Category Archives: Research

Research – Europe sees large drop in E. coli infections in 2020

Food Safety News

There was a big fall in the number of Shiga toxin-producing E. coli (STEC) infections in Europe in 2020, according to recently published data.

In 2020, 4,824 confirmed STEC infections were reported. This is down from 8,339 in 2019. STEC infection is mainly acquired through consumption of contaminated food or water and contact with animals or their feces.

Data on STEC infections were reported by 29 countries. Notification is voluntary in Belgium, France, Luxembourg, and Spain or based on another type of system in Italy.

Germany with 1,409 and Ireland with 734 had the most infections, accounting for 44 percent of all cases. The highest country-specific notification rates were in Ireland, Malta, Denmark, and Norway.

Research – Antibiofilm Efficacy of Quercetin against Vibrio parahaemolyticus Biofilm on Food-Contact Surfaces in the Food Industry


Vibrio parahaemolyticus, one of the most common foodborne pathogenic bacteria that forms biofilms, is a persistent source of concern for the food industry. The food production chain employs a variety of methods to control biofilms, although none are completely successful. This study aims to evaluate the effectiveness of quercetin as a food additive in reducing V. parahaemolyticus biofilm formation on stainless-steel coupons (SS) and hand gloves (HG) as well as testing its antimicrobial activities. With a minimum inhibitory concentration (MIC) of 220 µg/mL, the tested quercetin exhibited the lowest bactericidal action without visible growth. In contrast, during various experiments in this work, the inhibitory efficacy of quercetin at sub-MICs levels (1/2, 1/4, and 1/8 MIC) against V. parahaemolyticus was examined. Control group was not added with quercetin. With increasing quercetin concentration, swarming and swimming motility, biofilm formation, and expression levels of target genes linked to flagellar motility (flaAflgL), biofilm formation (vp0952vp0962), virulence (VopQvp0450), and quorum-sensing (aphAluxS) were all dramatically suppressed. Quercetin (0–110 μg/mL) was investigated on SS and HG surfaces, the inhibitory effect were 0.10–2.17 and 0.26–2.31 log CFU/cm2, respectively (p < 0.05). Field emission scanning electron microscopy (FE-SEM) corroborated the findings because quercetin prevented the development of biofilms by severing cell-to-cell contacts and inducing cell lysis, which resulted in the loss of normal cell shape. Additionally, there was a significant difference between the treated and control groups in terms of motility (swimming and swarming). According to our research, quercetin produced from plants should be employed as an antibiofilm agent in the food sector to prevent the growth of V. parahaemolyticus biofilms. These results indicate that throughout the entire food production chain, bacterial targets are of interest for biofilm reduction with alternative natural food agents in the seafood industry. View Full-Text

Research – Antimicrobial Resistance and Virulence Characterization of Listeria monocytogenes Strains Isolated from Food and Food Processing Environments


Listeria monocytogenes is a particularly foodborne pathogen associated with listeriosis, which can be disseminated in food and food processing environments. This study aimed to determine the serotypes and characteristics of virulence factors and antibiotic resistance among 40 L. monocytogenes strains isolated from food (n = 27) purchased in Olsztyn (Warmia and Mazury region, Poland) and food processing environments in Poland (n = 13). Isolates were assigned to serotypes 1/2a, 1/2c, 3a, and 3c using polymerase chain reaction (PCR). The results showed that serotype 1/2a (66.7%) was the most prevalent among strains from food, and serotype 1/2c (53.8%) among strains from the food processing environments. Five different virulence factors (hlyA, prfA, inlB, luxS, sigB) were detected in all isolates from the food processing environments using PCR. The hlyA (100.0%), prfA (100.0%), and inlB (96.3%) were the most prevalent in food strains. Seven (25.9%) of the strains of food and ten (76.9%) strains from the food processing environments showed the ability to form biofilm. The tested isolates were subjected to antibiotic susceptibility testing against 12 antibiotics used in the mitigation of listeriosis, using the disk diffusion method. The most frequent were intermediate resistance and resistance to clindamycin. Twelve (92.3%) strains from the food processing environments, and twenty-three (85.2%) from food were non-susceptible to clindamycin. Generally, antibacterial resistance determinants (LdeaadBaac(3)-IIa(aacC2)apenAmefAlnuAlnuBsulI, sulII) were detected in sixteen (59.0%) strains from food and four (30.8%) from the food processing environments, by PCR. The most frequent were the mefA-lnuA (n = 7; 20.0%) and lnuA (n = 6; 17.1%) genotypes. From this research, we can conclude that virulent and antimicrobial-resistant strains of L. monocytogenes are present in food and the food processing environment in Poland, which may pose a potential health risk to consumers. Monitoring for the control of virulent and antimicrobial-resistant L. monocytogenes strains in the food system can contribute to effective planning and prevention of their spread.

