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Research Activities – Professor J. Geoghegan

STAPHYLOCOCCAL PATHOGENESIS

Joan Geoghegan, B.A., Ph.D.

E-mail: geoghegj@tcd.ie

http://www.tcd.ie/genetics-microbiology/assets/pdf/Geoghegan.pdf

  • Research Interests

Our research focuses on  Staphylococcus aureus , an important cause of infection in humans. Methicillin-resistant  S. aureus  (MRSA) causes significant morbidity and mortality and new therapeutic approaches are urgently needed. Our team are using multidisciplinary approaches to study the bacterial factors that allow  S. aureus  to successfully colonise and infect humans. A major goal of our research activity is to provide a platform for the design of new agents for the treatment and prevention of  S. aureus  infection. Our current research interests include the following:

•  The molecular basis of S. aureus skin infection in atopic dermatitis (eczema). Atopic dermatitis, also known as eczema, is the most common skin disease in children. S. aureus exacerbates the severity of atopic dermatitis yet very little is known about the bacterial factors that allow the bacteria to colonise the skin and establish infection. By studying a collection of S.aureus strains isolated from patients with severe atopic dermatitis, my group are making new discoveries about the adhesive interactions that allow S. aureus to attach to corneocytes in skin.

•  What determines the success of new clones of MRSA? A better understanding of the factors that influence the fitness and virulence potential of S. aureus is necessary to explain how new clones of MRSA successfully colonise and infect people in the hospital and community. Our current research is focused on newly emerging clones of MRSA from recent outbreaks of invasive infection and the role of plasmid encoded genes in their success.

•  Biofilm formation by S. aureus and anti-biofilm agents. By growing as biofilm communities on catheters, heart valves and artificial joints, bacteria avoid being killed by antibiotics and the human immune system. Our team are studying the molecular basis of protein-mediated biofilm formation by S. aureus . We have found that it is possible to prevent staphylococci from building biofilms by targeting the protein linkages that hold the bacteria together and the interactions that facilitate adherence to surfaces. Our findings offer new opportunities for the development of compounds to prevent biofilm formation by staphylococci.

•  Response of S. aureus to wall teichoic acid depletion. Wall teichoic acid is an anionic polyol phosphate polymer that is covalently attached to peptidoglycan and plays key roles in growth, division and morphogenesis. We are studying the transcriptional changes that occur when the wall teichoic acid biosynthetic pathway is interrupted in S. aureus .

  • Selected Recent Publications

•  Fleury OM, McAleer MA, Feuillie C, Formosa-Dague C, Sansevere E, Bennett DE, Towell AM, McLean WHI, Kezic S, Robinson DA, Fallon PG, Foster TJ, Dufrêne YF, Irvine AD, Geoghegan JA (2017) Clumping factor B promotes adherence of Staphylococcus aureus to corneocytes in atopic dermatitis. Infection and immunity. 85(6). doi: 10.1128/IAI.00994-16. Read more about this paper here.

•  Feuillie C, Formosa-Dague C, Hays LMC, Vervaeck O, Derclaye S, Brennan MP, Foster TJ, Geoghegan JA, Dufrêne YF (2017) Molecular interactions and inhibition of the staphylococcal biofilm-forming protein SdrC. Proceedings of the National Academy of Sciences 114(14):3738-3743. Read more about this paper here, for media coverage click here, to read the manuscript click here.

•  Formosa-Dague C, Speziale P, Foster TJ, Geoghegan JA, Dufrêne YF (2016) Zinc-dependent mechanical properties of  Staphylococcus aureus  biofilm-forming surface protein SasG.  Proceedings of the National Academy of Sciences. 113(2):410-5. Read the paper here.

•  O'Halloran DP, Wynne K, Geoghegan JA (2015) Protein A is released into the  Staphylococcus aureus  culture supernatant with an unprocessed sorting signal.    Infection and Immunity .   83(4):1598-609. Read the paper here.

•  McCourt J, O'Halloran DP, McCarthy H, O'Gara JP,  Geoghegan JA (2014) Fibronectin-binding proteins are required for biofilm formation by community-associated methicillin-resistant Staphylococcus aureus strain LAC. FEMS Microbiology Letters . 353(2):157-64. Read the paper here.

Click here for a full list of publications

  • Media Coverage

https://www.rte.ie/news/2017/0321/861423-tcd-discovery-could-stop-medical-device-infections/

https://www.tcd.ie/news_events/articles/new-discovery-to-prevent-infections-spreading-on-medical-devices/7669

  • Research Personnel

Research Fellow:
Dr Marta Zapotoczna  zapotocm@tcd.ie Publications

Postgraduate Researchers:  
Ms Leanne Hays     hayslm@tcd.ie  Publications
Mr Keenan Lacey (co-supervisor)   klacey@tcd.ie Publications
Ms Aisling Towell   towella@tcd.ie Publications

  • Financial support
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Last updated 3 May 2017 by Microbiology (Email).