Category Archives: Food Microbiology Research

Research – Rapid detection of the source of a Listeria monocytogenes outbreak in Switzerland through routine interviewing of patients and whole-genome sequencing

Posted on May 19, 2024 | Leave a comment

SMW

In summer 2022, 20 patient-derived L. monocytogenes serotype 4b sequence type 388 strains were found to belong to an outbreak cluster (≤10 different alleles between neighbouring isolates) based on core genome multilocus sequence typing analysis. Geographically, 18 of 20 outbreak cases occurred in northeastern Switzerland. The median age of patients was 77.4 years (range: 58.1–89.7), with both sexes equally affected. Rolling analysis of the interview data revealed smoked trout from a local producer as a suspected infection source, triggering an on-site investigation of the production facility and sampling of the suspected products by the responsible cantonal food inspection team on 15 July 2022. Seven of ten samples tested positive for L. monocytogenes and the respective cantonal authority ordered a ban on production and distribution as well as a product recall. The Federal Food Safety and Veterinary Office released a nationwide public alert covering the smoked fish products concerned. Whole-genome sequencing analysis confirmed the interrelatedness of the L. monocytogenes smoked trout product isolates and the patient-derived isolates. Following the ban on production and distribution and the product recall, reporting of new outbreak-related cases rapidly dropped to zero.

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Posted in food bourne outbreak, Food Illness, Food Microbiology Research, Foodborne Illness, foodborne outbreak, foodbourne outbreak, Illness, Listeria, Listeria monocytogenes, Listeria Smoked Fish, outbreak, Research

Research – Inactivation mechanism of phenyllactic acid against Bacillus cereus spores and its application in milk beverage

Posted on May 19, 2024 | Leave a comment

Science Direct

Phenyllactic acid (PLA) as a natural phenolic acid exhibits antibacterial activity against non-spore-forming bacteria, while the inhibitory effect against bacterial spore remained unknown. Herein, this study investigated the inactivation effect of PLA against Bacillus cereus spores. The results revealed that the minimum inhibitory concentration of PLA was 1.25 mg/mL. PLA inhibited the outgrowth of germinated spores into vegetative cells rather than germination of spores. PLA disrupted the spore coat, and damaged the permeability and integrity of inner membrane. Moreover, PLA disturbed the establishment of membrane potential due to the inhibition of oxidative metabolism. SEM observations further visualized the morphological changes and structural disruption caused by PLA. Besides, PLA caused the degradation of DNA of germinated spores. Finally, PLA was applied in milk beverage, and showed promising inhibitory effect against B. cereus spores. This finding could provide scientific basis for the application of PLA against spore-forming bacteria in food industry.

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Posted in Bacillus, Bacillus cereus, Bacterial Spores, Food Microbiology Research, Food Technology, Phenyllactic Acid, Research, Technology

Research -Shiga Toxin–Producing Escherichia coli O157:H7 Illness Outbreak Associated with Untreated, Pressurized, Municipal Irrigation Water — Utah, 2023

Posted on May 18, 2024 | Leave a comment

CDC

During July–September 2023, an outbreak of Shiga toxin–producing Escherichia coli O157:H7 illness among children in city A, Utah, caused 13 confirmed illnesses; seven patients were hospitalized, including two with hemolytic uremic syndrome. Local, state, and federal public health partners investigating the outbreak linked the illnesses to untreated, pressurized, municipal irrigation water (UPMIW) exposure in city A; 12 of 13 ill children reported playing in or drinking UPMIW. Clinical isolates were genetically highly related to one another and to environmental isolates from multiple locations within city A’s UPMIW system. Microbial source tracking, a method to indicate possible contamination sources, identified birds and ruminants as potential sources of fecal contamination of UPMIW. Public health and city A officials issued multiple press releases regarding the outbreak reminding residents that UPMIW is not intended for drinking or recreation. Public education and UPMIW management and operations interventions, including assessing and mitigating potential contamination sources, covering UPMIW sources and reservoirs, indicating UPMIW lines and spigots with a designated color, and providing conspicuous signage to communicate risk and intended use might help prevent future UPMIW-associated illnesses.

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Posted in Boil Water Notice, Contaminated water, E.coli O157, E.coli O157:H7, food bourne outbreak, Food Illness, Food Microbiology Research, Foodborne Illness, foodborne outbreak, foodbourne outbreak, Illness, outbreak, Research, Water, water microbiology, Water Safety

Research – Differential mechanism between Listeria monocytogenes strains with different virulence contaminating ready-to-eat sausages during the simulated gastrointestinal tract

