Category Archives: Decontamination Microbial

Research – Emerging Method to Protect Food Crops from Carcinogenic Aflatoxins

Food Safety.Com

Researchers from the U.S. Department of Agriculture’s Agricultural Research Service (USDA’s ARS) are using a bioplastic coating to naturally shield seeds from Aspergillus, a type of fungi that produces aflatoxin. Exposure to aflatoxins is a food safety issue due to the compound’s carcinogenic and other harmful effects.

In the U.S., Southern agriculture is most affected by aflatoxins, as hot, dry conditions promote Aspergillus growth and aflatoxin production. Recent science has shown, however, that the Midwestern Corn Belt may be increasingly affected in the near future due to climate change. Corn is highly susceptible to aflatoxin contamination, as are seeds, nuts, feed, stored grain, and other important crops.

The new method for mitigating aflatoxin contamination of crops involves coating seeds with a protective, innocuous strain of Aspergillus, delivered via a mixture of biodegradable, corn starch-based bioplastic and biochar. The competitive Aspergillus strain found in the coating prevents aflatoxin-producing Aspergillus from infecting the seed, and other components of the mixture create a physical barrier that prevents contamination.  

Research – Tofu Whey Wastewater as a Beneficial Supplement to Poultry Farming: Improving Production Performance and Protecting against Salmonella Infection

MDPI

Tofu whey wastewater (TWW) is a by-product of the tofu production process, and contains high amounts of organic products and Lactobacillus ap. However, no studies have been reported on whether naturally fermented TWW can be used as a beneficial additive for poultry production. This study analyzed the main nutritional components and microbial flora of naturally fermented TWW from rural tofu processing plants and their effect on chick production performance, role in modulating the biochemical and immune parameters, and protection against Salmonella enteritidis (S. enteritidis) infection. It was observed that the average pH of TWW was 4.08; therefore, the total viable count was 3.00 × 109 CFU/mL and the abundance of Lactobacillus was 92.50%. Moreover, TWW supplementation increased the total weight gain and feed intake, reduced the feed/gain ratio, increased the length and relative weight of the gut, and reduced the colonization and excretion of S. enteritidis in chickens. Additionally, TWW decreased oxidative damage and pro-inflammatory cytokine secretion caused by S. enteritidis infection. In addition, TWW supplementation ensured the structure of the intestine remained relatively intact in S. enteritidis-infected chicken. Furthermore, TWW markedly promoted the intestinal barrier integrity and up-regulated the relative abundance of Lactobacillus, counteracting the changes in gut microbiota caused by S. enteritidis infection in chicken. In conclusion, our data demonstrated that TWW could be used as a beneficial addition to poultry production, providing a research basis for the further development of TWW as a health care application in in food-producing animal.

Research – Antimicrobial Phage Spray Effective Against Foodborne Bacteria, Including Multidrug Resistant E. Coli

Food Safety.Com

Researchers at McMaster University have developed a new, highly effective tool to mitigate bacterial contamination of foods, including pathogens displaying antimicrobial resistance (AMR). The technology involves the application of bacteriophages (phages)—benign viruses that eat bacteria—to goods in the form of microgels.

Phages are natural predators to bacteria, and because phages attack bacteria in a highly targeted manner, they can be used in food and agriculture without disturbing the balance of microbial communities. Phage products have been approved by the US Food and Drug Administration (FDA) for controlling dangerous bacterial contaminants such as Escherichia coli in food products. Though they do not affect the taste, texture, and nutritional quality of foods, phages are not widely used by industry due to challenges with delivery and stability of phage products.

Research -Risk assessment of enteric viruses along the food chain and in the population

EFSA

Abstract

Food-borne microbial illness contributes up to one third of global disease burden. The largest category of food-borne illness is gastroenteritis, the majority of which is caused by enteric viruses. Viruses like these are transmitted to food either by waste-contaminated waters, or by handling and transfer during processing.

An important tool for reducing or controlling food-borne microbial risk is risk analysis. This framework has been adopted globally to manage risks associated with microbial contamination in food. Several hundred microbial risk assessments (MRAs) have been published by different national and international organisations, for different food-hazard combinations. The use of MRAs in controlling and understanding virus risk has, to date, been limited, compared with the efforts made on bacterial pathogens. Given the large disease burden that viruses are responsible for, this disparity should be addressed. 

