Staff Profile

General Profile Information
Staff Name
Research Statement

Professor Sheila Patrick

Chair of Molecular Medical Bacteriology

1977 BSc (Honours Microbiology); University of Edinburgh

1981 PhD Microbiology; University of Edinburgh

2006 DSc  Opportunistic pathogens of the normal human microbiota; University of Edinburgh

Fellow of the the Higher Education Academy

Chair, Society for Anaerobic Microbiology




Opportunistic bacterial infections that arise from the normal resident human microbiota, with emphasis on anaerobic bacteria.

The aim of Professor Patrick’s research is to contribute to our understanding of opportunistic bacterial infection so that we can better understand these diseases and improve on prevention, diagnosis and treatment.

Professor Patrick has nearly 30 years experience of studying the obligately anaerobic bacterium Bacteroides fragilis.  B. fragilis is a member of the normal resident human intestinal microbiota and an important opportunistic pathogen capable of causing considerable morbidity and mortality. Professor Patrick is Principal Investigator on the Wellcome Trust Sanger Institute UK B. fragilis whole genome sequencing project (

This has generated exciting data in relation to our understanding of the mechanisms that generate the heterogeneity of surface component expression, which she first reported in the 1980s.  These mechanisms involve DNA recombination events at an extensive number of loci in a variety and number that have not been observed, to date, in other bacteria. 

Since the mid 1990s her studies of biofilm associated prosthetic joint infection in artificial hip failure have highlighted the importance the anaerobe, Propionibacterium acnes. P. acnes, predominantly colonises human skin and is also implicated in a variety of inflammatory conditions including acne. In 2004 Professor Patrick was invited to present her studies at the Association of Bone and Joint Surgeons Carl T Brighton Annual Workshop on Musculoskeletal Infection, Tampa, Florida. This has resulted in the adoption of her techniques in the USA. Her studies have resulted in a re-assessment of the phylogeny of this group of bacteria and the discovery of variable expression of putative virulence determinants amongst the different groups.

Professor Patrick’s research has generated considerable global interest and resulted in collaborations in Africa, USA, Europe, Australia and South America.


Mechanisms of virulence of Bacteroides fragilis (Department of Education and Learning NI funded)

The data generated by the complete genome sequencing project (Cerdeño-Tárraga AM, Patrick S et al 2005 Science 307, 1463-1465) is being exploited in relation to putative virulence determinants. Selected genes, identified in silico in the B. fragilis genome sequences, are being studied in relation to their potential involvement in virulence and host colonisation. The effects of allelic replacement gene knockouts on phenotype, in collaboration with Dr Garry Blakely University of Edinburgh, are being examined.


Propionibacterium acnes as an important risk factor for prostate cancer (Prostate Cancer Charity UK funded)

Recent studies, including collaboration between Dr Andrew McDowell (project PI and Senior Post-doctoral Researcher in Professor Patrick’s laboratory) and laboratories in Australia and Sweden, have provided evidence that Propionibacterium acnes infects the human prostate gland where it is associated with acute and chronic inflammatory changes that could potentially lead to cancer development. This discovery may represent a breakthrough in our understanding of the complex origins of this common cancer and highlight new treatments. Currently, studies to confirm P. acnes infection in prostate cancer tissue from patients in Northern Ireland, as well as in vitro studies to determine the interaction between different phylogenetic types of P. acnes with human tissue culture cell lines in relation to key inflammatory mediators (in collaboration with Dr Lorraine Martin, Pharmacy QUB)  that are important in carcinogenesis, are ongoing.


Skin bacteria as a source of surgical infections: molecular epidemiology and prevention of wound contamination (NI Health & Social Care R & D Office funded)

A recent study of spinal surgery, carried out in Professor Patrick’s Laboratory showed that nearly 30% of operative wounds contained bacteria of the normal skin microbiota, despite pre-operative treatment of the patient’s skin with the antiseptic povidone-iodine (PVI); however, as peroperative antibiotic prophylaxis was successful, these patients did not have post-surgical infection. The rise in antibiotic resistance, typified by meticillin resistant Staphylococcus aureus (MRSA), will inevitably result in an increase in life threatening post-operative wound infection, potentially to the 30% level of wound contamination observed in this study. It is therefore proposed to pre-empt such a scenario by addressing the current procedures for skin antisepsis prior to surgery. Chlorhexidine gluconate (CHG) and PVI are skin disinfection antiseptics with different modes of bacterial killing; however, there have been no randomised controlled trials to determine if CHG used in addition to PVI reduces wound contamination in the operative setting.  The effect of the sequential pre-operative treatment of patient skin with antiseptic CHG and PVI, on surgical wound contamination in a randomised controlled trial of patients undergoing surgery at Musgrave Park Hospital Belfast is ongoing.  This study will enable us to determine if by using both CHG and PVI it will be possible to counter the potential rise in post-operative infection arising from antibiotic resistant bacteria.





