Canada is a leading producer of wild lowbush blueberries, most of which are mechanically harvested, washed, individually quick frozen (IQF), and bulk packaged. Still, some berries are harvested by more gentle methods and sold as fresh-packed products. These berries do not undergo a wash step, nor are subjected to antimicrobial treatments.
View Article and Find Full Text PDFspp. are opportunistic human and animal pathogens found ubiquitously in marine environments. Globally, there is a predicted rise in the prevalence of spp.
View Article and Find Full Text PDFCompr Rev Food Sci Food Saf
January 2024
Vibrio spp., known human foodborne pathogens, thrive in freshwater, estuaries, and marine settings, causing vibriosis upon ingestion. The rising global vibriosis cases due to climate change necessitate a deeper understanding of Vibrio epidemiology and human transmission.
View Article and Find Full Text PDFSpecies identification and growth rates for a collection of Cronobacter strains from clinical and non-clinical sources have been previously reported. However, advancements in DNA sequencing-based identification methods now allow for more accurate identification. Here we report the sequence types (STs) for 24 strains of Cronobacter sakazakii and examine any possible correlation between sequence type and growth rate, which could influence risk through greater pathogen multiplication and reach of infectious doses during time between formula preparation and feeding.
View Article and Find Full Text PDFAdv Colloid Interface Sci
March 2020
The attachment of microbial communities to surfaces is a well-known problem recognized to be involved in a variety of critical issues in the sectors of food processing, chronic wounds, infection from implants, clogging of membranes and corrosion of equipment. Considering the importance of the detrimental impact of biofouling, it has received much attention in the scientific community and from concerned stakeholders. With the development of nanotechnology and the nowadays widespread use of engineered nanoparticles (ENPs), concerns have been raised regarding their fate in terrestrial and aquatic environments.
View Article and Find Full Text PDFThe formation of biofilms in the food industry is a major issue, as they are a frequent source of contamination of products, which can result in significant economic losses for processors through spoilage of foods or pose serious health concerns for consumers when foodborne pathogens are present. In this study, experiments were carried out using CDC Biofilm Reactors to produce biofilms on two test surfaces (polystyrene and stainless steel coupons) under a regimen for simulated meat processing conditions (SMPC). This entailed a 12 day regimen of daily cycles of filling the reactors with a meat slurry and letting stand for 16 h, followed by draining and refilling with water for an 8 h period in order to mimic a possible scenario of fluctuating periods of nutrient availability and starvation in a meat processing facility.
View Article and Find Full Text PDFThis study aimed to determine the impact of bacteria from a beef plant conveyor belt on the biofilm formation of Salmonella in dual-species cultures. Beef plant isolates (50) including 18 Gram-negative aerobes (GNA), 8 Gram-positive aerobes (GPA), 5 lactic acid bacteria (LAB), 9 Enterobacteriaceae (EB), and 10 generic Escherichia coli (GEC) were included for developing biofilms in mono- and co-culture with S. Typhimurium at 15 °C for 6 days.
View Article and Find Full Text PDFUnlabelled: Rapid methods to detect bacterial pathogens on food and strategies to control them are needed to mitigate consumer risk. This study assessed volatile emissions from whole cantaloupe melons (Cucumis melo) as an indicator of Listeria contamination and in response to steam vapor decontamination. Cantaloupe were inoculated with Listeria innocua, a nonpathogenic surrogate for L.
View Article and Find Full Text PDFUnlabelled: Recent bacterial illnesses and outbreaks associated with the consumption of fresh and fresh-cut fruit and vegetables emphasize the need to supply produce that is microbiologically safe while retaining its quality and nutrient value. We assessed the capacity of aerated steam to reduce initial levels and control the posttreatment proliferation of a 4-strain mixture of Listeria innocua, a surrogate for L. monocytogenes, and microflora native to the rind of whole cantaloupes.
View Article and Find Full Text PDFListeria monocytogenes is a pathogenic foodborne microorganism noted for its ability to survive in the environment and food processing facilities. Survival may be related to the phenotype of individual strains including the ability to form biofilms and resist desiccation and/or sanitizer exposure. The objectives of this research were to compare 14 L.