The main reasons for the relative lack of risk assessments are the difficulty in detecting and monitoring viruses compared with bacteria. This means less data on prevalence, concentration and inactivation, and allows viruses to remain silent contributors to global disease. There are also key conceptual differences between virus risk assessment and bacterial risk assessment. This project aimed to assess the current state of the art for food-borne virus risk assessment, then to progress the field further by using the data available to produce risk rankings and risk assessments.

This was done by a combination of literature reviewing and various risk assessment tools. The result was an assessment of the overall evidence base in the literature, a semi-quantitative ranking comparison between the viruses and foods of most concern, and a survey of inactivation methods, leading to a quantitative ranking of the effectiveness of each in reducing and managing food-borne virus risk.

Research – Identification of Genetic Markers for the Detection of Bacillus thuringiensis Strains of Interest for Food Safety

MDPI

Abstract

Bacillus thuringiensis (Bt), belonging to the Bacillus cereus (Bc) group, is commonly used as a biopesticide worldwide due to its ability to produce insecticidal crystals during sporulation. The use of Bt, especially subspecies aizawai and kurstaki, to control pests such as Lepidoptera, generally involves spraying mixtures containing spores and crystals on crops intended for human consumption. Recent studies have suggested that the consumption of commercial Bt strains may be responsible for foodborne outbreaks (FBOs). However, its genetic proximity to Bc strains has hindered the development of routine tests to discriminate Bt from other Bc, especially Bacillus cereus sensu stricto (Bc ss), well known for its involvement in FBOs. Here, to develop tools for the detection and the discrimination of Bt in food, we carried out a genome-wide association study (GWAS) on 286 complete genomes of Bc group strains to identify and validate in silico new molecular markers specific to different Bt subtypes. The analyses led to the determination and the in silico validation of 128 molecular markers specific to Bt, its subspecies aizawaikurstaki and four previously described proximity clusters associated with these subspecies. We developed a command line tool based on a 14-marker workflow, to carry out a computational search for Bt-related markers from a putative Bc genome, thereby facilitating the detection of Bt of interest for food safety, especially in the context of FBOs.

Australia – Cause of illnesses from spinach in Australia identified; Costco among stores that received product

Food Safety News

Investigations into almost 200 foodborne illnesses in Australia after eating a brand of baby spinach have revealed what caused the illnesses.

Riviera Farms said the spinach was contaminated with a weed called thornapple. The scientific name is Datura stramonium and it is also known as jimsonweed. How the weed got into the food supply is still being investigated by Victorian authorities with site inspections underway.

Riviera Farms issued a recall of baby spinach after reports of customers falling ill. The company then contacted its 20 clients. Costco is the only direct major retail client, however, the product was also sold to stores such as Coles, Aldi, and Woolworths.

Spinach products were grown on a farm in Victoria and shipped to several stores across the country. More than 190 potential cases were reported in New South Wales, Australian Capital Territory, Victoria, and Queensland.

There have been several hospitalizations. Toxicological impacts are still to be confirmed but it is understood most people experienced symptoms for a short time and then recovered.

The Handwashing Handbook

Global Handwashing Org

The Handwashing Handbook is based on the experience of the Global Handwashing Partnership and presents best practices and new concepts to improve the uptake of handwashing. The Handwashing Handbook focuses on:

  • Making the Case for Handwashing
  • Designing and Implementing Handwashing Programs
  • Improving Handwashing in Specific Contexts
  • Addressing Handwashing at a Systems Level

The Handwashing Handbook is available in Arabic, Chinese, English, French, Portuguese, and Spanish.

