Category Archives: Decontamination Microbial

Research – Possible explanation for limited reduction of pathogens on radish microgreens after spray application of chlorinated water during growth with disperse contamination spread of abiotic surrogate on leaves

Wiley Online

The purpose of this study was to determine the efficacy of spray application of chlorinated water before harvest on the population of Salmonella enterica Typhimurium and Escherichia coli O157:H7 on radish microgreens. The transfer of abiotic surrogate to radish microgreens was also evaluated to track possible pathogen contamination spread by inoculating seed and growth media. During growth, microgreens inoculated with strains of pathogens were sprayed with chlorinated water at three different concentrations (0.50, 1.00, and 2.00 ± 0.05 ppm free chlorine). Spray application of chlorinated water was performed on microgreens once (day 9), twice (day 8 and 9), three (day 7, 8, and 9), and four times (day 6, 7, 8, and 9). Microgreens were harvested 12 hr after the last application of chlorinated water. Salmonella and E. coli O157:H7 populations were reduced with the increase in chlorine concentration. Chlorinated water reduced Salmonella and E. coli O157:H7 populations up to 1.1 log CFU/g (p < .05) and 0.9 log CFU/g (p > .05), respectively. Images taken under UV illumination provided the visualization of abiotic surrogate spread on cotyledon and upper hypocotyl (all edible parts) of radish microgreen plants regardless of seed or growth media inoculation. Scanning Electron Microscopy showed the presence of abiotic surrogate and generic E. coli on microgreen leaves. Spray application of chlorinated water during microgreen growth may help to reduce microbial load but cannot be used as the only control measure.

Research – Determination of Listeria monocytogenes, competitive microflora, microbial hygiene indicators and physico-chemical parameters during the shelf-life of the typical Mediterranean style fermented sausage “Salsiccia Sarda”

Journal of Food Protection

The aim of the present study was the determination of Listeria monocytogenes , competitive microbiota, microbial hygiene indicators and physico-chemical parameters in the typical Mediterranean Style fermented sausages “Salsiccia Sarda” . A batch of “Salsiccia Sarda” (25 samples) naturally contaminated by L. monocytogenes and vacuum packaged after 24 days of ripening was included in the study. Fifteen samples stored at 8° C were analysed after 13, 90 and lastly at the end of shelf-life, after 180 days from vacuum packaging. Ten vacuum packaged samples were stored at 12°C in a domestic fridge simulating temperature abuse and were evaluated at the end of the shelf-life. Samples were subjected to physico-chemical analysis (pH and aw) and investigated for the presence and enumeration of L. monocytogenes . Competitive microbiota, Lactic Acid Bacteria (LAB) and Coagulase negative Staphylococci (CNS), and microbial hygiene indicators (Total mesophilic bacterial counts, Enterobacteriaceae, Enterococcuss spp. and Staphylococcus aureus ) were determined in all the samples. Although a decreasing trend in L. monocytogenes prevalence was observed through the shelf-life, the detection of the pathogen in fermented sausages confirms the ability of L. monocytogenes to overcome the hurdles of the manufacturing process. The results of the present study highlight the importance to carefully evaluate the “Salsiccia Sarda” production process by Food Business Operators (FBOs) in order to maintain unfavourable conditions for the growth of L. monocytogenes .

Research – Researchers study use of blue light technology for foodborne outbreaks

National Hog Farmer

Researchers from the University of Georgia Center for Food Safety are beginning a new study to investigate the effectiveness of antimicrobial blue light technology to reduce the foodborne pathogens that cause food poisoning.

When used as a means of disinfecting surfaces in a hospital setting, antimicrobial blue light technology has shown promising results, but little research has yet been done to explore its potential efficacy to control foodborne pathogens.

Through a three-year, $599,900 grant awarded by the U.S. Department of Agriculture’s National Institute of Food and Agriculture, UGA College of Agricultural and Environmental Sciences researchers will test the technology to uncover possible applications in the food production process.

