Dr Stephen Kwong

A12 - Macleay Building
The University of Sydney

Telephone +61 2 9351 5998
Fax +61 2 9351 4771

Website Room 216, A12 Macleay Building

Research interests

Plasmids are extrachromosomal DNA elements that are an important genetic component in many bacteria. Plasmids promote the spread of genes between bacterial cells leading to remarkable diversity and adaptability. In hospital environments, plasmids have played a central role in the evolution of antibiotic resistant ¿superbugs¿ such as multi-drug resistant Staphylococcus aureus.

I am interested in the molecular biology of plasmid replication and maintenance systems. These genetic systems define the ability of plasmids to establish and persist in new bacterial hosts. The multiresistance staphylococcal plasmids pSK41 and pSK1 serve as prototypes in our laboratory for the study of replication. Areas that are actively being studied include:

  • Molecular characterisation of antisense RNA-mediated replication control systems
  • Molecular interactions between replication initiation proteins and origins of replication
  • Identification of host-factors required for efficient plasmid replication
  • Novel strategies for the elimination of plasmids

Selected grants

2015

  • Horizontal and vertical transmission mechanisms of Staphylococcus aureus multiresistance plasmids; Firth N, Schumacher M, Redinbo M, Kwong S, Jensen S; National Health and Medical Research Council (NHMRC)/Project Grants.

2012

  • Mechanisms Of Stable Gene Inheritance In Multiresistant Staphylococcus Aureus; Firth N, Schumacher M, Kwong S, Jensen S; National Health and Medical Research Council (NHMRC)/Project Grants.

2009

  • Identification and analysis of novel replication initiation factors in Staphlylococcus aureus; Firth N, Cordwell S, Kwong S; National Health and Medical Research Council (NHMRC)/Project Grants.

2007

  • Molecular mechanisms of plasmid maintenance in multiply-resistant staphylococci; Firth N, Schumacher M, Kwong S, Jensen S, Skurray R; National Health and Medical Research Council (NHMRC)/Project Grants.

