Research Publications (Food Safety)

In our previous study, we observed the sporadic presence of potentially heat-injured cells of Listeria innocua in ice cream mix following a selective enrichment protocol. Although injured cells have not yet been reported to cause any disease outbreaks, it is important to understand their presence in heat-treated food matrices.

A series of food safety incidents related to domestically produced dairy in China harmed consumer confidence and caused a dramatic decrease in dairy consumption from 2008 to 2010. Compared with previous studies that mainly assessed consumer confidence in food or dairy in general, this study focused on 2 specific dairy products, milk and infant milk formula (IMF).

The aims of this study were to determine whether non-aureus staphylococci (NAS) are present in rectal feces of healthy dairy cows, and if so, to delineate species to which they belong and to study several phenotypic and genotypic traits as a first step toward determining the potential impact of fecal shedding of NAS on bovine udder health.

Bloomy rind cheeses, including Brie, Camembert, and related varieties, are at high risk of contamination by environmental pathogens during manufacture and ripening. This risk is particularly high during ripening due to open-air exposure of the product. Currently, no kill step is applied after manufacture or post ripening to control food safety risks associated with Listeria monocytogenes contamination.

This study determined the prevalence, pulsed-field gel electrophoresis profiles, and antimicrobial resistance profile of Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7 isolates from dairy cattle farms in Jordan. Samples from bulk tank milk (n = 305), cattle feces (n = 610), and rectoanal mucosal swabs (n = 610) were collected from 61 dairy cattle farms. We confirmed 32 L. monocytogenes, 28 S. enterica, and 24 E. coli O157:H7 isolates from the samples.

The inhibitory effect of lactose oxidase on the growth of foodborne pathogens and spoilage microorganisms associated with dairy products was evaluated through an overlay inhibition assay. Lactose oxidase generates hydrogen peroxide via lactose oxidation into lactobionic acid. Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica ser. Typhimurium, Staphylococcus aureus, Pseudomonas fragi, and Penicillium chrysogenum were used as indicators.

The expression of genes associated with aflatoxin biosynthesis by different Aspergillus flavus strains growing on a cheese model system has not been studied. To control aflatoxin biosynthesis, it would be useful to understand the changes in gene expression during cheesemaking and relate those changes to toxin production.

Bacillus cereus sensu lato is one of the most harmful bacterial groups affecting the quality and safety of powdered infant formula (PIF). In this study, samples were collected from the raw materials and processing environments of PIF. A total of 84 isolates were identified as Bacillus cereus sensu stricto (B. cereus s. s.) by 16S rRNA analysis, molecular typing technology, and physiological and biochemical tests. The 84 B. cereus s. s.

Staphylococcus aureus is an important pathogen causing chronic and subclinical mastitis of cows. Autophagy is an important regulatory mechanism that participates in the elimination of invading pathogenic organisms. Here, we hypothesize that autophagy is involved in the process of Staph. aureus survival in bovine mammary epithelial cells (BMEC).

Escherichia coli has been frequently reported as a major foodborne bacterium contaminating raw milk or pasteurized milk. Therefore, the aim of this study was to explore a quantitative real-time PCR (qPCR) technique combined with sodium dodecyl sulfate (SDS) and propidium monoazide (PMA) to detect culturable E. coli in milk. An internal amplification control was also added into this reaction system as an indicator of false-negative results.

The process of fermentation contributes to the organoleptic properties, preservation, and nutritional benefits of food. Fermented food may interfere with pathogen infections through a variety of mechanisms, including competitive exclusion or improving intestinal barrier integrity. In this study, the effect of milk fermented with Lactococcus lactis ssp. cremoris JFR1 on Salmonella invasion of intestinal epithelial cell cultures was investigated.

Mesophilic and thermophilic spore-forming bacteria represent a challenge to the dairy industry, as these bacteria are capable of surviving adverse conditions associated with processing and sanitation and eventually spoil dairy products. The dairy farm environment, including soil, manure, silage, and bedding, has been implicated as a source for spores in raw milk.

The present study investigated whether delaying the first feeding of colostrum affected ileum and colon mucosa-associated microbiota in calves. Twenty-seven male Holstein calves were randomly assigned to 1 of 3 groups, fed colostrum at 45 min, 6 h, and 12 h after birth, respectively. Ileum and colon mucosa were collected at 51 h after birth, and their associated microbial profiles were assessed using amplicon sequencing.

