Category Archives: Food Microbiology Research

Research – A Systematic Quantitative Determination of the Antimicrobial Efficacy of Grape Seed Extract against Foodborne Bacterial Pathogens

Posted on February 26, 2023 by | Leave a comment

MDPI

Abstract

Concerns regarding the role of antimicrobial resistance (AMR) in disease outbreaks are growing due to the excessive use of antibiotics. Moreover, consumers are demanding food products that are minimally processed and produced in a sustainable way, without the use of chemical preservatives or antibiotics. Grape seed extract (GSE) is isolated from wine industry waste and is an interesting source of natural antimicrobials, especially when aiming to increase sustainable processing. The aim of this study was to obtain a systematic understanding of the microbial inactivation efficacy/potential of GSE against Listeria monocytogenes (Gram-positive), Escherichia coli and Salmonella Typhimurium (Gram-negative) in an in vitro model system. More specifically, for L. monocytogenes, the effects of the initial inoculum concentration, bacterial growth phase and absence of the environmental stress response regulon (SigB) on the GSE microbial inactivation potential were investigated. In general, GSE was found to be highly effective at inactivating L. monocytogenes, with higher inactivation achieved for higher GSE concentrations and lower initial inoculum levels. Generally, stationary phase cells were more resistant/tolerant to GSE as compared to exponential phase cells (for the same inoculum level). Additionally, SigB appears to play an important role in the resistance of L. monocytogenes to GSE. The Gram-negative bacteria under study (E. coli and S. Typhimurium) were less susceptible to GSE as compared to L. monocytogenes. Our findings provide a quantitative and mechanistic understanding of the impact of GSE on the microbial dynamics of foodborne pathogens, assisting in the more systematic design of natural antimicrobial-based strategies for sustainable food safety.

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Posted in Antimicrobials, Decontamination Microbial, escherichia coli, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Safety, Food Safety Management, Food Safety Regulations, food safety training, Listeria, Listeria monocytogenes, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Salmonella

Research – Microbial Biocontrol in the Agri-Food Industry

Posted on February 26, 2023 by | Leave a comment

MDPI

Abstract

In recent years there has been a growing interest in the use of natural antimicrobial compounds to limit or avoid the use of chemical antimicrobials. Natural antimicrobial compounds can come from plants (essential oils) or from microorganisms (bacteriocins, mycocines, and active peptides). Despite a wide range of possible applications, their exploitation at the industrial level is still limited and needs to be investigated. The actual and possible applications of natural antimicrobial compounds in agri-food are a growing research field. In addition to the use of antimicrobial compounds, microorganisms themselves can be used in the control of spoilage microorganisms along the entire production chain of the agri-food industry. Likewise, the papers collected in this Special Issue indicate the fast development of novelties in this research field.

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk

Research – Foodborne Pathogen Biofilms: Development, Detection, Control, and Antimicrobial Resistance

Posted on February 26, 2023 by | Leave a comment

MDPI

Bacteria can grow either as planktonic cells or as communities within biofilms. The biofilm growth mode is the dominant lifestyle of most bacterial species and 40–80% of microorganisms are associated with biofilms [1]. Biofilm is a sessile community that is irreversibly attached to a substratum or interface or to other members of the community [2]. It is surrounded by extracellular polymeric substances (EPS) that include extracellular polysaccharides, extracellular DNA, lipids, proteins, and other elements [3]. Biofilm formation is a complex but well-regulated process that can be classified into five distinct stages [4]. In the first stage, planktonic bacteria attach to a surface. Salmonella species, Listeria monocytogenes, Campylobacter jejuni, or Escherichia coli have specific structures on the surface of the bacteria, such as flagella, curli, fimbriae, and pili, which help the bacteria attach [5].
The second stage is the adhesion step, which includes an initial reversible adhesion resulting in loose adhesion and a subsequent irreversible adhesion resulting in more stable adhesion. The third stage is to secrete EPS and form microcolonies. This is followed by biofilm maturation, which produces large amounts of EPS to grow in size and build three-dimensional structures. The final stage is the stage in which the biofilm is dispersed, releasing the planktonic cells and initiating the formation of a new biofilm at another location.
Microbial cells living within biofilms are protected from various environmental stresses such as desiccation, osmotic changes, oxidative stress, metal toxicity, radiation, antibiotics, disinfectants, and the host immune system [6]. Biofilms are much less sensitive to antimicrobial agents than planktonic cells, and several mechanisms contribute to their resistance to antimicrobials [7]. The exopolysaccharide matrix prevents the entry of antimicrobial agents by reducing diffusion and acting as a primary barrier [8]. Most antimicrobial agents kill rapidly dividing cells more effectively, but slow growth of biofilms leads to resistance [9]. Changes in metabolic activity within biofilms, genetic changes of antimicrobial resistant determinants in target cells, extrusion of antimicrobial agents using efflux pumps, and the presence of persistent cells also contribute to antimicrobial resistance [10].

