Pathogenic Microbiology Commons^™

Isolation And Molecular Characterization Of Mycobacterium Avium Subsp. Paratuberculosis In Ireland, Pierre Emmanuel Douarre

Theses

MAP is a proven animal pathogen causing Johne's disease, one of the most widespread and economically important diseases of ruminants. Since 1992 and the opening of the European market, the prevalence of MAP in Ireland has increased considerably. Improvements in diagnostic strategies for Ireland and elsewhere are urgently required. MAP infects a wide host range and has emerged as a potential threat to human health and has been associated with Crohn's disease. The control of paratuberculosis infection requires a better understanding of the genetic diversity of the pathogen. The objective of this study was to isolate and characterize this enteric …

Phage Lysins - Structure, Genetics And Applications, Jennifer Garry

Theses

Antibiotics are of the utmost importance in the fight against pathogenic bacteria, however, in recent years there has been a continual increase in the development of antibiotic resistance among bacteria. As a result it has become essential to develop new technologies to combat these pathogens. One such technology is the application of phage lysins as antimicrobial agents against pathogenic infections. A promising phage lysin is LysK, a 495 amino-acid protein derived from Staphylococcal Phage K. LysK can lyse a wide range of staphylococcal species including MRSA. It is also capable of killing both live and dead cells increasing its potential …

The Rapid Identification Of Novel Anti-Mycobacterial Drugs And The Transporters Involved In Their Resistance, James Carroll

Theses

Despite the success of anti-mycobacterial drugs over the past 70 years, mycobacterial disease, particularly tuberculosis is still responsible for millions of deaths worldwide. Additionally, the emergence of Multidrug Resistant (MDR-TB) and Extensively Drug Resistant (XDR-TB) Tuberculosis throughout the world has motivated calls by the World Health Organization for novel mycobacterial drugs, vaccines and diagnostic tests. Consequently, this study sought to identify and evaluate the efficacy of a range of anti-mycobacterial compounds against a representative cohort of pathogenic mycobacterial species. The development and employment of the rapid, robust and inexpensive microtitre alamarBlue assay (MABA) facilitated the assessment of a vast array …

Identification And Molecular Characterisation Of Mycobacteriophages And Their Lysis Proteins, Marine Henry

Theses

Given their potential as specific and natural biocontrol agents, bacteriophages and their associated proteins have become the focus of renewed interest over the last decade. This study reviews the current state of mycobacterial diseases control worldwide and presents how phage therapy and the production of recombinant bacteriophage lysis proteins can be applied as novel biocontrol strategies for mycobacteria.

Chapter 11 presents an overview of the predicted LysA and LysB proteins in all the mycobacteriophages sequenced to date and proposes an in silico 3D predictive model of the lysin B of a recently isolated and characterised mycobacteriophage. Our data also confirms …

Development Of Pcr Assays To Detect And Characterise Salmonella Isolates From Cheese And Meat Products By Utilizing An Integrated Genomics Approach, Noelle Geraldine Mccarthy

Theses

Salmonella is an extremely important foodborne pathogen which is responsible for millions of cases of gastroenteritis annually. Salmonella outbreaks have been associated with numerous common food stuffs such as meat, dairy and seafood. Traditional culture based methods for the detection Salmonella are labourious and costly. Rapid detection and serovar identification would dramatically decrease the time required to identify Salmonella outbreaks and potential health risks.

In the US 99% of all Salmonella infections are caused by members of Salmonella enterica subspecies 1. Serovars within subspecies 1 can vary due to host specificity and pathogenicity. DNA sequencing projects have provided valuable genomic …

Mupirocin Resistance In Staphylococci: An Investigation Of Current Status And Potential Alternative Therapies, Susan O'Shea

Theses

Mupirocin is a topical antibiotic used in hospital infection control practices to control transmission of staphylococci, in particular MRSA, which has become a major problem in Irish hospitals and has a significant impact on patient morbidity and mortality. Overreliance on mupirocin to eradicate MRSA carriage and to prevent infection has led to mupirocin resistance among staphylococcal species. Two distinct types of resistance have developed within strains: low'-level mupirocin resistance (LMR) and high-level mupirocin resistance (HMR).

