Mark Walker

Research Interests

1. Molecular analysis of group A streptococcal virulence determinants.
2. Epidemiology of microbial pathogens.
3. Development of recombinant oral and intranasal vaccine delivery systems for the stimulation of immunity against pathogens of veterinary and human health significance.

Representative Publications

Sanderson-Smith, M.L., Dinkla, K., Cole, J.N., Cork, A.J., Maamary, P.G., McArthur, J.D., Chhatwal, G.S., Walker, M.J. (2008) M protein mediated plasminogen binding is essential for the virulence of an invasive Streptococcus pyogenes isolate. FASEB Journal (in press 10/4/08).

Gillen, C.M., Courtney, H.S., Schultze, K., Rohde, M., Wilson, M.R., Timmer, A.M., Guzman, C.A., Nizet, V., Chhatwal, G.S., Walker, M.J. (2008) Opacity factor activity and epithelial cell binding by the serum opacity factor protein of Streptococcus pyogenes are functionally discrete. Journal of Biological Chemistry 283: 6359-6366.

Walker, M.J., Hollands, H., Sanderson-Smith, M., Cole, J.N., Kirk, J.K., Henningham, A., McArthur, J.D., Dinkla, K., Aziz, R.K., Kansal, R.G., Buchanan, J.T., Simpson, A.J., Chhatwal, G.S., Kotb, M., Nizet, V. (2007) Selection pressure by the innate immune system switches Streptococcus pyogenes M1T1 into a hyperinvasive pathogen. Nature Medicine 13: 981-985.

Tart, A.H., Walker, M.J., Musser, J.M. (2007) New understanding of the group A streptococcus pathogenesis cycle. Trends in Microbiology 15: 318-325.

Cole, J.N., McArthur, J.D., McKay, F.C., Sanderson-Smith, M.L., Cork, A.J., Ranson, M., Rohde, M., Itzek, A., Sun, H., Ginsburg, D., Kotb, M., Nizet, V., Chhatwal, G.S., Walker, M.J. (2006) Trigger for group A streptococcal M1T1 invasive disease. FASEB Journal 20: 1745-1747.

Sanderson-Smith, M., Walker, M.J., Ranson, M. (2006) The maintenance of high affinity plasminogen binding by group A streptococcal plasminogen-binding M-like protein (PAM) is mediated by arginine and histidine residues within the a1 and a2 repeat domains. Journal of Biological Chemistry 281: 25965-25971.

Sanderson-Smith, M., Batzloff, M., Sriprakash, K.S., Dowton, M., Ranson, M., Walker, M.J. (2006) Divergence in the plasminogen-binding group A streptococcal M protein family - functional conservation of binding site and potential role for immune selection of variants.. Journal of Biological Chemistry 281: 3217-3226.

Timmer, A.M., Kristian, S.A., Datta, V., Jeng, A., Gillen, C.M., Walker, M.J., Beall, B., Nizet, V. (2006) Serum opacity factor promotes group A streptococcal epithelial cell invasion and virulence. Molecular Microbiology 62: 15-25.

Burnett, T.A., Dinkla, K., Rohde, M., Chhatwal, G.S., Srivasta, M., Cordwell, S.J., Geary, S., Liao, X., Minion, F.C., Walker, M.J., Djordjevic, S.P. (2006) P159 is a proteolytically processed, surface adhesin of Mycoplasma hyopneumoniae: defined domains of P159 bind heparin and promote adherence to eukaryote cells. Molecular Microbiology 60: 669-686.

McArthur, J.D., Walker, M.J. (2006) Domains of group A streptococcal M protein that confer resistance to phagocytosis, opsonisation and protection: implications for vaccine development. Molecular Microbiology 59:1-4.

Current Students

F. Dawes Ph.D. 2003-present, Project title: Molecular analysis of antibiotic resistance genes associated with integrons in Escherichia coli. Currently enrolled at the University of Wollongong. (Co-supervision with Dr. S. Djordjevic).

J. Liu Ph.D. 2004-present, Project title: Molecular analysis of non-integron associated antibiotic resistance genes associated in Salmonella typhimurium. Currently enrolled at the University of Wollongong. (Co-supervision with Dr. S. Djordjevic).

C. Venturini Ph.D. 2004-present, Project title: Molecular analysis of non-integron associated antibiotic resistance genes associated in Escherichia coli. Currently enrolled at the University of Wollongong. (Co-supervision with Dr. S. Djordjevic).

A. Cork Ph.D. 2004-present, Project title: Molecular analysis of group A streptococcal SEN and GAPDH: contribution to virulence. Currently enrolled at the University of Wollongong.

D. Bogema Ph.D. 2005-present, Project title: Molecular and proteomic analysis of Mycoplasma hyopneumonie. Currently enrolled at the University of Wollongong. (Co-supervision with Dr. S. Djordjevic).

