Category Archives: Food Microbiology Research

Research – Virulence Potential and Antimicrobial Resistance of Listeria monocytogenes Isolates Obtained from Beef and Beef-Based Products Deciphered Using Whole-Genome Sequencing

Posted on June 15, 2024 by | Leave a comment

MDPI

Abstract

Listeria monocytogenes is a ubiquitous bacterial pathogen that threatens the food chain and human health. In this study, whole-genome sequencing (WGS) was used for the genomic characterization of L. monocytogenes (n = 24) from beef and beef-based products. Multilocus Sequence Type (MLST) analysis revealed that ST204 of CC204 was the most common sequence type (ST). Other sequence types detected included ST1 and ST876 of CC1, ST5 of CC5, ST9 of CC9, ST88 of CC88, ST2 and ST1430 of CC2, and ST321 of CC321. Genes encoding for virulence factors included complete LIPI-1 (pfrA–hly–plcA–plcB–mpl–actA) from 54% (13/24) of the isolates of ST204, ST321, ST1430, and ST9 and internalin genes inlABC that were present in all the STs. All the L. monocytogenes STs carried four intrinsic/natural resistance genes, fosX, lin, norB, and mprF, conferring resistance to fosfomycin, lincosamide, quinolones, and cationic peptides, respectively. Plasmids pLGUG1 and J1776 were the most detected (54% each), followed by pLI100 (13%) and pLM5578 (7%). The prophage profile, vB_LmoS_188, was overrepresented amongst the isolates, followed by LP_101, LmoS_293_028989, LP_030_2_021539, A006, and LP_HM00113468. Listeria genomic island 2 (LGI-2) was found to be present in all the isolates, while Listeria genomic island 3 (LGI-3) was present in a subset of isolates (25%). The type VII secretion system was found in 42% of the isolates, and sortase A was present in all L. monocytogenes genomes. Mobile genetic elements and genomic islands did not harbor any virulence, resistance, or environmental adaptation genes that may benefit L. monocytogenes. All the STs did not carry genes that confer resistance to first-line antibiotics used for the treatment of listeriosis. The characterization of L. monocytogenes in our study highlighted the environmental resistance and virulence potential of L. monocytogenes and the risk posed to the public, as this bacterium is frequently found in food and food processing environments.

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Posted in Food Microbiology Research, Food Pathogen, Listeria, Listeria monocytogenes, Pathogen, Research, WGS, Whole Genomic Sequencing

Research – Salmonella Typhimurium caused an unprecedentedly large foodborne outbreak in Finland in 2021 – Mixed Veg

Posted on June 14, 2024 by | Leave a comment

Wiley Online

Aims

Salmonella infections are significant causes of foodborne outbreaks in the European Union. This study investigates a sudden increase in gastroenteritis patients in the hospital district of Central Finland in June 2021. The primary aim was to study the outbreak’s magnitude and source of the outbreak.

Methods and Results

Epidemiological, microbiological, environmental and traceback investigations were conducted. Over 700 persons fell ill during the outbreak caused by Salmonella Typhimurium associated with a daycare lunch. Similar S. Typhimurium was found in the patients and a vegetable mix containing iceberg lettuce, cucumber and peas served during lunch. The traceback investigation revealed that the batch information of vegetables from the wholesaler was not complete. The wholesaler had received quality complaints about the iceberg lettuce from the central kitchen. The manufacturer did not test the suspected batch for Salmonella since the production plant had given a certificate declaring it Salmonella negative.

Conclusions

The most suspect ingredient was one batch of iceberg lettuce due to quality complaints. The lettuce had not been served in two daycare centres without cases. We recommend that in order to enable thorough microbiological investigation, institutional kitchens store the food samples separately as part of the internal quality control and that food items should always be tested when Salmonella contamination in an outbreak is suspected.

Impacts

  • The largest Salmonella Typhimurium outbreak in the European Union in 2021 was linked to a vegetable mix served at daycare centres in Finland.
  • Food samples should be stored separately for possible outbreak investigation and tested when an outbreak is suspected.
  • Collaboration between healthcare and environmental health authorities in investigating and managing outbreaks is vital.

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Posted in food bourne outbreak, Food Illness, Food Microbiology Research, Foodborne Illness, foodborne outbreak, foodbourne outbreak, Illness, outbreak, Research, Salmonella

RASFF Alert- Bacillus cereus – Chilli Sauce

Posted on June 14, 2024 by | Leave a comment

RASFF

Bacillus cereus in chilli sauce, from China in  Austria, Belgium, China, Finland, France, Germany, Hong Kong, Ireland, Malta, Netherlands, Romania, Sweden.

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Posted in Bacillus, Bacillus cereus, food contamination, food handler, Food Hazard, Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Poisoning, Food Quality, food recall, Food Safety, Food Safety Alert, Food Safety Management, Food Safety Regulations, Food Testing, Food Toxin, RASFF

Czech Republic – Raspberry slice Staphylococcus aureus

Posted on June 13, 2024 by | Leave a comment

Potravinynapranyri

Illustrative photo #1

Place of inspection:
Štětí ( Obchodní 548, 411 08 Štětí )
ID: 71838601
Food group: Confectionery and dough / Confectionery

Raspberry slice
Category: Dangerous foods
Invalid parameter:

Coagulase-positive staphylococci

The food exceeded the limit for the content of pathogenic bacteria – coagulase-positive staphylococci. These bacteria cause staph infections.

