New resistant genes found in hospital superbugs

02 December, 2013

In cutting-edge genomics research conducted at Macquarie University, researchers have identified a new family of resistance genes that allow bacteria to survive chlorhexidine, a disinfectant commonly used in hospitals.

Drug resistant "superbugs", such as Acinetobacter baumannii, have become a consistent problem in Australian hospitals and health-care facilities, explained Prof Ian Paulsen, lead researcher.

"Antiseptics and disinfectants are a key defence used to control the spread of these bacteria in hospitals particularly.

"Chlorhexidine is an important antiseptic and disinfectant used in many soaps, hand washes, and mouthwashes. As these superbugs build up a resistance to it, the risk of patient infection and illness increases."

The prototype gene from Acinetobacter baumannii, which the researchers have called aceI, produces a protein that acts as a pump capable of removing the disinfectant from the cell, characterised in a collaboration with researchers from the University of Leeds in the UK. Genes similar to aceI that also provide resistance to the disinfectant are found in a range of other bacteria including several other superbugs.

"Following this discovery we plan to investigate ways to block this pump. Such work is important in ensuring that we can continue to use successfully this disinfectant to reduce rates of infection in hospitals."

The research was recently published in the journal Proceedings of the National Academy of Sciences of the USA this week.