Microbiology Commons^™

Investigating The Antimicrobial Potential Of Bovine Lactoferrin Against The Neonatal Pathogen, Staphylococcus Capitis, Anna Desmond, Lesley Cotter, Des Field, Fiona O'Halloran

Department of Biological Sciences Publications

Lactoferrin is an antimicrobial glycoprotein that demonstrates a broad-spectrum of activity against a wide variety of clinical pathogens. This study investigated the potential of bovine lactoferrin (bLf) against multidrug resistant Staphylococcus capitis (S. capitis) strains. Growth curve analysis and time-kill curves demonstrated that at 750 µg ml−1 lactoferrin significantly inhibited (50.6%, P < 0.05) the growth of most isolates tested (90%), and this effect was based on a bacteriostatic mechanism. At the same concentration, bLf also significantly inhibited (30%, P < 0.05) biofilm formation in 40% of strains tested. Combinations of bLf with selected antibiotics were assessed for enhanced antimicrobial activity using growth curves. BLf combined with β-lactam antibiotics reduced the growth of S. capitis strains, however, the effects were not significant. BLf displays antimicrobial effects against multidrug resistant S. capitis isolates, but with strain-specific effects.

Turbidimetric Bioassays: A Solution To Antimicrobial Activity Detection In Asymptomatic Bacteriuria Isolates Against Uropathogenic Escherichia Coli, Ciara Kenneally, Craig P. Murphy, Roy D. Sleator, Eamonn P. Culligan

Department of Biological Sciences Publications

Traditional bacteriocin screening methods often face limitations due to diffusion-related challenges in agar matrices, which can prevent the peptides from reaching their target organism. Turbidimetric techniques offer a solution to these issues, eliminating diffusion-related problems and providing an initial quantification of bacteriocin efficacy in producer organisms. This study involved screening the cell-free supernatant (CFS) from eight uncharacterized asymptomatic bacteriuria (ABU) isolates and Escherichia coli 83972 for antimicrobial activity against clinical uropathogenic E. coli (UPEC) strains using turbidimetric growth methods. ABU isolates exhibiting activity against five or more UPEC strains were further characterized (PUTS 37, PUTS 58, PUTS 59, S-07-4, and …

Screening And Analysis Of The Urobiome For The Production Of Antimicrobial Peptides To Target Uropathogenic Escherichia Coli, Jennifer Jones

Theses

Urobiome research is currently at a nascent stage, due to a previously incorrect assumption that the bladder is a sterile environment. Improvements in bacterial culturing and DNA sequencing techniques have revealed a diverse resident bacterial community within the urinary tract (urobiome). As global incidences of multidrug- resistant urinary tract infections (UTIs) continue to increase, so too does the demand for novel antimicrobial therapies. Due to its relatively understudied nature, the urobiome represents a reservoir that could be mined as a potential source of novel antimicrobial compounds (e.g., bacteriocins). The aim of this thesis was to identify urobiome bacteriocins that could …

Towards Better Detection And Treatment Of Mycobacterial Disease., Laura O'Connell

ORBioM (Open Research BioSciences Meeting)

Background

Mycobacterial disease is a major cause of fatality, with 1.5 million deaths per 10 million infections annually. Due to the emergence of multi- and extensively-drug resistant clinical isolates, mycobacteriophage (MP) are being investigated as an alternative to antibiotics.

Objectives

The objectives of this study were: to characterise an emerging cohort of MP, to determine suitable in vivo modes of delivery for MP including encapsulation, to examine the application of a MP-based viability assay, and to examine the functionality of MP in raw milk.

Methods

The fast-growing Mycobacterium smegmatis was used as a host in all assays to demonstrate phage …

Investigating The Ability Of Saltwater Isolates To Inhibit Biofilm Formation By Clinically Significant Pathogens, Monica Murphy

ORBioM (Open Research BioSciences Meeting)

Background

Nosocomial pathogens are responsible for chronic and persistent infections partly due to their ability to form protective biofilms which enhance their antibiotic tolerance. Biofilm disruption combats antimicrobial resistance as dispersed cells regain antibiotic susceptibility. The goal of this study was to evaluate the antibiofilm potential of isolates from marine environments against a pathogen panel consisting of MRSA and clinical Staphylococcus aureus strains, Acinetobacter baumannii and Escherichia coli pathogens.