Posted on May 18, 2024 | Leave a comment

Science Direct

Listeria monocytogenes exhibits varying levels of pathogenicity when entering the host through contaminated food. However, little is known regarding the stress response and environmental tolerance mechanism of different virulence strains to host gastrointestinal (GI) stimuli. This study analyzed the differences in the survival and genes of stress responses among two strains of L. monocytogenes 10403S (serotype 1/2a, highly virulent strain) and M7 (serotype 4a, low-virulence strain) during simulated gastrointestinal digestion. The results indicated that L. monocytogenes 10403S showed greater acid and bile salt tolerance than L. monocytogenes M7, with higher survival rates and less cell deformation and cell membrane permeability during the in vitro digestion. KEGG analysis of the transcriptomes indicated that L. monocytogenes 10403S displayed significant activity in amino acid metabolism, such as glutamate and arginine, associated with acid tolerance. Additionally, L. monocytogenes 10403S demonstrated a higher efficacy in promoting activities that preserve bacterial cell membrane integrity and facilitate flagellar protein synthesis. These findings will contribute valuable practical insights into the tolerance distinctions among different virulence strains of L. monocytogenes in the GI environment.

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Posted in Food Microbiology Research, Listeria, Listeria monocytogenes, Research

Research – Inactivation of Salmonella Typhimurium, Escherichia coli, and Staphylococcus aureus in Tilapia Fillets (Oreochromis niloticus) with Lactic and Peracetic Acid through Fogging and Immersion

Posted on May 18, 2024 | Leave a comment

MDPI

Abstract

This study investigated the antimicrobial effects of lactic acid (LA) (3%) and peracetic acid (PA) (300 ppm) on tilapia fillets (Oreochromis niloticus) by fogging (15 min) or by immersion (2 s) in a pool of Escherichia coli (NEWP 0022, ATCC 25922, and a field-isolated strain), Staphylococcus aureus (ATCC 25923 and a field-isolated strain), and Salmonella Typhimurium (ATCC 13311 and ATCC 14028), as well as the effects on the physicochemical characteristics of the fillets. Fogging was effective and the best application method to control S. Typhimurium regardless of the acid used, promoting reductions of 1.66 and 1.23 log CFU/g with PA and LA, respectively. Regarding E. coli, there were significant reductions higher than 1 log CFU/g, regardless of the treatment or acid used. For S. aureus, only immersion in PA showed no significant difference (p < 0.05). For other treatments, significant reductions of 0.98, 1.51, and 1.17 log CFU/g were observed for nebulized PA, immersion, and LA fogging, respectively. Concerning the pH of the samples, neither of the acids used differed from the control. However, treatments with LA, and fogging with PA, reduced the pH compared to immersion in PA. As for color parameters, L* and a* values showed changes regardless of the acid or method used, resulting in an improved perception of fillet quality. These results indicate that fogging and immersion are alternatives for reducing S. Typhimurium, E. coli, and S. aureus in tilapia fillets.

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Posted in E.coli, Food Microbiology Research, Food Technology, Research, Salmonella, Staphylococcus aureus, Technology

Research – Outbreak of Listeria monocytogenes in hospital linked to a fava bean product, Finland, 2015 to 2019

Posted on May 18, 2024 | Leave a comment

Eurosurveillance

Listeriosis is a severe bacterial infection caused by  (), usually via consumption of food contaminated with the bacterium. However, other ways of transmission than food-borne have been reported [1].  species are ubiquitous in the environment and many animals shed  in their faeces. Infections are often associated with raw, chilled or ready-to-eat (RTE) foods. Symptoms develop within 1–70 days after eating food contaminated with  [2]. The disease can manifest as severe, invasive illness, more likely in elderly people, pregnant women, unborn or newborn babies and people with weakened immune systems [3]. In these persons, listeriosis may present as septicaemia or meningitis and lead to high hospitalisation and mortality rates.

In 2021, an incidence of 0.5 per 100,000 population was reported for listeriosis in the European Union/European Economic Area (EU/EEA), while the incidence in Finland was 1.3 per 100,000 [4].

Listeriosis cases have been reported in healthcare facilities [5–11]. Two healthcare-associated  outbreaks have been reported in Finland during the last three decades. In 1999, a large hospital outbreak occurred with six deaths in 25 cases of invasive listeriosis. The source of the outbreak was butter which may have been contaminated after pasteurisation [12]. In 2012, RTE meat jelly was suspected to be the source of a hospital outbreak affecting 25 people [9].

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

France – Julienne slices 800g bag – Listeria monocytogenes

Posted on May 16, 2024 | Leave a comment

Gov France

Product category
Food
Product subcategory
Fishing and aquaculture products
Product brand name
Riberalves
Model names or references
Julienne slices 800g bag Riberalves
Product identification
GTIN Batch Date
5601809014875 23474963 Minimum durability date 05/16/2025
Packaging
800g bag
Start/end date of marketing
From 01/18/2024 to 05/10/2024
Storage temperature
Product to keep in the freezer
Health mark
PTB003101PCE
Geographical sales area
Departments: GUADELOUPE (971)
Distributors
Supermarkets, commercial catering, individuals, butchers

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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, Listeria, Listeria monocytogenes

