- LFS262 Medical Microbiology
- MBT352 Molecular Biotechnology
- MBT353 Microbial Pathogenesis
- pathogenesis of beta-hemolytic streptococci
- genetic and genomics of streptococci
- infections of medical devices
- development of novel vaccines for prevention of streptococcal infection
- evolution of antiseptic resistance in hospital pathogens
Dr David McMillan is a molecular microbiologist in the School of Health and Sports Sciences at the University of the Sunshine Coast. His major research interests are in the areas of pathogenesis and prevention of beta-hemolytic streptococcal infections, and prevention of Medical Device Infections.
Streptococcus pyogenes is a leading cause of bacterial derived mortality and morbidity. The bacterium is estimated to cause half a million deaths each year. Our research in this area is focused on
- understanding how streptococci evade innate immune responses
- developing and evaluating novel streptococcal vaccines
- characterising streptococcal populations at the genetic level
The colonisation of medical devices is a leading cause of hospital acquired infections. As the major species bacteria associated with these infections continue to increase in antibiotic resistance, the threat to health that medical device infections pose continues to increase. Our research in this area focuses on
- characterisation of bacterial communities present on medical devices
- the emergence of antiseptic resistant bacteria in hospital settings
Further details of postgraduate and undergraduate research projects in these areas can be found below.
Choudhury MA, March N, Banu S, Paterson D, Rickard CM, McMillan DJ. 2016. Molecular Comparison of Bacterial Communities on Peripheral Intravenous Catheters and Matched Skin Swabs.PLOS One11:e0146354
Smyth DJ, Cameron A, Davies MR, McNeilly C, Hafner L, Sriprakash S and McMillan DJ. 2014 DrsG from Streptococcus dysgalactiae subsp equisimilis inhibits the antimicrobial peptide LL-37. Infect Immun 82:2337-2344
Da Cunha V, Davies MR, Douarre PE, Rosinski-Chupin I, Margarit I, Spinali S, Perkins T, Lechat P, Dmytruk N, Sauvage E, Ma L, Romi B, Tichit M, Lopez-Sanchez MJ, Descorps-Declere S, Souche E, Buchrieser C, Trieu-Cuot P, Moszer I, Clermont D, Maione D, Bouchier C, McMillan DJ, Parkhill J, Telford JL, Dougan G, Walker MJ, Consortium D, Holden MT, Poyart C, Glaser P, Consortium D. 2014. Streptococcus agalactiae clones infecting humans were selected and fixed through the extensive use of tetracycline. Nat Commun 5:4544
Bauer MJ, Georgousakis MM, Vu T, Henningham A, Hofmann A, Rettel M, Hafner LM, Sriprakash KS, McMillan DJ. 2012. Evaluation of novel Streptococcus pyogenes vaccine candidates incorporating multiple conserved sequences from the C-repeat region of the M-protein. Vaccine 30:2197-2205.
McMillan DJ, Dreze P, Vu T, Bessen D, Gugliemini J, Steer A, Carapetis J, Van Melderen L, Sriprakash KS, Smeesters P and the M-protein study group. 2013. Updated model of group A Streptococcus M proteins based on a comprehensive worldwide study. Clinical Vaccines and Immunology 19(5):E222-9.
Evaluation of a vaccine to combat common streptococcal diseases. McMillan, D.J., N. Ketheesan, L. Hafner, M. Sanderson-Smith and K. Sriprakash. NHMRC Project grant 2012-2014
The SAVE Trial: Securing All intraVenous devices Effectively in hospitals. A randomised controlled trial. Rickard, C., J. Fraser, J. Webster, A. Marshall, J. Young, G. Playford., D.J. McMillan, M. McGrail, J. Gowardman, O. Thom, H. Reynolds, J. Whitty, J. Crilly, K. Dunster, N. Marsh, N, S. Keogh, L. Zhang. NHMRC Project Grant. 2013-2016
Intravascular device administration sets: Replacement after Standard Versus Prolonged use (The RSVP Trial). Rickard C., M. Wallis, J. Young, J. Gowardman, M. Whitby, D.J. McMillan, J. Fraser, and L. Zhang. NHMRC Project grant (APP1008428). 2011-2014
Potential research projects for HDR and Honours students
Development of polyvalent vaccines for prevention of infection with group A streptococcus
Infection with group A streptococcus (GAS) is estimated to kill half a million people each year. The prevalence of these diseases is particularly high in Australia’s Indigenous population. This project will use a combination of molecular epidemiology, immunology and bioinformatics to design and produce novel group A streptococcal vaccine candidates. The effectiveness of these candidates to induce immune responses that kill GAS will then be investigated.
Functional characterisation of SIC, a streptococcal protein that inhibit the host innate immune system
Antimicrobial peptides (AMPs) are small molecules produced by immune system that act as front-line defenders against bacterial infection. GAS produces a protein (SIC) that inhibit the anti-bacterial activity of this AMPs. We have recently shown SIC to possess amino acid motif that is associated with protein-protein interactions. The aim of this project is to determine whether this motif is responsible for the AMP inhibitory properties of SIC.
Characterisation of the function of the M-protein in SDSE
The M-protein is the major virulence factor of GAS, and also present, in the related Streptococcus dysgalactiae subsp equisimilis (SDSE). However the role this protein plays in the virulence of SDSE has not been characterised. The aim of this project is to (i) demonstrate the M-protein is expressed on the surface of SDSE, (ii) identify host ligands of the protein and (iii) characterise the role to the SDSE M-protein in the persistence of SDSE.
Molecular Characterisation of antiseptic resistance in Staphylococcus
Resistance to antiseptics such as chlorhexidine is associated with the presence of qac genes. These genes are often found on mobile genetic elements enabling them to be transferred between different staphylococcal strains. The mobile genetic elements may also contain antibiotic resistance determinants. The aim of this project is to characterise associations between qac genes and antibiotic resistance determinants in staphylococci.