Biochemistry, Biophysics, and Structural Biology Commons^™

Potential Use Of Biotherapeutic Bacteria To Target Colorectal Cancer-Associated Taxa, Gareth Lawrence, Maire Begley, Paul D. Cotter, Caitríona M. Guinane

Department of Biological Sciences Publications

The role of the gut microbiome in human health and disease is the focus of much attention. It has been widely agreed upon that our gut bacteria play a role in host immunity, nutrient absorption, digestion, metabolism, and other key drivers of health. Furthermore, certain microbial signatures and specific taxa have also been associated with the development of diseases, such as obesity; inflammatory bowel disease; and, indeed, colorectal cancer (CRC), which is the focus of this review. By extension, such taxa represent potential therapeutic targets. In particular, the emerging human pathogen Fusobacterium nucleatum represents an important agent in CRC development …

Odx: A Fitness Tracker-Based Device For Continuous Bacterial Growth Monitoring, Venkata V.B. Yallapragada, Uday Gowda, David Wong, Liam O'Faolain, Mark Tangney, Ganga C.R. Devarapu

Cappa Publications

Continuous monitoring of bacterial growth in aqueous media is a crucial process in academic research as well as in the biotechnology industry. Bacterial growth is usually monitored by measuring the optical density of bacteria in liquid media, using benchtop spectrophotometers. Due to the large form factor of the existing spectrophotometers, they cannot be used for live monitoring of the bacteria inside bacterial incubation chambers. Additionally, the use of benchtop spectrometers for continuous monitoring requires multiple samplings and is labour intensive. To overcome these challenges, we have developed an optical density measuring device (ODX) by modifying a generic fitness tracker. The …

Optimisation Of Ion Exchange Chromatography Purification Protocols For A Staphylococcal Peptidoglycan Degrading Hydrolase Enzyme, Fiona Maher

Theses

Bacteriophage (phage) are the most abundant biological entities on earth and were first discovered by d’Herelle in 1917. They are found wherever their hosts live and, like all viruses they do not have the ability to make their own protein. Therefore, in order to reproduce, phage must invade and infect bacterial cells. This project focused on the optimisation of Ion Exchange Chromatography purification protocols for a staphylococcal peptidoglycan degrading hydrolase enzyme (CHAPk). The project objective was to obtain the greatest yield of enzyme from the growth of the E.coU XL 1-Blue expression system into which the vector pQE60 was previously …

Comparing Apples And Oranges?: Next Generation Sequencing And Its Impact On Microbiome Analysis, Adam G. Clooney, Fiona Fouhy, Roy D. Sleator, Aisling O'Driscoll, Stanton Catherine, Paul D. Cotter, Marcus J. Claesson

Department of Biological Sciences Publications

Rapid advancements in sequencing technologies along with falling costs present widespread opportunities for microbiome studies across a vast and diverse array of environments. These impressive technological developments have been accompanied by a considerable growth in the number of methodological variables, including sampling, storage, DNA extraction, primer pairs, sequencing technology, chemistry version, read length, insert size, and analysis pipelines, amongst others. This increase in variability threatens to compromise both the reproducibility and the comparability of studies conducted. Here we perform the first reported study comparing both amplicon and shotgun sequencing for the three leading next-generation sequencing technologies. These were applied to …

Functional Screening Of The Cronobacter Sakazakii Baa-894 Genome Reveals A Role For Prop (Esa_02131) In Carnitine Uptake, Audrey Feeney, Roy D. Sleator

Department of Biological Sciences Publications

Cronobacter sakazakii is a neonatal pathogen responsible for up to 80% of fatalities in infected infants. Low birth weight infants and neonates infected with C. sakazakii suffer necrotizing enterocolitis, bacteraemia and meningitis. The mode of transmission most often associated with infection is powdered infant formula (PIF) which, with an aw of ∼0.2, is too low to allow most microorganisms to persist. Survival of C. sakazakii in environments subject to extreme hyperosmotic stress has previously been attributed to the uptake of compatible solutes including proline and betaine. Herein, we report the construction and screening of a C. sakazakii genome bank and …

Metagenomic Identification Of A Novel Salt Tolerance Gene From The Human Gut Microbiome Which Encodes A Membrane Protein With Homology To A Brp/Blh-Family Beta-Carotene 15,15'-Monooxygenase, Eamonn P. Culligan, Roy D. Sleator, Julian R. Marchesi, Colin Hill

