Category Archives: Microbiological Risk Assessment

Research – Effects of High-Voltage Atmospheric Cold Plasma Treatment on Microbiological and Quality Characters of Tilapia Fillets

MDPI

Cold plasma (CP) has become an alternative to conventional thermal processing of food products. In this study, the effect of cold plasma treatment time on the inactivation and quality of tilapia fillets was investigated. The surfaces of tilapia fillets were inoculated with Salmonella enteritis (S. enteritis), Listeria monocytogenes (L. monocytogenes), and a mixture of both before being treated with cold plasma at 70 kV for 0, 60, 120, 180, 240, and 300 s. With the extension of treatment time, the number of colonies on the surface of the fillets decreased gradually; after 300 s of cold plasma treatment, S. enteritis and L. monocytogenes populations were reduced by 2.34 log CFU/g and 1.69 log CFU/g, respectively, and the a* value and immobile water content decreased significantly (p < 0.05), while the free water content increased significantly (p < 0.05). TBARS value increased significantly (p < 0.05) to 1.83 mg MDA/kg for 300 s treatment. The carbonyl value and sulfhydryl value of sarcoplasmic protein significantly (p < 0.05) increased and decreased, respectively, as treatment time extension, while no significant changes were found in myofibrillar protein. No significant differences were observed in pH, b* value, elasticity, chewiness, thiol value, and TVB-N value. The results showed that cold plasma had an inactivation effect on tilapia fillets and could preserve their original safety indicators. It was concluded that CP treatment could be used as an effective non-thermal method to maintain the quality of tilapia fillets and extend their shelf-life. View Full-Text

Denmark – Health and Economic Burden of Seven Foodborne Diseases in Denmark, 2019

Mary Anne Liebert

We ranked seven foodborne pathogens in Denmark on the basis of their health and economic impact on society in 2019. We estimated burden of disease of infections with Campylobacter spp., Salmonella spp., Shiga toxin-producing Escherichia coli (STEC), Yersinia enterocoliticaListeria monocytogenes, norovirus, and hepatitis A virus in terms of incidence, mortality, disability-adjusted life years (DALY), and economic burden in terms of direct and indirect health costs. These seven pathogens accounted for 268,372 cases, 98 deaths, and 3121 DALYs, and led to a total expenditure of 434 million Euro in 1 year in a country with 5.8 million citizens. Foodborne infections by CampylobacterSalmonella, and norovirus caused the most DALYs, whereas Campylobacter, and norovirus and STEC had the higher costs. A combination of disease burden and cost of illness estimates is useful to inform policymaking and establish food safety priorities at the national level.

Research – Oil-based systems show promise for eradicating Salmonella on food production machinery

Science Daily

Recent outbreaks of food-borne Salmonella have been associated with chocolate and peanut butter. Although Salmonella cannot grow in either of these low-water foods, the cells survive, becoming more resistant to heat treatment, which has contributed to recent outbreaks. New research published in Applied and Environmental Microbiology suggests that oil formulations with food-grade organic acids can kill dried Salmonella on stainless steel surfaces.

“Cleaning and sanitation of manufacturing environments are critical for a safe food supply,” said lead author Lynne McLandsborough, Ph.D., a professor of food science at University of Massachusetts Amherst. However, water-based cleaning is rarely used in processing peanut butter, because it promotes microbial growth. “Also, as anyone who has baked peanut butter cookies can tell you, peanut butter and water do not mix, and cleanup with water is challenging,” said McLandsborough.

Instead, manufacturers often remove residual peanut butter from manufacturing systems using heated oil, followed by overnight cooling and application of flammable alcohol-based sanitizing agents.

In the study, McLandsborough and collaborators dried Salmonella on stainless steel surfaces at controlled relative humidity. They then covered the dried bacteria with various oils with organic acids, varying the acid type, concentration, contact time and treatment temperature to identify highly antimicrobial formulations.

By using peanut oil mixed with acetic acid at a concentration about half that of household vinegar and applying heat, “killing was much greater than expected, indicating a synergistic effect,” said McLandsborough. “Our results show that acidified oils could be used as an effective means of sanitation in low-moisture food processing facilities, where water-based cleaning can be challenging.”

“To our knowledge, using oils as a carrier of organic acids is a novel approach to delivering antimicrobial compounds against food-borne pathogens,” said McLandsborough. The research may thus lead to adaptation of oil-based systems for industrial cleaning, for example, of machinery for processing chocolate and peanut butter, said McLandsborough. “That would enable more frequent cleaning, boosting the safety of these products.”