Research – Collective food poisoning (TIAC) ​​with E. coli O157 producing Shiga toxins, associated with the consumption of raw cucumbers

Sante Publique

On September 9, 2021, the Regional Health Agency (ARS) of Hauts-de-France was informed of a suspicion of collective food poisoning (TIAC) ​​affecting half-board students, educated in several schools in a municipality. of the Lille metropolis. On September 13, 2021, two cases of hemolytic and uremic syndrome (HUS) were diagnosed in two hospitalized children attending school in this town. Public Health France Hauts-de-France was asked by the Hauts-de-France ARS to provide support for the investigations and management of this TIAC. A total of 35 cases of gastroenteritis, with bloody diarrhea and fever (>38°C) in half of the cases, were identified. Ten cases were hospitalized and two children developed HUS. The cases identified were half-board students in four school groups (29 cases), a parent of a student and elderly people benefiting from the municipality’s home meal delivery service (5 cases). The case canteens were all supplied by the central municipal kitchen. The shape of the epidemic curve was in favor of a common and point source of contamination during meals on September 2 or 3, 2021. The case-control survey, carried out in schools, concluded that only the consumption of cucumbers in salad, served with the meal on September 2, was statistically and significantly associated with the occurrence of the disease. A strain of E. highly pathogenic Shiga toxin-producing (STEC) O157 coli was isolated from the stool cultures of eight cases, including the two children who developed HUS and in the offending cucumber salad. Genomic analysis of the strains confirmed the genetic clustering of clinical and food strains that belonged to the same genomic cluster. The veterinary investigation revealed that a failure in the decontamination process, associated with incomplete peeling of the contaminated cucumbers, contributed to the occurrence of this TIAC. The cucumbers in question came from Belgium and the Belgian health authorities were informed via the dedicated European alert circuits. No other episodes of clusters of STEC infection related to this TIAC have been reported to the ARS over the period while cucumbers from the same batch had been widely distributed in communities and commercial catering services in the Hauts-de-France region. The food vehicle, incriminated in this TIAC, is part of the plants at risk because of its raw mode of consumption. It is important to remind vulnerable populations and collective catering services that preventing the risk of STEC infection, linked to the consumption of raw vegetables, requires washing, disinfection and peeling.

Research -Microbial safety and sanitary quality of strawberry primary production in Belgium: risk factors for Salmonella and Shiga toxin producing Escherichia coli (STEC) contamination