Dr Andrew McDowell (Senior post-doctoral Research Fellow), Dr Emma Barnard (Post-doctoral Research Assistant), Dr Andrew Lee (Post-doctoral Research Assistant) Ms Una Martin (Research Nurse), Mr Danny O’Connor (Post-graduate Student), Mr Darragh McCafferty (Post-graduate Student)



Patrick S, Larkin MJ 1995. Immunological and molecular aspects of bacterial virulence. Chichester; J. Wiley. 275pp

Patrick, S. 2002. Bacteroides. Chapter 91, pp 1921-1948. In: Molecular Medical Microbiology B Boulnois, G Griffin, C Hormaeche, G Keusch, M Levine, H Smith, P Williams, M Sussman (Eds).  London: Academic Press.

Patrick S and Duerden BI. 2006. Gram-negative non-spore forming obligate anaerobes. Chapter 45, pp 541-556.  In: Principles and Practice of Clinical Bacteriology 2nd Edn. SH Gillespie, P Hawkey (Eds). London: Wiley.

Patrick S and McDowell A The Propionibacteriaceae. In: Volume 5  Bergey's Manual of Systematic Bacteriology 2nd Edn. H-J Busse, M Goodfellow, P Kämpfer, W Ludwig, JT Staley, K Suzuki, WB Whitman (Eds). New York: Springer-Verlag. In press.

McDowell A and Patrick S. 2011. Propionibacterium Chapter 13 In: Molecular detection of human bacterial pathogens. D Liu (Ed). Boca Raton, Florida: Taylor & Francis Group.  




Professional Qualifications



Public Health, Research Council and related Committees

2011- present Member of Healthcare Associated Infections Research Forum of the Public Health Agency, Health and Social Care NI

2010- present Member of Northern Ireland Antimicrobial Resistance Action Committee

2011-present Member of HSC NI Infection and Immunity TRG Grants Committee

2002- present Health and Social Care NI Research and Development Office Infection and Immunity Translational (previously Infectious Diseases Recognised) Research Group (HSC NI Infection and ImmunityTRG) Management Committee

2000-2001 Member of steering group to initiate Infectious Diseases Recognised Research Group under the auspices of the HSC R & D Office

1999-2000 Wellcome Trust strain selection committee for the Bacteroides fragilis whole genome sequencing project (invited by the Wellcome Trust to be a member and to nominate other members of the committee). Principal Investigator on the subsequent Wellcome Trust funded sequencing project and corresponding author on publication in the journal Science, 2005.

Professional Societies

2011-present Symposium proposer, organizer and session chair for European Congress of Clinical Microbiology and Infectious Diseases (European Society for Clinical Microbiology and Infectious Diseases) by invitation of the Chair of the European Study Group for Anaerobic Infections.

2008-present Council Member of Federation of European Microbiological Societies (FEMS) FEMS brings together 46 Microbiological societies from 36 countries across Europe and organises regular congresses, workshops and symposia and publishes journals.

2005- present Chair, Society for Anaerobic Microbiology (SAM) Council. The SAM is a UK based society with an international membership.  I progressed SAM's membership of the Federation of European Microbiological Societies from provisional to full membership.

2005 - present Honorary member Anaerobe Society of the Americas. The Anaerobe Society of the Americas was founded as a result of researchers from the USA attending SAM meetings and continues to have close association with SAM.

Elected (3 year appointment) to Society for General Microbiology, the leading general Microbiology Society in Europe, special interest group committees for Microbial Infection, 2000, Clinical Microbiology, 2006

Editorial Board Membership

2002- 2012. Journal of Medical Microbiology Editorial Board member; this involves sending papers for review, making decisions with respect to publication based on referees' comments and communicating directly with authors. JMM is a journal of the Society for General Microbiology with a wide international readership.


Since 2009

  • External Examiner for Infectious Diseases Honours programme in the College of Medicine, and Veterinary Medicine, University of Edinburgh. This honours programme is taken by Intercalating MBChB students, Biological and Biomedical Science students.
  • External Examiner for PhD Thesis (2010) and MSc by Research (2011) in the College of Science and Engineering, University of Edinburgh.

