Research Publications (Food Safety)

The purpose of this study was to conduct challenge studies in raw pork by strictly following all aspects of the 2014 EURL technical guidance document for conducting shelf-life studies on Listeria monocytogenes. Growth potential was assessed on three batches of self-cut pork chops and one batch of in-house prepared pure minced pork without any additives in air and MAP (70 % O2/30% CO2) packaging.

Listeria monocytogenes is a food-borne bacterium that causes listeriosis upon the ingestion of contaminated food. Traditional methods to detect L. monocytogenes require pre-enrichment broths to increase its concentration. To improve the screening of contaminated food and prevent listeriosis outbreaks, rapid, specific and sensitive assays are needed to detect L.

This study investigated the antimicrobial and antibiofilm efficacy of separate and combined treatments of Lactobacillus curvatus B67-produced postbiotic and the polyphenolic flavanol quercetin against Listeria monocytogenes and Salmonella enterica ser. Typhimurium. The antimicrobial potentiality of the postbiotic was chiefly associated with organic acids (e.g., lactic and acetic acids).

Intrinsic characteristics of fresh produce, such as pH, water activity, acid content and nutrient availability are critical factors in determining the survival and growth of Listeria monocytogenes (Lm). In this study, sterile fresh produce juice was used to analyze Lm growth potential among 14 different commodities and to identify physicochemical characteristics in those juices that affect Lm growth.

Geraniol nanoemulsions (G-NE) based on Tween 80 and medium chain triglyceride (MCT) as surfactant and co-surfactant, respectively, has been prepared by the spontaneous emulsification method. Its physical and chemical properties such as mean particle size, zeta potential, PDI, pH, viscosity, contact angle, appearance morphology, and stability (storage stability, thermal stability, centrifugal properties, acid-base stability, and freeze-thaw properties) of the droplet were analyzed.

Temperature is a major determinant of Listeria (L.) monocytogenes adherence and biofilm formation on abiotic surfaces. However, its role on gene regulation of L. monocytogenes mature biofilms has not been investigated. In the present study, we aimed to evaluate the impact of temperature up- and down-shift on L. monocytogenes biofilms gene transcription. L.

The presence of Listeria monocytogenes (Lm) in the food processing environment (facilities and products) is a challenging problem in food safety management. Lm is one of the main causes of mortality in foodborne infections, and the trend is continuously increasing.

With the discovery of antibiotics, a productive period of antibacterial drug innovation and application in healthcare systems and agriculture resulted in saving millions of lives. Unfortunately, the misusage of antibiotics led to the emergence of many resistant pathogenic strains. Some riboswitches have risen as promising targets for developing antibacterial drugs. Here, we describe the design and applications of the chimeric antisense oligonucleotide (ASO) as a novel antibacterial agent.

Infection and Immunity, Ahead of Print. The intracellular pathogen Listeria monocytogenes is one of the leading causes of death from foodborne illness in the United States. Internalin A is the key surface protein that drives Listeria uptake by epithelial cells expressing E-cadherin. G. C. Gyanwali, T. U. B. Herath, A. Gianfelice, and K.

Table olives are one of the most important fermented vegetables in the Mediterranean countries. Although this fermented vegetable has a long record of microbial safety, various studies have shown the presence of Listeria monocytogenes during table olive processing. This study focused on evaluating the behaviour of a cocktail of L. monocytogenes strains during fermentation of Spanish-style green Manzanilla olives.

The present study evaluates the anti-biofilm activity of a coating applied with an atmospheric-pressure plasma jet system on AISI 316 stainless steel (SS) against multispecies biofilms containing L. monocytogenes (using background microbiota from three different meat industries) using culture-dependent and culture-independent approaches. Also, the disinfection effectiveness and biofilm evolution after sanitization with two food industry biocides were assessed.

Biofouling in the food industry is a huge issue, and one possible way to reduce surface fouling is to understand how naturally cleaning surfaces based on biomimetic designs influence bacterial binding. Four self-cleaning leaves (Tenderheart cabbage, Cauliflower, White cabbage and Leek) were analysed for their surface properties and artificial replicates were produced.

Listeria monocytogenes is a ubiquitous foodborne pathogen causing both invasive and non-invasive listeriosis. Sequence type (ST) 9 strains is common in food and food processing environments. In this study, the whole-genome sequences (WGS) of 207 ST9 isolates from different sources, geographical locations (14 countries), and isolated years were analyzed.

