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

1992 …2020

Research output per year

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Personal profile


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


Research area keywords

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

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Research Output

A mouse model of Staphylococcus aureus small intestinal infection

Larcombe, S., Jiang, J-H., Hutton, M. L., Abud, H. E., Peleg, A. Y. & Lyras, D., 31 Jan 2020, In : Journal of Medical Microbiology. 69, 2, p. 290-297 8 p.

Research output: Contribution to journalArticleResearchpeer-review

Open Access

Clostridioides difficile infection damages colonic stem cells via TcdB, impairing epithelial repair and recovery from disease

Mileto, S. J., Jardé, T., Childress, K. O., Jensen, J. L., Rogers, A. P., Kerr, G., Hutton, M. L., Sheedlo, M. J., Bloch, S. C., Shupe, J. A., Horvay, K., Flores, T., Engel, R., Wilkins, S., McMurrick, P. J., Lacy, D. B., Abud, H. E. & Lyras, D., 7 Apr 2020, In : Proceedings of the National Academy of Sciences of the United States of America. 117, 14, p. 8064-8073 10 p.

Research output: Contribution to journalArticleResearchpeer-review

Paeniclostridium (Clostridium) sordellii-associated enterocolitis in 7 horses

Nyaoke, A. C., Navarro, M. A., Fresneda, K., Diab, S. S., Moore, J., Lyras, D., Awad, M. & Uzal, F. A., 1 Mar 2020, In : Journal of Veterinary Diagnostic Investigation. 32, 2, p. 239-245 7 p.

Research output: Contribution to journalArticleResearchpeer-review

Reply to: Caution is warranted in using cephamycin antibiotics against recurrent Clostridioides difficile infection

Lyras, D., Srikhanta, Y. & McGowan, S., Feb 2020, In : Nature Microbiology. 5, 2, p. 237-238 2 p.

Research output: Contribution to journalLetterOtherpeer-review

Repurposing auranofin as a Clostridioides difficile therapeutic

Hutton, M. L., Pehlivanoglu, H., Vidor, C. J., James, M. L., Thomson, M. J. & Lyras, D., Feb 2020, In : Journal of Antimicrobial Chemotherapy. 75, 2, p. 409-417 9 p.

Research output: Contribution to journalArticleResearchpeer-review

2 Citations (Scopus)


  • 1 Membership of industry collaboration/ network

Monash Antimicrobial Resistance Group (Event)

Trevor Lithgow (Chair/Co-Chair), , Max Cryle (Member), , Kellie Tuck (Member), , Ana Traven (Member), , Thomas Naderer (Member), , Julian Rood (Member), , Dena Lyras (Member), , Anton Peleg (Member), , Mibel Aguilar (Member), , Fasseli Coulibaly (Member), , Sheena McGowan (Member), , Meredith Anne Okeeffe (Member), , Matthew Belousoff (Member), & Philip Heraud (Member)

1 Mar 20171 Jan 2019

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