Despite industry efforts, the number of foodborne infections has remained steady and, in some cases, has increased in recent years according to the Centers for Disease Control and Prevention (CDC).

Large-scale outbreaks and recalls still occur, particularly due to environmental contamination — like food preparation and processing surfaces — with Salmonella enterica and Listeria monocytogenes, both of which can cause illness and even death.

Most food manufacturers use chemical sanitizers on food preparation surfaces to help control the spread of foodborne pathogens.

This is typically effective in easy-to-reach areas, but areas that are hard to reach may not receive the same degree of sanitation.

These hard-to-reach places sometimes harbor biofilms, which are clusters of microorganisms such as bacteria that are hard to eliminate. The inadvertent spread of these microorganisms can occur during food production both by humans and machinery. Viruses pose a further challenge as many, such as norovirus, can survive on a variety of surfaces for long periods of time.

Australia – Nutricia infant formula tests positive for Cronobacter in Australia

Food Safety News

Nutricia infant formula has been found to contain Cronobacter after testing in Australia.

A batch of KetoCal 3:1 was positive for Cronobacter spp. during testing at the border by customs officials. There have been no illnesses linked to the product, and the source of contamination is being investigated by the company.

The implicated formula is a specialist product not sold to the general public but available under prescription for children with special nutritional needs.

Affected tins are batch number 101101598 with best before July 8, 2023. For many patients there is no alternative feeding option so Nutricia has provided advice to consumers on how to make the product safe.

Research – Invasive listeriosis outbreaks and salmon products: a genomic, epidemiological study

Tandfonline

Invasive listeriosis, caused by Listeria (L.) monocytogenes, is a severe foodborne infection, especially for immunocompromised individuals. The aim of our investigation was the identification and analysis of listeriosis outbreaks in Germany with smoked and graved salmon products as the most likely source of infection using whole-genome sequencing (WGS) and patient interviews.

In a national surveillance program, WGS was used for subtyping and core genome multi locus sequence typing (cgMLST) for cluster detection of L. monocytogenes isolates from listeriosis cases as well as food and environmental samples in Germany. Patient interviews were conducted to complement the molecular typing.

We identified 22 independent listeriosis outbreaks occurring between 2010 and 2021 that were most likely associated with the consumption of smoked and graved salmon products. In Germany, 228 cases were identified, of 50 deaths reported (22%) 17 were confirmed to have died from listeriosis. Many of these 22 outbreaks were cross-border outbreaks with further cases in other countries.

This report shows that smoked and graved salmon products contaminated with L. monocytogenes pose a serious risk for listeriosis infection in Germany. Interdisciplinary efforts including WGS and epidemiological investigations were essential to identifying the source of infection. Uncooked salmon products are high risk foods frequently contaminated with L. monocytogenes. In order to minimise the risk of infection for consumers, food producers need to improve hygiene measures and reduce the entry of pathogens into food processing. Furthermore, susceptible individuals should be better informed of the risk of acquiring listeriosis from consuming smoked and graved salmon products’.

Research – Will climate change increase the risk of aflatoxin in U.S. corn?

Science Daily

As climate change continues to alter weather patterns around the planet including the Midwest, researchers at Michigan State University are modeling the impact on crops such as corn.

“The United States is the largest exporter and donor of field corn around the world,” said Felicia Wu, a John A. Hannah Distinguished Professor and an international expert on food safety in the Department of Food Science and Human Nutrition and the Department of Agricultural, Food, and Resource Economics in the College of Agriculture and Natural Resources at MSU. “Here in the U.S., we consume field corn in the form of corn chips, corn flakes, corn grits and corn tortillas; as opposed to sweet corn, which is frozen, canned and eaten off the cob. Field corn is also used for animal feed and for ethanol production.”

The fungi Aspergillus flavus and Aspergillus parasiticus produce aflatoxin which can infect peanuts, tree nuts and corn. Aflatoxin not only degrades corn quality but can also cause health problems for humans and animals depending on the amount and length of time it is ingested. While aflatoxin contamination occurs annually in the southern United States because of the hot and dry climate, it has rarely been a serious problem in the Corn Belt region of the U.S.

