Dr. Siobhan O'Brien

• Elze Hesse, S. O'Brien, AM Lujan, D Sanders, F Bayer, E van Veen, DJ Hodgson & A. Buckling. , Stress causes interspecific facilitation within a compost community, Ecology Letters, 24, (10), 2021, p2169--2177Journal Article, 2021, DOI
• Siobhan O'Brien , Michael Baumgartner, Alex Hall, Species interactions drive the spread of ampicillin resistance in human-associated gut microbiota, Evolution, Medicine, and Public Health, 9, (1), 2021, p256--266Journal Article, 2021, DOI , TARA - Full Text
• Peter Stilwell, S. O'Brien, E. Hesse, C. Lowe, A Gardner, A Buckling, Resource heterogeneity and the evolution of public goods cooperation, Evolution Letters, 4, (2), 2020, p155--163Journal Article, 2020, DOI , TARA - Full Text
• Siobhán O'Brien, Rolf Kümmerli, Steve Paterson, Craig Winstanley, Michael A. Brockhurst, Transposable temperate phages promote the evolution of divergent social strategies in Pseudomonas aeruginosa populations, Proceedings of the Royal Society B: Biological Sciences, 286, (1912), 2019, p20191794Journal Article, 2019, DOI , TARA - Full Text
• Hesse, E., O'Brien, S., Tromas, N., Bayer, F., Luján, A.M., van Veen, E.M., Hodgson, D.J., Buckling, A., Ecological selection of siderophore-producing microbial taxa in response to heavy metal contamination, Ecology Letters, 21, (1), 2018, p117-127Journal Article, 2018, DOI , TARA - Full Text
• O'Brien, S., Hesse, E., Luján, A., Hodgson, D.J., Gardner, A., Buckling, A., No effect of intraspecific relatedness on public goods cooperation in a complex community, Evolution, 72, (5), 2018, p1165-1173Journal Article, 2018, URL , TARA - Full Text
• O'Brien, S., Williams, D., Fothergill, J.L., Paterson, S., Winstanley, C., Brockhurst, M.A., High virulence sub-populations in Pseudomonas aeruginosa long-term cystic fibrosis airway infections, BMC Microbiology, 17, (1), 2017Journal Article, 2017, URL
• O'Brien, S., Fothergill, J.L., The role of multispecies social interactions in shaping Pseudomonas aeruginosa pathogenicity in the cystic fibrosis lung, FEMS Microbiology Letters, 364, (15), 2017Journal Article, 2017
• Winstanley, C., O'Brien, S., Brockhurst, M.A., Pseudomonas aeruginosa Evolutionary Adaptation and Diversification in Cystic Fibrosis Chronic Lung Infections, Trends in Microbiology, 24, (5), 2016, p327-337Journal Article, 2016, DOI
• Davies, E.V., James, C.E., Williams, D., O'Brien, S., Fothergill, J.L., Haldenby, S., Paterson, S., Winstanley, C., Brockhurst, M.A., Temperate phages both mediate and drive adaptive evolution in pathogen biofilms, Proceedings of the National Academy of Sciences of the United States of America, 113, (29), 2016, p8266-8271Journal Article, 2016, URL
• O'Brien, S., Brockhurst, M.A., Social evolution: Slimy cheats pay a price, Current Biology, 25, (9), 2015, pR378-R381Journal Article, 2015, DOI
• O'Brien, S., Buckling, A., The sociality of bioremediation: Hijacking the social lives of microbial populations to clean up heavy metal contamination, EMBO Reports, 16, (10), 2015, p1241-1245Journal Article, 2015, URL
• O'Brien, S., Hodgson, D.J., Buckling, A., Social evolution of toxic metal bioremediation in Pseudomonas aeruginosa, Proceedings of the Royal Society B: Biological Sciences, 281, (1787), 2014Journal Article, 2014, URL
• O'Brien, S., Rodrigues, A.M.M., Buckling, A., The evolution of bacterial mutation rates under simultaneous selection by interspecific and social parasitism, Proceedings of the Royal Society B: Biological Sciences, 280, (1773), 2013Journal Article, 2013, DOI
• O'Brien, S., Hodgson, D.J., Buckling, A., The interplay between microevolution and community structure in microbial populations, Current Opinion in Biotechnology, 24, (4), 2013, p821-825Journal Article, 2013, DOI
• Siobhán O'Brien, Chris Culbert, Timothy G. Barraclough, Community composition drives siderophore dynamics in multispecies bacterial communities. , BMC Ecology and Evolution, 23, (45), 2023Journal Article, 2023, DOI , TARA - Full Text
• Siobhan O'Brien, Development of liquid culture media mimicking the conditions of sinuses and lungs in cystic fibrosis and health, F1000Research, 11, 2022, p1007Journal Article, 2022, DOI
• Matthew Kelbrick, Elze Hesse, Siobhan O'Brien, Cultivating antimicrobial resistance: how intensive agriculture ploughs the way for antibiotic resistance, Microbiology, 169, (8), 2023Journal Article, 2023, DOI , TARA - Full Text
• Elze Hesse, Siobhán O"Brien, Ecological dependencies and the illusion of cooperation in microbial communities, Microbiology, 170, (2), 2024Journal Article, 2024, URL , TARA - Full Text
• Dilem Ruhluel, Lewis Fisher, Thomas E Barton, Hollie Leighton, Sumit Kumar, Paula Amores Morillo, Siobhan O"Brien, Joanne L Fothergill, Daniel R Neill, Secondary messenger signalling influences Pseudomonas aeruginosa adaptation to sinus and lung environments, ISME, 2024Journal Article, 2024
• Experimental Evolution with Microbes in, editor(s)Katrina McGuigan , Encyclopedia of Evolutionary Biology (2nd Edition), Elsevier, 2024, [Tiffany Taylor, Ellie Harrison, Siobhan O'Brien]Book Chapter, 2024

