Research Publications (Food Safety)

Shiga toxins (Stx1 and Stx2, also called verocytotoxins) are commonly associated with Shiga toxin-producing Escherichia coli (STEC) and Shigella dysenteriae type 1 (Tesh and O’Brien 1991). Recent studies have documented cases of stx carriage in other Shigella species, including S. sonnei linked to travel to Morocco (Nyholm et al. 2015) and S. flexneri with travel history to Caribbean (Gray et al. 2014, 2015).

Publication date: Available online 25 September 2015

Author(s): Ute Wessels, Olga Stech, El-Sayed M. Abdelwhab, Andreas Judel, Thomas C. Mettenleiter, Jürgen Stech

Within the European activities for the ‘Monitoring and Collection of Information on Zoonoses’, annually EFSA publishes a European report, including information related to the prevalence of Campylobacter spp. in Germany. Spatial epidemiology becomes here a fundamental tool for the generation of these reports, including the representation of prevalence as an essential element.

Raccoons are common in urban and rural environments and can carry a wide range of bacteria, including Salmonella, that can negatively affect human and livestock health. Although previous studies have reported that raccoons shed a variety of Salmonella serovars in their faeces, it is unknown whether Salmonella is carried on raccoon paws. Our objective was to compare the prevalence of Salmonella on the paws and in the faeces of raccoons in south-western Ontario.

Menéndez, Rosa Ana et al. The objective of this research was to determine the behavior of Listeria monocytogenes in three types of sliced ready-to-eat meat products packaged under vacuum or modified atmosphere conditions and stored at three temperatures. Slices of about 25 g of chorizo (a fermented dry pork sausage), jamón (cured ham), and cecina (a salted, dried beef product) were inoculated with L. monocytogenes NCTC 11994.

Sallam, Khalid Ibrahim et al. The emergence of livestock-associated methicillin-resistant Staphylococcus aureus (MRSA) in food-producing animals is of increasing interest, raising questions about the presence of MRSA in food of animal origin and potential sources of transmission to humans via the food chain.

Piras, Francesca et al. Quantitative assessment of in vitro biofilm formation by 40 Salmonella enterica isolates isolated in pig abattoirs from animal and environmental sources (surfaces in contact and not in contact with meat) and classified in eight seroytpes was carried out by using a microtiter plate assay with spectrophotometric reading (optical density at 620 nm).

Zhou, Huimin et al. Two application methods were used to investigate the effect of plantaricin BM-1 on the control of Listeria monocytogenes and background spoilage bacteria in sliced vacuum-packaged cooked ham without the addition of any chemical preservatives, including sodium nitrite, during 35 days of storage at 4°C.

Beuchat, Larry R. et al. A study was done to determine the rate of inactivation of Salmonella in cookie and cracker snack sandwiches. Two cookie bases (chocolate and vanilla) and cheese crackers, along with high-sugar chocolate and peanut butter–based crème cookie fillings and peanut butter–and cheese-based cracker fillings, were obtained from commercial sources.

Oscar, T. P. et al. Mathematical models that predict the behavior of human bacterial pathogens in food are valuable tools for assessing and managing this risk to public health. A study was undertaken to develop a model for predicting the behavior of Salmonella enterica serotype 8,20:–:z6 in chicken meat during cold storage and to determine how well the model would predict the behavior of other serotypes of Salmonella stored under the same conditions.

Mohammed, Hussni O. et al. Escherichia coli O157:H7, non-O157 E. coli, and Campylobacter spp. are among the top-ranked pathogens that threaten the safety of food supply systems around the world. The associated risks and predisposing factors were investigated in a dynamic animal population using a repeat-cross-sectional study design.

Harada, Tetsuya et al. Shiga toxin family members have recently been classified using a new nomenclature into three Stx1 subtypes (Stx1a, Stx1c, and Stx1d) and seven Stx2 subtypes (Stx2a, Stx2b, Stx2c, Stx2d, Stx2e, Stx2f, and Stx2g). To develop screening methods for Stx genes, including all of these subtype genes, and Escherichia coli O26-, O111-, and O157-specific genes in laboratory investigations of Shiga toxin–producing E.

Oni, Ruth A. et al. Concerns about the microbiological safety of fresh produce have attracted attention in the past three decades due to multiple foodborne outbreaks. Animal manure contaminated with enteric pathogens has been identified as an important preharvest pathogen source. This study investigated the survival of Salmonella enterica in dust particles of dehydrated turkey manure and how association with manure dust may enhance the survival of salmonellae on leafy greens in the field.

Xiao, Zhenlei et al. Radish (Raphanus sativus var. longipinnatus) microgreens were produced from seeds inoculated with Escherichia coli O157:H7 by using peat moss–based soil-substitute and hydroponic production systems. E. coli populations on the edible and inedible parts of harvested microgreen plants (7 days postseeding) and in growth medium were examined. E.

Abstract

In this researchthe effects of lyophilized Urtica dioica L. water extract (LUDWE) on the shelf life of vacuum-packaged beef steaks were evaluated. For this purpose, beef steaks were arranged as control (vacuum packaging, VP), 150 ppm LUDWE + VP, 300 ppm LUDWE + VP and 450 ppm LUDWE + VP, and were stored at 2 ± 0.5C for 21 days.

Botulinum neurotoxin A (BoNT/A) is a toxin produced by the naturally-occurring Clostridium botulinum that causes botulism. The potential of BoNT/A as a useful medical intervention was discovered by scientists developing a vaccine to protect against botulism. They found that, when injected into a muscle, BoNT/A causes a flaccid paralysis.

Foodborne Pathogens and Disease , Vol. 0, No. 0.

Sensing potential nitrogen-containing respiratory substrates such as nitrate, nitrite, hydroxylamine, nitric oxide (NO) or nitrous oxide (N2O) in the environment and subsequent up-regulation of corresponding catabolic enzymes is essential for many microbial cells. The molecular mechanisms of such adaptive responses are, however, highly diverse in different species.

Foodborne Pathogens and Disease , Vol. 0, No. 0.

Foodborne Pathogens and Disease , Vol. 0, No. 0.

Banya Banowary, Van Tuan Dang, Subir Sarker, Joanne H. Connolly, Jeremy Chenu, Peter Groves, Michelle Ayton, Shane Raidal, Aruna Devi, Thiru Vanniasinkam, Seyed A. Ghorashi

The cholera toxin genes of Vibrio cholerae are encoded by CTX, a lysogenic bacteriophage. Infection with this phage plays a determinant role in toxigenicity conversion and the emergence of new clones of pathogenic V. cholerae. Multiple phage alleles, defined by sequence types of the repressor gene rstR, have been found, showing the divergence of phage genomes. Pre-CTX, which is characterized by the absence of toxin genes, is predicted to be the precursor of CTX.

Enterohemorrhagic Escherichia coli (EHEC) is the causative agent of bloody diarrhea and extraintestinal sequelae in humans, most importantly hemolytic-uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Besides the bacteriophage-encoded Shiga toxin gene (stx), EHEC harbors the locus of enterocyte effacement (LEE), which confers the ability to cause attaching and effacing lesions.

The microcin PDI inhibits a diverse group of pathogenic Escherichia coli strains. Coculture of a single-gene knockout library (BW25113; n = 3,985 mutants) against a microcin PDI-producing strain (E. coli 25) identified six mutants that were not susceptible (atpA, atpF, dsbA, dsbB, ompF, and ompR). Complementation of these genes restored susceptibility in all cases, and the loss of susceptibility was confirmed through independent gene knockouts in E. coli O157:H7 Sakai.