Research – A multi-jurisdictional outbreak of Salmonella Typhimurium infections linked to backyard poultry—Australia, 2020

Wiley Online

Zoonotic salmonellosis can occur either through direct contact with an infected animal or through indirect contact, such as exposure to an infected animal’s contaminated environment. Between May and August 2020, a multi-jurisdictional outbreak of Salmonella Typhimurium (STm) infection due to zoonotic transmission was investigated in Australia. In total, 38 outbreak cases of STm with a median age of 5 years were reported. Epidemiological investigation showed contact with live poultry to be a common risk factor with most cases recently purchasing one-week old chicks from produce/pet stores. Traceback investigation of cases identified 25 product/pet stores of which 18 were linked to a single poultry breeder farm. On farm environmental sampling identified the same STm genotype as identified in cases. Whole genome sequencing of both environmental and human outbreak isolates found them to be highly related by phylogenetic analysis. This investigation describes the first documented widespread zoonotic salmonellosis outbreak in Australia attributed to backyard poultry exposure and identified potential risk factors and prevention and control measures for future outbreaks. Prevention of future outbreaks will require an integrated One Health approach involving the poultry industry, produce/pet store owners, animal healthcare providers, public health and veterinary health agencies and the public.

USA – Method Change – Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg, and Siluriformes (Fish)Products and Carcass and Environmental Sponges

FSIS USDA

Introduction
The methods described in this guidebook are for use by the FSIS laboratories. FSIS does not specifically endorse any of the mentioned test products and acknowledges that equivalent products may be available for laboratory use.
FSIS utilizes the following performance criteria when evaluating the suitability of an alternative laboratory method or product for a given analyte and sample matrix pair:
•Sensitivity of 90% or greater
•Specificity of 90% or greater
•Accuracy of 90% or greater
•Positive predictive value of 90% or greater
•Negative predictive value of 90% or greater
Performance criteria are relative to the reference cultural method for that analyte and sample matrix as outlined in the corresponding MLG chapter. Method validation is necessary to demonstrate the equivalence of alternative tests as detailed in the document titled “FSIS Guidance for Evaluating Test Kit Performance.”
This method describes the analysis of various meat, poultry and Siluriformes (fish) products, sponge and rinse samples, and egg products for Salmonella.
It is not intended for the isolation and identification of Salmonella typhi.
Success in isolating Salmonella from any food can be related to a number of factors including food preparation procedures, the number of organisms present, sample handling after collection, etc. With raw samples, the competitive flora may be the most important factor. It varies from sample to sample and from one kind of matrix to another.
Another consideration is whether the examination is for routine monitoring or epidemiological purposes. The analyst may choose to augment the method for epidemiological purposes with additional enrichment procedures and culture media, two temperatures of incubation, intensified selection of colonies from plates, and/or rapid screening methods.
Unless otherwise stated all measurements cited in this method have a tolerance range of +/-2%.

Virginia Tech researcher to test vaccine for Norovirus

VTX

Norovirus Food Safety kswfoodworld

Lijuan Yuan, professor of virology and immunology at the Virginia-Maryland College of Veterinary Medicine at Virginia Tech, will evaluate a potential live oral vaccine for norovirus, the No. 1 cause of foodborne illness.

Indiana University’s John Patton and colleagues are developing a norovirus vaccine that uses the Rotarix rotavirus vaccine as a platform. Using reverse genetics, they will insert a norovirus protein into Gene 7 of the rotavirus. The virus will then express the norovirus protein in the gut, inducing an immune response against norovirus.

Yuan’s lab will evaluate the replication capacity, immunogenicity, and protective efficacy of the vaccine using gnotobiotic pig models of human rotavirus and norovirus infection and diarrhea. A gnotobiotic animal is one that has been specially raised to contain zero germs or bacteria so researchers can better study the effects of bacteria and viruses such as rotavirus and norovirus.

According to the Centers for Disease Control and Prevention, norovirus is the leading cause of vomiting and diarrhea from acute gastroenteritis in the United States, resulting in 19 million to 21 million cases every year.

Norovirus tends to affect young children and the elderly the most. It’s responsible for about 24,000 hospitalizations and 925,000 outpatient visits for American children each year, according to the National Center for Biotechnology Information. Rotavirus also causes acute gastroenteritis and hits young children the hardest.