• Matthew Kelbrick, Andy Fenton, Steven Parratt, James P. J Hall, Siobhán O'Brien, Spatial refuges and nutrient acquisition predict the outcome of evolutionary rescue in evolving microbial populations, BioRxiv, 2023Journal Article

• Title

  How is pyocyanin mediated virulence in Pseudomonas aeruginosa driven by species interactions in the cystic fibrosis lung?
  Summary

  Cystic fibrosis (CF) is one of the most common recessively inherited rare diseases, affecting over 70000 people worldwide. The most common cause of mortality in CF is chronic lung infection with Pseudomonas aeruginosa - a virulent pathogen that is virtually impossible to eradicate once established. Successful treatment of P. aeruginosa infections is hampered by rapid evolutionary adaptation of P. aeruginosa within the lung, leading to diverse and unpredictable infections consisting of highvirulent subtypes. However, we do not yet understand the drivers of P. aeruginosa virulence evolution over the course of a chronic infection, making it difficult to predict the onset of exacerbated symptoms. This work will yield new insights into the drivers of clinically-important evolutionary changes in P. aeruginosa lung infections " so we will go from understanding what evolutionary changes occur to why they occur. It is now abundantly clear that P. aeruginosa is a pathogen that cannot be understood in isolation. Hence, successful treatment relies on predicting the dynamics of this pathogen in the context of the lung microbiota.
  Funding Agency

  IRC
  Date From

  Sept 2023
  Date To

  Sept 2026
• Title

  Investigating the interplay between pesticides and antimicrobial resistance in soil bacterial populations.
  Summary

  Antimicrobial resistance (AMR) is a pressing global issue that is expected to cause upwards of 10 million deaths a year by 2050. While responsible antibiotic stewardship has been advocated as crucial for controlling AMR, emerging evidence suggests that reducing antibiotic use alone may not be sufficient for curbing or reversing AMR. Anthropogenic activities, such as intensive agricultural practices, are now recognized as important and overlooked predictors of AMR evolution in natural bacterial populations. This can occur in three main ways: Firstly, antibiotics used in agriculture can discharge into soils, selecting for AMR bacteria in the natural environment. Secondly, agricultural stressors (e.g. pesticides and heavy metal waste) can select for resistance mechanisms in bacteria that inadvertently cause cross-resistance to antibiotics. Thirdly, agricultural stressors can "prime" soil bacteria for resistance to subsequent antibiotic influx, by generating the genetic variation required for subsequent selection to act on. Together, this suggests that agricultural chemicals can be key drivers of AMR, however we lack causative experiments that bridge the gap between simplified laboratory studies, and correlations based on natural soil communities. This project will examine how a commonly used fungicide (Fubol Gold), drives AMR evolution in the soil-dwelling opportunistic pathogen, Pseudomonas fluorescens.
  Funding Agency