Selected publications

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Journals

  • Schumacher, M., Tonthat, N., Kwong, S., Chinnam, N., Liu, M., Skurray, R., Firth, N. (2014). Mechanism of staphylococcal multiresistance plasmid replication origin assembly by the RepA protein. Proceedings of the National Academy of Sciences (PNAS) of the United States of America, 111(25), 9121-9126. [More Information]
  • Solis, N., Parker, B., Kwong, S., Robinson, G., Firth, N., Cordwell, S. (2014). Staphylococcus aureus Surface Proteins Involved in Adaptation to Oxacillin Identified Using a Novel Cell Shaving Approach. Journal of Proteome Research, 13(6), 2954-2972. [More Information]
  • Liu, M., Kwong, S., Jensen, S., Brzoska, A., Firth, N. (2013). Biology of the staphylococcal conjugative multiresistance plasmid pSK41. Plasmid, 70(1), 42-51. [More Information]
  • Edwards, J., Betts, L., Frazier, M., Pollet, R., Kwong, S., Walton, W., Ballentine, K., Huang, J., Habibi, S., Campo, M., Firth, N., et al (2013). Molecular basis of antibiotic multiresistance transfer in Staphylococcus aureus. Proceedings of the National Academy of Sciences (PNAS) of the United States of America, 110(8), 2804-2809. [More Information]
  • Liu, M., Kwong, S., Pon, C., Skurray, R., Firth, N. (2012). Genetic requirements for replication initiation of the staphylococcal multiresistance plasmid pSK41. Microbiology, 158(6), 1456-1467. [More Information]
  • Jensen, S., Apisiridej, S., Kwong, S., Yang, J., Skurray, R., Firth, N. (2010). Analysis of the prototypical Staphylococcus aureus multiresistance plasmid pSK1. Plasmid, 64(3), 135-142. [More Information]
  • Perez-Roth, E., Kwong, S., Alcoba-Florez, J., Firth, N., Mendez-Alvarez, S. (2010). Complete Nucleotide Sequence and Comparative Analysis of pPR9, a 41.7-Kilobase Conjugative Staphylococcal Multiresistance Plasmid Conferring High-Level Mupirocin Resistance. Antimicrobial Agents and Chemotherapy, 54(5), 2252-2257. [More Information]
  • Kwong, S., Jensen, S., Firth, N. (2010). Prevalence of Fst-like toxin–antitoxin systems. Microbiology, 156(4), 975-977. [More Information]
  • Weaver, K., Kwong, S., Firth, N., Francia, M. (2009). The RepA_N replicons of Gram-positive bacteria: a family of broadly distributed but narrow host range plasmids. Plasmid, 61(2), 94-109.
  • Ni, L., Jensen, S., Tonthat, N., Berg, T., Kwong, S., Guan, F., Brown, M., Skurray, R., Firth, N., Schumacher, M. (2009). The Staphylococcus aureus pSK41 plasmid-encoded ArtA protein is a master regulator of plasmid transmission genes and contains a RHH motif used in alternate DNA-binding modes. Nucleic Acids Research, 37, 6970-6983.
  • Kwong, S., Lim, R., LeBard, R., Skurray, R., Firth, N. (2008). Analysis of the pSK1 replicon, a prototype from the staphylococcal multiresistance plasmid family. Microbiology, 154(10), 3084-3094.
  • Jensen, S., Kwong, S., Lyon, B., Firth, N. (2008). Evolution of multiple drug resistance in staphylococci. Microbiology Australia, 29(3), 120-124.
  • Kwong, S., Skurray, R., Firth, N. (2007). Antisense RNA-mediated replication control of staphylococcal multiresistance plasmid Psk41. Plasmid, 57(2), 189-189.
  • Jensen, S., Guan, T., Kwong, S., Berg, T., Brown, M., Skurray, R., Firth, N. (2007). Global regulation of survival functions in conjugative Staphylococcal multiresistance plasmids. Plasmid, 57(2), 197-198.
  • Kwong, S., Firth, N. (2006). Regulatory RNA molecules. Microbiology Australia, September, 124-127.
  • Kwong, S., Skurray, R., Firth, N. (2006). Replication control of staphylococcal multiresistance plasmid pSK41: an antisense RNA mediates dual-level regulation of Rep expression. Journal of Bacteriology, 188(12), 4404-4412.
  • Kwong, S., Skurray, R., Firth, N. (2004). Staphylococcus Aureus Multiresistance Plasmid pSK41: Analysis Of The Replication Region, Initiator Protein Binding And Antisense RNA Regulation. Molecular Microbiology, 51(2), 497-509.
  • Kwong, S., Yeo, C., Poh, C. (2001). Molecular analysis of the pRA2 partitioning region: ParB autoregulates parAB transcription and forms a nucleoprotein complex with the plasmid partition site, parS. Molecular Microbiology, 40(3), 621-633.

2014

  • Schumacher, M., Tonthat, N., Kwong, S., Chinnam, N., Liu, M., Skurray, R., Firth, N. (2014). Mechanism of staphylococcal multiresistance plasmid replication origin assembly by the RepA protein. Proceedings of the National Academy of Sciences (PNAS) of the United States of America, 111(25), 9121-9126. [More Information]
  • Solis, N., Parker, B., Kwong, S., Robinson, G., Firth, N., Cordwell, S. (2014). Staphylococcus aureus Surface Proteins Involved in Adaptation to Oxacillin Identified Using a Novel Cell Shaving Approach. Journal of Proteome Research, 13(6), 2954-2972. [More Information]