“Together, rotavirus and norovirus cause over 415,000 deaths every year, and norovirus also has a very significant burden even in the countries that don’t have a lot of deaths. The economic cost is huge, $4.2 billion in direct costs and $60 billion in indirect societal costs. You hear about norovirus outbreaks on the news all the time in hospitals, nursing homes, and cruise ships and how it’s closing down restaurants, so it’s got a lot of economic implications,” said Yuan.

Research – An 11-Year Analysis of Bacterial Foodborne Disease Outbreaks in Zhejiang Province, China

MDPI

Background: Foodborne diseases are a growing public health problem and contribute significantly to the global burden of disease and mortality. Bacteria are the most common foodborne pathogens. We aimed to explore characteristics of bacterial foodborne disease outbreaks (FBDOs) in Zhejiang Province and to provide data support for foodborne disease prevention and control. Methods: Descriptive statistical methods were used to analyze the data reported by centers for disease control (CDCs) at all levels in Zhejiang Province through Foodborne Disease Outbreaks Surveillance System (FDOSS) during 2010–2020. Results: CDCs in Zhejiang Province reported 517 bacterial FBDOs in 11 years, resulting in 7031 cases, 911 hospitalizations, and 3 deaths. Vibrio parahaemolyticus had the highest number of outbreaks, accounting for 58.41% of the total bacterial outbreaks, followed by Salmonella (18.38%). In all settings, restaurants (37.14%), staff canteens (11.99%), and households (11.80%) were responsible for the large number of outbreaks. Aquatic products (42.08%), meat and meat products (23.56%), cereals (10.81%), and flour products (9.27%) were the most common single foods reported. Further analysis showed that the settings and food vehicles of outbreaks caused by different pathogens were different. Conclusions: Bacterial outbreaks are the most common type of FBDOs in Zhejiang Province. By analyzing the epidemiological characteristics of common pathogenic bacteria, we can identify the etiology, food, and setting that the government needs to focus on, and issue relevant targeted policies to reduce the number of FBDOs. View Full-Text

Researchers introduce rapid diagnostic test for Listeria

Phys Org

Researchers in the University of Georgia College of Engineering are developing a new way to detect potentially deadly Listeria contamination in food.

Listeriosis, an infection caused by eating food contaminated by the bacterium Listeria monocytogenes, can cause severe illness in pregnant women, newborns, the elderly and people with compromised immune systems. Listeria is the third leading cause of death from foodborne illness, or food poisoning, in the United States. An estimated 1,600 people get sick each year and about 260 die, according to the Centers for Disease Control and Prevention.

Currently, Listeria contamination in food products is identified only through molecular tests conducted in diagnostic laboratories on samples taken at specific control points during the manufacturing and distribution process. Although very accurate, this method requires significant processing time, transportation of samples, and expensive skilled labour and equipment.

In a new study published in the Journal of The Electrochemical Society, UGA researchers introduce a rapid diagnostic method based on electrochemical biosensing principles. Electrochemical biosensors are promising alternatives to molecular detection methods because of their ease of use, high specificity, sensitivity and low cost, according to the researchers.

The UGA researchers use bacteriophages, viruses that infect and replicate within bacteria, as bioreceptors to identify L. monocytogenes using an electrochemical sensor.

Denmark – Risk of disease-causing bacteria in grilled sausages and cocktail sausages

DVFA

Danish Crown is recalling grilled sausages and cocktail sausages, as there is a risk that they are not thoroughly cooked.

Recalled Foods , Published: August 11, 2022

Modified August 12, 2022

What foods

Steff Houlberg Hotdog 375 gr – Production date: 10-08-2022; Best before: 09-09-2022. Sold in Rema 1000

Salling Cocktail sausages 200 gr – Production date: 08-08-2022; Best before: 07-09-2022. Sold in Bilka and Føtex

Smart Cooking Cocktail sausages 200 gr – Production date: 08-08-2022; Best before: 07-09-2022. Sold in Netto

Company that revokes

Danish Crown Foods, ​Tulipvej 1, 8940 Randers

Cause

The company has established that it cannot be documented that the sausages have been thoroughly cooked.

Risk

There may be a risk of disease-causing bacteria in the products.

Advice for consumers

The Danish Food and Drug Administration advises consumers to return the sausages to the shop where they were bought, or to discard them.

RASFF Animal Feed – Salmonella – Rapeseed Extraction Meal – Chicken Meal

RASFF

Salmonella spp. in rapeseed extraction meal dispatched from the Netherlands in Switzerland, Germany and Denmark

RASFF

Salmonella spp in farina di pollo (ABP Cat. 3) dalla Slovenia//Salmonella spp in chicken meal (ABP Cat. 3) from Slovenia in Italy and Germany