Expiration date: 9/5/2024
Quantity of the product in the package: 240 g
Manufacturer: Smetanová cukrárna as, Panenské Břežany 199, 250 70 Panenské Břežany
Date of sample collection: 7/5/2024
Reference number: 24-000245-SZPI-CZ
The sample was detected by the official control of the State Agricultural and Food Inspection.

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Posted in food contamination, food handler, Food Hazard, Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Quality, food recall, Food Safety, Food Safety Alert, Food Safety Management, Food Safety Regulations, Food Testing, Food Toxin, Potravinynapranyri, Staphylococcal Toxin, Staphylococcus aureus

Research – The Hidden Risks of Rice and Flour: Brazilian Study Uncovers Alarming Mycotoxin Levels in Everyday Foods

Posted on June 13, 2024 by | Leave a comment

Scitech Daily

The foods, found in the homes of Brazilian families participating in the research, were stored for future consumption. The study is the first in Brazil to use biomarkers to characterize the risk associated with mycotoxins in the diet.

Researchers from the University of São Paulo (USP) analyzed samples of flour and rice stored in homes in Ribeirão Preto, São Paulo, Brazil, and discovered high levels of fungal toxins (mycotoxins). The study, supported by FAPESP, was published in the journal Food Research International.

As the authors point out, dietary exposure to mycotoxins can trigger a range of health problems, especially in children and adolescents. The data therefore reinforce the importance of storing foods such as grains and flour in dry places and protecting them from insects to avoid the risk of contamination.

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Posted in Aflatoxin, Aflatoxin B1, aflatoxin m1, Alternaria Toxin, Animal Feed Mould Toxin, Aspergillus Toxin, Food Microbiology Research, Food Toxin, Fusarium Toxin, Mold Toxin, Mould Toxin, Mycotoxin, Ochratoxin, Ochratoxin A, Research, Toxin

Italy- Clams Arselle Cuore – Lipophilic Marine Botoxin

Posted on June 10, 2024 by | Leave a comment

Salute

Brand : cirdu

Name : arselle Cuore

Reason for reporting : Recall due to chemical risk

Publication date : 10 June 2024

Documentation

Documentation

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Posted in Algal Toxin, food contamination, food handler, Food Hazard, Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Research, Food Microbiology Testing, Food Poisoning, Food Quality, food recall, Food Safety, Food Safety Alert, Food Safety Management, Food Safety Regulations, Food Testing, Food Toxin, Lipophilic Marine Biotoxin, Marine Biotoxin, Shellfish, shellfish toxin

Research – Campylobacter jejuni in Vacuum Packaged Processed Turkey

Posted on June 9, 2024 by | Leave a comment

Science Direct

This study evaluated the effect of vacuum packaged storage at 4°C upon survival of Campylobacter jejuni in processed turkey roll and turkey ham. Turkey ham and turkey roll samples were sliced, inoculated with C. jejuni, vacuum packaged, and stored at 4°C for up to 28 d. Three different strains of C. jejuni were evaluated. After appropriate incubation, the inoculated samples were analyzed for culturable C. jejuni. Control samples were analyzed for aerobic plate count and enterococci. Culturable C. jejuni decreased significantly during vacuum packaged storage at 4°C over time (P<0.05). A significant difference in viability existed between the three test strains used (P<0.05). Higher levels of C. jejuni were detected in the turkey roll than the turkey ham. Aerobic plate counts and enterococci increased significantly during storage (P<0.05) providing competition for C. jejuni. Though survival of C. jejuni decreased over time, greater than 500 viable cells per gram were detected with some strains for up to 28 d.

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Posted in Campylobacter, Campylobacter jejuni, Food Microbiology Research, Research

Research – Bacteria Can Transfer from Plastic Mulch to Basil and Spinach Salad Leaves