The University of Edinburgh is a Russell Group University ranked 20th in the QS World University Ranking 2011/2012.




2001-2005 Medical School, University of Sheffield, MSc (taught) in Microbial Pathogenicity

2002-2006 School of Life and Health Sciences, Aston University BSc Biology Programmes, Single and Combined Honours

2011-2016 University of Edinburgh Honours BSc Infectious diseases

External examiner for PhD Theses (e.g. University of Edinburgh, University of Aston Birmingham, University of Westminster, University of Cape Town) and Internal PhD examiner.

Membership Of Other Societies / Professional Activities


Invited Oral Presentations PRE-2010

'Phagocytosis of Bacteroides fragilis'. Presented at the 5th Biennial International Symposium organised by the Anaerobe Discussion Group, Cambridge, July, 1987

'Bacteroides fragilis surface structure expression in relation to virulence'.

Presented at the symposium on Anaerobes and Mixed Infections held at the International Congress for Infectious Diseases, Montreal, Canada, July 1990.

'The instability of antigenic expression in Bacteroides fragilis: a possible genetic basis?'

Presented at the Institut Pasteur, Paris by invitation of Dr M Sebald, Director of the Unites des Anaerobies, October 1990.

'Flow cytometric analysis of antigenic variation in pathogenic bacteria'

Presented at 'New horizons in cellular analysis', a flow cytometer user's meeting organised by Coulter Immunology UK, Blackpool, May 1991.

'Immunological and structural characterisation of the surface polysaccharides of Bacteroides fragilis: structural and antigenic variation'

Presented at 3rd Scientific Meeting of the European Society of Chemotherapy; Infectious Diseases, Paris, France, May 1995.

‘Approches nouvelles dans l'etude des bacteries anaerobies a Gram negatif d'interet medical'

Presented at Universite Rene Descartes (Paris V) by invitation of Professeur A Rimbault, Paris, France, May 1995.

'Variation of Bacteroides fragilis surface structures'

Presented at IX International Symposium of the Society for Anaerobic Microbiology, Cambridge, July 1995.

‘Virulence of Bacteroides species'

Presented at Society for General Microbiology 139th Meeting, University of Bradford, January 1998

‘Infection as a cause of prosthetic joint failure: an underestimated problem'

Presented at Ecole Superieure de Chemie Physique Electronique de Lyon by invitation of Professeur M Jourlin, Lyon, France, March 1999.

‘Virulence mechanisms of Bacteroides fragilis'

Presented at Anaerobe 2000, an International Congress of the Confederation of Anaerobe Societies. Manchester July 2000

‘The Bacteroides fragilis complete genome sequence answers a 20-year old question'

Presented at University of Edinburgh, Department of Medical Microbiology, May 2002

‘DNA inversion and antigenic variation in the opportunistic pathogenic bacterium Bacteroides fragilis'

Presented at University of Edinburgh, Institute of Cell and Molecular Biology, May 2002

Propionibacterium acnes - an important pathogen?'

Presented at Anaerobes in the patient and the laboratory, St Bartholomew's Hospital, London, December 2002.

‘Infection in joint replacement. New thoughts on causative bacteria - the role of Propionibacterium acnes' Presented at the British Orthopaedic Research Society Symposium, Nottingham April 2003-05-16

‘The genome sequence of Bacteroides fragilis answers a 20-year old question' Presented at the Molecular Aspects of Anaerobes symposium at the Society for General Microbiology 152nd Meeting, Edinburgh, April 2003

Patrick S and Glakely G. Exploring and exploiting the genome of the opportunistic pathogen Bacteroides fragils. Sixth Framework Programme of the European Commission workshop on ‘Strategies to address antimicrobial resistance through the exploitation of microbial genomics' at Magalia, Las Navas del Marqués, Spain, April 2004.

‘The complete genome sequence of Bacteroides fragilis NCTC 9343' presented at Anaerobe 2004, Congress of the Anaerobe Society of the Americas, Annapolis Maryland, July 2004.

‘Prosthesis biofilm infection: the importance of Propionibacterium acnes'

Presented at the Association of Bone and Joint Surgeons Workshop on Muskuloskeletal Infection, Tampa, Florida November 2004.

‘The Bacteroides fragilis genome sequencing project answers a 20-year old question' Presented at the University of Cape Town, Department of Molecular and Cell Biology, by invitation of Dr V Abratt, March 2005.