“When we ran our near-term climate model scenarios, we found that between 2031-2040, aflatoxin is going to become more of a problem in the U.S. Corn Belt in the Midwest,” Wu said. “The last time there was a serious problem was in 2012 when we had an unusually hot and dry summer throughout the Midwest; particularly Iowa, Illinois and Indiana.”

Wu’s research was published April 5, 2022 in the journal Environmental Research Letters. Co-authors on the paper include her former doctoral student Jina Yu (Hong Kong Baptist University), David Hennessy (Iowa State University) and Jesse Tack (Kansas State University).

Hot and dry conditions encourage fungi spores to be airborne which increases their chances of contaminating crops. Water helps plants withstand stress that makes them vulnerable to harmful fungi. Steps growers, grain elevators and processors can take to reduce the risk of aflatoxin contamination include storing corn harvests in cool, dry conditions and keeping crops irrigated to the extent possible given declining water tables.

Researchers are already using both biotechnological and conventional breeding techniques to develop hybrid crops that can withstand drought, insect damage and fungal infections. In many parts of the world, corn growers are using biocontrol to reduce aflatoxin. Biocontrol infects plants with Aspergillus fungi which is unable to produce aflatoxin because this these fungi competitively exclude the fungi that produce aflatoxin.

Another possibility shifts crop production further north or further south geographically where the climate is cooler or wetter to reduce aflatoxin risk. That, however, impacts farms that have been passed down for generations.

For consumers concerned about eating field corn and their aflatoxin risk, Wu suggests eating your greens and garlic. “Green leafy vegetables are good for your overall health,” Wu said. “Chlorophyll has a sandwich molecular structure that traps aflatoxin molecules so that humans excrete them before the toxin can enter our bloodstream.”

Also, cruciferous vegetables like broccoli, cauliflower, kale and allium vegetables like garlic, onions and leeks can help detoxify carcinogens in our bodies.

“We predict seeing an increase in aflatoxin problems over the next 10-20 years,” Wu said. “So, we need to rely on technologies and a whole suite of interventions that can reduce the problem.”


Story Source:

Materials provided by Michigan State University. Original written by Emilie Lorditch. Note: Content may be edited for style and length.

India – Shigella caused food poisoning in girl who died after eating shawarma: Kerala health department

India Express

Shigella - kswfoodworld

Kerala health department on Tuesday identified shigella bacteria as the cause of food poisoning which claimed the life of a student and led to the hospitalisation of around 30 others in the state’s Kasaragod district.

District medical officer Dr S K Ramdas said the presence of shigella was confirmed after testing the blood and faeces of those undergoing treatment for food poisoning. The samples collected from the hospitalised persons were tested at the government medical college hospital in Kozhikode, he said.

Philippines – Food poisoning downs 98 in Bayambang

Philstar

BAYAMBANG, Pangasinan, Philippines — Ninety-eight residents of Barangay Inirangan in this town were taken to a hospital for treatment on Friday due to food poisoning.

Municipal health officer Paz Vallo said 29 of the victims are children.

The victims reportedly experienced abdominal pain, itchiness and vomiting after eating galunggong or round scad and green mussels.

Samples of the food they ate were brought to the Bureau of Fisheries and Aquatic Resources (BFAR) for examination.

BFAR said shellfish gathered from the coastal waters of Bolinao remain positive for red tide toxin.

USA – In Food Safety Study, 25% of Participants Contaminated Salad with Raw Chicken

NCSU

Foodborne Pathogen

In a study aimed at assessing the impact of washing poultry on kitchen contamination, researchers found that more than a quarter of study participants contaminated salad with raw poultry – including many study participants who did not wash the poultry. The study highlights the importance of hand-washing and cleaning and sanitizing the kitchen in order to reduce the risk of foodborne illness when cooking at home.

Washing raw poultry is not recommended, due to concerns about inadvertently contaminating other foods and surfaces – and increasing the risk of foodborne illness.

