Research Publications (Food Safety)

Norovirus is one of the most common causes of acute viral gastroenteritis. The virus is spread via the fecal-oral route, most commonly from infected food and water, but several outbreaks have originated from contamination of surfaces with infectious virus.

The suitability of traditional microbial indicators (i.e., Escherichia coli and enterococci) has been challenged due to the lack of correlation with pathogens and evidence of possible regrowth in the natural environment.

The impact of proximity to a beef cattle feedlot on Escherichia coli O157:H7 contamination of leafy greens was examined. In each of 2 years, leafy greens were planted in nine plots located 60, 120, and 180 m from a cattle feedlot (3 plots at each distance). Leafy greens (270) and feedlot manure samples (100) were collected six different times from June to September in each year. Both E. coli O157:H7 and total E. coli bacteria were recovered from leafy greens at all plot distances. E.

Shiga toxin (Stx), a major virulence factor of enterohemorrhagic Escherichia coli, binds to target cells through a multivalent interaction between its B-subunit pentamer and the cell surface receptor globotriaosylceramide, resulting in a remarkable increase in its binding affinity.

Salmonella enterica is a member of the plant microbiome. Growth of S. enterica in sprouting-seed exudates is rapid; however, the active metabolic networks essential in this environment are unknown. To examine the metabolic requirements of S. enterica during growth in sprouting-seed exudates, we inoculated alfalfa seeds and identified 305 S. enterica proteins extracted 24 h postinoculation from planktonic cells.

In Mekong Delta farms (Vietnam), antimicrobials are extensively used, but limited data are available on levels of antimicrobial resistance (AMR) among Escherichia coli isolates. We performed a structured survey of AMR in E. coli isolates (n = 434) from 90 pig, chicken, and duck farms. The results were compared with AMR among E. coli isolates (n = 234) from 66 small wild animals (rats and shrews) trapped on farms and in forests and rice fields.

Growth of enteropathogenic Escherichia coli E2348/69 was inhibited by bicarbonate in a dose-dependent manner, showing approximately 5% growth reduction at 5 mmol l−1 while kanamycin at 3.12 μg ml−1 inhibited growth by 15%, yet when kanamycin and bicarbonate were combined at these concentrations, inhibition increased to 80%. Unexpectedly, at bicarbonate concentrations >20 mmol l−1 enhancement of the antibiotic activity virtually disappeared, i.e. there was a paradoxical Eagle-like effect.

When exposed to nutrient or non-nutrient germinants, individual Bacillus spores can return to life through germination followed by outgrowth. Laser tweezers Raman spectroscopy, and either differential interference contrast or phase contrast microscopy were used to analyze the slow dipicolinic acid (DPA) leakage (normally ~20% of spore DPA) from individual spores that takes place prior to the lag time, Tlag, when spores begin rapid release of remaining DPA.

Ultrahigh-performance liquid chromatography using positive electrospray ionization and quadrupole orbital ion trap high-resolution mass spectrometry was evaluated for analyzing mycotoxins in finished cereal and nut products. Optimizing the orbital ion trap mass analyzer in full-scan mode using mycotoxin-fortified matrix extracts gave mass accuracies, δM, of <±2.0 ppm at 70 000 full width at half maximum (FWHM) mass resolution (RFWHM).

Publication date: March 2015
, Volume 101
Author(s): Oleksandr Tokarskyy , Keith R. Schneider , Adrian Berry , Steven A. Sargent , Aswathy Sreedharan

Publication date: Available online 9 January 2015

Author(s): Zhihong Zhang , Wenting Liu , Hengyi Xu , Zoraida P. Aguilar , Nagendra P. Shah , Hua Wei

Publication date: June 2015
, Volume 52
Author(s): Hande Kaya-Celiker , P. Kumar Mallikarjunan , Archileo Kaaya

Publication date: June 2015
, Volume 52
Author(s): Jose Ignacio Ruiz de Galarreta , Ana Butrón , Amaia Ortiz-Barredo , Rosa Ana Malvar , Amando Ordás , Arsenio Landa , Pedro Revilla

In this study, the growth of Arcobacter butzleri in poultry was evaluated as a function of storage temperature (5, 22.5, and 40°C), pH (5, 7, and 9), and NaCl concentration (0, 4, and 8%). A predictive model was developed using the absorbance-based response surface methodology to describe the growth rate.