This study aims to identify lactic acid bacteria (LAB) isolated from honeybees (Apis mellifera workers and larvae) in detail and to determine their functional probiotic properties. A total of 11 strains were classified based on morphological and biochemical characteristics. Preliminary probiotic properties of strains, that were molecularly identified using 16 S rRNA, such as antimicrobial activity, tolerance to digestive conditions, aggregation ability, were investigated.

Rapid and accurate identification of foodborne pathogenic bacteria is of great importance because they are often responsible for the majority of serious foodborne illnesses. The confocal Raman microspectroscopy (CRM) is a fast and easy-to-use method known for its effectiveness in detecting and identifying microorganisms.

Honey is an important bee product with its nutritional and medicinal properties. Characterization of different monofloral honey has importance for focusing on honey’s biocomponents and the potential use of its medicinal applications. Although Black cumin (Nigella sativa L.) is a valuable monofloral honey, there are less study about its both chemical and biochemical study in literature.

Bacteriophage potential in combating bacterial pathogens has been recognized nearly since the moment of discovery of these viruses at the beginning of the 20th century. Interest in phage application, which initially focused on medical treatments, rapidly spread throughout different biotechnological and industrial fields. This includes the food safety sector in which the presence of pathogens poses an explicit threat to consumers.

Human listeriosis outbreaks are often associated with consumption of contaminated food, especially meat products. To better understand meat contamination of L. monocytogenes, whole genome sequencing(WGS) was performed on all detected isolates to investigate genetic relationships between retail markets and slaughterhouses. 110 and 13 isolates were isolated from 1914 food samples and 67 food and environmental samples, respectively.

This study aimed to determine the changes in metabolites in the culture media of foodborne pathogens using nuclear magnetic resonance (NMR) spectroscopy. Extracellular metabolites in tryptic soy broth inoculated with none, Listeria monocytogenes ATCC 19111, and Staphylococcus aureus ATCC 29213 and 27213 at 37 °C were collected and analyzed by 1D 1H NMR and 2D 1H–13C heteronuclear single quantum coherence (HSQC) NMR.

The photodynamic inactivation (PDI) uses molecules (photosensitizers) that absorb visible light (385–450 nm) energy, transfer it to adjacent molecular oxygen and thereby generating the biocidal singlet oxygen and other reactive oxygen species in situ. Efficacy of PDI was tested against Listeria monocytogenes and Salmonella enterica in three ways. Firstly, by adding the photosensitizer to bacterial suspensions.

Between 1 July and 26 October 2019 in Andalusia, Spain, a large outbreak with 207 confirmed cases of listeriosis was identified. Confirmed cases had a median age of 44 years (range: 0–94) and 114 were women (55.1%). Most cases (n = 154) had mild gastroenteritis, 141 (68.1%) required hospitalisation and three died; five of 34 pregnant women had a miscarriage.

Applied and Environmental Microbiology, Ahead of Print. The contamination of ready-to-eat produce with Listeria monocytogenes (LM) can often be traced back to environmental sources in processing facilities and packinghouses. To provide an improved understanding of Listeria sources and transmission in produce operations, we performed whole-genome sequencing (WGS) of LM (n = 169) and other Listeria spp.

Foodborne illnesses are being reported everyday; thus, there is an obvious need for faster and sensitive methodologies to detect foodborne pathogens in order to assure the safeness of foods. In the present study, the detection of L. monocytogenes, Salmonella spp., and E. coli O157 was performed combining a multiplex short enrichment of 7 h in Tryptic Soy Broth, with a colorimetric LAMP-based naked-eye detection.

The adaptive response of bacterial cells to changing environmental conditions depends on the behavior of single cells within the population. Exposure of Listeria monocytogenes to sublethal acidic conditions in foods or in the gastrointestinal track of the host may induce injuries relevant to difficult physiological states within the dormancy continuum.

Listeria monocytogenes is a psychrotrophic food-borne pathogen mostly associated with consumption of ready-to eat foods. Due to its high prevalence in raw materials, it is fundamental to control its growth at low temperature. In lipid-rich products, fatty acids can be heterogeneously distributed in the food matrix and can be present in the environment immediately surrounding the pathogen.