“We wanted to know what effect an educational intervention would have on getting people to stop washing poultry before cooking, and what effect any resulting change in behavior might have on reducing contamination in the kitchen,” says Ellen Shumaker, corresponding author of the study and an extension associate at North Carolina State University. “We also wanted to get a better idea of how, if at all, washing poultry actually led to increased contamination in the kitchen.”

For the study, researchers recruited 300 home cooks who said they washed poultry before cooking it. The researchers sent food safety information to 142 of the study participants via email, outlining risk-reduction efforts – including the recommendation to not wash raw poultry during food preparation. The remaining 158 study participants did not receive the education intervention.

All 300 study participants were then invited to test kitchens equipped with video cameras that filmed meal preparation. Participants were asked to cook chicken thighs and prepare a salad. After preparing the chicken thighs, but before putting the chicken in the oven, participants were called out of the kitchen to conduct a short interview. Participants were then sent back into the kitchen to cook the chicken thighs, prepare the salad, and clean the kitchen as they would at home.

What the study participants didn’t know was that the chicken thighs were inoculated with a harmless strain of bacteria, which the researchers would be able to detect. This allowed researchers to swab surfaces in the kitchen to see whether any cross-contamination occurred during the food preparation and cooking process.

When study participants left the kitchen to conduct the interview, researchers swabbed the kitchen to identify any potential contamination. This process was repeated after each participant had completed cooking the meal and cleaned the kitchen. The prepared salad was also tested for possible contamination.

Ninety-three percent of the participants who received the intervention did not wash the chicken, as compared to 39% of the participants who did not receive the intervention.

However, the researchers were surprised to see that people who did wash the chicken and people who didn’t wash the chicken had similar levels of contamination from the raw chicken in their prepared salads.

Research – Do You Really Need to Wash Fruits and Vegetables?

AARP

During the journey from farm to table, the fruits, vegetables and other foods we eat are exposed to countless people, places, substances and surfaces before ever reaching our mouths. It would seem a given, then, that everything we bring home from the grocery store needs to be thoroughly washed and sanitized.

“Produce comes from the environment; it comes from the ground. The way that it’s grown and harvested, it can have dirt on it and other bacteria,” says Meredith Carothers, technical information specialist at the U.S. Department of Agriculture (USDA). “Unlike meat and poultry, which is packaged, a lot of times produce is just out in the grocery store on display.”

From a food safety standpoint, experts say it’s not necessary to wash all foods. In fact, washing some foods can actually increase the risk of contamination and illness. To help clear up any confusion, we asked Carothers to break down the do’s and don’ts of food washing.

Rules for washing produce

Do rinse fruits and vegetables under running water. After produce is harvested, it gets sorted, delivered and put on display in the grocery store. During this process there are many opportunities for produce to encounter a number of hands and surfaces. Before consuming fresh produce, remove any torn or bruised parts (bacteria that can cause illness thrive in these places) and rinse under running water to remove germs and dirt.

Do scrub hard produce with a clean brush. Foods like potatoes or apples can be scrubbed to thoroughly remove dirt from the exterior, including crevices that rinsing alone may not reach.

Do dry rinsed produce on a clean surface. That means spreading a clean cloth or paper towel on a clean surface to avoid recontamination. If you use a salad spinner, make sure it’s clean before you add greens to it, and clean it again between batches.

Don’t wash produce labeled “prewashed” or “ready to eat.” It is already safe to eat out of the package. Just make sure that prewashed produce doesn’t encounter unclean surfaces or utensils — especially if those surfaces have had raw meat or its juices on them.

Don’t use soap to clean produce. The USDA does not recommend any type of detergent on fruits or vegetables because it can leave behind a film that is not intended to be consumed. Some produce is also porous and may absorb the soap. Although you can buy commercial produce washes, they aren’t approved or labeled by the Food and Drug Administration (FDA) and are not recommended.

Don’t soak produce. Soaking may remove the germs initially, but the now-tainted water can recontaminate your produce as well as nearby surfaces. When produce is rinsed under running water, the dirt and germs go down the drain.