Method

A large bank of saltwater bacterial isolates was cultured in glucose-supplemented trypticase soy broth (TSBg) and resulting colonies were screened against the pathogen panel. Isolates of interest were further examined …

Short Chain Fatty Acid Combination Treatment Protects Against 6-Ohda And Wt Α-Synuclein Induced Decreases In Neurite Growth In In Vitro Models Of Parkinson’S Disease., Alex Morris

ORBioM (Open Research BioSciences Meeting)

Background

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by dopaminergic neuron degeneration. This degeneration is partly driven by over expression of α-synuclein (α-syn) and development of α-syn aggregates known as Lewy bodies throughout the substantia nigra. As well as motor dysfunction, PD presents with several chronic gastrointestinal comorbidities, which cause a decline of gut microbial diversity and microbially derived short chain fatty acids (SCFAs). Recent in vivo studies have shown SCFAs to be neuroprotective in various degenerative disease states, suggesting that SCFAs may protect against dopaminergic degeneration.

Methods

Human neuroblastoma SH-SY5Y cells were used as a model of human …

Urobiome Screening For Antimicrobial Peptides Against Uropathogenic Escherichia Coli, Jennifer Jones

ORBioM (Open Research BioSciences Meeting)

BACKGROUND: Urinary tract infections (UTIs) are one of the most common bacterial infections worldwide. As global incidences of UTIs caused by multidrug resistant bacteria continue to increase, so too does the demand for novel antimicrobial therapies.

Due to its relatively understudied nature, the urinary microbiome represents a niche with an untapped source of potentially novel antimicrobials (e.g., bacteriocins). Improvements to bacterial culturing and sequencing techniques have highlighted these potential alternative treatments and control strategies to target antibiotic resistant uropathogenic E. coli (UPEC).

METHODS: Expanded quantitative urine culture (EQUC) was used to culture bacterial isolates from mid-stream urine samples. Urinary isolates …

Examining The Absorbance Maximum, Protein Concentration And Antimicrobial Activity Of Seaweed Extracts, Claudia Kenneally

ORBioM (Open Research BioSciences Meeting)

Background

The emergence of antimicrobial resistance (AMR) has highlighted the need for novel antimicrobials. Antimicrobial compounds can be isolated from various marine sources, including seaweed, which contain pigments and proteins. This study focuses on screening seaweeds for potential antimicrobial compounds.

Methods

Four seaweed types (A, B, C, D) were collected from beaches in Cork, Ireland, and extracts of each were prepared using both methanol (-M) and water (-H₂O). The absorbance maximum (λ_max)of seaweed extracts was determined from 220 – 800 nm to investigate potential pigment interference at 600 nm. The bicinchoninic acid (BCA) assay was preformed …

Bactericidal Effects Of Chlorine And Bacteriophages On Mycobacteria In Conventionally Treated Water., Max Kevane-Campbell

ORBioM (Open Research BioSciences Meeting)

Introduction

Mycobacteria are members of the order Actinomycetales and the only genus in the family Mycobacteriaceae. The distinguishing characteristics that are found in mycobacteria include acid-fastness and the presence of mycolic acids. Mycobacteria can be commonly classified as non-spore-forming, aerobic, slender rod-shaped, and are slow-growers. Natural reservoirs that mycobacteria can be found in are aquatic and terrestrial environments. Recent studies have shown that mycobacteria that can cause skin lesions, immune and/or pulmonary dysfunctions and chronic diseases, i.e., Mycobacterium avium subsp. Paratuberculosis, M. kansasii, and M. xenopi, can be isolated from common household tap water. Tap water can originate from …

Development Of A Protocol For The Extraction Of Genomic Material From Fecal Matter For Metagenome And Virome Sequencing, Keith Coughlan

ORBioM (Open Research BioSciences Meeting)

With the advent of increasingly more accurate and reliable sequencing methods, the requirement for extraction methods yielding large volumes of high-quality genomic material has become progressively more significant. While the analysis of genomic material through bioinformatics can offer some methods of “cleaning” and standardizing data, it is essential that the “wet lab” aspects of data produce abundant amounts of high-quality genetic material. Therefore, the purpose of this project is to develop an optimized method of DNA extraction for fecal material sequencing in microbiome and virome investigations. The samples used for the optimized protocol are infant fecal samples collected and stored …