‘Propionibacterium acnes - an important pathogen?' Presented at University of Cape Town, Medical Microbiology, by invitation of Professor G Elisha, March 2005.

‘The genome of Bacteroides fragilis' Presented at ‘Anaerobes from the patient to the laboratory' held at the Health Protection Agency, Colindale, December 2005.

'Bacteroides fragilis: an important opportunistic pathogen' Presented at

University of Tubingen, by invitation of Professor G Doering, June 2006.

'Complete genome sequencing of Bacteroides fragilis answers a 20 year old question'Trinity College Dublin by invitation of Professor Cyril Smyth February 2007.

‘Improved detection and treatment of prosthetic joint infection' Presented at ECM IX - Musculoskeletal Trauma: 50 Years of AO Research,Davos Switzerland June 2008.

‘ Improved detection of biofilm infection' presented at Society for General Microbiology 163rd meeting Trinity College Dublin September 2008.'

‘LPS and capsule biosynthesis in Bacteroides fragilis' Presented at Society for General Microbiology meeting ‘Putting Microbes to Work' Heriot Watt University Edinburgh September 2009.

‘Clinical importance of the skin commensal Propionibacterium acnes ‘ presented at ‘The human microbiome and anaerobic infection' held at the Health Protection Agency, Colindale, London UK February 2011.


My research has been reported in the media and as result has contributed to the wider public understanding of science e.g.

BBC News 2003 ‘Discovery could cut bowel infection risk'

BBC News 2005 ‘Bacteria 'map' to help beat bug'


Awards And Honours/major Prizes


Council Member of Federation of European Microbiological Societies (FEMS)

FEMS brings together 46 Microbiological societies from 36 countries across Europe and organises regular congresses, workshops and symposia and publishes journals

Elected to the Society for General Microbiology (SGM) Prokaryote Committee and nominated Chair of Federation of Infections Societies 2015 committee and member of SGM Scientific Conferences Committee


