Research Publications (Food Safety)

Many bacterial species, including several pathogens, can enter a so-called “viable but non-culturable” (VBNC) state when subjected to stress. Bacteria in the VBNC state are metabolically active but have lost their ability to grow on standard culture media, which compromises their detection by conventional techniques based on bacterial division.

We monitored viability of Shiga toxin-producing Escherichia coli (STEC), Salmonella spp., and Listeria monocytogenes during preparation and storage of fuet. Coarse ground pork (ca. 35% fat) was mixed with salt (2.5%), dextrose (0.3%), starter culture (ca. 7.0 log CFU/g), celery powder (0.5%), and ground black pepper (0.3%), and then separately inoculated with a multi-strain cocktail (ca. 7.0 log CFU/g) of each pathogen. The batter was stuffed into a ca.

by Sabrina Wamp, Patricia Rothe, Daniel Stern, Gudrun Holland, Janina Döhling, Sven Halbedel Gram-positive bacteria are protected by a thick mesh of peptidoglycan (PG) completely engulfing their cells. This PG network is the main component of the bacterial cell wall, it provides rigidity and acts as foundation for the attachment of other surface molecules.

Due to the ubiquitous character of Listeria monocytogenes, multiple strains of the pathogen may end up co-existing in/on the same final products and could potentially cause infection during consumption. Such multiple strain contamination may occur in different stages of the food supply chain. The present study evaluated the effect of oxygen availability and matrix structure on inter-strain interactions of L.

The importance of single-cell variability is increasingly prominent with the developments in foodborne pathogens modeling. Traditional predictive microbiology model cannot accurately describe the growth behavior of small numbers of cells due to individual cell heterogeneity. The objective of the present study was to develop predictive models for single cell lag times of Salmonella Enteritidis after heat and chlorine treatment.

Staphylococcus aureus (S. aureus) is a foodborne pathogen that endangers human health worldwide. Antimicrobial photodynamic inactivation (aPDI), mediated by titanium dioxide nanoparticles (TiO2NP), was recently used to control the growth of S. aureus, however, UV illumination had to be offered to initiate the photodynamic reaction.

Microorganisms in low-moisture foods (LMFs) exhibit prolonged survivability and high heat resistance. Various external factors (water, food texture, nutritional compounds, etc.) influence the microbial heat resistance in LMFs; yet, the influential degree of each factor is not fully understood. In this study, the thermal resistance parameters (D and z values) of Salmonella enterica Enteritidis PT 30 (S.

In 2016, the United States Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS) established guidelines which modified the Buffered Peptone Water (BPW) rinsate material to include additional compounds that would better neutralize residual processing aids and allow for better recovery of sublethal injured Salmonella spp. cells.

Background The Thermo Scientific SureTect™ Escherichia coli O157:H7 and STEC Screening PCR Assay and SureTect Escherichia coli STEC Identification PCR Assay are real-time PCR kits for the rapid detection of E. coli O157:H7 and non-E. coli O157 Shiga toxin-producing E. coli (STEC) serotypes (O26, O45, O103, O111, O121, O145) from fresh raw spinach, fresh baby leaves, fresh cut tomatoes, frozen raw beef, raw beef trim, and beef carcass sponges.

Background The Thermo Scientific SureTect™ Campylobacter jejuni, C. coli, and C. lari PCR Kit is a real-time PCR assay for the detection and differentiation of C. jejuni, C. coli, and C. lari from raw poultry, ready-to-cook poultry products, and environmental samples. Objective The Thermo Scientific SureTect Campylobacter jejuni, C. coli, and C. lari PCR Kit was evaluated for AOAC®Performance Tested MethodsSM certification.

Background The Thermo Scientific™ SureTect™Staphylococcus aureus PCR Assay is a real-time PCR assay for the detection of Staphylococcus aureus in dairy samples. Objective The Thermo Scientific SureTect Staphylococcus aureus PCR Assay was evaluated for AOAC Performance Tested MethodSM certification. Methods Inclusivity/exclusivity, matrix studies, product consistency and stability, and robustness testing were conducted to assess the method’s performance.

Probiotic bacteria help maintain microbiome homeostasis and promote gut health. Maintaining the competitive advantage of the probiotics over pathogenic bacteria is a challenge, as they are part of the gut microbiome that is continuously exposed to digestive and nutritional changes and various stressors. Witch hazel that is rich in hamamelitannin (WH, whISOBAXTM) is an inhibitor of growth and virulence of pathogenic bacteria.

