Leftover rice risks from Lifehacker

One of my former roommates was a straight edge punk-loving vegan for a while. Now he eats meat and drinks beer, but for a while he survived on rice and sriracha. Sometimes he left his steamed rice out overnight – making some egg-free fried rice the next day. This was before either of us knew much about Bacillus cereus and rice.

Earlier this week Claire Lower from Lifehacker emailed a couple of questions about leftover rice safety. The Lifehacker folks often ask really good questions about the science and why behind food safety recommendations – Claire included. Claire wanted to know why some guidelines say not to leave rice out on the stove over night.

I sent Claire a couple of papers including this one which is an oldie (1974), but a goodie from Gilbert and colleagues which included this awesome B. cereus spore/vegetative cell growth figure (right, exactly as shown) highlighting anincrease of a log or more within 4 hours once in vegetative state.

We looped Don into our discussion and he pointed out the somewhat common practice of boiled and then fried rice in some Asian cooking techniques.

According to Benjamin Chapman, Food Safety Specialist from North Carolina State University, cooking rice doesn’t necessarily kill all the pathogens that may be lurking about. “The issue with rice,” he explained to me over email, “is that one pathogen, Bacillus cereus, is quite prevalent in dried rice (some sources say ubiquitous), likely as spores. The spores may survive cooking. If cooked rice is subsequently held at room temperature, the spores can come out of their protective form, germinate, and vegetative forms multiply. The cooked rice environment provides a lot of water and nutrients for growth. As a by-product of growth, they create a couple of toxins, including a heat-stable one.”

Beyond refrigerating any home-cooked rice, a sense of vigilance is helpful when dining out. According to food scientist Donald Schaffner of Rutgers University, some restaurants “cook up a large batch of rice, hold it at room temperature all day,” and then take portions from the batch as needed. “Because Bacillus makes a heat stable toxin,” he explained “this is not a best practice, and has led to outbreaks in the past.” “Heat stable” means that the toxin can survive boiling and, once the rice is cooled into the “danger zone” of 59-122°F, the bacteria can multiply, making even more of the toxin. Sushi rice, he noted, shouldn’t be a problem as vinegar is added to lower the pH, allowing it to be held safely at room temperature.

Surely you can’t be cereus: Pay attention to temperature control, esp when cooking for large numbers

The aim of this study was to identify and characterise Bacillus cereus from a unique national collection of 564 strains associated with 140 strong-evidence food-borne outbreaks (FBOs) occurring in France during 2007 to 2014.

surely-you-cant-be-seriousStarchy food and vegetables were the most frequent food vehicles identified; 747 of 911 human cases occurred in institutional catering contexts. Incubation period was significantly shorter for emetic strains compared with diarrhoeal strains.

A sub-panel of 149 strains strictly associated to 74 FBOs and selected on Coliphage M13-PCR pattern, was studied for detection of the genes encoding cereulide, diarrhoeic toxins (Nhe, Hbl, CytK1 and CytK2) and haemolysin (HlyII), as well as panC phylogenetic classification. This clustered the strains into 12 genetic signatures (GSs) highlighting the virulence potential of each strain. GS1 (nhe genes only) and GS2 (nhe, hbl and cytK2), were the most prevalent GS and may have a large impact on human health as they were present in 28% and 31% of FBOs, respectively.

Our study provides a convenient molecular scheme for characterisation of B. cereus strains responsible for FBOs in order to improve the monitoring and investigation of B. cereus-induced FBOs, assess emerging clusters and diversity of strains.

Baccillus cereus-induced food-borne outbreaks in France, 2007 to 2014: Epidemiology and genetic characteristics

Eurosurveillance, Vol 21, Issue 48, 01 December 2016

http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=22657

Mighty Taco outbreak pathogen revealed; John McEnroe was wrong

Almost every time someone mentions B. cereus to me I respond with ‘you cannot B. cereus’ as an homage to tennis legend and tantrum thrower John McEnroe’s excellent autobiography. I don’t know if anyone gets the joke.

WGRZ news reports that over 160 Mighty Taco patrons were ill because of B. cereus in refried beans.mte4mdazndewnja3nzy5mtay

The bacteria Bacillus cereus was found in patient clinical specimens and in samples of refried beans from Mighty Taco restaurants, according to a statement from the DOH released Monday.

Bacillus cereus usually causes vomiting within 30 minutes to 6 hours after eating contaminated food, the department says, which is consistent with symptoms described by those who ate at Mighty Taco.

The FDA is looking into the refried beans supplier, Pellegrino Food Products in Warren, Pennsylvania.

 

It was the bacillus cereus: £20k fine for UK caterers after hundreds of wedding guests get food poisoning

A catering company has been fined £20,111 after hundreds of wedding guests were struck with food poisoning from eating contaminated rice.

wedding.crashersEaling Council’s food safety team were first alerted by the father of the bride on September 24, 2013, who that 90% of the 470 wedding guests were suffering with food poisoning.

