Gerald F. Fitzgerald

University College Cork

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R. Paul Ross

APC Microbiome Institute

193

Catherine Stanton

Teagasc - The Irish Agriculture and Food Development Authority

153

Douwe van Sinderen

University College Cork

Colin Hill

APC Microbiome Institute

Charles Daly

University College Cork

Aidan Coffey

University College Cork

Paul D. Cotter

Teagasc - The Irish Agriculture and Food Development Authority

Olivia McAuliffe

Teagasc - The Irish Agriculture and Food Development Authority

Paul W. O’Toole

University College Cork

Marco Ventura

University of Parma

Cooperative Institutions

University College Cork

259

Teagasc - The Irish Agriculture and Food Development Authority

160

National University of Ireland

APC Microbiome Institute

University College Dublin

Alimentary Health (Ireland)

Cork University Hospital

University of Groningen

University of Michigan–Ann Arbor

Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement

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Species and Type Phages of Lactococcal Bacteriophages

Intervirology (1991)

Audrey W. Jarvis Gerald F. Fitzgerald Mireille Mata Annick Mercenier Horst Neve

Lactococcal phages are classified according to morphology and DNA homology. Phages are differentiated into 12 phage species, and type phages of each species are proposed. Members and possible members of each species are named. Available data on type phages are tabulated including morphology, DNA characteristics and phage protein bands.

Homology

10.1159/000150179

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Citations (214)

Transcriptional Analysis and Regulation of Expression of the Scr FI Restriction-Modification System of Lactococcus lactis subsp. cremoris UC503

Journal of Bacteriology (2001)

Derek Butler Gerald F. Fitzgerald

ABSTRACT Scr FI is a type II restriction-modification system from Lactococcus lactis which recognizes the nucleotide sequence 5′-CC↓ NGG-3′, cleaving at the point indicated by the arrow, and it comprises an endonuclease gene that is flanked on either side by genes encoding two 5-methylcytosine methylases. An open reading frame ( orfX ) of unknown function is located immediately upstream of these genes. In this study Northern analysis was performed, and it revealed that orfX, scrFIBM, and scrFIR are cotranscribed as a single polygenic mRNA molecule, while scrFIAM is transcribed independently. 5′ extension analysis indicated that the start site for the scrFIAM promoter was a thymine located 4 bp downstream of the −10 motif. The transcriptional start site for the orfX promoter was also found to be a thymine which is more atypically located 24 bp downstream of the −10 motif proximal to the start codon. A helix-turn-helix motif was identified at the N-terminal end of one of the methylases (M. Scr FIA). In order to determine if this motif played a role in regulation of the Scr FI locus, M. Scr FIA was purified. It was then employed in gel retardation assays using fragments containing the two promoters found on the Scr FI operon, one located upstream of orfX and the other located just upstream of scrFIAM . M. Scr FIA was found to bind to the promoter region upstream of the gene encoding it, indicating that it may have a regulatory role. In further studies the two putative promoters were introduced into a vector (pAK80) upstream of a promoterless lacZ gene, and cloned fragments of the Scr FI locus were introduced in trans with each of these promoter constructs to investigate the effect on promoter activity. These results implicated M. Scr FIA in regulation of both promoters on the Scr FI locus.

Primer extension

10.1128/jb.183.15.4668-4673.2001

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Citations (28)

Unraveling the digestion of milk protein

American Journal of Clinical Nutrition (2013)

R. Paul Ross Gerald F. Fitzgerald Catherine Stanton

Digestion

10.3945/ajcn.113.063321

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Citations (7)

Enhanced Survival of GroESL-Overproducing Lactobacillus paracasei NFBC 338 under Stressful Conditions Induced by Drying

Applied and Environmental Microbiology (2006)

B. M. Corcoran R. Paul Ross Gerald F. Fitzgerald Peter Dockery Catherine Stanton

ABSTRACT GroESL-overproducing Lactobacillus paracasei NFBC 338 was dried, and its viability was compared with that of controls. Spray- and freeze-dried cultures overproducing GroESL exhibited ∼10-fold and 2-fold better survival, respectively, demonstrating the importance of GroESL in stress tolerance, which can be exploited to enhance the technological performance of sensitive probiotic cultures.

Lactobacillus paracasei

10.1128/aem.02626-05

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Citations (76)

Surface Microflora of Four Smear-Ripened Cheeses

Applied and Environmental Microbiology (2005)

Jérôme Mounier Roberto Gelsomino Stefanie Goerges Marc Vancanneyt Katrien Vandemeulebroecke

ABSTRACT The microbial composition of smear-ripened cheeses is not very clear. A total of 194 bacterial isolates and 187 yeast isolates from the surfaces of four Irish farmhouse smear-ripened cheeses were identified at the midpoint of ripening using pulsed-field gel electrophoresis (PFGE), repetitive sequence-based PCR, and 16S rRNA gene sequencing for identifying and typing the bacteria and Fourier transform infrared spectroscopy and mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) analysis for identifying and typing the yeast. The yeast microflora was very uniform, and Debaryomyces hansenii was the dominant species in the four cheeses. Yarrowia lipolytica was also isolated in low numbers from one cheese. The bacteria were highly diverse, and 14 different species, Corynebacterium casei , Corynebacterium variabile , Arthrobacter arilaitensis , Arthrobacter sp., Microbacterium gubbeenense , Agrococcus sp. nov., Brevibacterium linens , Staphylococcus epidermidis , Staphylococcus equorum , Staphylococcus saprophyticus , Micrococcus luteus , Halomonas venusta , Vibrio sp., and Bacillus sp., were identified on the four cheeses. Each cheese had a more or less unique microflora with four to nine species on its surface. However, two bacteria, C. casei and A. arilaitensis , were found on each cheese. Diversity at the strain level was also observed, based on the different PFGE patterns and mtDNA RFLP profiles of the dominant bacterial and yeast species. None of the ripening cultures deliberately inoculated onto the surface were reisolated from the cheeses. This study confirms the importance of the adventitious, resident microflora in the ripening of smear cheeses.