Mycobacteriophage: A Demonstration Of The Reduction Of M. Smegmatis In Various Matrices., Laura O'Connell

ORBioM (Open Research BioSciences Meeting)

Background

Mycobacterial disease is a major cause of fatality worldwide, with approximately 1.5 million deaths for every 10 million infections. These infections are difficult to treat due to the intrinsic resistance of its mycolic acid rich cell wall to many antibiotics. There is potential for mycobacteriophage (MP) to be used therapeutically for multidrug- and extensively-drug resistant infections. Mycobacterium smegmatis mc² 155 is a useful substitute for slow-growing pathogenic mycobacteria, as it propagates quickly under lab conditions. This feature of M. smegmatis increases the pace of analysis, by ensuring the quick isolation and characterisation of MP and acting as a …

Bioengineered Nisin A Derivatives Display Enhanced Activity Against Clinical Neonatal Pathogens, Anna Desmond

ORBioM (Open Research BioSciences Meeting)

Neonatal infection is a significant cause of mortality and morbidity in infants. Globally, neonatal pathogens are increasingly becoming multi-drug resistant, indicating the need to discover novel alternative treatment strategies. Nisin is an antimicrobial peptide that exhibits broad-spectrum activity against Gram-positive and Gram-negative bacteria including a wide variety of clinical pathogens. Nisin can be used in combination with antibiotics to improve their efficacy. This study examined the activity of nisin and bioengineered derivatives against multi-drug resistant Streptococcus agalactiae and Staphylococcus capitis isolates and investigated the potential synergy between nisin peptides and selected antibiotics. Whole genome sequence analysis of the strains revealed …

In Vitro Antimicrobial Activity Of Cell-Free Supernatants From Asymptomatic Bacteriuria (Abu) Isolates Against Multi-Drug Resistant Uropathogenic Escherichia Coli (Upec), Ciara Kenneally

ORBioM (Open Research BioSciences Meeting)

Background

Multi-drug resistant uropathogenic Escherichia coli (UPEC) cause > 80% of community acquired urinary tract infections (UTIs) and > 40% of nosocomial UTIs. Preliminary evidence suggests a beneficial role for UPEC’s commensal counterparts, asymptomatic bacteriuria (ABU), in establishing bacterial interference against UPEC. The aim of this study was to analyse the antimicrobial activity of cell free supernatants (CFS) from ABU isolates against UPEC.

Methods

In vitro antagonistic effects of nine uncharacterised ABU isolates were compared against the inhibitory affect induced by the prototype ABU isolate, E. coli 83972. Turbidimetric growth assays were performed using the CFS of the ABU isolates against eight …

Investigating The Thermotolerance Of Cronobacter Sakazakii In Powdered Infant Formula, Fiona Ryan O'Connor

ORBioM (Open Research BioSciences Meeting)

Background

The powdered infant formula (PIF) sector is a growing global market, with Ireland at the forefront of the European exports market; reaching €1.5bn and accounting for 35% of all dairy exports in 2015. However, a major concern associated with PIF is the risk of contamination with the neonatal pathogen Cronobacter sakazakii. Although PIF undergoes thermal treatment during manufacture, it is possible that re-contamination of the product may occur via later processing measures. We investigated the resistance of C. sakazakii to thermal inactivation following inoculation in commercial PIF as a potential treatment for contaminated powder.

Method

Five strains of C. …

Detection Of Microbial Growth In Aseptic Food Products Using Non-Invasive Tunable Diode Laser Absorption Spectroscopy (Tdlas), Peter Myintzaw, Nicholas Brian Johnson, Máire Begley, Michael J. Callanan

Department of Biological Sciences Publications

The sensitivity and reliability of Tunable Diode Laser Absorption Spectroscopy (TDLAS) for monitoring the growth of microorganisms in real food matrices was explored. The rapid and non-destructive TDLAS equipment uses laser light to monitor carbon dioxide changes due to microbial growth in the container head space which has the additional advantage of detecting contamination in products and packaging where visual inspection is not possible. TDLAS growth detection of Bacillus fengqiuensis, Candida albicans, Lactococcus lactis, Microbacterium luteolum, Paenibacillus chitinolyticus and Staphylococcus pasteuri was studied in various Ready To Feed (RTF) infant formula products. Detection of growth was correlated with cell numbers …

