• Monash Biomedicine Discovery institute Department of Microbiology Office 152, 19 Innovation Walk, Monash University Victoria 3800 Australia Web monash.edu/discovery-institute

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1992 …2021
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Biography


A superbug of our own creation

The rapid evolution of bacteria and the excessive use of antibiotics have turned our hospitals from institutions of healing to incubators of new breeds of superbugs. The challenge for researchers such as Dr Dena Lyras is to uncover the secrets and weaknesses of bacteria that are changing before their eyes.




Dena has spent her research career developing world-leading knowledge of the bacterium Clostridium difficile, a gut bacterium that causes disease in the intestines. The bacterium usually attacks hospital patients that are being treated with antibiotics for other, unrelated, infections.

Over the past decade the bug has undergone a radical evolution that has allowed it to thrive in hospital environments and develop into the leading cause of death from hospital-acquired antibiotic associated intestinal infection.

Clostridium difficile has become so successful at exploiting our modern hospital practices that it is now found in every hospital in the world that uses antibiotics. And not only is the bactrium surviving medical science's best attempts to kill it, it is actually becoming more deadly.

"I'm interested in this bacterium because it has adapted so well to our modern hospital environments. It is really a product of our times," Dena says.

"It was not known to cause problems before antibiotics, but the introduction of antibiotics changed things and it found a new niche to occupy. As a consequence it has become a significant problem in hospitals worldwide.

"It has also changed genetically and now causes more severe disease. Where people would normally be treated and recover, now we have people who are far sicker, and more people are dying because they cannot recover from these infections.

"The reason for this is that the bacteria quickly adapt to the environment they are in - in this case hospitals - resulting in newer versions of the bacteria that are far better at causing disease. In other words, superbugs. I am interested in how that process happens."

Researchers in Dena's lab, the Clostridial Genetics Laboratory, are trying to understand how Clostridium difficile causes disease, and in particular why these new versions of the bacterium have become more potent.

Part of the bug's success lies in the use of antibiotics in hospitals. Not only have the bacteria developed increasing resistance to antibiotic treatments, but the devastating effect some drugs have on the good bacteria that protect our bodies is creating a space that harmful bacteria can exploit.

Dena's team have enjoyed some success in better understanding the bug through genetic manipulation. She was the lead author of a study published in the prestigious journal Nature, which shed new light on the essential role specific toxins play in causing disease, a discovery that disproved prevailing opinion.

More recently, Dena's team have discovered new genetic factors responsible for creating the increased virulence of the bacteria in research that has recently been accepted for publication in another prestigious journal.

Dena is now using this knowledge to develop new therapeutic strategies capable of tackling the ever-changing super bug. She heads an ARC Linkage project in collaboration with industry partners who are developing strategies for handling these infections.

But there are no promises of an easy fix.

"We think of these bacteria as lacking complexity, but when we see what they can do we see that they are incredibly complex and can change at a frighteningly fast rate," Dena says.

External positions

President, The Australian Society for Microbiology

20182020

Keywords

  • Gastrointestinal infections
  • Host-pathogen interactions
  • Antibiotic resistance in bacteria
  • Mobile DNA and lateral gene transfer
  • Therapeutics for gut infections

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Projects 2001 2021

Research Output 1992 2019

Clostridium difficile toxins induce VEGF-A and vascular permeability to promote disease pathogenesis

Huang, J., Kelly, C. P., Bakirtzi, K., Villafuerte Gálvez, J. A., Lyras, D., Mileto, S. J., Larcombe, S., Xu, H., Yang, X., Shields, K. S., Zhu, W., Zhang, Y., Goldsmith, J. D., Patel, I. J., Hansen, J., Huang, M., Ylä-Herttuala, S., Moss, A. C., Paredes-Sabja, D., Pothoulakis, C. & 3 othersShah, Y. M., Wang, J. & Cheng, X., Feb 2019, In : Nature Microbiology. 4, 11 p.

Research output: Contribution to journalArticleResearchpeer-review

Lectin activity of the TcdA and TcdB toxins of Clostridium difficile

Hartley-Tassell, L. E., Awad, M. M., Seib, K. L., Scarselli, M., Savino, S., Tiralongo, J., Lyras, D., Day, C. J. & Jennings, M. P., 1 Mar 2019, In : Infection and Immunity. 87, 3, 9 p., e00676-18.

Research output: Contribution to journalArticleResearchpeer-review

Open Access
File
Open Access
File

pCP13, a representative of a new family of conjugative toxin plasmids in Clostridium perfringens

Watts, T. D., Vidor, C. J., Awad, M. M., Lyras, D., Rood, J. I. & Adams, V., 1 Mar 2019, In : Plasmid. 102, p. 37-45 9 p.

Research output: Contribution to journalArticleResearchpeer-review

Antibacterial activity of rhodomyrtone on Clostridium difficile vegetative cells and spores in vitro

Srisuwan, S., Mackin, K. E., Hocking, D. M., Lyras, D., Bennett-Wood, V. R., Voravuthikunchai, S. P. & Robins-Browne, R. M., 1 Nov 2018, In : International Journal of Antimicrobial Agents. 52, 5, p. 724-729 6 p.

Research output: Contribution to journalArticleResearchpeer-review

Activities 2017 2017

  • 1 Membership of industry collaboration/ network

Monash Biomedicine Discovery Institute (Organisational unit)

Trevor Lithgow (Inventor), Matthew James Belousoff (Member), Meredith Anne O'Keeffe (Member), Max Cryle (Member), Ana Traven (Member), John Dallas Boyce (Member), Julian Ian Rood (Member), Fasseli Joseph Coulibaly (Member), Anton Yariv Peleg (Member), Sheena McGowan (Member), Dena Lyras (Member), Philip Robert Heraud (Member)
20172018

Activity: Industry, Government and Philanthropy Engagement and PartnershipsMembership of industry collaboration/ network