Research Publications (Food Safety)

Thermophilic Campylobacter species colonize the intestine of agricultural and domestic animals commensally, but cause severe gastroenteritis in humans. In contrast to other enteropathogenic bacteria, Campylobacter have been considered to be non-glycolytic, a metabolic property originally used for their taxonomic classification. Contrary to this dogma, we demonstrate that several Campylobacter coli strains are able to utilize glucose as a growth substrate.

Campylobacters are a leading cause of gastrointestinal morbidity worldwide and the majority of human infections are triggered by eating foods contaminated with Campylobacter jejuni or Campylobacter coli. Campylobacters are equally notorious for their ability to mimic human glycoconjugate structures and for their capacity to synthesize both N- and O-linked glycoproteins.

Foodborne Pathogens and Disease Aug 2015, Vol. 12, No. 8: 679-685.

Clostridium perfringens type D strains are usually associated with diseases of livestock and their virulence requires the production of epsilon toxin (ETX). We previously showed (Li et al. PLoS Pathogen. 2011, 7 (12): e1002429) that BMC202, a nanI null mutant of type D strain CN3718, produces less ETX than does wild-type CN3718.

Four trials were carried out at a broiler processing plant to examine the effectiveness of spraying lactic acid solutions for reducing the numbers of Campylobacter on carcasses. The carcasses were naturally contaminated and treated after the inside–outside washer and before the air chiller. Carcasses were treated by spraying in a tunnel or with one of two hand-held sprayers.

Publication date: February 2016
, Volume 60
Author(s): Marta Mikš-Krajnik, Hazel Sin Yue Lim, Qianwang Zheng, Matthew Turner, Hyun-Gyun Yuk

Publication date: February 2016
, Volume 60
Author(s): Junjie Li, Ligong Zhai, Xiaomei Bie, Zhaoxin Lu, Xiaohan Kong, Qian Yu, Fengxia Lv, Chong Zhang, Haizhen Zhao

Extended spectrum-lactamase (ESBL) and plasmid-mediated AmpC β-lactamase (pAmpC) producing Escherichia coli have been shown to be present in humans and animals representing a significant problem worldwide. This study aimed to search the presence of ESBL and/or AmpC-producing E. coli in retail meats (chicken and beef) in Turkey. A total of 88 β-lactamase-producing E.

The presence of toxicogenic Staphylococcus aureus in foods and the dissemination of methicillin-resistant Saureus (MRSA) in the food chain are matters of concern.

Publication date: 2 December 2015
, Volume 214
Author(s): H. Margot, M.H. Zwietering, H. Joosten, Emer O'Mahony, R. Stephan

The life cycles of many enteric bacterial species require a transition between two very distinct environments. Their primary habitat is the gastrointestinal tract of the host, while their secondary habitat, during transmission from one host to another, consists of environments external to the host, such as soil, water, and sediments. Consequently, both host and environmental factors shape the genetic structure of enteric bacterial populations.

The ability to acetylate lysine residues is conserved across organisms, and acetylation of lysine residues plays important roles in various cellular functions. Maintaining intracellular pH homeostasis is crucial for the survival of enteric bacteria in the acidic gastric tract. It has been shown that eukaryotes can stabilize the intracellular pH by histone deacetylation.

This study determined the effect of feed fermentation with Lactobacillus reuteri on growth performance and the abundance of enterotoxigenic Escherichia coli (ETEC) in weanling piglets. L. reuteri strains produce reuteran or levan, exopolysaccharides that inhibit ETEC adhesion to the mucosa, and feed fermentation was conducted under conditions supporting exopolysaccharide formation and under conditions not supporting exopolysaccharide formation.

Clostridium botulinum group II isolates (n = 163) from different geographic regions, outbreaks, and neurotoxin types and subtypes were characterized in silico using whole-genome sequence data. Two clusters representing a variety of botulinum neurotoxin (BoNT) types and subtypes were identified by multilocus sequence typing (MLST) and core single nucleotide polymorphism (SNP) analysis.

Temporal changes in the distribution of Salmonella subtypes in livestock populations may have important impacts on human health. The first objective of this research was to determine the within-farm changes in the population of subtypes of Salmonella on Michigan dairy farms that were sampled longitudinally in 2000-2001 and again in 2009. The second objective was to determine the yearly frequency (2001 through 2012) of reported human illnesses in Michigan associated with the same subtypes.

While the food-borne pathogen Listeria monocytogenes can persist in food associated environments, there are no whole-genome sequence (WGS) based methods to differentiate persistent from sporadic strains. Whole-genome sequencing of 188 isolates from a longitudinal study of L. monocytogenes in retail delis was used to (i) apply single-nucleotide polymorphism (SNP)-based phylogenetics for subtyping of L.

While rain and irrigation events have been associated with an increased prevalence of foodborne pathogens in produce production environments, quantitative data are needed to determine the effects of various spatial and temporal factors on the risk of produce contamination following these events. This study was performed to quantify these effects and to determine the impact of rain and irrigation events on the detection frequency and diversity of Listeria species (including L.

Diarrhea causes significant morbidity and mortality in Indian children under 5 years of age. Flies carry enteric pathogens and may mediate foodborne infections. In this study, we characterized fly densities as a determinant of infectious diarrhea in a longitudinal cohort of 160 urban and 80 rural households with 1,274 individuals (27% under 5 years of age) in Vellore, India. Household questionnaires on living conditions were completed at enrollment.

Aims
The aim of the present study was to examine the effects of caprylic acid (CA) on pathogens in apple juice having intrinsic organic acids, and to determine any synergistic effects.

Publication date: 30 September 2015
, Volume 179, Issues 3–4
Author(s): Tim R. Crawshaw, Jeremy I. Chanter, Stuart C.L. Young, Shaun Cawthraw, Adrian M. Whatmore, Mark S. Koylass, Ana B. Vidal, Francisco J. Salguero, Richard M Irvine

We evaluated immune responses following bivalent oral cholera vaccination (Shanchol [Shantha Biotechnics]; BivWC) in a cohort of 25 human immunodeficiency virus (HIV)–infected adults in Haiti. Compared with adults without HIV infection, vaccination in HIV-infected individuals resulted in lower vibriocidal responses against Vibrio cholerae O1, and there was a positive relationship between the CD4+ T-cell count and vibriocidal responses following vaccination.

Background. Q fever is an infection caused by Coxiella burnetii. Persistent infection (chronic Q fever) develops in 1%–5% of patients. We hypothesize that inefficient recognition of C. burnetii and/or activation of host-defense in individuals carrying genetic variants in pattern recognition receptors or adaptors would result in an increased likelihood to develop chronic Q fever.

Aims
To investigate the differential expression of virulence genes and role of gyrA mutations in quinolone resistant and susceptible strains of Salmonella isolated from seafood.

This study examined the effect of feeding heat-killed Lactobacillus cells on the survival of C. elegans nematodes after Salmonella Typhimurium and Yersinia enterocolitica infection. The feeding of heat-killed L. plantarum 133 (LP133) and L. fermentum 21 (LP21) cells to nematodes was shown to significantly increase the survival rate as well as stimulate the expression of pmk-1 gene that key factor for C.

Publication date: January 2016
Source:LWT - Food Science and Technology, Volume 65
Author(s): Mariel Calderón-Oliver, Héctor B. Escalona-Buendía, Omar N. Medina-Campos, José Pedraza-Chaverri, Ruth Pedroza-Islas, Edith Ponce-Alquicira