Category Archives: Pathogen

UK – FSA assesses raw pet food risk to animals and people

Food Safety News

The Food Standards Agency (FSA) has analyzed the risk to dogs and cats from eating contaminated raw pet food and the impact on the people who feed them such products.

Raw pet food has become increasingly popular in recent years. Such items are made from Category 3 Animal-By-Products (ABP) that have been passed fit for human consumption in a slaughterhouse but are surplus to requirements. They do not undergo cooking or heat treatment so that the end product can be contaminated with pathogens. The majority are sold frozen and typically have a best-before date of over one year.

The assessment considers the risk of dogs and cats acquiring Salmonella, beta-glucuronidase-positive E. coli, Shiga toxin-producing E. coli (STEC), Campylobacter, and methicillin-resistant Staphylococcus aureus (MRSA) infection from contaminated products. It also covers the risk of infection to animal owners by handling these products at home or via transmission from an infected pet.

Research – Avoiding Food Poisoning: How a Tiny Chip Can Make Your Food Safer Than Ever

Scitech Daily

A new microfluidic chip developed by researchers enables quick, effective detection of multiple foodborne pathogens simultaneously, improving food safety and preventing contaminated products from entering the market.

Every so often, a food product is recalled because of some sort of contamination. For consumers of such products, a recall can trigger doubt in the safety and reliability of what they eat and drink. In many cases, a recall will come too late to keep some people from getting ill.

In spite of the food industry’s efforts to fight pathogens, products are still contaminated and people still get sick. Much of the problem stems from the tools available to screen for harmful pathogens, which are often not effective enough at protecting the public.

Research – Nisin Inhibition of Gram-Negative Bacteria

MDPI

Abstract

Aims: This study investigates the activity of the broad-spectrum bacteriocin nisin against a large panel of Gram-negative bacterial isolates, including relevant plant, animal, and human pathogens. The aim is to generate supportive evidence towards the use/inclusion of bacteriocin-based therapeutics and open avenues for their continued development.
Methods and Results: Nisin inhibitory activity was screened against a panel of 575 strains of Gram-negative bacteria, encompassing 17 genera. Nisin inhibition was observed in 309 out of 575 strains, challenging the prevailing belief that nisin lacks effectiveness against Gram-negative bacteria. The genera AcinetobacterHelicobacterErwinia, and Xanthomonas exhibited particularly high nisin sensitivity.
Conclusions: The findings of this study highlight the promising potential of nisin as a therapeutic agent for several key Gram-negative plant, animal, and human pathogens. These results challenge the prevailing notion that nisin is less effective or ineffective against Gram-negative pathogens when compared to Gram-positive pathogens and support future pursuits of nisin as a complementary therapy to existing antibiotics.
Significance and Impact of Study: This research supports further exploration of nisin as a promising therapeutic agent for numerous human, animal, and plant health applications, offering a complementary tool for infection control in the face of multidrug-resistant bacteria.

Research- Chine -Pre-planned Studies: Pathogenic Surveillance of Foodborne Illness-Related Diarrhea — Beijing Municipality, China, 2013–2023

China CDC

  • Summary

    What is already known about this topic?Foodborne diseases present a significant public health concern, particularly in China, where they represent a significant food safety challenge. Currently, there is a need for a thorough and systematic analysis of the extended epidemiological patterns of foodborne diseases in Beijing Municipality.

    What is added by this report?Monitoring results show that Norovirus and diarrheagenic Escherichia coli (DEC) are the most commonly identified foodborne diarrheal pathogens. Individuals aged 19–30 are at a higher risk of foodborne diarrhea in Beijing, with Salmonella infection being associated with fever symptoms.

    What are the implications for public health practice?This study analyzes 11 years of consecutive monitoring data to enhance understanding of the epidemiological and clinical features of foodborne diarrhea in Beijing. It aims to identify high-risk populations, assist in clinical pathogen identification and treatment, and support the development of tailored preventive strategies.

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

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 (pfrAhlyplcAplcBmplactA) 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, fosXlinnorB, 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.

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

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.

Research – Cold plasma processing for food safety

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.

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

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.

Research – Foodborne Illnesses from Leafy Greens in the United States: Attribution, Burden, and Cost

Science Direct

Abstract

Leafy green vegetables are a major source of foodborne illnesses. Nevertheless, few studies have attempted to estimate attribution and burden of illness estimates for leafy greens. This study combines results from three outbreak-based attribution models with illness incidence and economic cost models to develop comprehensive pathogen-specific burden estimates for leafy greens and their subcategories in the United States. We find that up to 9.18% (90% CI: 5.81%-15.18%) of foodborne illnesses linked to identified pathogens are attributed to leafy greens. Including ‘Unknown’ illnesses not linked to specific pathogens, leafy greens account for as many as 2,307,558 (90% CI: 1,077,815–4,075,642) illnesses annually in the United States. The economic cost of these illnesses is estimated to be up to $5.278 billion (90% CI: $3.230-$8.221 billion) annually. Excluding the pathogens with small outbreak sizes, Norovirus, Shiga toxin-producing Escherichia coli (both non-O157 and O157:H7), Campylobacter spp., and nontyphoidal Salmonella, are associated with the highest number of illnesses and greatest costs from leafy greens. While lettuce (romaine, iceberg, “other lettuce”) takes 60.8% of leafy green outbreaks, it accounts for up to 75.7% of leafy green foodborne illnesses and 70% of costs. Finally, we highlighted that 19.8% of Shiga toxin-producing Escherichia coli O157:H7 illnesses are associated with romaine among all food commodities, resulting in 12,496 estimated illnesses and $324.64 million annually in the United States.

Research – Scientists call for more awareness of raw pet food risks for people

Food Safety News

A study has added to evidence of the risk posed by contaminated raw pet food to human health.

Researchers investigated whether dog food, including raw meat-based diets (RMBD), available in Portugal can be a source of Salmonella or other Enterobacteriaceae strains resistant to last-line antibiotics such as colistin.

Since 2020, there have been more than 20 reports or recalls of pet food and RMBD in the EU because of the detection of pathogens.

Fifty-five samples from 25 brands of various meat and dog food types from 12 suppliers were screened by standard cultural methods between September 2019 and January 2020. Forty-one of the 55 samples were processed, and 14 were raw, according to the study published in the journal Eurosurveillance.