  Trinity College Dublin Doctorate Award
  Date From

  September 2023
  Date To

  August 2027
• Title

  Exploring how species interactions shape adaptive evolution in soil microbial communities
  Summary

  Agricultural soil microbial communities provide vital ecosystem services such as providing nutrients to crops, protection against pathogens, breaking down toxic heavy metals and carbon storage. However, these communities are increasingly faced with harsh environmental conditions imposed by human activity - such as intensive use of pesticides, increased salinity from rising sea levels, and antibiotic run-off from pig farms. While experiments in vitro reveal that microbes can rapidly evolve resistance to such stressors, such studies are limited to a single species evolving in the presence of a single stressor in a highly artificial laboratory environment. In a complex natural community, however, evolutionary responses may be impeded because adapting to the presence of other competing species is more important than adapting to the environment. The ability of microbes to persist in the face of anthropogenic stress has clear consequences for maintaining ecosystem functions that rely on stable and efficient microbial communities. The proposed research will use real-time experimental evolution of soil microbial communities, to test if and how species interactions in complex soil microbial communities influence evolutionary responses to a stressful environment. We will focus on stressors highly relevant to agriculture: a broad-spectrum azole fungicide, antibiotic run-off from pig farms and increasing salinity and temperatures driven by climate change. Since environmental stressors are commonly encountered in combination, we will test the impact of these stressors individually and in combination. This research will yield insights into if and how evolutionary responses to agricultural stress occur in natural soil communities. Such questions are particularly relevant as we face challenges such as climate change and growing threats from agricultural pests, while simultaneously needing to feed over 9 billion people worldwide by 2050. This research will meet challenges associated with the BBSRC strategic priority 'Bioscience for sustainable agriculture and food', by gaining fundamental insights into the role of microbial evolutionary adaptation in an intense agricultural setting. Such fundamental understanding will inform future research that aims to harnass and manipulate microbial communties for efficient, environmentally friendly, food production. The need for fundamental, causal, microbiome research is highlighted by BBSRC prioritising Integrative Microbiome Research as a responsive mode priority in 2019.
  Funding Agency

  BBSRC
  Date From

  April 2020
• Title

  How is P. aeruginosa virulence driven by multispecies interactions in the cystic fibrosis lung?
  Summary

  Cystic fibrosis (CF) is an inherited chronic genetic disorder that negatively affects the respiratory and digestive system. The most common cause of mortality in CF is chronic lung infection with Pseudomonas aeruginosa (PA), a virulent pathogen that increases vulnerability to fatal secondary infections and is virtually impossible to eradicate once established. PA undergoes evolutionary changes as it adapts to life in the lung, leading to a diverse resident population of PA that are highly virulent and antibiotic-resistant. However, the drivers of PA evolution in the CF lung are not fully understood. Chronically colonized CF airways represent a surprisingly complex and diverse microbiota. Interactions between PA and other members of the lung microbiota can drive PA virulence and antibiotic resistance. However, our current understanding is largely limited to predictions based on simplified two-species environments in laboratory media. This project will begin to tackle the ambitious question of how multispecies interactions within complex CF lung communities drive the evolution of clinically-relevant changes in PA and vice versa.
  Funding Agency

  TCD Research Boost Award
  Date From

  November 2021
  Date To

  October 2022
• Title

  Investigating the impact of anthropogenic change on soil microbiome functioning and crop health
  Summary
  Funding Agency

  IRC

Environmental management, Ecology, Immunology, Microbiology, Genetics, Soil sciences,

• George C. Williams Prize Finalist (ISEMPH) 2022
• European Corporation in Science & Technology Award 2012
• University of Cambridge, Travel Award 2014
• National Academy of Sciences working group, California, USA. Travel Award 2014
• Communication for Collaboration Workshop, Bristol, UK. Travel award 2014
• European meeting for PhD students in Evolutionary Biology, Finland. Travel award 2012
• John Maynard Smith Prize (European Society for Evolutionary Biology) 2018
• Society for Molecular Biology & Evolution. Travel award 2017

• Society for Applied Microbiology
• Society for Molecular Biology and Evolution
• Microbiology Society (UK & IRELAND)
• Society for the Study of Evolution, USA

• Associate Editor, Evolution 2024