Debaryomyces hansenii

Cheese ripening

Brevibacterium

Staphylococcus xylosus

Micrococcus

10.1128/aem.71.11.6489-6500.2005

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Citations (169)

Effect of disaccharides on survival during storage of freeze dried probiotics

Dairy Science and Technology (2008)

Song Miao Susan Mills Catherine Stanton Gerald F. Fitzgerald Yrjö H. Roos

Lactobacillus rhamnosus

Lactobacillus paracasei

Acetoin

10.1051/dst:2007003

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Citations (92)

In vitro evaluation of the probiotic properties of human intestinal Bifidobacterium species and selection of new probiotic candidates

Journal of Applied Microbiology (2008)

Susana Delgado Eleanor O’Sullivan Gerald F. Fitzgerald Baltasar Mayo

Aims: The aim of this work was to identify and select new probiotic strains among majority intestinal bifidobacterial species from healthy Spaniards. Methods and Results: One hundred and eighty isolates belonging to seven Bifidobacterium species were subjected to a subtractive system of in vitro analysis addressing beneficial and undesirable traits. Approx. 45% of the isolates were able to grow in 2% bovine bile, and about 20% of these grew at pH 3·5. Undesirable enzymatic activities, such as α‐chymotrypsin, β‐glucuronidase and N‐acetyl‐β‐glucosaminidase were not detected. Atypical antibiotic resistances were not observed, except for tetracycline resistance in a single strain. Intestinal pathogens were inhibited to some extent by all analysed strains. All selected strains adhered to human epithelial cells in a strain‐dependent manner, and none was able to degrade pig mucin. Conclusions: Based on these in vitro analyses, strains of Bifidobacterium catenulatum, Bifidobacterium longum and Bifidobacterium pseudocatenulatum are here proposed as new probiotic candidates. Significance and Impact of the Study: Although in vivo analyses are still needed, these strains belonging to unusual species in the portfolio of probiotic suppliers are thought to be more appropriated than those currently in use, as they show desirable properties and are preponderant among human intestinal populations.

Bifidobacterium longum

Bifidobacterium bifidum

10.1111/j.1365-2672.2007.03642.x

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Citations (60)

Intestinal microbiota, diet and health

British Journal Of Nutrition (2013)

Susan Power Paul W. O’Toole Catherine Stanton R. Paul Ross Gerald F. Fitzgerald

The human intestine is colonised by 10 13 to 10 14 micro-organisms, the vast majority of which belong to the phyla Firmicutes and Bacteroidetes. Although highly stable over time, the composition and activities of the microbiota may be influenced by a number of factors including age, diet and antibiotic treatment. Although perturbations in the composition or functions of the microbiota are linked to inflammatory and metabolic disorders (e.g. inflammatory bowel diseases, irritable bowel syndrome and obesity), it is unclear at this point whether these changes are a symptom of the disease or a contributing factor. A better knowledge of the mechanisms through which changes in microbiota composition (dysbiosis) promote disease states is needed to improve our understanding of the causal relationship between the gut microbiota and disease. While evidence of the preventive and therapeutic effects of probiotic strains on diarrhoeal illness and other intestinal conditions is promising, the exact mechanisms of the beneficial effects are not fully understood. Recent studies have raised the question of whether non-viable probiotic strains can confer health benefits on the host by influencing the immune system. As the potential health effect of these non-viable bacteria depends on whether the mechanism of this effect is dependent on viability, future research needs to consider each probiotic strain on a case-by-case basis. The present review provides a comprehensive, updated overview of the human gut microbiota, the factors influencing its composition and the role of probiotics as a therapeutic modality in the treatment and prevention of diseases and/or restoration of human health.

Dysbiosis

10.1017/s0007114513002560

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Citations (443)

Identification of four loci isolated from twoStreptococcus thermophilusphage genomes responsible for mediating bacteriophage resistance

FEMS Microbiology Letters (2000)

Elizabeth Stanley Linda Walsh Anneke Zwet Gerald F. Fitzgerald Douwe van Sinderen

Sequence data derived from the Streptococcus thermophilus phages φO1205 and φ7201 indicated that each of these phages contains a distinct DNA region dedicated to replication. Southern blotting experiments showed that phages infecting S. thermophilus may be divided into at least two groups, each containing the presumptive replication functions of either φO1205 (group I) or φ7201 (group II). Specific regions from the putative replication module of each of the two phages were examined for their ability to provide phage resistance.

Southern blot

Replication

10.1111/j.1574-6968.2000.tb08907.x

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Citations (58)

Characterisation ofStreptococcus thermophilusCNRZ1205 and its cured and re-lysogenised derivatives

FEMS Microbiology Letters (1999)

Elizabeth Stanley Gerald F. Fitzgerald Douwe van Sinderen

Streptococcus thermophilus CNRZ1205 is the lysogenic host for the temperate phage phi O1205. A derivative of CNRZ1205 was isolated which was cured of phi O1205 and this strain was used to construct a re-lysogenised derivative. Pulse field gel electrophoresis and sequencing of the attachment site regions confirmed that excision and re-integration of the phage was a site-specific event. Interestingly, cells from the cured, as well as its re-lysogenised derivative, were found to have a very long chain length.

Lysogenic cycle

Derivative (finance)

Strain (injury)

Temperateness

10.1111/j.1574-6968.1999.tb13704.x

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Citations (7)