,” according to a company release on FDA’s website.

Thus far, illnesses have only been linked to consumers who said they ate or handled uncooked dough or ate uncooked batter made with raw flour, not with flour that was baked, cooked or handled.

Recall

More E. Coli Illnesses, General Mills Expands Flour Recall

By Food Safety Tech Staff
No Comments
Recall

Consumers should check their pantry. As a result of newly reported illnesses connected to raw dough or batter consumption, General Mills has expanded its recall of Gold Medal flour, Wondra flour and Signature Kitchens flour to include products made last fall. The FDA and CDC have warned consumers against eating any raw products made with flour.

According to the CDC, the multi-state outbreak of Shiga toxin-producing E. Coli O121 has sickened at least 42 consumers (with 11 hospitalizations) across 21 states. No deaths have been reported. The bacteria was isolated from samples of General Mills flour that was collected from the homes of those sickened in Arizona, Colorado and Oklahoma.

General Mills has already conducted a voluntary recall of 10 million pounds of flour (unbleached, all purpose and self rising). A full list of the products included in the recall are available on FDA’s website.