Reports of β-lactam-resistant Staphylococcus aureus in artisanal goat cheese are increasing, and this phenomenon is relevant to public health. The objective of the present study was to determine the prevalence of S. aureus strains carrying the blaZ and mecA resistance genes, as well as the genes encoding the staphylococcal enterotoxins SEA, SEB, SEC, SED, SEE, and TSST-1 in artisanal coalho cheese made from goat milk produced in northeastern Brazil.

Fermented whey dairy beverages are dairy products obtained by fermentation from a mixture of milk and whey. These beverages have important health benefits, which could be improved with the addition of probiotic cultures. This study assessed the protective effect of the cosupplementation of a probiotic culture (Lactobacillus casei 01) with a fermented whey dairy beverage against infection by Salmonella enterica ssp. enterica serovar Typhimurium in a murine model.

Reporting guidelines are increasingly used by journals to remind authors about important criteria needed to evaluate scientific papers. The Reporting Guidelines for Randomized Controlled Trials for Livestock and Food Safety (REFLECT; https://meridian.cvm.iastate.edu/reflect/; O'Connor et al., 2010) was published in 2010 to provide guidance to authors on minimum reporting standards in designed experimental studies using livestock.

Invited review: Completeness of reporting of experiments: REFLECTing on a year of animal trials in the . By Winder et al., page 4759. Reproducibility in science requires comprehensive and accurate reporting of study design, conduct, and analysis. This observational study examined the prevalence of reporting of the 18 objective items in the Reporting Guidelines for Randomized Control Trials in Livestock and Food Safety (REFLECT) in trials published in the in 2017.

Staphylococcus aureus is one of the leading causes of food-borne illness worldwide. Raw milk and dairy products are often contaminated with enterotoxigenic strains of this bacterium. Some of these strains carry antimicrobial resistance, leading to a potential risk for consumers. The aim of this study was to characterize S. aureus strains circulating in raw milk and traditional dairy products for carriage of staphylococcal enterotoxin (se) genes and antimicrobial resistance.

Some Lactobacillus strains may contribute to the health of the host when administered in adequate concentrations, demonstrating their probiotic potential. In contrast, Listeria monocytogenes is a foodborne pathogen that can cause enteropathy, meningoencephalitis, abortion, and septicemia.

Following the persistent detection of Listeria monocytogenes in raw bovine milk sold through a vending machine, the 120 lactating cows of the herd producing the milk were subjected to bacteriological investigation. A single cow with subclinical mastitis (1.2–1.3 × 105 somatic cells/mL) and persistent L. monocytogenes excretion was detected. The cow was subjected to antimicrobial therapy, but L. monocytogenes excretion remained high (>3.0 × 102 cfu/mL).

The rapid and sensitive detection of foodborne pathogens is one of the most important issues in food safety control. In this work, we developed a novel fluorescence immunoassay method for the sensitive detection of Salmonella choleraesuis.

Cronobacter turicensis is a food-borne pathogen found in dairy products. It has been reported to cause bacteremia and enteritis in immunocompromised people, especially infants. Cronobacter turicensis has been isolated from various food sources, and contaminated powdered infant formula was found to be the most common source of infection among infants. Although some gene targets are used for the identification of C. turicensis, they are not specific at the species level.

A longitudinal study was conducted to assess to what extent intramammary infection (IMI) with non-aureus staphylococci (NAS) within the first 4 d after calving in dairy heifers affects quarter milk yield (qMY) and quarter milk somatic cell count (qSCC) during the first 4 mo of lactation. In total, 324 quarters from 82 Holstein Friesian heifers from 3 commercial dairy herds equipped with an automatic milking system were included and followed from calving up to 4 mo in lactation.

The objective was to evaluate the efficacy of 2 dietary mycotoxin sequestrants, Toxy-Nil (TN) or Unike Plus (UP), in reducing aflatoxin (AF) M1 concentrations in milk of dairy cows challenged with dietary AF.

Coxiella burnetii is a gram-negative and polymorphic rod bacterium that causes Q fever, a common zoonotic disease distributed worldwide. Widespread occurrences of the disease outbreaks indicate the importance of coordinated animal and human health efforts to control these outbreaks. Different tests are available to determine the C.