Resource Attachments:
https://globalhandwashing.org/wp-content/uploads/2020/10/GHP_Handwashing-Handbook_FINAL.pdf (pdf)
https://globalhandwashing.org/wp-content/uploads/2020/10/Handwashing-Handbook-Arabic.pdf (pdf)
https://globalhandwashing.org/wp-content/uploads/2020/10/Handwashing-Handbook-Chinese.pdf (pdf)
https://globalhandwashing.org/wp-content/uploads/2020/10/Handwashing-Handbook-French.pdf (pdf)
https://globalhandwashing.org/wp-content/uploads/2020/10/Handwashing-Handbook-Portuguese.pdf (pdf)
https://globalhandwashing.org/wp-content/uploads/2020/10/Handwashing-Handbook-Spanish.pdf (pdf)

Spain – New regulations on food safety applied to retail trade

ACSA

Published in the BOE Royal Decree 1021/2022, of December 13, which regulates certain hygiene requirements for the production and marketing of food products in retail establishments.

This royal decree establishes measures for the correct application throughout the State of the EU regulations on food safety, with the aim that its implementation is homogeneous throughout the territory and also makes use of flexibility provisions to favor the sustainability of the food system.

The new text compiles in a single regulation the requirements for meat and derivatives, for fishery products, raw milk, foods made with eggs, prepared meals, thus repealing the specific regulations for these food groups and that were prior to the hygiene pack.

In addition, it incorporates in its articles the regulation of the preparation of meals in private homes, the requirements in the tasting areas, vending machines, the access of pets to these establishments and establishes measures against food waste and the use of reusable containers. .

The bill regulates, among others, hygiene requirements such as temperature and establishes guidelines for freezing, thawing and refreezing operations and specific requirements for prepared meals.

In the case of large pieces of fruit, such as watermelon, melon, pineapple, cut into halves or quarters, it will be allowed to keep them for a while at room temperature.

Table 1. Temperature requirements of food products

Food refrigeration temperature

1. Meat of domesticated ungulates and of wild or farmed large game, except rats.

Equal to or less than 7 °C.
2. Carcasses of domestic ungulates, farmed and wild game, poultry and lagomorphs. Equal to or less than 3 °C.
3. Meat of poultry, lagomorphs, small wild game and rats. Equal to or less than 4 °C.
4. Meat preparations. Equal to or less than 4 °C.
5. Minced meat. Equal to or less than 2 °C.
6. Live bivalve molluscs and fishery products that are kept alive. Temperature that does not negatively affect its safety and viability.
7. Fresh fishery products, unprocessed thawed fishery products, cooked and refrigerated crustaceans and molluscs. Temperature close to that of melting ice (0-4 °C).
8. Raw milk. 1-4°C
9. Filled pastry products (unless stable at room temperature). Equal to or less than 4 °C.
10. Cut or peeled fruits, cut or peeled vegetables and unpasteurized juices ready for consumption and made in the retail trade. Equal to or less than 4 °C.
11. Frozen or deep-frozen foods. Equal to or less than –18 °C.

Research – Microbiological Quality of Ready-to-Eat Salad Products Collected from Retail and Catering Settings in England during 2020 to 2021

Journal of Food Protection

ABSTRACT

Salad and other fresh produce were collected in England from retail and catering businesses during 2020 to 2021 and were tested for Salmonella, Shiga toxin–producing Escherichia coli (STEC), Listeria, Bacillus cereus, and E. coli. Of the 604 samples collected, 57% were from retail settings and 43% were from catering settings; 61% were either salad leaves or salad leaves mixed with other products.

Equal numbers of samples were prepacked or loose, and 50% were refrigerated at the time of sampling. Combining results for all microbiological parameters, 84% were interpreted as satisfactory, 12% were interpreted as borderline, and 4% were interpreted as unsatisfactory. One sample (prepacked leaves, cucumber, and tomato from a caterer) was categorized as unacceptable and potentially injurious because of detection of STEC O76; no STEC from human infections in the United Kingdom matched this isolate.

No Salmonella enterica was detected, but Listeria monocytogenes was recovered from 11 samples: 1 at 20 CFU/g and the remainder at <20 CFU/g. B. cereus was detected at borderline levels (103 to ≤105 CFU/g) in 9% of samples and at an unsatisfactory level (>105 CFU/g) in one sample. E. coli was detected in 3% of samples at borderline levels (20 to ≤102 CFU/g) and in 4% at unsatisfactory levels (>102 CFU/g).