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Posted in antimicrobial resistance, Antimicrobials, Biofilm, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk

Research – Recent insights into green antimicrobial packaging towards food safety reinforcement: A review

Posted on February 25, 2023 by | Leave a comment

Wiley Online

Abstract

Food packaging is widely used method of food preservation around the world. It is an element that enhances the quality and food product safety. The primary function of packaging is to protect food from contamination, undesirable chemical reactions and to provide physical protection. Food spoilage caused by food-borne pathogens and microbes is increasing tremendously posing an enormous threat. In the field of food packaging, new biodegradable and natural antimicrobial agents from plants and animals are gaining popularity. Recent foodborne outbreaks have prompted more creative and safe ways to initiate efficient packaging systems in food industries. However, as consumer demand for natural food ingredients has grown as a result of increasing safety and availability, natural substances are thought to be safer. Antimicrobial packaging that incorporates natural antimicrobials is thus a viable active packaging innovation. One possibility for increasing the safety and quality of foods while prolonging their shelf life is to employ natural antibacterial packaging. This article focuses on environmentally friendly bio-based polymers that can be utilized in food packaging to enhance mechanical strength, gas permeability, and water resistance, among other features. It also includes useful information about natural antimicrobial agents found in fruits and vegetables, as well as animal by-products, their properties, safety laws, and uses aimed at improving and increasing food quality and safety.

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Posted in Antibacterial, antimicrobial resistance, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk

Research – The Anti-Listeria Activity of Pseudomonas fluorescens Isolated from the Horticultural Environment in New Zealand

Posted on February 25, 2023 by | Leave a comment

MDPI

Abstract

Beneficial bacteria with antibacterial properties are attractive alternatives to chemical-based antibacterial or bactericidal agents. Our study sourced such bacteria from horticultural produce and environments to explore the mechanisms of their antimicrobial properties. Five strains of Pseudomonas fluorescens were studied that possessed antibacterial activity against the pathogen Listeria monocytogenes. The vegetative culture of these strains (Pseudomonas fluorescens-PFR46I06, Pseudomonas fluorescens-PFR46H06, Pseudomonas fluorescens-PFR46H07, Pseudomonas fluorescens-PFR46H08 and Pseudomonas fluorescens-PFR46H09) were tested against Listeria monocytogenes (n = 31), Listeria seeligeri (n = 1) and Listeria innocua (n = 1) isolated from seafood and horticultural sources and from clinical cases (n = 2) using solid media coculture and liquid media coculture. All Listeria strains were inhibited by all strains of P. fluorescens; however, P. fluorescens-PFR46H07, P. fluorescens-PFR46H08 and P. fluorescens-PFR46H09 on solid media showed good inhibition, with average zones of inhibition of 14.8 mm, 15.1 mm and 18.2 mm, respectively, and the other two strains and P. fluorescens-PFR46H09 had a significantly greater zone of inhibition than the others (p < 0.05). There was no inhibition observed in liquid media coculture or in P. fluorescens culture supernatants against Listeria spp. by any of the P. fluorescens strains. Therefore, we hypothesized that the structural apparatus that causes cell-to-cell contact may play a role in the ejection of ant-listeria molecules on solid media to inhibit Listeria isolates, and we investigated the structural protein differences using whole-cell lysate proteomics. We paid special attention to the type VI secretion system (TSS-T6SS) for the transfer of effector proteins or bacteriocins. We found significant differences in the peptide profiles and protein summaries between these isolates’ lysates, and PFR46H06 and PFR46H07 possessed the fewest secretion system structural proteins (12 and 11, respectively), while PFR46H08 and PFR46H09 had 18 each. P. fluorescens-PFR46H09, which showed the highest antimicrobial effect, had nine tss-T6SS structural proteins compared to only four in the other three strains.

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Pseudomonas

Research – Outbreak of Shigella sonnei in the EU/EEA and the United Kingdom among travellers returning from Cabo Verde

Posted on February 23, 2023 by | Leave a comment

ECDC

As of 16 February 2023, 10 EU/EEA countries and the UK reported and the US reported 221 confirmed Shigella sonnei infections and 37 possible cases, all with a link to Cabo Verde.

Information on possible ways of infection or common exposure have not yet been identified but investigations are ongoing in Cabo Verde. Multiple modes of transmission are plausible, and the most likely way is through food, including via infected food handlers. However, person-to-person transmission is also possible.

The S. sonnei strain in the current outbreak indicates predicted resistance to trimethoprim and streptomycin but in some cases, multidrug resistance has also been detected.

Based on the available information, many cases are reported to have stayed in all-inclusive hotels located in the region of Santa Maria on the island of Sal. The most recent cases were reported in Sweden on 19 January 2023, suggesting an ongoing moderate risk of new infections among travellers to Cabo Verde, particularly among those staying in the region of Santa Maria on the Island of Sal.

