Research Publications (Food Safety)

Small RNAs are principal elements of bacterial gene regulation and physiology. Two small RNAs in Brucella abortus, AbcR1 and AbcR2, are required for wild-type virulence. Examination of the abcR loci revealed the presence of a gene encoding a LysR-type transcriptional regulator flanking abcR2 on chromosome 1. Deletion of this lysR gene (bab1_1517) resulted in the complete loss of abcR2 expression, while no difference in abcR1 expression was observed. The B.

The effects of the addition of oregano (0.25% v/v) and thyme (0.25% v/v) essential oils (EOs) on the microbiological, biochemical and sensory characteristics of a Tunisian dry fermented poultry meat sausage were investigated. The antimicrobial activity of oregano and thyme EOs improved the hygienic quality of dry fermented sausages by reducing the Enterobacteriaceae counts, total coliform counts and Staphylococcus aureus counts.

Fresh vegetables are a frequent cause of foodborne disease outbreaks because they often do not undergo heat treatment prior to consumption. Pathogenic Escherichia coli strains are the major causative agents of produce-related outbreaks.

The aim of our study was to assess the antibiotic resistance among commercially available probiotic Lactobacilli. A total of 30 isolates were characterized after isolation from 19 commercial products, including Lactobacillus rhamnosus, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus reuteri, Lactobacillus plantarum and Lactobacillus fermentum. All the isolates were further subjected to antibiotic susceptibility test using disc diffusion method against a total of 45 antibiotics.

Infections with the Shiga toxin–producing bacterium Escherichia coli O157 can cause severe illness and death. We summarized reported outbreaks of E. coli O157 infections in the United States during 2003–2012, including demographic characteristics of patients and epidemiologic findings by transmission mode and food category. We identified 390 outbreaks, which included 4,928 illnesses, 1,272 hospitalizations, and 33 deaths.

The effects of UV-C irradiation on the inactivation of Escherichia coli K-12ATCC 25253), a surrogate of E. coli O157:H7, and on the shelf life of freshly squeezed turbid white grape juice (FSWGJ) were investigated. FSWGJ samples were processed at 0.90 mL/s for 32 min by circulating 8 times in an annular flow UV system. The UV exposure time was 244 s per cycle. The population of E.

Publication date: December 2015
, Volume 52
Author(s): Lan Hu , Christopher J. Grim , Augusto A. Franco , Karen G. Jarvis , Vengopal Sathyamoorthy , Mahendra H. Kothary , Barbara A. McCardell , Ben D. Tall

Kentaro Tsukamoto, Chikako Ozeki, Tomoko Kohda, Takao Tsuji

Gamma irradiation (GI) was evaluated for its in vitro and in vivo antifungal activity against Penicillium expansum on pear fruits. GI showed a complete inhibition of spore germination, germ tube elongation, and mycelial of P. expansum, especially 1.8 kGy. GI affected the membrane integrity and cellular leakage of conidia in a dose-dependent manner. Furthermore, the leakage of protein and sugar from mycelia increased along with the dose.

Virulence traits are essential for pathogen fitness but whether they affect microbial performance in the environment, where they are not needed, remains experimentally unconfirmed. We investigated this question with the facultative pathogen Listeria monocytogenes and its PrfA virulence regulon. PrfA-regulated genes are activated intracellularly (PrfA “ON”) but shut down outside the host (PrfA “OFF”).

We have functionally and structurally defined an essential protein phosphorelay that regulates expression of genes required for growth, division, and intracellular survival of the global zoonotic pathogen Brucella abortus. Our study delineates phosphoryl transfer through this molecular pathway, which initiates from the sensor kinase CckA and proceeds through the ChpT...

Tetrodotoxin is a deadly neurotoxin which selectively inhibits Na+ activation mechanism of nerve impulse, without affecting the permeability of K+ ions. Because of this sodium channel blocking action, it is majorly being studied for biomedical applications. Tetrodotoxin is present in taxonomically diverse groups of animals inhabiting terrestrial, marine, fresh water and brackish water environments, still its origin remains unclear.

Aims
Epidemiological evidence suggests that hepatitis A virus (HAV) is the most common pathogen transmitted by bivalve mollusks such as clams, cockles, mussels, and oysters. This study aimed to generate thermal inactivation kinetics for HAV as a first step to design adequate thermal processes to control clam-associated HAV outbreaks.

The fruit juice industry recognizes Alicyclobacillus as a major quality control target microorganism. In this study, we analysed 19 bacterial isolates to identify Alicyclobacillus species by polymerase chain reaction (PCR) and sequencing analyses. Phenotypic and genomic diversity among isolates were investigated by API 50CHB system and ERIC-PCR (enterobacterial repetitive intergenic consensus-PCR), respectively.

Publication date: Available online 14 July 2015

Author(s): Guo Ping Wu , Su Hua Chen , Robert E. Levin

The emerging foodborne and waterborne pathogen, Arcobacter, has been linked to various gastrointestinal diseases. Currently, 19 species are established or proposed; consequently, there has been an increase in the number of publications regarding Arcobacter since it was first introduced in 1991.

The aim of this study was to investigate the phenotypic and genotypic diversity and anti-microbial resistance among staphylococci of dairy herds that originated from Paraiba State, north-eastern Brazil, a region where such studies are rare. Milk samples (n = 552) were collected from 15 dairy farms. Isolates were evaluated for anti-microbial susceptibility by Kirby–Bauer disc diffusion method.

Publication date: December 2015
, Volume 52
Author(s): Shiowshuh Sheen , Jennifer Cassidy , Butch Scullen , Christopher Sommers

Ectoine and hydroxyectoine are excellent compatible solutes for bacteria to deal with environmental osmotic stress and temperature damages. The biosynthesis cluster of ectoine and hydroxyectoine is widespread among microorganisms and its expression is activated by high salinity and temperature changes.

Many bacterial pathogens and symbionts utilize type III secretion systems to interact with their hosts. These machines have evolved to deliver bacterial effector proteins into eukaryotic target cells to modulate a variety of cellular functions. One of the most conserved components of these systems is an ATPase, which plays an essential role in the recognition and unfolding of proteins destined for secretion by the type III pathway.

Publication date: December 2015
Source:LWT - Food Science and Technology, Volume 64, Issue 2
Author(s): Praveen Kumar Srivastava , Mukesh Kapoor

Publication date: December 2015
Source:LWT - Food Science and Technology, Volume 64, Issue 2
Author(s): Laura Inés Schelegueda , Marisol Vallejo , María Fernanda Gliemmo , Emilio Rogelio Marguet , Carmen Adriana Campos

Publication date: December 2015
Source:LWT - Food Science and Technology, Volume 64, Issue 2
Author(s): Sang-Soon Kim , Dong-Hyun Kang

Background. Noroviruses are a leading cause of acute gastroenteritis worldwide. Mucosal and cellular immune responses remain poorly understood, with most studies of noroviruses having focused on serological responses to infection.

Background. Hepatitis A vaccines are highly immunogenic in healthy patients, but there is uncertainty about their immunogenicity in immunocompromised patients.