Transboundary and Emerging Diseases, Accepted Article. Live bird markets (LBMs) provide integral hubs for 95% of poultry produced for food. Surveillance systems in LBMs serving smallholder farmers in sub-saharan Africa are often non-functional and data about public health risks and emerging pathogens are lacking. Studies in Kenya have reported 29% – 44% Campylobacter-prevalence in poultry.

Journal of Applied Microbiology, Accepted Article. To isolate the slow-growing or viable but non-culturable competitive exclusion (CE) microorganisms from composts and then verify the anti-Listeria monocytogenes activities of those CE isolates in compost. CE strains were isolated from composts using double- or triple-layer agar methods, purified, and then characterized. Both compost extracts and solid compost samples were spiked with a cocktail of 3 L.

Alternatives to combat the persistence of pathogens need to consider the microbiota established on industrial surfaces as they can influence the protection or replacement (i.e. reduction/inhibition) of pathogens.

Aim: To evaluate the antibacterial and synergistic effect of a new 8-hydroxyquinoline derivative (PH176) against MRSA. Materials & methods: PH176 activity was determined by broth microdilution against 38 Staphylococcus aureus clinical isolates. The antibacterial and synergistic effects with oxacillin and nitroxoline were evaluated by time–kill assays to five MRSA isolates.

Antibiotic-resistant Vibrio alginolyticus becomes a worldwide challenge threatening both human health and food safety. The approach in managing such infection is largely absent, despite the fact that the mechanisms of antibiotic resistance have been extensively investigated. Metabolic modulation has been documented to be a novel approach in improving antibiotic efficacy. In this study, we characterize the metabolic signature of V. alginolyticus exposed to 0.3 or 0.5 μg/ml of ofloxacin (OFX).

Biological soil crusts (biocrusts) harbor a diverse community of various microorganisms with microalgae as primary producers and bacteria living in close association. In mesic regions, biocrusts emerge rapidly on disturbed surface soil in forest, typically after clear-cut or windfall. It is unclear whether the bacterial community in biocrusts is similar to the community of the surrounding soil or if biocrust formation promotes a specific bacterial community.

Salmonella enterica sv. Typhimurium modulates the expression of factors essential for virulence, contributing to its survival against the surge of copper (Cu) in the Salmonella-containing vacuole. This bactericidal host innate immune component primarily targets the bacterial envelope, where most cuproproteins are localized.

Non-typhoidal Salmonella remains a leading cause of foodborne illness in the United States, with food animal products serving as a key conduit for transmission. The emergence of antimicrobial resistance (AMR) poses an additional public health concern warranting better understanding of its epidemiology. In this study, 958 retail meat samples collected from January to December 2018 in California were tested for Salmonella.

The bacterial pathogen Listeria monocytogenes invades host cells, ruptures the internalization vacuole, and reaches the cytosol for replication. A high-content small interfering RNA (siRNA) microscopy screen allowed us to identify epithelial cell factors involved in L. monocytogenes vacuolar rupture, including the serine/threonine kinase Taok2. Kinase activity inhibition using a specific drug validated a role for Taok2 in favoring L. monocytogenes cytoplasmic access.

A novel sandwich strategy based on the dual recognition by teicoplanin (Teic) and IgG was developed for the rapid separation and identification of Staphylococcus aureus.

Red dragon fruit peel, as a fruit waste, is rich in plant-based nutritional pectins that can be applied as food additives. The present study aims to characterize a novel phosphorylated red dragon fruit peel pectin (PRDFP-P) and to explore its functional activities. The thermal analysis, morphology analysis, antibacterial, antioxidant and antitumor activities of PRDFP-P were evaluated. The results showed that the phosphorylated derivative PRDFP-P had typical phosphate groups.

Small fruits such as strawberries have been increasingly implicated in outbreaks of foodborne illnesses. Salmonella enterica and Listeria monocytogenes may contaminate strawberries leading to potential public health concern. The objective of this study was to investigate the efficacy of a combined lactic acid bacteria (LAB) treatment of Lactobacillus plantarum and Pediococcus pentosaceus for controlling S.

Increasing microbial safety and prolonging the shelf life of products is one of the major challenges in the food industry. Active food packaging made from nanofibrous materials enhanced with antimicrobial substances is considered a promising way.