Characterisation Of Selected Microbes In Terrestrial And Simulated Extraterrestrial Habitats: Human Health And Environmental Applications, Daniel Joseph Keaney

Theses

The rapid development of the Space industry and associated technologies over the past decade is leading to the inevitable consideration of establishing human-based colonies on extra-terrestrial bodies such as the moon and Mars. With Mars being the focus of not only this body of work, but current New Space Age travel (NASA and SpaceX), a significant issue posed by Martian colonists includes establishing a safe and sustainable food source. Owing to its constantly evolving prehistoric landscape, the soils of Mars are contaminated with sodium perchlorate, a water-soluble salt that is toxic to humans, leftover from once inferred brine seeps that …

Investigating The Antagonistic Activity Of Asymptomatic Bacteriuria Against Uropathogenic E. Coli., Ciara Kenneally

ORBioM (Open Research BioSciences Meeting)

Asymptomatic bacteriuria (ABU) is the presence of bacteria in urine, resembling a state of commensalism. Bacteria are characterised as ABU when they have been isolated from two consecutive urine samples (≥ 10⁵ CFU/ml) from individuals, but without symptoms attributable to a urinary tract infection (UTI). ABU Escherichia coli strains have evolved from uropathogenic ancestors and lack virulence factors associated with uropathogenic E. coli (UPEC). UPEC are the main etiological agent of urinary tract infections (UTIs), attributable to > 80% of cases. The frequency at which multidrug-resistant UPEC are isolated is affecting guidelines for use of former first-line antibiotics for UTIs, …

Biowill - Characterising Willow Bark Bio-Actives For Skin Therapies, Arnold Marisa

ORBioM (Open Research BioSciences Meeting)

Willow bark is considered as a disposable by-product when processing willow for biomass. Willow (Salix) is known to contain high value bioactive compounds which include salicin and its derivatives, and other phytochemicals of interest such as polyphenols and flavonoids. The plant is historically known as the primary source of salicylates to which the well-known drug aspirin is derived from. The work forms part of the Interreg project BioWILL, which is focused on integrated “Zero Waste” biorefinery utilising all fractions of willow feedstock for the production of biochemicals and renewable energy. This project aims to investigate the crude and …

Investigation Of The Antimicrobial Activity Of Coagulase Negative Staphylococci Of Human Origin, Ellen Twomey

ORBioM (Open Research BioSciences Meeting)

Coagulase Negative Staphylococci (CoNS) are significant members of the human microbiome and have been identified as a source of bacteriocins, small bioactive substances recognised for their antimicrobial properties. In this study we screened a bank of 37 human derived CoNS for the production of these peptides with emphasis on identifying those with the ability to inhibit the growth of Methicillin Resistant Staphylococcus aureus (MRSA). Deferred antagonism assays confirmed potential antimicrobial activity in all 37 isolates against sensitive indicator M. luteus, with nine inhibiting the growth of at least one MRSA strain they were overlaid against. Tests performed with the …

Short Chain Fatty Acid Combination Treatment Protects Against 6-Ohda Induced Decrease In Neurite Growth In An In Vitro Model Of Parkinson’S Disease., Alex Morris

ORBioM (Open Research BioSciences Meeting)

Title: Short chain fatty acid combination treatment protects against 6-OHDA induced decrease in neurite growth in an in vitro model of Parkinson’s disease.

Authors: Alex Morris¹, Louise M. Collins^1,2,3, Gerard W. O’Keeffe², Caitriona M. Guinane¹

¹ Department of Biological Sciences, Munster Technological University (MTU), Cork, Ireland.

² Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland.

³ Department of Physiology, University College Cork, Cork, Ireland.

