Research Publications (Food Safety)

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.

Spices are widely used in daily life such as diet and have certain activity. Especially in China, spices have been mainly used as condiments for thousands of years in order to improve the sensory quality of food; in addition, they and their derivatives can also be used as preservatives.

This study evaluated the chlorine dioxide (ClO2) gas mediated inactivation of the biofilm cells of foodborne pathogens on food contact surfaces. Biofilm cells of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes were developed on stainless steel (SS) and high density polyethylene (HDPE) coupon surfaces, and 5-day-old biofilms were treated with ClO2 gas at 60 and 90% relative humidity (RH) for up to 20 min.

The antimicrobial properties of two different emulsion formulations contained lemon essential oil (coarse emulsion; CE and nanoemulsion; NE) and emulsions based edible solutions incorporated with lemon essential oil and sodium caseinate (coarse emulsion based solution; CESC and nanoemulsion based solution; NESC) on food-related microorganisms (Photobacterium damselae, Pseudomonas luteola, Salmonella Paratyphi A NCTC13, and Listeria monocytogenes ATCC19112)

The active pectin-polyvinylpyrrolidone nanocomposite film incorporated with titania nanoparticles and bael shell extract was fabricated via the casting solution method. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) was utilized to analyze the nanocomposite films. The titanium nanoparticles were found to be uniformly dispersed throughout the matrix of the pectin-polyvinylpyrrolidone polymer, as shown by the SEM analysis.

Infection and Immunity, Ahead of Print. The bacterial pathogen Listeria monocytogenes induces its internalization (entry) into intestinal epithelial cells through interaction of its surface protein, internalin A (InlA), with the human cell-cell adhesion molecule, E-cadherin. While InlA-mediated entry requires bacterial stimulation of actin polymerization, it remains unknown whether additional host processes are manipulated to promote internalization.

This study evaluated Listeria monocytogenes cross-contamination between inoculated fruits, waxing brush, and uninoculated fruits during apple wax coating and investigated the fate of L. monocytogenes on wax-coated apples introduced via different wax coating schemes. There were 1.8–1.9 log10 CFU/apple reductions of L.

The current study was carried out to investigate metabolic activities and main probiotic characteristics of two Latilactobacillus sakei strains (8.P1 and 28.P2) isolated from pastırma, a highly seasoned, air-dried cured beef. Both strains showed antimicrobial activity against important foodborne pathogens like Listeria monocytogenes, Staphylococcus aureus, Pseudomonas aeruginosa and so forth.

There is a need to identify the presence of microorganisms, in particular human pathogens, in food processing facilities and products. Adhesion of pathogens to surfaces poses a detection challenge with biofilms greatly hindering detection by precluding the transfer of specific material to downstream sensors. Enzymes that disrupt biofilms can therefore enhance detection of foodborne pathogens through facilitating their release from abiotic and biotic surfaces.

Applied and Environmental Microbiology, Ahead of Print. For decades, quaternary ammonium compounds (QAC)-based sanitizers have been broadly used in food processing environments to control foodborne pathogens such as Listeria monocytogenes. Still, there is a lack of consensus on the likelihood and implication of reduced Listeria susceptibility to benzalkonium chloride (BC) that may emerge due to sublethal exposure to the sanitizers in food processing environments.

Active investment in research time in the development and study of novel unconventional antimicrobials is trending for several reasons. First, it is one of the ways which might help to fight antimicrobial resistance and bacterial contamination due to uncontrolled biofilm growth. Second, minimizing harmful environmental outcomes due to the overuse of toxic chemicals is one of the highest priorities nowadays.

Whole genome sequencing (WGS) of foodborne pathogens such as Listeria monocytogenes is globally on the rise in the food industry.

The objectives of this study were to determine the prevalence of Listeria monocytogenes in ready-to-eat (RTE) foods, and the growth boundaries of two strains of L. monocytogenes isolated from RTE foods and one ATCC7644 strain under different temperature (4, 20, and 37°C), salt (0, 1, 2, 3, and 4% w/v), and nisin (0, 50, 100, 200, and 400 µg/mL) levels with different inoculum sizes (3, 4, 5, and 6 log10 CFU/mL).

Some water disinfection treatments, such as chlorine and chlorine dioxide, used in the fresh-cut industry to maintain the microbiological quality of process water (PW), inactivate bacterial cells in the water but they also lead to the induction of an intermediate state between viable and non-viable known as viable but non-culturable (VBNC) state.

Cheese belongs to the category of foods most frequently contaminated with Listeria monocytogenes. Antibiotics, disinfectants, and various preservatives have been conventionally utilized as a microbial control strategy.

Foodborne pathogens detection is important to ensure food safety and human health. In this study, we designed a comet structure to rapidly and sensitively detect foodborne Listeria monocytogenes.

Plant essential oils (EOs), which are acknowledged as generally recognized as safe (GRAS) by the Food and Drug Administration (FDA), have the potential to be used as a flavoring agent. However, there are limitations to some EOs, such as low water solubility and high volatility, which limit their application in food technology.

In this work, the chemical composition of Thymus zygis subsp. gracilis collected from Ifrane, Morocco, along with the evaluation of the antibacterial, anti-biofilm of Listeria monocytogenes activities, larvicidal effect against L3 larvae

This study evaluated the survival of Listeria monocytogenes on fresh-cut melon and papaya treated with citral nanoemulsion (CN) during 7 days of storage at 4, 8, 12, and 16 °C.

Fresh vegetables play a significant role in the human diet. However, ready-to-eat (RTE) vegetables have been associated with increasing foodborne outbreaks including L. monocytogenes, which is a common human pathogen associated with foodborne infections resulting in listeriosis. This study aims to assess the resistance of vegetable-borne L. monocytogenes to antibiotics. L.

Journal of Food Safety, EarlyView. The objective was to explore the effects of dielectric barrier discharge (DBD) plasma on bacterial reduction, physiological characteristics (pH and moisture), and sensorial quality against Listeria monocytogenes on the surface of smoked salmon. Reductions were treated with 5, 10, 20, 30, 40, 50, and 60 min with DBD plasma varied from 0.17, 0.25, 0.32, 0.70, 0.81, 1.05, and 1.25 log10 CFU/g, respectively.

The human gastrointestinal tract (GIT) harbors numerous defensive mechanisms to impede pathogen colonization, including gastric acidity and bile acids in the small intestine.

A novel saltatory rolling circle amplification (SRCA) assay was established for prompt identification of L. monocytogenes in milk and Indian milk cake (kalakhand). The SRCA and conventional PCR were independently able to detect 63 fg and 630 fg L. monocytogenes DNA per reaction, respectively. The detection limit of SRCA was evaluated in artificially contaminated milk and kalakhand.

Transcriptomic analysis was used to investigate the antibacterial mechanism of phenolic compounds from kefir fermented soy whey (FSP) against Escherichia coli 0157:H7 and Listeria monocytogenes. The kefir fermentation increased the concentration of several phenolic aglycones with proven antibacterial efficacy in the FSP. The time-kill curve showed that 2× MICs of the FSP killed >99.9 % of the strains within 2 h of exposure.