Pathogenic Microbiology Commons^™

Transcriptome Analysis Of Listeria Monocytogenes Exposed To Biocide Stress Reveals A Multi-System Response Involving Cell Wall Synthesis, Sugar Uptake, And Motility, Aidan Casey, Edward M. Fox, Stephan Schmitz-Esser, Aidan Coffey, Olivia Mcauliffe, Kieran Jordan

Department of Biological Sciences Publications

Listeria monocytogenes is a virulent food-borne pathogen most often associated with the consumption of “ready-to-eat” foods. The organism is a common contaminant of food processing plants where it may persist for extended periods of time. A commonly used approach for the control of Listeria monocytogenes in the processing environment is the application of biocides such as quaternary ammonium compounds. In this study, the transcriptomic response of a persistent strain of L. monocytogenes (strain 6179) on exposure to a sub-lethal concentration of the quaternary ammonium compound benzethonium chloride (BZT) was assessed. Using RNA-Seq, gene expression levels were quantified by sequencing …

Phages Of Non-Diary Lactococci: Isolation And Characterization Of Phi L47, A Phage Infecting The Grass Isolate Lactococcus Lactis Ssp Cremoris Dpc6860, Daniel Cavanagh, Caitríona M. Guinane, Horst Neve, Aidan Coffey, R. Paul Ross, Gerald F. Fitzgerald, Olivia Mcauliffe

Department of Biological Sciences Publications

Lactococci isolated from non-dairy sources have been found to possess enhanced metabolic activity when compared to dairy strains. These capabilities may be harnessed through the use of these strains as starter or adjunct cultures to produce more diverse flavor profiles in cheese and other dairy products. To understand the interactions between these organisms and the phages that infect them, a number of phages were isolated against lactococcal strains of non-dairy origin. One such phage, ΦL47, was isolated from a sewage sample using the grass isolate L. lactis ssp. cremoris DPC6860 as a host. Visualization of phage virions by transmission electron …

Gastroenteritis Viruses In Ireland: Epidemiology And Evolution, Lynda Gunn

Theses

Viral gastroenteritis is a common disease of both humans and animals. This thesis focuses on the use of classical virology, coupled with phylogenetics to study gastroenteritis viruses [Bocavirus (BoV), Coronavirus (CoV), and Rotavirus A (RVA)], isolated from selected samples from humans and animals. RVA was associated with outbreaks in elderly care facilities in Northern Ireland, isolates were genotyped and we reported the first detection of G2 lineage lie RVA in Ireland, with other common human RVA genotypes G1P[8], G2P[4] and G9P[8]. Evolutionary dynamics of human RVA VP7 genotypes was examined using codon models of evolution, results show heterogeneous selective pressure …

Detection, Identification And Characterization Of The Novel Campylobacter Species: Campylobacter Ureolyticus And Campylobacter Corcagiensis From Their Reservoirs., Monika Koziel

Theses

Campylobacter ureolyticus has been identified in a large proportion of diarrhoeal samples from patients in Ireland. However, the source of human infections has not been established and little is currently known about the potential reservoirs of C. ureolyticus in nature.

The aim of this project was to investigate a range of environmental and animal samples for the presence of this emerging pathogen using a molecular approach, to support the hypothesis of its zoonotic origin.

During the study, C. ureolyticus was detected in 30 out of 1,254 (2.4%) human diarrheic samples and isolated from 11 patients, describing, to the best of …

Characterisation Of The Enzybiotic Potential Of Selected Staphylococcus Aureus Bacteriophages, Ruth Keary

Theses

The work presented in this thesis focuses on harnessing the bactericidal potential of bacteriophage (phage) encoded peptidoglycan hydrolase enzymes to combat the significant pathogen Staphylococcus aureus. In order to identify novel peptidoglycan hydrolases lytic against S. aureus, the complete genomes of two staphylococcal temperate Siphoviridae bacteriophages, DW2 and CSl, were sequenced and annotated. Screening of these genomes identified genes for several putative peptidoglycan hydrolases including two endolysins and three virion-associated peptidoglycan hydrolases. The identification of putative genes relating to virulence and host fitness lends to the understanding of the role played by such temperate phages in the evolution of this …