Posted on June 9, 2024 by | Leave a comment

Natural Science

Key Findings

  • The University of Stirling study found that human pathogens can transfer from plastic mulch fragments to ready-to-eat crops like basil and spinach within 24 hours
  • Pathogens such as Salmonella Typhimurium and Vibrio cholerae can persist on plastic mulch fragments for up to 14 days
  • The study highlights that removing plastic fragments and washing crops may not be enough to eliminate these pathogens, stressing the need for better management practices in agriculture
Plastic pollution is increasingly found in agricultural environments, where it contaminates soil and crops. A recent study from the University of Stirling[1] examined whether human pathogens can transfer from plastic mulch fragments to ready-to-eat crop plants, posing a risk to food safety and human health. The study focused on two pathogens, Salmonella Typhimurium and Vibrio cholerae, and found that both could persist on plastic mulch fragments for 14 days and transfer to the leaves of basil and spinach within 24 hours. This finding is significant as it highlights a new pathway for pathogen contamination in fresh produce, which has been a persistent issue with severe health, economic, and social impacts[2]. The study’s results suggest that even removing plastic fragments and washing crops may not be sufficient to eliminate these pathogens, emphasizing the need for better management practices in agricultural systems that use plastic mulches. Previous research has shown that biodegradable plastic films, although more environmentally friendly, can degrade rapidly and potentially release more microplastics into the soil compared to conventional films[3]. These microplastics can alter soil microbial communities and nutrient cycling, potentially affecting plant health and crop productivity. The University of Stirling study expands on this by demonstrating that these microplastics can also serve as vectors for human pathogens, further complicating the issue. Moreover, the degradation of plastic fragments in soil is highly variable, with some commercial polymer mixtures taking up to 48 days to degrade, while biodegradable formulations can degrade completely within 32 days[4]. The incorporation of plant growth-promoting bacteria like Bacillus subtilis can even accelerate this process. However, the rapid degradation of biodegradable plastics also means they can release pathogens more quickly into the environment, posing a continuous risk. Another concern is the contamination of agricultural soils through fertilizers composted from livestock and poultry manure, which often contain microplastics[5]. These microplastics can enter the soil and potentially carry pathogens, adding another layer of complexity to managing plastic pollution in agricultural settings. The University of Stirling study underscores the urgent need to address the co-pollutant pathogen risk associated with plastic pollution in agriculture. As the demand for intensive food production grows, so does the use of plastic mulches, making it crucial to understand and mitigate the risks they pose to food safety and human health. This research calls for improved agricultural practices and further studies to develop effective strategies for managing plastic pollution and its associated risks in food production systems.

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Posted in Food Microbiology Research, Food Pathogen, Food Technology, Pathogen, pathogenic, Research

Research – Cold plasma processing for food safety

Posted on June 8, 2024 by | Leave a comment

Food Safety News

 Cold plasma is an emerging food processing technology which has been shown to effectively inactivate pathogenic bacteria, viruses, parasites, and fungi. The process uses high-voltage electricity to ionize air and/or defined gas blends to create a mixture of ions, free electrons, ozone, radical species, and other reactive products. This energetic plasma, which operates near room temperature, has been tested with fruits, vegetables, nuts, meats, cheeses, poultry, seeds, powders, and other foods.

Once created at the high voltage electrodes, the cold plasma is applied to foods and food contact surfaces. Forced air can blow the cold plasma over products and surfaces, as with plasma jet systems. This allows for the varying treatment distances of irregularly shaped foods. The commodity may also be moved in and out of the plasma field, as with dielectric barrier (DBD) systems. In either case, reactive chemical species in the cold plasma break the cellular structures, DNA, and proteins of pathogens on foods, inactivating them. Efficacy is dependent on treatment intensity and duration. Combining cold plasma with chemical sanitizers, high intensity light, or other food safety interventions can provide enhanced, synergistic pathogen inactivation. Short treatments with cold plasma can induce sublethal injury in pathogens, rendering them more susceptible to another sanitizing processes.

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Posted in Cold Atmospheric Plasma, Cold Plasma, Food Microbiology Research, Food Pathogen, Food Technology, Hurdle Technology, Pathogen, pathogenic, Research, Technology

Research – Acid Adaptation Enhances Tolerance of Escherichia coli O157:H7 to High Voltage Atmospheric Cold Plasma in Raw Pineapple Juice

Posted on June 8, 2024 by | Leave a comment

MDPI

Abstract

Pathogens that adapt to environmental stress can develop an increased tolerance to some physical or chemical antimicrobial treatments. The main objective of this study was to determine if acid adaptation increased the tolerance of Escherichia coli O157:H7 to high voltage atmospheric cold plasma (HVACP) in raw pineapple juice. Samples (10 mL) of juice were inoculated with non-acid-adapted (NAA) or acid-adapted (AA) E. coli to obtain a viable count of ~7.00 log10 CFU/mL. The samples were exposed to HVACP (70 kV) for 1–7 min, with inoculated non-HVACP-treated juice serving as a control. Juice samples were analyzed for survivors at 0.1 h and after 24 h of refrigeration (4 °C). Samples analyzed after 24 h exhibited significant decreases in viable NAA cells with sub-lethal injury detected in both NAA and AA survivors (p < 0.05). No NAA survivor in juice exposed to HVACP for 5 or 7 min was detected after 24 h. However, the number of AA survivors was 3.33 and 3.09 log10 CFU/mL in juice treated for 5 and 7 min, respectively (p < 0.05). These results indicate that acid adaptation increases the tolerance of E. coli to HVACP in pineapple juice. The potentially higher tolerance of AA E. coli O157:H7 to HVACP should be considered in developing safe juice processing parameters for this novel non-thermal technology.

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Posted in Cold Atmospheric Plasma, Cold Plasma, E.coli, E.coli O157:H7, Enteropathogenic E. coli, ETEC E.coli, Food Microbiology Research, Food Pathogen, Food Technology, Hurdle Technology, Pathogen, pathogenic, Research