The aim of this study was to assess the prevalence and types of mupirocin resistance in a large population of clinical staphylococcal isolates including Methicillin …

Epidemiology And Drug Resistant Profiles Of Candida Species, In Cork Hospitals., Emma Mccurtin

Theses

Candida causes superficial infections in healthy individuals; however in the immunocompromised host Candida can cause invasive, systemic infections and is a significant cause of morbidity and mortality. This is not due to a more virulent phenotype but to a weakened immune system unable to fight this opportunistic pathogen. The immunocompromised population is ever increasing, due to medical advancements and more aggressive treatments, and hence is the need for epidemiological data of these potentially life threatening infections. The aim of this study was to provide an epidemiological snapshot, of Candida infections from the immunocompromised population in Cork hospitals. Surveillance programmes from …

Molecular Epidemiology Of Antibiotic Resistant Salmonella Enterica Strains From Different Animal And Human Sources In Ireland, David George Lee

Theses

In this study, 176 isolates of Salmonella were collected from different laboratories in Ireland. All isolates were confirmed to be of the genus Salmonella by performing bacteriological and biochemical tests. Briefly, all isolates were cultured onto XLD agar after which pure cultures were verified and stocked at this institute. Definitive identification was carried out using the API 20-E system and a separate urease test was also performed on all isolates. After confirmation of the genus, all isolates were prepared for antibiotic susceptibility testing and r-types were determined using sixteen antibiotics. Depending on the antibiotic resistance profiles, isolates were selected for …

Validation Of An Immunomagnetic-Electrochemiluminescence Detection System For The Detection Of Escherichia Coli 0157 In Food And Comparison With An Iso Standard Method, Eimear Carney

Theses

Rapid and sensitive methods for detecting Escherichia coli 0157 in contaminated food, water and other biological samples are important in limiting and preventing the spread of this pathogen. Traditional culture based methods for bacterial identification and detection can be time consuming and labour intensive. Modem alternative methods should be faster whilst maintaining sensitivity. Immunomagnetic separation (IMS) methodology has been investigated and appears promising for rapid bacterial detection in unrelated food and environmental samples. In this study, a commercial sensor which combined IMS with electrochemiluminescence (ECL) was evaluated for the detection of E. coli 0157 in unrelated food matrices. Emitted signals …

Integronlike Structures In Campylobacter Spp. Of Human And Animal Origin, Brigid Lucey, D. Crowley, P. Moloney, B. Cryan, M. Daly, F. O'Halloran, E. J. Threlfall, S. Fanning

Department of Biological Sciences Publications

Resistance to antimicrobial agents used to treat severe Campylobacter spp. gastroenteritis is increasing worldwide. We assessed the antimicrobial resistance patterns of Campylobacter spp. isolates of human and animal origin. More than half (n = 32) were resistant to sulphonamide, a feature known to be associated with the presence of integrons. Analysis of these integrons will further our understanding of Campylobacter spp. epidemiology.

The Molecular Characterisation Of Selected Epidemic Associated Gram Negative Pathogens In Southern Ireland, Mairéad Daly

Theses

This study was undertaken to evaluate various molecular techniques for the analysis of Gram negative bacterial associated epidemics. The first investigation dealt with bovine mastitis outbreaks, where the causative agent was identified as Pseudomonas aeruginosa. Epidemiological findings, suggested that all herds were infected from teat wipes that were contaminated with this organism. Initial investigations using the polymerase chain reaction (PCR), indicated a possible clonal relationship between all outbreak linked strains, with one exception. This finding was confirmed following pulsed-field gel electrophoresis (PFGE) and ribotype analysis. PCR was again employed to study a rather unusual epidemic, involving Salmonella tel-el-kebir over a …