There was a significant association between detection of L. monocytogenes and borderline or unsatisfactory levels of E. coli. There were no specific risk profiles associated with products with the higher levels of B. cereus, STEC, or Listeria, but elevated levels of E. coli were predominantly confined to loose products from the United Kingdom collected from caterers in summer or autumn 2021 and may have resulted from relaxation of COVID-19 restrictions. Among the L. monocytogenes isolates, only one matched those from human cases and was recovered from a prepacked mixed salad from a catering business in 2021. This isolate was the same strain as that responsible for a multicountry outbreak (2015 to 2018) associated with Hungarian-produced frozen sweet corn; no link to the outbreak food chain was established.

New Zealand – The 12 food safety myths of Kirihimete – How to Avoid Food Poisoning

MPI

Ho! Ho! Uh-oh! New Zealand Food Safety deputy director-general Vincent Arbuckle busts some food safety myths to help you avoid giving your whānau and friends food poisoning over the festive season (and beyond).

1. You can reheat leftovers as many times as you like

One of the joys of the holiday season is having a mountain of leftovers. Reheating them once, to piping-hot temperature, shouldn’t be a problem (unless you’ve left them out too long before refrigerating or freezing). But every time you cool your food and reheat it, you give germs the opportunity to multiply, so doing this more than once raises the risk of foodborne illness. If you have a big batch of leftovers in the fridge, reheat only what you need, or divide it into meal-sized potions before freezing. Bin any unfinished reheated food. And, if your leftovers aren’t frozen, eat them within 2 days. While we’re at it, let’s bust the myth that leftovers are safe to eat if they look and smell okay. Although many nasties cause spoilage that will quicky make itself known in looks, texture, smell and (if you regrettably get that far) taste, there are many that are undetectable in the usual way. If in doubt, throw it out!

More information about food poisoning symptoms and causes

2. Hot leftovers should be left out to cool completely before refrigerating

Although it’s true that putting hot food in the fridge can drop its overall temperature slightly, it’s not as potentially detrimental to your health as waiting for your leftovers to cool completely. So, to decrease the risk of giving bacteria more time to grow on hot food, cool it for up to 30 minutes at room temperature (or wait till it’s stopped steaming), put it in a shallow dish (to help the food cool faster), cover, and pop it in the fridge, making sure there’s room for the air to circulate. Hot tip: most harmful bacteria can’t grow at low temperatures, so set your fridge to between 2°C and 5°C

More information about chilling your food

3. Freezing food kills bacteria and viruses

Given how much frozen berries and Hepatitis A have been talked about over the past few months, this myth is fortunately losing a bit of traction. But to be clear, freezing doesn’t necessarily kill the germs that can contaminate food. The recent frozen berry recall is a good reminder that viruses, such as Hepatitis A, can survive freezing, freeze-drying, and heat of less than 85°C. Washing frozen berries also doesn’t get rid of the problem. When the berries start defrosting, the warmer conditions allow the bacteria to wake up and start multiplying. If you want to be sure your berries are safe to eat, boil them or cook them for at least a minute at more than 85°C. Then refreeze them in an ice tray to have handy as needed.

Media release: frozen berries recall

More information about making frozen berries safe to eat

4. The best way to defrost food is to leave it out on the kitchen bench

Leaving your defrosting food on the bench is, in reality, the best way to give bacteria time to grow in a nice, warm environment. Bacteria thrive in temperatures between 5°C and 60°C, so, to decrease the likelihood of bacteria multiplying, and your food spoiling and making you sick, defrost it in the fridge, or in the microwave. Fun fact: bacteria are some of the fastest-reproducing organisms on Earth – they can double in number every 4 to 20 minutes!

More information about preparing and storing food safely at home

5. It’s okay to eat shellfish that you have gathered raw, as long as it’s fresh

Kiwis love their seafood –  and many people have traditionally gathered and eaten shellfish like mussels, kina, and pipi raw. But times have unfortunately changed. Vibrio is a type of bacteria naturally living in the sea, and some strains can cause gastroenteritis when consumed. Thanks in part to warmer sea temperatures, there’s more Vibrio around, so eating raw or undercooked shellfish, even fresh, can make you and your whānau very ill. Cases of Vibrio parahaemolyticus illness and hospitalisations have been increasing every year over summer. So, to help prevent illness, keep your gathered shellfish alive and cool, cook it thoroughly before eating, and keep raw shellfish away from other cooked or ready-to-eat food (so Vibrio can’t transfer to uncontaminated food).