2013

  • Liu, M., Kwong, S., Jensen, S., Brzoska, A., Firth, N. (2013). Biology of the staphylococcal conjugative multiresistance plasmid pSK41. Plasmid, 70(1), 42-51. [More Information]
  • Edwards, J., Betts, L., Frazier, M., Pollet, R., Kwong, S., Walton, W., Ballentine, K., Huang, J., Habibi, S., Campo, M., Firth, N., et al (2013). Molecular basis of antibiotic multiresistance transfer in Staphylococcus aureus. Proceedings of the National Academy of Sciences (PNAS) of the United States of America, 110(8), 2804-2809. [More Information]

2012

  • Liu, M., Kwong, S., Pon, C., Skurray, R., Firth, N. (2012). Genetic requirements for replication initiation of the staphylococcal multiresistance plasmid pSK41. Microbiology, 158(6), 1456-1467. [More Information]

2010

  • Jensen, S., Apisiridej, S., Kwong, S., Yang, J., Skurray, R., Firth, N. (2010). Analysis of the prototypical Staphylococcus aureus multiresistance plasmid pSK1. Plasmid, 64(3), 135-142. [More Information]
  • Perez-Roth, E., Kwong, S., Alcoba-Florez, J., Firth, N., Mendez-Alvarez, S. (2010). Complete Nucleotide Sequence and Comparative Analysis of pPR9, a 41.7-Kilobase Conjugative Staphylococcal Multiresistance Plasmid Conferring High-Level Mupirocin Resistance. Antimicrobial Agents and Chemotherapy, 54(5), 2252-2257. [More Information]
  • Kwong, S., Jensen, S., Firth, N. (2010). Prevalence of Fst-like toxin–antitoxin systems. Microbiology, 156(4), 975-977. [More Information]

2009

  • Weaver, K., Kwong, S., Firth, N., Francia, M. (2009). The RepA_N replicons of Gram-positive bacteria: a family of broadly distributed but narrow host range plasmids. Plasmid, 61(2), 94-109.
  • Ni, L., Jensen, S., Tonthat, N., Berg, T., Kwong, S., Guan, F., Brown, M., Skurray, R., Firth, N., Schumacher, M. (2009). The Staphylococcus aureus pSK41 plasmid-encoded ArtA protein is a master regulator of plasmid transmission genes and contains a RHH motif used in alternate DNA-binding modes. Nucleic Acids Research, 37, 6970-6983.

2008

  • Kwong, S., Lim, R., LeBard, R., Skurray, R., Firth, N. (2008). Analysis of the pSK1 replicon, a prototype from the staphylococcal multiresistance plasmid family. Microbiology, 154(10), 3084-3094.
  • Jensen, S., Kwong, S., Lyon, B., Firth, N. (2008). Evolution of multiple drug resistance in staphylococci. Microbiology Australia, 29(3), 120-124.

2007

  • Kwong, S., Skurray, R., Firth, N. (2007). Antisense RNA-mediated replication control of staphylococcal multiresistance plasmid Psk41. Plasmid, 57(2), 189-189.
  • Jensen, S., Guan, T., Kwong, S., Berg, T., Brown, M., Skurray, R., Firth, N. (2007). Global regulation of survival functions in conjugative Staphylococcal multiresistance plasmids. Plasmid, 57(2), 197-198.

2006

  • Kwong, S., Firth, N. (2006). Regulatory RNA molecules. Microbiology Australia, September, 124-127.
  • Kwong, S., Skurray, R., Firth, N. (2006). Replication control of staphylococcal multiresistance plasmid pSK41: an antisense RNA mediates dual-level regulation of Rep expression. Journal of Bacteriology, 188(12), 4404-4412.

2004

  • Kwong, S., Skurray, R., Firth, N. (2004). Staphylococcus Aureus Multiresistance Plasmid pSK41: Analysis Of The Replication Region, Initiator Protein Binding And Antisense RNA Regulation. Molecular Microbiology, 51(2), 497-509.

2001

  • Kwong, S., Yeo, C., Poh, C. (2001). Molecular analysis of the pRA2 partitioning region: ParB autoregulates parAB transcription and forms a nucleoprotein complex with the plasmid partition site, parS. Molecular Microbiology, 40(3), 621-633.

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