Fiona Walsh

Dr. Fiona Walsh

Department of Biology, Maynooth University, Maynooth, Ireland
orcid

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 March 2015 in Nature Reviews Microbiology
Verified
Journal Article
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TBThomas U. Berendonk
Thomas U. Berendonk
Célia ManaiaCélia Manaia
Célia Manaia
CMChristophe Merlin
Christophe Merlin
DFDespo Fatta-Kassinos
Despo Fatta-Kassinos
ECEddie Cytryn
Eddie Cytryn
JMJose Martinez
Jose Martinez

1 March 2018 in Trends in Microbiology
Verified
Journal Article
Closed access
AKAntti Karkman
Antti Karkman
TDThi Thuy Do
Thi Thuy Do
FWFiona Walsh
Fiona Walsh
MVMarko P.J. Virta
Marko P.J. Virta

1 July 2020 in Environment International
Verified
Journal Article
Open access
SRSara Rodriguez-Mozaz
Sara Rodriguez-Mozaz
Ivone Vaz-MoreiraIvone Vaz-Moreira
Ivone Vaz-Moreira
SGSaulo Varela Della Giustina
Saulo Varela Della Giustina
MLMarta Llorca
Marta Llorca
DBDamià Barceló
Damià Barceló
Célia ManaiaCélia Manaia
Célia Manaia
A comprehensive monitoring of a broad set of antibiotics in the final effluent of wastewater treatment plants (WWTPs) of 7 European countries (Portugal, Spain, Ireland, Cyprus, Germany, Finland, and Norway) was carried out in two consecutive years (2015 and 2016). This is the first study of this kind performed at an international level. Within the 53 antibiotics monitored 17 were detected at least once in the final effluent of the WWTPs, i.e.: ciprofloxacin, ofloxacin, enrofloxacin, orbifloxacin, azithromycin, clarithromycin, sulfapyridine, sulfamethoxazole, trimethoprim, nalidixic acid, pipemidic acid, oxolinic acid, cefalexin, clindamycin, metronidazole, ampicillin, and tetracycline. The countries exhibiting the highest effluent average concentrations of antibiotics were Ireland and the southern countries Portugal and Spain, whereas the northern countries (Norway, Finland and Germany) and Cyprus exhibited lower total concentration. The antibiotic occurrence data in the final effluents were used for the assessment of their impact on the aquatic environment. Both, environmental predicted no effect concentration (PNEC-ENVs) and the PNECs based on minimal inhibitory concentrations (PNEC-MICs) were considered for the evaluation of the impact on microbial communities in aquatic systems and on the evolution of antibiotic resistance, respectively. Based on this analysis, three compounds, ciprofloxacin, azithromycin and cefalexin are proposed as markers of antibiotic pollution, as they could occasionally pose a risk to the environment. Integrated studies like this are crucial to map the impact of antibiotic pollution and to provide the basis for designing water quality and environmental risk in regular water monitoring programs.

4 May 2016 in mBio
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Journal Article
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STSophie Thanner
Sophie Thanner
DDDavid Drissner
David Drissner
FWFiona Walsh
Fiona Walsh
In this article, the current knowledge and knowledge gaps in the emergence and spread of antimicrobial resistance (AMR) in livestock and plants and importance in terms of animal and human health are discussed. Some recommendations are provided for generation of the data required in order to develop risk assessments for AMR within agriculture and for risks through the food chain to animals and humans.

1 January 2013 in Frontiers in Microbiology
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Journal Article
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LCL. Cantas
L. Cantas
SSSyed Q. A. Shah
Syed Q. A. Shah
LCL. M. Cavaco
L. M. Cavaco
Célia ManaiaCélia Manaia
Célia Manaia
FWFiona Walsh
Fiona Walsh
HSH. Sørum
H. Sørum
The discovery and introduction of antimicrobial agents to clinical medicine was one of the greatest medical triumphs of the 20th century that revolutionized the treatment of bacterial infections. However, the gradual emergence of populations of antimicrobial-resistant pathogenic bacteria resulting from use, misuse, and abuse of antimicrobials has today become a major global health concern. Antimicrobial resistance (AMR) genes have been suggested to originate from environmental bacteria, as clinically relevant resistance genes have been detected on the chromosome of environmental bacteria. As only a few new antimicrobials have been developed in the last decade, the further evolution of resistance poses a serious threat to public health. Urgent measures are required not only to minimize the use of antimicrobials for prophylactic and therapeutic purposes but also to look for alternative strategies for the control of bacterial infections. This review examines the global picture of antimicrobial resistance, factors that favor its spread, strategies, and limitations for its control and the need for continuous training of all stake-holders i.e., medical, veterinary, public health, and other relevant professionals as well as human consumers, in the appropriate use of antimicrobial drugs.

12 June 2013 in PLOS ONE
Verified
Journal Article
Open access
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FWFiona Walsh
Fiona Walsh
BDBrion Duffy
Brion Duffy
Understanding the soil bacterial resistome is essential to understanding the evolution and development of antibiotic resistance, and its spread between species and biomes. We have identified and characterized multi-drug resistance (MDR) mechanisms in the culturable soil antibiotic resistome and linked the resistance profiles to bacterial species. We isolated 412 antibiotic resistant bacteria from agricultural, urban and pristine soils. All isolates were multi-drug resistant, of which greater than 80% were resistant to 16–23 antibiotics, comprising almost all classes of antibiotic. The mobile resistance genes investigated, (ESBL, blaNDM-1, and plasmid mediated quinolone resistance (PMQR) resistance genes) were not responsible for the respective resistance phenotypes nor were they present in the extracted soil DNA. Efflux was demonstrated to play an important role in MDR and many resistance phenotypes. Clinically relevant Burkholderia species are intrinsically resistant to ciprofloxacin but the soil Burkholderia species were not intrinsically resistant to ciprofloxacin. Using a phenotypic enzyme assay we identified the antibiotic specific inactivation of trimethoprim in 21 bacteria from different soils. The results of this study identified the importance of the efflux mechanism in the soil resistome and variations between the intrinsic resistance profiles of clinical and soil bacteria of the same family.