Background: Parkinson’s disease (PD) is a neurodegenerative disorder characterized by dopaminergic neuron degeneration. This leads to motor dysfunction which is accompanied by gastrointestinal comorbidities such as constipation …

Effect Of Sub-Inhibitory Concentrations Of Nitrofurantoin, Ciprofloxacin And Trimethoprim On In-Vitro Biofilm Formation In Uropathogenic Escherichia Coli, Shane Whelan

ORBioM (Open Research BioSciences Meeting)

The purpose of the current study was to determine the effect of sublethal concentrations of nitrofurantoin, ciprofloxacin and trimethoprim on biofilm formation in 57 uropathogenic Escherichia coli strains (UPEC).

The MIC of nitrofurantoin, ciprofloxacin and trimethoprim was determined for 57 UPEC isolates. Biofilm formation for each isolate with and without sub-lethal concentrations of each antibiotic was then quantified, and the statistical significance of changes in biofilm formation was ascertained by way of a Dunnett's test.

The effects of sub-MIC antibiotics on biofilm formation of UPEC were variable. A total of 22.8% of strains were induced to form biofilm by nitrofurantoin, …

An Investigation Of The Novel Use Of Bacteriophages To Diagnose And Treat Johne's Disease In Cattle, Max Kevane-Campbell

ORBioM (Open Research BioSciences Meeting)

Johne’s disease is a scourge to dairy farmers all over the world. It is an infectious disease that causes chronic inflammation and lesions along the inside of the small intestine of, primarily, ruminant animals (i.e., cattle and sheep). It is an incurable disease and urgently requires new and radical intervention strategies. Apart from careful on-site farm management practices, little can be offered to farmers to reduce the risk of infection, and nothing short of livestock culling is effective once an animal becomes infected. Currently, there are no vaccines licensed in Ireland or antibiotic treatment strategies available for Johne’s disease. This …

Investigation Of The Urobiome For The Production Of Novel Antimicrobials Against Uropathogenic E. Coli (Upec), Jennifer Jones

ORBioM (Open Research BioSciences Meeting)

BACKGROUND: Urinary tract infections (UTIs) are one of the most common bacterial infections globally with antibiotic treatment becoming increasingly less effective. The urobiome remains a relatively understudied niche as a source of potentially novel antimicrobials (e.g., bacteriocins). Improvements to bacterial culturing and sequencing techniques have highlighted the potentially rich source of alternative treatments and control strategies to target uropathogenic E. coli (UPEC).

MATERIALS AND METHODS: (a) BAGEL 4 was used for bioinformatic screening of the genomes of urobiome isolates to identify bacteriocin gene clusters (BGC).

(b) Expanded quantitative urine culture (EQUC) was used to culture mid-stream urine samples to isolate …

'Investigating The Effect Of Cell-Free Supernatant Of Probiotic Strains On The Viability Of Pancreatic Cancer Cell Lines', Claire M. Doocey

ORBioM (Open Research BioSciences Meeting)

Background

Pancreatic cancer (PC) is a prevalent cancer accounting for over 450,000 deaths globally in 2020, and is associated with limited treatment options and high mortality rates. Mounting evidence implicates the human microbiome in tumorigenesis and cancer progression with key players including Helicobacter pylori in gastric cancer and Fusobacterium nucleatum in colorectal cancer and PC. Current research, however, also suggests a potential role for certain microbial residents in oncological treatment and biotherapeutic development. Recent studies have shown a link between cell-free supernatants (CFS) from probiotic strains and cancer cell death, suggesting their potential in targeting the tumour microenvironment. Probiotic genera …

Tunable Diode Laser Absorption Spectroscopy As An Alternative Method For Non-Invasive Sterility Detection In Ready To Feed Infant Milk Products, Peter Myintzaw

ORBioM (Open Research BioSciences Meeting)

Background: The potential application of rapid, non-destructive, and user-friendly TDLAS technology to detect contamination in commercially sterile dairy beverages where visual inspection is not possible was investigated for the first time. The TDLAS equipment uses laser light to monitor carbon dioxide changes due to microbial growth in the container headspace which has the advantage of being rapid and non-destructive. This study aimed to provide detailed scientific evidence for the application of TDLAS technology as a method to determine product sterility in real food products.