Publication date: 15 June 2015
, Volume 177
Author(s): Marlena K. Sheridan , Ryan J. Elias

Publication date: 1 June 2015
, Volume 176
Author(s): Agnieszka Dudkiewicz , Alistair B.A. Boxall , Qasim Chaudhry , Kristian Mølhave , Karen Tiede , Peter Hofmann , Thomas P.J. Linsinger

Eischeid, Anne C. et al. Real-time PCR has been used widely in numerous fields. In food safety, it has been applied to detection of microbes and other contaminants, including food allergens. Interest in rapid (fast) cycling real-time PCR has grown because it yields results in less time than does conventional cycling. However, fast cycling can adversely affect assay performance.

Mormann, Sascha et al. The transfer of human norovirus (hNV) to food via contaminated surfaces is highly probable during food production, processing, and preparation. In this study, the tenacity of hNV and its cultivable surrogates feline calicivirus (FCV) and murine norovirus (MNV) on two common nonporous surface materials at two storage temperatures was directly compared.

Moscoso, S. et al. Previously, we reported the use of quinolones in broiler chickens resulted in residues in retail poultry meat obtained from nine districts in the Santiago Province of the Dominican Republic. Residues in poultry products are a concern due to consumer allergies and the potential to develop antibiotic-resistant bacteria.

Arsi, K. et al. Campylobacter is a leading cause of foodborne illness worldwide. It is common in poultry, and human infections are often associated with consumption of contaminated poultry products. One strategy to reduce Campylobacter colonization in poultry is the use of oral probiotics, but this produces variable results, possibly because the probiotics are destroyed in the stomach's acidic environment.

Wood, Jayde L. et al. Increased consumer demand for fresh leafy produce has been paralleled by an increase in outbreaks and illness associated with these foods. Presently, data on the microbiological quality and safety of produce harvested in the Lower Mainland of British Columbia is lacking.

Wheeler, Sarita Raengpradub et al. Although serotype O157:H7 remains the pathogenic Shiga toxin–producing Escherichia coli (STEC) of primary concern worldwide, some focus in the United States has shifted to six particular non-O157 STEC serogroups (O26, O45, O103, O111, O121, and O145). Some of these serogroups have also emerged as concerns elsewhere around the world, including Europe. The objective of this work was to compare commercial detection methods with the U.S.

Norton, D. M. et al. Surveillance data indicate that handling of food by an ill worker is a cause of almost half of all restaurant-related outbreaks. The U.S. Food and Drug Administration (FDA) Food Code contains recommendations for food service establishments, including restaurants, aimed at reducing the frequency with which food workers work while ill. However, few data exist on the extent to which restaurants have implemented FDA recommendations.

Kosa, Katherine M. et al. Salmonella and Campylobacter cause an estimated combined total of 1.8 million foodborne infections each year in the United States. Most cases of salmonellosis and campylobacteriosis are associated with eating raw or undercooked poultry or with cross-contamination. Between 1998 and 2008, 20% of Salmonella and 16% of Campylobacter foodborne disease outbreaks were associated with food prepared inside the home. A nationally representative Web survey of U.S.

Hajeb, Parvaneh et al. High-quality fish oil for human consumption requires low levels of toxic elements. The aim of this study was to compare different oil extraction methods to identify the most efficient method for extracting fish oil of high quality with the least contamination. The methods used in this study were Soxhlet extraction, enzymatic extraction, wet reduction, and supercritical fluid extraction.