A. Bazun Ph.D. 2005-present, Project title: Molecular analysis of a Mycoplasma hyopneumonie heparin binding protein. Currently enrolled at the University of Wollongong. (Co-supervision with Dr. S. Djordjevic).

A. Henningham Ph.D. 2005-present, Project title: Group A streptococcal vaccine development. Currently enrolled at the University of Wollongong.

A. Hollands Ph.D. 2006-present, Project title: Molecular analysis of a Streptococcus pyogenes M1T invasive diseasse. Currently enrolled at the University of Wollongong. (Co-supervision with Prof. V. Nizet).

L. Seymour Ph.D. 2007-present, Project title: Molecular analysis of a Mycoplasma hyopneumonie ECM binding proteins. Currently enrolled at the University of Wollongong. (Co-supervision with Dr. S. Djordjevic and Dr. T. Burnett).

P. Maamary Ph.D. 2008-present, Project title: Invasive disease initiation by non-M1T1 group A streptococci. Currently enrolled at the University of Wollongong.

L. Wooley Ph.D. 2008-present, Project title: Development of intranasal and DNA vaccines against Mycoplasma hyopneumoniae. Currently enrolled at the University of Wollongong. (Co-supervision with Dr. S. Djordjevic).

Suggested Topics for Future Students

1. Molecular analysis of group A streptococcal virulence determinants.
2. Epidemiology of microbial pathogens.
3. Development of recombinant oral and intranasal vaccine delivery systems for the stimulation of immunity against pathogens of veterinary and human health significance.

Abbreviated CV

EDUCATION

Doctoral Degree 1984-1987

Department of Microbiology

University of Queensland

Brisbane, Australia

Dissertation Title: Genetic and Molecular Analysis of a Klebsiella oxytoca Clinical Isolate

Bachelor of Science Honours Degree 1983

First class, Major: Microbiology

Department of Microbiology

University of Queensland

Brisbane, Australia

Research topic: Isolation and Characterisation of bacteriophages infecting Rhodopseudomonas sphaeroides

Bachelor of Science Degree 1980-1982

Major: Microbiology

Department of Microbiology

University of Queensland

Brisbane, Australia

PROFESSIONAL SOCIETIES

1984 to 1988 Student member of the Australian Society for Microbiology

1989 to 1992 Associate member of the Australian Society for Microbiology

1990 to present Member of the American Society for Microbiology

1993 to present Member of the Australian Society for Microbiology

1993 to 2001 Member of the Australian Biotechnology Association

HONORARY APPOINTMENTS AND INVITATIONS

1991 to 1993 Member of the editorial board of the Journal of Bacteriology

1996 to 1997 Australian Genomic Information Centre board member (responsible for ANGIS)

2001 to 2002 NHMRC grant review panel 2b (microbiology) member

2003 to present Asian Institute of Nanobioscience and Technology (Pusan National University, Korea) international advisory committee

2003 to 2004 NHMRC grant review panel 2d (microbiology) deputy chairperson

2004 to 2005 Scientific committee member of the XVI Lancefield International Symposium on Streptococci and Streptococcal Diseases, Cairns, Australia

NHMRC grant review panel 2d (microbiology) member

2007 NHMRC grant review panel 2d (microbiology) deputy chairperson

AWARDS AND SCHOLARSHIPS

1991 Gesellschaft für Biotechnologische Forschung research prize for outstanding scientific contribution (Division Microbiology)

1998 Alexander Von Humboldt fellowship

2000 Australian College of Education (Illawarra/South Coast NSW Chapter) excellence in tertiary teaching award

2003 Vice Chancellor's award for outstanding contribution to teaching and learning in science

2003 Australian Society of Microbiology David White excellence in teaching award

2005 – 2006 Fulbright Senior Scholar fellowship (UCSD and University of Tennessee)

RECENT GRANTS

2006 to 2008 National Health and Medical Research Council research grant for the investigation of the surface of group A streptococci and vaccine development. (Dr. M. Walker, Dr. A. Aquilina, Dr. M. Kotb and Dr. V. Nizet), $495,000

2007 to 2009 National Health and Medical Research Council research grant for development of a unified model for group A streptococcal invasive disease. (M. Walker, V. Nizet, G.S. Chhatwal and M. Kotb), $581,750

2007 to 2009 DEST International Science Linkages grant for defining the mechanism of group A streptococcal flesh-eating invasive disease. (M. Walker, V. Nizet and M. Kotb), $446,250

2007 to 2009 ARC linkage grant for development of an Mycoplasma hyopneumoniae anti-adhesion vaccine. (Dr. S. Djordjevic and Dr. M. Walker), $324,000.

Last reviewed: 21 April, 2008