Academia Edu

Hepatitis A kswfoodworld

Strawberries are an important fruit in Belgium both in production and consumption, but little
information is available about the presence of Salmonella  and STEC in these berries, the risk
factor in agricultural production and possible specific mitigation options. In 2012, a survey
was undertaken of three soil and three soilless cultivation systems in Belgium.
No Salmonella spp. was isolated. No STEC was detected in the strawberry samples (0 out of 72), but STEC
was detected by qPCR in 11 out of 78 irrigation water and 2 out of 24 substrate samples.
Culture isolates were obtained for 2 out of 11 qPCR positive irrigation water samples and 2
out of 2 substrate samples. Multivariable logistic regression analysis revealed elevated generic  E. coli
numbers (odds ratio (OR) for 1 log increase being 4.6) as the most important risk factor for STEC, together with the berry picking season (elevated risk in summer). Presence of generic  E. coli in the irrigation water (≥ 1 cfu per 100 ml) was mainly influenced by the type of irrigation water (collected rainfall water stored in ponds was more often contaminated than ground water pumped from boreholes (OR = 5.8)) and the lack of prior treatment (untreated water versus water subjected to sand filtration prior to use (OR = 19.2)). The follow-up study in 2013 at one of the producers indicated cattle as the most likely source of 
STEC contamination of the irrigation water.

Research – Biofilm formation in food industries: A food safety concern

Academia Edu

Foodborne diseases have always been a threat to human health. They are considered an emergent public health concern throughout the world. Many outbreaks have been found to be associated with biofilms. It is well documented that biofilms have become a problem in food industries as it renders its inhabitants resistant to antimicrobial agents and cleaning. In this review, biofilms formation in dairy, fish processing, poultry, meat, and Ready-To-Eat foods industries are discussed, as well as the biofilms forming abilities of various microorganisms and the influence of food contact surface materials on biofilm formation. In addition, the conventional and emergent control strategies used to gain more proximity to efficiently maintain good hygiene throughout food industries is discussed.

Research – Study Examines Listeria, Salmonella Survival in Dry Packaging Facilities, Efficacy of Sanitizers

Food Safety Magazine

An ongoing study funded by the Center for Produce Safety (CPS) is examining the survival of Salmonella and Listeria monocytogenes on surfaces in dry food packaging facilities, as well as the efficacy of dry cleaning processes on pathogen reduction. The study, led by Clemson University researchers Paul Dawson, Ph.D., and Kay Cooksey, Ph.D., aims to improve produce safety by identifying and investigating critical areas for microbial risk that exist in packinghouse environments after the washing, waxing, and drying steps.

Dr. Dawson chose to focus on Salmonella and L. monocytogenes due to their prevalence in produce packaging facilities, as well as their differing physiological characteristics. For instance, packaging facilities issued recalls for stone fruits contaminated with L. monocytogenes and peaches contaminated with Salmonella in 2016 and 2020, respectively. Additionally, while Salmonella is resistant to drying and can persist on surfaces with low water activity, L. monocytogenes survives and grows under cool, damp conditions. Salmonella can still survive in lower temperatures, but its growth is inhibited.

Research – Increase in food outbreaks by Escherichia coli. How to prevent them


In recent months, outbreaks caused by Escherichia coli have increased (Ireland, Scotland, etc.). Recently, in France, pizzas contaminated by this bacterium affected 56 people─ including 55 small children─ and caused two deaths.

This bacterium is naturally present in our digestive microflora. Although most strains of E. coli  are harmless to humans, others can cause infections or carry antibiotic resistance genes. Among the pathogenic strains, shigatoxigenic E. coli is responsible for serious infections in children and the elderly.

Ruminants, especially cattle, are healthy carriers of these bacteria. Therefore, the bacteria present in their excrement can contaminate animal products (meat and dairy) and the environment (soil and water). Contamination occurs, for example, in the meat slaughterhouse (through the remains or after the evisceration of the animals) or at the time of milking the milk of cattle, sheep or goats.

With regard to plants, this contamination can occur during the spreading of manure or livestock effluents on farmland, or during the use of contaminated irrigation water.

The main foods implicated in outbreaks of shigatoxigenic E. coli infections are undercooked minced beef, non-pasteurized dairy products (raw milk and raw milk cheeses), raw vegetables (salad, young shoots, sprouts), unpasteurized fruits or vegetables and contaminated drinking water .