Shigellosis is a gastrointestinal infection caused by one of four species of Shigella bacteria: Shigella sonnei, S. flexneri, S. boydii and S. dysenteriae. Humans are the primary reservoirs for Shigella.

Shigellosis is caught by oral contact with material contaminated by faeces, either through direct person-to-person contact, via contaminated food or water, or via objects which have been in contact with faeces. The necessary dose for infection is small, which increases transmissibility.

Food-related outbreaks are often caused by infected food handlers, who contaminate ready-to-eat food items like salads. Waterborne infection can occur if drinking or recreational water is contaminated with faeces from an infected person.

Handwashing with soap and water is important, especially after using the toilet and before preparing or eating food. Additional care with food and drinking water when travelling abroad is also important. There is no vaccine currently available to prevent Shigella infection.

People with shigellosis should not attend school, handle food, or provide child or patient care whilst ill. Children under the age of five, food handlers, and healthcare staff should stay at home for 48 hours after their symptoms have ceased.

ECDC encourages public health authorities in the EU/EEA to increase awareness among healthcare professionals on the possibility of Shigella infections among people that recently travelled to Cabo Verde.

Together with WHO/Europe, ECDC is in regular contact with authorities in Cabo Verde to support investigations on the sources of infection and to increase awareness among healthcare professionals in the country.

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Posted in Contaminated water, Decontamination Microbial, food bourne outbreak, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, foodborne outbreak, foodbourne outbreak, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, outbreak, Shigatoxin, Shigella, Shigella flexneri, Shigella Sonnei, water microbiology, Water Safety

World-first voluntary guidelines: Singapore introduces food safety standards in the e-commerce space

Posted on February 22, 2023 by | Leave a comment

Food Navigator Asia

Singapore has developed a new set of voluntary food safety guidelines for businesses across the food e-commerce supply chain.

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Posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk

India – Shirdi: 100 children admitted in hospital after falling ill due to food poisoning

Posted on February 22, 2023 by | Leave a comment

Free Press Journal

Shirdi: A fun day for the school kids who had gone to Shirdi on a picnic trip turned tragic after at least 100 children had to be admitted to a hospital after they showed symptoms of food poisoning.

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Posted in Food Illness, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Poisoning, Foodborne Illness, Illness, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Poisoning

France – Roasted chicken nuggets – Listeria monocytogenes

Posted on February 22, 2023 by | Leave a comment

Gov france

Identification information of the recalled product

  • Product category Feed
  • Product subcategory Meats
  • Product brand name VOLAE
  • Model names or references Roasted chicken nuggets
  • Identification of products
    GTIN Batch Date
    3250391341924 045 Use-by date 08/03/2023
  • Packaging 500g bag
  • Marketing start/end date From 02/16/2023 to 02/20/2023
  • Storage temperature Product to be stored in the refrigerator
  • Health mark FR72264002CE
  • Geographic area of ​​sale Departments: ALLIER (03), HAUTES-ALPES (05), ARDECHE (07), CHER (18), CORREZE (19), CREUSE (23), DROME (26), GARD (30), INDRE (36), INDRE -ET-LOIRE (37), ISERE (38), LOIR-ET-CHER (41), LOIRE (42), LOIRET (45), NIEVRE (58), PUY-DE-DOME (63), SAONE-ET- LOIRE (71), VAUCLUSE (84), YONNE (89)
  • Distributors Intermarché
  • List of points of sale Listing_clients.pdf

Practical information regarding the recall

  • Reason for recall Suspicion of the presence of Listeria monocytogenes
  • Risks incurred by the consumer Listeria monocytogenes (causative agent of listeriosis)

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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 recall, Food Safety, Food Safety Alert, Food Safety Management, Food Safety Regulations, food safety training, Food Testing, Listeria, Listeria monocytogenes

France – Cheese – SAINT NECTAIRE FARMER – Listeria monocytogenes

Posted on February 22, 2023 by | Leave a comment

Gov france

Identification information of the recalled product

  • Product category Feed
  • Product subcategory Milk and dairy products
  • Product brand name WITHOUT
  • Model names or references BATCH NUMBER: AAD49 Best before: 02/23/2023
  • Identification of products
    Batch
    AAD49
  • Marketing start/end date From 09/01/2023 to 16/02/2023
  • Storage temperature Product to be stored in the refrigerator
  • Geographic area of ​​sale INTERMARCHE SAINT GENIEZ D’OLT
  • Distributors CHARRADE

Practical information regarding the recall

  • Reason for recall CONTAMINATION BY LISTERIA
  • Risks incurred by the consumer Listeria monocytogenes (causative agent of listeriosis)

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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 recall, Food Safety, Food Safety Alert, Food Safety Management, Food Safety Regulations, Food Testing, Listeria, Listeria monocytogenes