However, the prosecution could only be based on the 93 guests who formally reported their symptoms of food poisoning to investigators.

Investigators linked the food poisoning with rice prepared by the Royal Club of 116 – 118 Ruislip Road, Greenford, which a Public Health England food examiner found to be ‘potentially injurious to health and/or unfit for human consumption’.  It was found to contain E.coli – a bacteria associated with fecal contamination – and Bacillus bacteria.

Inspections of the Royal Club kitchen revealed serious food hygiene violations. Only one member of staff was trained in food safety. Both the head chef and remaining staff had not received any food safety training at all. Inspectors also discovered that The Royal Club had no refrigerated vehicles in which to safely transport food to events. 

U.K. restaurant fines are no joke; caterer fined £20k for outbreak

Wedding season for Dani and I lasted three years. Not our wedding (which was organized somewhat hastily) but the ones we attended and participated in for our friends. At one point we had attended 30 in 24 months.

We didn’t experience an outbreak though. According to Get West London a caterer contributed to what sounds like the worst wedding ever – over 400 guests came down with Bacillus cereus intoxication.

A food inspector in a chip shop

And U.K. health officials slapped a £20,111 fine on Royal Club and it’s owner is banned from running a food business for 5 years.

Ealing Council’s food safety team were first alerted by the father of the bride on September 24, 2013, who contacted them claiming that 90% of the 470 wedding guests were suffering with food poisoning.

However, the prosecution could only be based on the 93 guests who formally reported their symptoms of food poisoning to investigators.

Greenford catering company, the Royal Club, was given a £20,111 penalty by Ealing Magistrates Court on Tuesday November 25. The company’s sole director, Mr Biku Thapa, was ordered to complete 200 hours of unpaid work and is banned from being a director of any company for five years.

Inspections of the Royal Club kitchen revealed serious food hygiene violations. Only one member of staff was trained in food safety. Both the head chef and remaining staff had not received any food safety training at all. Inspectors also discovered that The Royal Club had no refrigerated vehicles in which to safely transport food to events.

139 sickened: characterization of three Bacillus cereus strains involved in outbreak of food poisoning after consumption of fermented black beans (douchi) in Yunan, China

Three Bacillus cereus strains isolated from an outbreak of food poisoning caused by the consumption of fermented black beans (douchi) containing B. cereus is described.

douchiThe outbreak involved 139 persons who had nausea, vomiting, and diarrhea. The strains were isolated from vomit and the unprepared douchi.

Two of the strains produced the emetic toxin cereulide, as evidenced by polymerase chain reaction analysis for the presence of the nonribosomal synthetase cluster responsible for the synthesis of cereulide and by chemical analysis by high-performance liquid chromatography–mass spectrometry. These two strains belong to genetic group III of B. cereus, and multiple locus sequence typing revealed that the type was ST26, as a major part of B. cereus emetic strains. One of these strains produced significantly more cereulide at 37°C than the type cereulide producer (F4810/72), and it was also able to produce the toxin at 40°C and 42°C. The third strain belongs to genetic group IV, and it is a new multiple locus sequence type closely related to strains that are cytotoxic and enterotoxigenic. It possesses genes for hemolysin BL, nonhemolytic enterotoxin, and cytotoxin K2; however, it varies from the majority of strains possessing genes for hemolysin BL by not being hemolytic. Thus, two B. cereus strains producing the emetic toxin cereulide and a strain producing enterotoxins might have been involved in this food-poisoning incident caused by the consumption of a natural fermented food.

The ability of one of the strains to produce cereulide at ≥37°C makes it possible that it is produced in the human gut in addition to occurring in the food.

Foodborne Pathogens and Disease. Online Ahead of Print: September 4, 2014. doi:10.1089/fpd.2014.1768.

Guoping Zhou, Kai Bester, Bin Liao, Zushun Yang, Rongrong Jiang, and Niels Bohse Hendriksen

http://online.liebertpub.com/doi/abs/10.1089/fpd.2014.1768

44 kids sickened: Ottawa Chinese food takeout fined in summer camp food poisoning

A west Ottawa restaurant has been fined by Ottawa Public Health after rice it served made dozens of people sick and sent six children to hospital from a summer camp.

Lotus Chinese Food TakeoutParamedics were called to St. Cecilia School the afternoon of July 31 after several children and adults from the Tian Tian Chinese Summer Camp reported feeling ill.

Six children suffering from vomiting, dizziness and diarrhea were taken to hospital with suspected food poisoning. They were all released later that day.

Ottawa Public Health said in a statement Friday they inspected three restaurants that provided food for the camp that week. Two of those restaurants passed but the third, Lotus Chinese Food Takeout on Fallowfield Road, did not.

After interviewing more than 90 people from the camp, Ottawa Public Health said a total of 44 people felt sick after eating a fried rice dish from Lotus.