View Article and Find Full Text PDFA stochastic model describing the growth of Listeria monocytogenes during enrichment in half Fraser was developed for the purpose of estimating the effects of modifications to the first enrichment step of the EN ISO 11290-1 detection method. Information pertaining to the variability of growth rates, physiological state of the cell, and the behavior of individual cells contaminating the food were obtained from previously published studies. We used this model to investigate the impact of pooling enrichment broths (wet pooling) on the performance of the standard method.
View Article and Find Full Text PDFThis research aimed to determine whether the SigB (σ(B)) regulon and osmolytes impact the survival of the foodborne pathogen, Listeria monocytogenes, during desiccation in simulated food soils with varying salt and nutrient contents on food grade stainless steel (SS) surfaces. L. monocytogenes 568 (Lm568, serotype 1/2a), its isogenic sigB mutant (ΔsigB) and the back-complemented ΔsigB were desiccated in BHI, TSB with 1% glucose (TSB-glu), peptone physiological saline (PPS) and minimal media (MM) for 21 days at 43% relative humidity (RH) and 15 °C on SS.
View Article and Find Full Text PDFIt is recognized that bacterial adhesion usually occurs on conditioning films made of organic macromolecules absorbed to abiotic surfaces. The objectives of this study were to determine the extent to which milk protein-coated polystyrene (PS) pegs interfere with biofilm formation and the synergistic effect of this conditioning and hypertonic growth media on the bacterial adhesion and biofilm formation of Listeria innocua, used as a nonpathogenic surrogate for Listeria monocytogenes. PS pegs were uncoated (bare PS) or individually coated with whey proteins isolate (WPI), β-lactoglobulin, bovine serum albumin, or tryptic soy broth (TSB) and were incubated in bacterial suspensions in modified Welshimer's broth.
View Article and Find Full Text PDFIn a standard procedure of food safety testing, the presence of the pathogenic bacterium Listeria monocytogenes can be masked by non-pathogenic Listeria. This phenomenon of Listeria overgrowth is not well understood. We present a mathematical model for the growth of a mixed population of L.
View Article and Find Full Text PDFThe food-borne pathogen Listeria monocytogenes is a problem for food processors and consumers alike, as the organism is resistant to harsh environmental conditions and inimical barriers implemented to prevent the survival and/or growth of harmful bacteria. One mechanism by which listeriae mediate survival is through the accumulation of compatible solutes, such as proline, betaine and carnitine. In other bacteria, including Escherichia coli, the synthesis and accumulation of another compatible solute, trehalose, are known to aid in the survival of stressed cells.
View Article and Find Full Text PDFMild thermal processing can enhance the shelf life of cut fruits and vegetables by delaying the onset of spoilage and preserving the organoleptic properties of shredded cabbage. However, food safety issues related to this process have not been fully investigated. Therefore, the survival and growth of Listeria spp.
View Article and Find Full Text PDFEnterobacter sakazakii has been identified as the causative agent of serious neonatal infections, associated with high mortality rate. In many cases, powdered infant formula (PIF) has been identified as the source of infection. Recently, E.
View Article and Find Full Text PDFThe objectives of this study were to identify molecular mechanisms of thermotolerance using transposon mutants of Listeria monocytogenes 568, serotype 1/2a, and to compare their thermal death kinetics at 52, 56 and 60 degrees C. Sixteen Tn917 transposon mutants with enhanced heat resistance were acquired from a library of 4300 mutants following a multi-step screening process. Genetic regions with Tn917 insertions encompassed a broad range of functionalities including; transport, metabolism, replication and repair, general stress, and structural properties.
View Article and Find Full Text PDFInt J Food Microbiol
August 2006
Twenty four Listeria strains representing three different species and two serotypes of L. monocytogenes were investigated for their ability to attach to and colonize cabbage tissue. All strains exhibited a preference to attach to cut tissues compared to the intact leaf surfaces.
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