Life Sciences Commons^™

Comparative Genomic Analysis Of Two Serotype 1/2b Listeria Monocytogenes Isolates From Analogous Environmental Niches Demonstrates The Influence Of Hypervariable Hotspots In Defining Pathogenesis, Aidan Casey, Kieran Jordan, Aidan Coffey, Edward M. Fox, Olivia Mcauliffe

Department of Biological Sciences Publications

The vast majority of clinical human listeriosis cases are caused by serotype 1/2a, 1/2b, 1/2c, and 4b isolates of Listeria monocytogenes. The ability of L. monocytogenes to establish a systemic listeriosis infection within a host organism relies on a combination of genes that are involved in cell recognition, internalization, evasion of host defenses, and in vitro survival and growth. Recently, whole genome sequencing and comparative genomic analysis have proven to be powerful tools for the identification of these virulence-associated genes in L. monocytogenes. In this study, two serotype 1/2b strains of L. monocytogenes with analogous isolation sources, but …

The Use Of Lactic Acid Bacteria To Control The Growth Of Foodborne Pathogens On Fresh-Cut Fruits And Sprout Vegetables, Franca Gabriela Rossi

Master's Theses

Growing consumer awareness of the health benefits associated with fruits and vegetables and demand for easy to prepare products has prompted the development of a wide variety of minimally processed fruits and vegetables. Minimally processed fruits and vegetables are often peeled, cut, or diced which compromise the produces’ natural protective barriers, exposing a nutrient rich medium and providing an ideal environment for the growth of microorganisms, including foodborne pathogens. The germination conditions of sprout vegetables consisting of relatively high temperatures and humidity, low light and abundance of nutrients are also conducive to the proliferation of foodborne pathogens. Recent outbreaks and …

Effect Of Phytosanitary Irradiation And Methyl Bromide Fumigation On The Physical, Sensory, And Microbiological Quality Of Blueberries And Sweet Cherries, Karen Thang, Kimberly Au, Cyril Rakovski, Anuradha Prakash

Food Science Faculty Articles and Research

Background

The objective of this study was to determine whether irradiation could serve as a suitable phytosanitary treatment alternative to methyl bromide (MB) fumigation for blueberries and sweet cherry and also to determine the effect of phytosanitary irradiation treatment on survival of Salmonella spp. and Listeria monocytogenes on these fruit. ‘Bluecrop’ blueberries (Vaccinium corymbosum) and ‘Sweetheart’ cherries (Prunus avium) were irradiated at 0.4 kGy or fumigated with methyl bromide and evaluated for quality attributes during storage.

Results

Irradiation caused an immediate decrease in firmness of both fruit without further significant change during storage. Fumigated fruit, in …

The Microbial Ecology Of Listeria Monocytogenes As Impacted By Three Environments: A Cheese Microbial Community; A Farm Environment; And A Soil Microbial Community, Panagiotis Lekkas

Graduate College Dissertations and Theses

This dissertation examined the microbial ecology of Listeria monocytogenes in three distinctly different environments: a cheese microbial community; a farm environment; and a soil microbial community.

The aim of the first study was to investigate the effects of L. monocytogenes on the composition of the surface microflora on washed rind soft cheese. Two trials with washed rind cheeses that were inoculated with 100cfu cm⁻² of a L. monocytogenes six strain cocktail were conducted. The first trial had to be terminated early (day 28) as contamination of Pseudomonas spp. from the initial brine did not produce the expected characteristics of the …