Research – Decontamination of egg-associated pathogens by plasma-activated water and hydrogen peroxide

Posted on May 15, 2024 | Leave a comment

Wiley Online

Abstract

This study investigated the effectiveness of plasma-activated water (PAW) and plasma-activated hydrogen peroxide (PAHP) in reducing egg-associated pathogens. The antimicrobial activity of these solutions against Salmonella Enteritidis, Campylobacter jejuni, and Staphylococcus aureus on eggs was evaluated at different plasma treatment durations. The results demonstrated that increasing the duration of plasma treatment enhanced the antimicrobial efficacy of both PAW and PAHP. The bacterial counts of the egg-associated pathogens significantly decreased from 7.61, 7.59, and 7.54 log (CFU/egg) to 5.4 and 3.09, 5.36 and 3.11, and 5.08 and 3.73 log (CFU/egg) for PAW and PAHP, respectively. The characteristics of the plasma solutions, including electrical conductivity, pH, H2O2, NO3¯, and NO2¯, synergistically acted as antimicrobial agents in both PAW and PAHP treatments. The storage study revealed that PAHP treatment had no adverse effects on the eggs’ pH, albumen and yolk color, Haugh unit, and yolk index. However, it did result in reduced eggshell strength and compromised cuticle integrity. Overall, this study demonstrates the successful application of PAW and PAHP in effectively inhibiting egg-associated pathogens while preserving essential egg quality attributes. Further research is needed to optimize the treatment conditions and investigate the long-term effects of PAW and PAHP on eggs in larger-scale applications. This research contributes to developing innovative and sustainable approaches for enhancing the safety and quality of eggs in the food industry.

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Posted in Campylobacter, Campylobacter jejuni, Food Microbiology Research, Plasma Activated Water, Plasma-activated hydrogen peroxide (PAHP), Research, Salmonella

Research – Foodborne Pathogenic Bacteria: Prevalence and Control—Volume I

Posted on May 15, 2024 | Leave a comment

MDPI

1. Introduction

From the farm to the dining table, foodborne pathogenic bacteria can contaminate food at any stage of the food production, processing, delivery, preparation, and consumption chain, posing a critical threat to the safety of food systems worldwide [1]. Staphylococcus aureus, Escherichia coli, Salmonella, Listeria monocytogenes, Campylobacter, and Vibrio parahaemolyticus are some of the most common foodborne pathogenic bacteria, and food products contaminated by them traverse intricate global trade networks, posing many disease risks to millions of consumers annually [2]. Foodborne diseases can result from unsafe food storage, processing, preservation, and infected workers, as well as several forms of environmental contamination, including pollution in water, soil, air, infected livestock, and animal feces [3]. Some other factors that increase the incidence of foodborne diseases include the adaptation of pathogens to new environments, the formation of biofilms, the acquisition of virulence factors, and the development of antimicrobial resistance in foodborne pathogenic bacteria [4].
To enhance the safety of our food system, the first step is to know how the food system has been, and could still be, contaminated by common pathogenic bacteria, as well as other emerging and re-emerging pathogenic bacteria. On the other hand, we need to know how these bacteria could survive different storage, processing, and preservation processes in the food system. Biofilm formation and antimicrobial resistance could explain the mechanisms of bacterial survival. However, much is unknown. Once basic information is acquired, we can prevent and control the contamination of foodborne pathogenic bacteria to keep us far away from the pathogens’ attacks.
We are pleased to present this Special Issue on “Foodborne Pathogenic Bacteria: Prevalence and Control”, which contains eleven research articles and two review articles on the detection, prevalence, growth, survival and control. In addition, this Special Issue also covered topics related to rapid detection, persistence in food processing environment, antimicrobial resistance, stress adaptation, antibacterial and antibiofilm mechanisms, etc., as alternative and sustainable innovations to prevent and control the contamination of pathogenic bacteria in the food system. We present a brief overview of each contribution.

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Posted in Bio-Preservative, Campylobacter, escherichia coli, Food Microbiology Research, Listeria, Listeria monocytogenes, Research, Salmonella, Vibrio

France – Yellow Wine Triangle – Salmonella

Posted on May 15, 2024 | Leave a comment

Gov France

Product category
Food
Product subcategory
Others
Product brand name
Killed by Grandpa Gaby
Model names or references
Yellow wine triangle sausages
Product identification
Batch Date
0204 Minimum durability date 06/01/2024
Products List
FT_SAAUCISSON_TRIANGLE_VIN_JAUNE_240313.pdfAttachment
Start/end date of marketing
From 04/23/2024 to 05/04/2024
Storage temperature
Product to keep in the refrigerator
Geographical sales area
Whole France
Distributors
Killed by grandpa gaby; the cheese boys; SARL Desserteau; Chalet Jacquet; Cremerie les Fins; Boillot Chantal; Direct doubles; The orchards of the sun; SARL Lehmann Cheeses

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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, Salmonella