More information about how to collect, store and cook shellfish – including recipes

6. You need to wash raw chicken before cooking it

Chicken in New Zealand has already been washed, so you don’t need to do it again. Although Campylobacter, Salmonella and other illness-causing bacteria live on raw chicken, it’s not a good idea to wash it again at home. Rinsing or washing it allows these bacteria to spread to other areas of your kitchen. If you’re worried about chicken juices, just pat it dry with a clean paper towel and then throw the paper towel away. While we’re on the topic of chicken, it’s also not okay to use the same chopping board, utensils, or plate for both your raw and cooked chicken. Anything that’s touched raw chicken needs to be washed in hot, soapy water before being used for any other food – and that includes your hands.

More information about handling chicken safely

7. Eating foods after the ‘use by’ date is fine

We know times are tough and few can afford to throw away food, but if the ‘use by’ date on a packaged product in your fridge or pantry has come and gone, bin it. It is not safe to eat. In fact, it’s illegal to sell food past its ‘use by’ date. However, food should still be safe to eat after the ‘best before’ date, but it’s likely to have lost some quality. Stores can sell food beyond a ‘best before’ date, as long as it’s still fit for human consumption. Make sure to check the date on your food labels, so you can make a good call on whether to chow down or chuck out.

More information about food labels

8. Plastic chopping boards are more hygienic than wooden ones

The key to a chopping board being hygienic is to thoroughly clean it after every use with hot, soapy water – particularly if you’ve been using it for raw meat, fish or shellfish. But, to bust the myth, research by food microbiology and toxicology expert Dr Dean O. Cliver showed wooden chopping boards retain less bacteria than plastic boards, particularly if the plastic has been damaged by knives, providing convenient spots for bacteria to hide before transferring onto other food. He found that wood, because it’s porous, absorbs the bacteria – and although the bacteria doesn’t die immediately, neither does it return to the surface of the board. So wood is the better option. As for glass and stainless-steel cutting boards, they’re not porous like wood and don’t scratch easily like plastic, so keep them clean, and happy chopping!

More information about food safety at home

9. It’s okay to eat a little bit of raw cookie dough or cake batter

Unfortunately, it’s not okay. Raw flour – and raw whatever-else-you’ve-popped-in-your-dough – can carry illness-inducing bacteria. Baking will kill that bacteria. Although there are clear food standards and food safety guidelines in New Zealand, raw flour can be contaminated with Salmonella, so, remember the rhyme: ‘Just a lick can make you sick!’

More information about safe cooking tips

10. You don’t need to wash bagged greens or salads

Any bagged lettuce, salad, or other manner of greens you buy, still need to be washed first before using. Under running water in a clean colander in the sink will do. This will reduce any food safety risks due to bacteria or chemical residues.

More information about other cleaning tips

11. If you drop food on the floor and pick it up within 5 seconds, it’s safe to eat

Sorry, the ‘5-second rule’ is a myth. Whether it’s 1 second or 10, all bacteria and viruses need to get onto your food – and into your gut – is any contact at all. Although the moisture and stickiness of the food will affect the number of germs that will attach to the food, to be safe, if you’ve dropped it on the way to your mouth, best to bin it – and wash your hands. If you’ve dropped it during food preparation – and it can be salvaged (we’re not talking spilt milk and broken eggs) – and if you really can’t bear to throw it away, rinse it and make sure it’s cooked thoroughly to kill unwanted nasties.

More information about food poisoning

12. Mouldy food is okay to eat, as long as I cut off the mouldy bit

That spot of mould you scrape of your bread, or the one you cut off your cheese, is the tip of the iceberg. Mould have spores and roots going into the food, which you often can’t see. They can also produce toxic chemicals called mycotoxins that can make you really ill. Not all moulds are bad – some make life-saving medicine (penicillin) and delicious cheeses. Fun fact: the mould used in the production of camembert and brie is named Penicillium camemberti, after the cheese first made in the late 18th century in Camembert, France.

More information about food poisoning