Methods: TDLAS growth detection of Bacillus fengqiuensis, Candida albicans, Lactococcus lactis, Microbacterium …

Application Of Fructans-Degrading Lachancea Fermentati Fst5.1 As An Alternative To Baker’S Yeast In The Production Of A Low-Fodmap Whole Wheat Bread., Małgorzata Borowska

ORBioM (Open Research BioSciences Meeting)

FODMAPs are a group of poorly absorbed dietary carbohydrates comprised of easily fermentable oligo-, di-, monosaccharides and polyols. When consumed, they can exert gastrointestinal symptoms of pain, flatulence, or an irregular bowel movement in individuals with irritable bowel syndrome. Whole wheat bread is an excellent source of proteins, vitamins, polyphenols, and other nutrients, but its consumption is restricted in a low-FODMAP diet due to high fructans content. Although alternatives exist, these are primarily gluten-free, often inferior in terms of quality, nutritional profile, and consumer acceptance. Bioprocessing using microbial fermentation has a proven capacity to reduce FODMAPs in cereal products, but …

The Urinary Microbiome And Biological Therapeutics: Novel Therapies For Urinary Tract Infections, Ciara Kenneally, Craig P. Murphy, Roy D. Sleator, Eamonn P. Culligan

Department of Biological Sciences Publications

The discovery of microbial communities in the urinary tract (the urobiome) has fundamentally altered the previous doctrine regarding urine sterility and associated urinary disorders. Recent advances in culturing and culture-independent DNA sequencing technologies have characterised the resident microbial community in the urobiome, and has, in turn, demonstrated how community imbalances potentially contribute to infection and disease. As we enter a post-antibiotic era, the effectiveness of standard antimicrobial treatments against multi-drug resistant (MDR) uropathogens is vastly diminished. Preliminary research is accumulating surrounding microbiome-based therapies, and their potential as non-antibiotic therapeutics. In this context, the urobiome is significantly underexplored, and knowledge regarding …

Elucidation Of Novel And Established Campylobacter Species With Clinical And Agricultural Significance Through Phenotypic, Genotypic, And Taxonomic Investigation, Caoimhe Lynch

Theses

Campylobacter spp. are well-established human, veterinary and economic pathogens, with a broad host range spanning from terrestrial and marine mammalian, avian and reptilian hosts. The scope of the study includes novel and notorious species within the genus, with reference to zoonotic agents Campylobacter jejuni and Campylobacter coli - the leading cause of human bacterial gastroenteritis in the EU and Ireland, Campylobacter fetus that represents the most common campylobacter causing bacteraemia and two novel species isolated from pigs not described in the literature previously. C. jejuni and C. coli isolates (n = 350) recovered from broiler caecal and neck skin samples, …

An Investigation Into The Prevalence Of Vancomycin-Resistant Enterococci Within An Irish Hospital, Dylan Casey

International Undergraduate Journal of Health Sciences

Vancomycin-resistant enterococci (VRE) are well-recognised nosocomial pathogens that pose a significant threat to public health. Associated with poorer clinical outcomes than their vancomycin-sensitive counterparts, the prevalence of VRE in Ireland has increased in recent times, with the European Antimicrobial Resistance Surveillance Network reporting that out of 29 countries, Ireland demonstrated the highest rates of vancomycin resistance among invasive Enterococcus faecium isolates between 2011 and 2014 (2011; 34.9%, 2012; 44.0%, 2013; 42.7%, 2014; 45.1%). Herein, we investigate VRE prevalence in the Mercy University Hospital (MUH) – an acute care hospital in southern Ireland. A total of 21 first-time VRE infections were …

Cryptosporidium Spp. Diagnosis And Research In The 21st Century, Jennifer K. O'Leary, Roy D. Sleator, Brigid Lucey

Department of Biological Sciences Publications

The protozoan parasite Cryptosporidium has emerged as a leading cause of diarrhoeal illness worldwide, posing a significant threat to young children and immunocompromised patients. While endemic in the vast majority of developing countries, Cryptosporidium also has the potential to cause waterborne epidemics and large scale outbreaks in both developing and developed nations. Anthroponontic and zoonotic transmission routes are well defined, with the ingestion of faecally contaminated food and water supplies a common source of infection. Microscopy, the current diagnostic mainstay, is considered by many to be suboptimal. This has prompted a shift towards alternative diagnostic techniques in the advent of …