Throughout the food chain, the management of this risk is based on the application of effective self-controls and the verification of the effectiveness of the measures implemented.

With regard to the consumer, the prevention of infections through food is based on the application of the following measures:

  • Wash hands with soap and water when leaving the toilet, before preparing and eating food, and after handling raw or non-raw food.
  • Wash and peel the vegetables, if possible; and also fruits and aromatic herbs, especially those that are eaten raw.
  • For sensitive populations (young children and the elderly), thoroughly cook ground meat and ground meat products (70°C), avoid consumption of raw milk and raw milk products (except for cooked pressed cheeses), and of raw or undercooked flour.

Research – Salmonella in animals and feed in Great Britain 2021

Gov UK

This publication presents data on Salmonella reports from livestock species in Great Britain (England, Wales and Scotland) collected and collated by the Animal and Plant Health Agency (APHA) during 2021 and also provides data from previous years for comparative purposes.
The data in the first 12 chapters cover reports of Salmonella in animals, with separate chapters for the main livestock species, reports of Salmonella in dogs, reports of Salmonella in wildlife and reports of Salmonella in animal feeding stuffs.
The 13th chapter covers antimicrobial resistance data for Salmonella (England and Wales only).Since 1993, the date of a Salmonella incident has been recorded as the date it was reported to an Officer of the Minister. Under the present system, any Salmonella reports that are confirmed or identified after the publication of the annual report will be incorporated into the revised tables that appear in the following year’s publication. This may result in the number of incidents and/ or isolations differing from that previously given for a particular year.
The most recent version of the report should therefore always be used when comparing data from year to year. Revisions in the way that data have been compiled and presented since 1993 mean that, with the exception of the tables on Salmonella in animal feeding stuffs, data in this report cannot be compared directly with information published prior to 1993. A more detailed comparison can be generated, if required, for any Salmonella serovar, or phage type in the case of S.Enteritidis and S. Typhimurium. Requests for such data should be made to the Department of Epidemiological Sciences, APHA Weybridge who will be happy to assist with requests at Care should be taken when comparing data from one year to another as an increase or decrease in the number of isolations and incidents does not necessarily indicate a similar change in prevalence. This is because the total number of samples examined and their distribution are often not known.

Research-Sources and trends of human Salmonellosis in Europe, 2015-2019: an analysis of outbreak data


Study published in the International Journal of Food Microbiology. The aim of this study was to determine the main food sources and recent trends of  Salmonella outbreaks in Europe. Data from outbreaks in 34 European countries during the 2015-2019 period are taken into account. 

In general, the most important food source of the salmonellosis outbreaks were eggs, pork series and meat products in general. While eggs were the most important source of infection in all regions, pork was the second most common source in Northern and Western Europe, and meat products (in general) in Eastern and Southern Europe. 

There were 939 outbreaks caused by Salmonella enteritidis , 130 by Salmonella typhimurium and its monophasic variant, 107 by other known serotypes, and 332 by other unknown types.

Complex food categories such as baked goods, buffet meals, mixed foods, sweets and chocolate, canned food products, and beverages were grouped as unknown sources in the analysis because it was not possible to identify the exact components responsible for the infection.

In total, 1,508 salmonella outbreaks were included in the analysis. Of these, 1,040 were caused by simple foods and 468 by unknown food sources. Most of the outbreaks were reported in Eastern Europe, followed by Southern, Western and Northern Europe.

Outbreaks caused by S. enteritidis (SE) and other known serotypes (other than SE and S. typhimurium and its monophasic variant [STM]) were attributed primarily to eggs, whereas outbreaks caused by STM were primarily attributed to the Pork Meat. In general, there was a significant increase in the number of reported outbreaks between 2015 and 2019, mainly due to the increase in outbreaks in Eastern Europe while, in Northern and Southern Europe, outbreaks caused by SE decreased significantly between the years 2015 and 2019. Outbreaks related to the consumption of cheese and fish are steadily declining.