TitleBook TitleYear
Propionibacterineae Bergey's Manual of Systematic Bacteriology 2012
Propionibacterium acnes: a new emerging pathogen in biomaterial associated infection Medical device associated infection 2012
Propionibacterium Molecular Detection of Human Bacterial Pathogens 2011
Non-sporing Gram Negative Anaerobes Principles and Practice of Clinical Bacteriology 2006
Bacteroides Molecular Medical Microbiology 2002
TitleJournal NameYear
An increased incidence of Propionibacterium acnes biofilms in acne vulgaris: a case-control study British Journal of Dermatology Vol in press  2012
Pattern of tissue invasion by Propionibacterium acne in acne vulgaris Journal of Dermatological Science Vol in press (00-00)  2012
No link between rosacea and Propionibacterium acnes Acta Pathologica, Microbiologica et Immunologica Scandinavica Vol in press (00-00)  2012
Draft genome sequence of an antibiotic resistant Propionibacterium acnes strain PRP-38 from the novel type 1C cluster Journal of Bacteriology Vol in press (00-00)  2012
Identification of a Collagen Type I Adhesin of Bacteroides fragilis Research in Microbiology Vol in press (00-00)  2012
The role of Bacteroides fragilis RecQ DNA helicases in cell survival after metronidazole exposure FEMS Microbiology Letters Vol in press (00-00)  2011
Multi-Drug Resistant Bacteroides fragilis Recovered from Blood and Severe Leg Wounds Caused by an Improvised Explosive Device (IED) in Afghanistan Anaerobe Vol 17 (152-155)  DOI 2011
A unique homologue of the eukaryotic protein-modifier ubiquitin present in the bacterium Bacteroides fragilis, a predominant resident of the human gastro-intestinal tract. Microbiology (Reading, England) Vol 157 (in press-155)  DOI   2011
A Novel Multilocus Sequence Typing Scheme for the Opportunistic Pathogen Propionibacterium acnes and Characterisation of Type I Cell Surface-Associated Antigens. Microbiology (Reading, England) Vol 157 (1990-2003)  DOI   2011
Complete Genome Sequence of Propionibacterium acnes Type IB Strain 6609 Journal of Bacteriology Vol 193 (4561-4562)  DOI   2011
Binding and degradation of fibrinogen by Bacteroides fragilis and characterization of a 54 kDa fibrinogen-binding protein Microbiology (Reading, England) Vol 156 (2516-2526)  DOI   2010
A Biofilm Approach to Detect Bacteria on Removed Spinal Implants Spine Vol 35 (1218-1224)  2010
Twenty-eight divergent polysaccharide loci specifying within and amongst strain capsule diversity in three strains of Bacteroides fragilis Microbiology (Reading, England) Vol 156 (3255-3269)  DOI   2010
Bacteroides fragilis RecA protein over-expression causes resistance to metronidazole Research in Microbiology Vol 161 (346-354)  2010
Bacteroides fragilis signals through Toll-like receptor (TLR) 2 and not through TLR4 Journal of Medical Microbiology Vol 58 (1015-1022)  DOI 2009
Overexpression of the rhamnose catabolism regulatory protein, RhaR: a novel mechanism for metronidazole resistance in Bacteroides thetaiotaomicron Journal of Antimicrobial Chemotherapy Vol 64 (267-273)  DOI   2009
Species of Propionibacterium and Propionibacterium acnes phylotypes associated with orthopedic implants Diagnostic Microbiology and Infectious Disease Vol 64 (138-145)  2009
Microbiologic Diagnosis of Prosthetic Shoulder Infection by Use of Implant Sonication Journal of Clinical Microbiology Vol 47 (1878-1884)  DOI   2009
Mutational analysis of genes implicated in LPS and capsular polysaccharide biosynthesis in the opportunistic pathogen Bacteroides fragilis Microbiology (Reading, England) Vol 155 (1039-1049)  DOI   2009
Rhamnose catabolism in Bacteroides thetaiotaomicron is controlled by the positive transcriptional regulator RhaR. Research in Microbiology Vol 159 (678-684)  2008
In vitro study of the efficacy of acrylic bone cement loaded with supplementary amounts of gentamicin: effect on mechanical properties, antibiotic release, and biofilm formation Acta Orthopaedica Vol 78 (774-785)  2008
Detection of Anaerobic bacteria in high numbers in sputum from patients with cystic fibrosis American Journal of Respiratory and Critical Care Medicine Vol 177 (995-1001)  DOI 2008
Incorporation of large amounts of gentamicin sulphate to acrylic bone cement: effect on handling and mechanical properties, antibiotic release and biofilm formation. Proceedings of the Institution of Mechanical Engineers, Part H, Journal of Engineering in Medicine Vol 222 (355-366)  2008
AnAraC/XylSfamily transcriptional regulator homologue from Bacteroides fragilis is associated with cell survival following DNA damage FEMS Microbiology Letters Vol 278 (249-256)  2008
A new phylogenetic group of Propionibacterium acnes. Journal of Medical Microbiology Vol 57 (218-224)  2008
Improved detection and treatment of prosthetic joint infection European Cells and Materials Vol 16 (suppl 2) (30-30)  2008
Biofilm Formation by Bacteria Isolated from Retrieved Failed Prosthetic Hip Implants in and in vitro Model of Hip Arthroplasty Antibiotic Prophylaxis Journal of Orthopaedic Research Vol 25 (2-10)  2007
Propionibacterium acnes and lipopolysaccharide induce the expression of antimicrobial peptides and proinflammatory cytokines/chemokines in human sebocytes Microbes and Infection Vol 8 (2195-2205)  2006
Variable expression of immunoreactive surface proteins of Propionibacterium acnes Microbiology (Reading, England) Vol 152 (3667-3681)  2006
Propionibacterium acnes wound contamination at the time of spinal surgery Clinical Orthopaedics and Related Research Vol 437 (67-73)  2005
Evaluation of nonculture methods for the detection of prosthetic hip biofilms Clinical Orthopaedics and Related Research Vol 437 (74-82)  2005
CAMP factor homologues in Propionibacterium acnes: a new protein family differentially expressed by types I and II Microbiology (Reading, England) Vol 151(5) (1369-1379)  DOI 2005
Propionibacterium acnes types I and II represent phylogenetically distinct groups Journal of Clinical Microbiology Vol 43(1) (326-334)  DOI 2005
Extensive DNA inversions in the B. fragilis genome control variable gene expression Science Vol 307(5714) (1463-1465)  DOI 2005
Multiple inverted DNA repeats of Bacteroides fragilis that control polysaccharide antigenic variation are similar to the hin region inverted repeats of Salmonella typhimurium Microbiology (Reading, England) Vol 149(4) (915-924)  DOI 2003
Formulation of Propionibacterium acnes biofilms on orthopaedic biomaterials and their susceptibility to antimicrobials Biomaterials Vol 24 (3221-3227)  2003
Studies of Microthrix parvicella in situ and in laboratory culture: production and use of specific antibodies Water Science and Technology Vol 46 (115-118)  2002