Analysis showed the presence of Bacillus cereus, a bacterium that releases toxins causing symptoms reported by those who got sick, in the rice and a noodle dishes from Lotus.

Are you cereus?

Our usual evening schedule is dinner, a bit of hockey on TV and then wind the kids down with books or a bath before bed. Sometimes it takes 20 minutes to get them to sleep, sometimes 2 hrs. After losing a few meals by leaving our dinner leftovers out for too long due to an extended bedtime routine, we’re now in the habit of refrigerating extras before we sit down to eat.

Tonight’s risotto was packed up and chilling to avoid growing Bacillus cereus (linked to rice dishes 50 per cent of the time).

Bacillus cereus is sort of a fun pathogen (except for those who are affected by it): Two different toxic proteins can be produced by the bacteria as it grows. The one that causes vomit is preformed in food, the one that causes diarrhea is released by the bacteria as it grows in the body.

Turns out that toxin stability in food also plays a part in illnesses.

Effect of temperatures on the growth, toxin production, and heat resistance of bacillus cereus in cooked rice
Foodborne Pathogens and Disease. February 2014, 11(2): 133-137. doi:10.1089/fpd.2013.1609
WangJun, DingTian, and OhDeog-Hwan

ABSTRACT
Bacillus cereus is capable of producing enterotoxin and emetic toxin, and Bacillus foodborne illnesses occur due to the consumption of food contaminated with endospores. The objectives of this study were to investigate the growth and toxin production of B. cereus in cooked rice and to determine the effect of temperature on toxin destruction. Cooked rice inoculated with B. cereus was stored at 15, 25, 35, and 45°C or treated at 80, 90, and 100°C. The results indicated that emetic toxin was produced faster than enterotoxin (which was not detected below 15°C) at all the storage temperatures (15–45°C) during the first 72 h. Emetic toxin persisted at 100°C for 2 h, although enterotoxin was easily to be destroyed by this treatment within 15 min. In addition, B. cereus in cooked rice stored at a warm temperature for a period was not inactivated due to survival of the thermostable endospores. These data indicate that the contaminated cooked rice with B. cereus might present a potential risk to consumers. Results from this study may help enhance the safety of such food, and provide valuable and reliable information for risk assessment and management, associated with the problem of B. cereus in cooked rice.

And from the sort of obvious file, the authors say, “These data indicate that the contaminated cooked rice with B. cereus might present a potential risk to consumers.” Uh huh. It’s not just the data, but the many recorded outbreaks.

Effect of temperatures on the growth, toxin production, and heat resistance of Bacillus cereus in cooked rice

I never order rice when I’m out. I cook it better than I used to for the gluten-free wife, and the kid, who is friends with a kid whose Chinese mom makes excellent stir-fry that I can’t replicate.

But it only took me about 15 years to learn how to cook steak properly, so maybe, soon.

When I make rice, it’s into the refrigerator reasonably fast. But lots of asparagus-and-chicken-fried-ricepeople leave it out overnight and that’s the problem.

As explained by Wang et al in Foodborne Pathogens and Disease:

Bacillus cereus is capable of producing enterotoxin and emetic toxin, and Bacillus foodborne illnesses occur due to the consumption of food contaminated with endospores. The objectives of this study were to investigate the growth and toxin production of B. cereus in cooked rice and to determine the effect of temperature on toxin destruction. Cooked rice inoculated with B. cereus was stored at 15, 25, 35, and 45°C or treated at 80, 90, and 100°C. The results indicated that emetic toxin was produced faster than enterotoxin (which was not detected below 15°C) at all the storage temperatures (15–45°C) during the first 72 h. Emetic toxin persisted at 100°C for 2 h, although enterotoxin was easily to be destroyed by this treatment within 15 min. In addition, B. cereus in cooked rice stored at a warm temperature for a period was not inactivated due to survival of the thermostable endospores. These data indicate that the contaminated cooked rice with B. cereus might present a potential risk to consumers. Results from this study may help enhance the safety of such food, and provide valuable and reliable information for risk assessment and management, associated with the problem of B. cereus in cooked rice.

Kamfen Noodles recalled for Bacillus cereus in Australia

EKO Australia Pty Ltd is recalling batches of their imported noodles sold in NSW in specialty Asian grocery stores.

The batches are being recalled because of the presence of Bacillus cereus, a harmful bacteria.
The recalled products are:

• Kamfen Buckwheat Noodles in 340g plastic bag with ‘best before’ date 2013.04.15
• Kamfen Beijing Noodles, Abalone Chicken Soup Flavour in 160g plastic bag, with ‘best before’ date 2013.01.15
• Kamfen Sichuan Noodles, Abalone Chicken Soup Flavour in 160g plastic bag, with ‘best before’ date 2013.01.15

The recall applies only to the above batches of the products and dates.

Consumers should not consume the products. Consumers can return the products to the place of purchase for a refund.