Research Publications (Food Safety)

Author(s): Zenghai Jiang, Tanveer Muhammad Anwar, Xianqi Peng, Silpak Biswas, Mohammed Elbediwi, Yan Li, Weihuan Fang, Min Yue

Salmonella Typhimurium is a Gram-negative bacterium that causes enterocolitis in humans and pigs. Lipopolysaccharide (LPS) is a component of the outer leaflet of Gram-negative bacteria that provokes endotoxin shock. LPS can be synthesized completely or incompletely and creates S (smooth) or R (rough) chemotypes. Toll-like receptors (TLR) 2, 4, and 9 initiate an inflammatory reaction to combat bacterial infections. We associated/challenged one-week-old gnotobiotic piglets with wild-type S.

Author(s): Rui Dong, Xiaojie Qin, Shoukui He, Xiujuan Zhou, Yan Cui, Chunlei Shi, Yiping He, Xianming Shi

Author(s): Amreeta Sarjit, Joshua T. Ravensdale, Ranil Coorey, Narelle Fegan, Gary A. Dykes

ABSTRACT Salmonellaenterica has been shown to survive in low moisture foods (LMF) for extended periods. The objectives of this study were to statistically identify the effects of environmental stress factors; growth temperature (GTemp), osmotic (Osmo), oxidation (Oxi) and pH on the potential cross‐tolerance effect on the survivability of S. enterica in LMF. A factorial design was utilized to investigate these stressors and their potential effect on survivability of S.

Salmonella is a common causative agent of enteric disease and is developing mechanisms of resistance to antimicrobials. Probiotics, such as bifidobacteria and lactobacilli, and prebiotic fibers are a potential alternative to counteract this pathogen as they have demonstrated effectiveness in preventing its adhesion, reducing intestinal damage, and enhancing the host immune system. Furthermore, the benefits are expected to be potentiated when these compounds are administered together.

The processing and storage conditions of flour food inevitably pose environmental stress, which promote bacteria to enter a viable but non-culturable (VBNC) state. The existence of VBNC cells causes false-negative detection in traditional culture-based detection methods, resulting in food quality and safety issues.

Author(s): Ahmed G. Abdelhamid, Ahmed E. Yousef

Prior efforts to model bacterial thermal inactivation in/on low-moisture foods generally have been based on isothermal and iso-moisture experiments and rarely included dynamic product and process variables. Therefore, the objective of this study was to test appropriate secondary models to quantify the effect of product temperature, product moisture, and process humidity on thermal inactivation of Salmonella Enteritidis PT30 on pistachios subjected to dynamic dry- or moist-air heating.

The study used PCR to determine the molecular basis of the antibiotic resistance and virulence profiles of isolates of Salmonella by targeting genes encoding for carriage and persistence in the poultry.  A total of 1503 cecal samples from poultry were collected, 91 (6.1%) were positive for Salmonella spp.

The aim of this study was to compare the effectiveness of real-time Polymerase Chain Reaction PCR (RT-PCR) molecular method and Crystal Diagnostic Xpress  ( CDx) immunoassay for detecting  Salmonella  and STEC in air samples collected from abattoirs in Texas. A total of 70 air samples were collected from two small and two large plants in the spring and summer season using a wall wetted cyclone (WWC) air sampler.

With its ability to easily infect each step of food production chain, Salmonella spp. stands as one of the most important foodborne pathogens which impose threats against economy and human health by creating high morbidity and mortality, worldwide.

Clinical surveillance of enteric pathogens like Salmonella is integral to track outbreaks and endemic disease trends. However, clinic-centered disease monitoring biases toward detection of severe cases and underestimates the incidence of self-limiting gastroenteritis and asymptomatic strains. Monitoring pathogen loads and diversity in municipal wastewater (MW) can provide insight into asymptomatic or subclinical infections which are not reflected in clinical cases.

by Amanda Aparecida Seribelli, Marcelo Ferreira Cruz, Felipe Pinheiro Vilela, Miliane Rodrigues Frazão, Mario H. Paziani, Fernanda Almeida, Marta Inês Cazentini Medeiros, Dália dos Prazeres Rodrigues, Marcia R. von Zeska Kress, Marc W. Allard, Juliana Pfrimer Falcão

All cells require Mg2+ to replicate and proliferate. The macrophage protein Slc11a1 is proposed to protect mice from invading microbes by causing Mg2+ starvation in host tissues. However, the Mg2+ transporter MgtB enables the facultative intracellular pathogen Salmonella enterica serovar Typhimurium to cause disease in mice harboring a functional Slc11a1...

Salmonella enterica is among the most important foodborne pathogens. In Ecuador, there is limited information about non-typhoidal S. enterica occurrence in raw meats, its serotype distribution, and antimicrobial resistance. In this study, we addressed this issue in 1095 retail fresh meats (chicken, pork, veal, lamb, beef, and turkey) in Quito by performing a traditional culture methodology and molecular detection. We found that S.

Author(s): Marie Noel Mansour, Joseph Yaghi, André El Khoury, Arnaud Felten, Michel-Yves Mistou, Ali Atoui, Nicolas Radomski

Salmonella enterica serovar Typhimurium (S. Typhimurium, STM) is a leading cause of non‐typhoidal salmonellosis (NTS) worldwide. The pathogenesis of NTS has been studied extensively using a streptomycin‐pretreated mouse colitis model with the limited numbers of laboratory S. Typhimurium strains. However, the pathogenicity of the clinically isolated S. Typhimurium (STMC) strains endemic in Thailand in mice has not been explored.

Author(s): Ruixue Chang, Pramod Pandey, Yanming Li, Chandrasekar Venkitasamy, Zhao Chen, Rodrigo Gallardo, Bart Weimer, Michele Jay-Russell, Bart Weimer

Host organisms utilize nutritional immunity to limit the availability of nutrients essential to an invading pathogen. Nutrients may include amino acids, nucleotide bases, and transition metals, the essentiality of which varies among pathogens. The mammalian macrophage protein Slc11a1 (previously Nramp1) mediates resistance to several intracellular pathogens. Slc11a1 is proposed to restrict growth of Salmonella enterica serovar Typhimurium in host tissues by causing magnesium deprivation.

Author(s): Yilan Li, Qiuping Yang, Chenyang Cao, Shenghui Cui, Yun Wu, Hua Yang, Yingping Xiao, Baowei Yang

Multiple studies have demonstrated atmospheric cold plasma as an effective non-thermal technology for inactivating bacteria, spores, and other microbial contaminants in foods and on non-food surfaces. However, few studies have applied this technique to semi-solid food within a package. This study evaluates the efficacy and the interaction mechanism of high voltage atmospheric cold plasma (HVACP) on Salmonella enterica serovar Typhi (S.

A new selective broth, SSEL, was developed for simultaneous enrichment of S. enterica, S. aureus, E. coli O157: H7, and L. monocytogenes, optimizing by single factor experiments and a L9 (34) orthogonal test.

The objective of this study was to compare the impact of ultrasound (US; 30 kHz; 2, 4, 6, and 8 min) and malic acid (MA; 0.5 and 1%), individually and in combination, on inactivation of food borne pathogens (Salmonella Typhi, Shigella dysenteriae, Listeria monocytogenes and Shigella flexneri) and the effect of US treatment on β‐carotene and total phenolics content in sweet lemon juice.