Department of Biological Sciences Publications

The human gut microbiome consists of at least 3 million non-redundant genes, 150 times that of the core human genome. Herein, we report the identification and characterisation of a novel stress tolerance gene from the human gut metagenome. The locus, assigned brpA, encodes a membrane protein with homology to a brp/blh-family β-carotene monooxygenase. Cloning and heterologous expression of brpA in Escherichia coli confers a significant salt tolerance phenotype. Furthermore, when cultured in the presence of exogenous β-carotene, cell pellets adopt a red/orange pigmentation indicating the incorporation of carotenoids in the cell membrane.

A Single Point Mutation In The Listerial Betl Sigma(A)-Dependent Promoter Leads To Improved Osmo- And Chill-Tolerance And A Morphological Shift At Elevated Osmolarity, Ronald F. Hoffman, Susan Mclernon, Audrey Feeney, Colin Hill, Roy D. Sleator

Department of Biological Sciences Publications

Betaine uptake in Listeria monocytogenes is mediated by three independent transport systems, the simplest of which in genetic terms is the secondary transporter BetL. Using a random mutagenesis approach, based on the E. coli XL1 Red mutator strain, we identified a single point mutation in a putative promoter region upstream of the BetL coding region which leads to a significant increase in betL transcript levels under osmo- and chill-stress conditions and a concomitant increase in stress tolerance. Furthermore, the mutation appears to counter the heretofore unreported “twisted” cell morphology observed for L. monocytogenes grown at elevated osmolarities in tryptone soy …

Emerging Dynamics Of Human Campylobacteriosis In Southern Ireland, Susan Bullman, Daniel Corcoran, James O'Leary, Derry O'Hare, Brigid Lucey, Roy D. Sleator

Department of Biological Sciences Publications

Infections with Campylobacter spp. pose a significant health burden worldwide. The significance of Campylobacter jejuni/Campylobacter coli infection is well appreciated but the contribution of non-C. jejuni/C. coli spp. to human gastroenteritis is largely unknown. In this study, we employed a two-tiered molecular study on 7194 patient faecal samples received by the Microbiology Department in Cork University Hospital during 2009. The first step, using EntericBio® (Serosep), a multiplex PCR system, detected Campylobacter to the genus level. The second step, utilizing Campylobacter species-specific PCR identified to the species level. A total of 340 samples were confirmed as Campylobacter genus positive, 329 of …

Campylobacter Ureolyticus: An Emerging Gastrointestinal Pathogen?, Susan Bullman, Daniel Corcoran, James O'Leary, Brigid Lucey, Deirdre Byrne, Roy D. Sleator

Department of Biological Sciences Publications

A total of 7194 faecal samples collected over a 1-year period from patients presenting with diarrhoea were screened for Campylobacter spp. using EntericBios, a multiplex-PCR system. Of 349 Campylobacter-positive samples, 23.8% were shown to be Campylobacter ureolyticus, using a combination of 16S rRNA gene analysis and highly specific primers targeting the HSP60 gene of this organism. This is, to the best of our knowledge, the first report of C. ureolyticus in the faeces of patients presenting with gastroenteritis and may suggest a role for this organism as an emerging enteric pathogen.

Molecular Characterisation Of A Bovine-Like Rotavirus Detected From A Giraffe, Emily Mulherin, Jill Bryan, Marijke Beltman, Luke O'Grady, Eugene Pidgeon, Lucie Garon, Andrew Lloyd, John Bainbridge, Helen O'Shea, Paul Whyte, Séamus Fanning

Department of Biological Sciences Publications

Background

Rotavirus (RV), is a member of the Reoviridae family and an important etiological agent of acute viral gastroenteritis in the young. Rotaviruses have a wide host range infecting a broad range of animal species, however little is known about rotavirus infection in exotic animals. In this paper we report the first characterisation of a RV strain from a giraffe calf.

Results

This report describes the identification and detailed molecular characterisation of a rotavirus strain detected from a 14-day-old Giraffe (Giraffa camelopardalis), presenting with acute diarrhea. The RV strain detected from the giraffe was characterized molecularly as G10P[11]. …