A study led jointly by the University of Leeds and Macquarie University in Australia showed how the superbug Acinetobacter baumannii-prevalent among soldiers treated in medical facilities in Iraq and Afghanistan-can pump the disinfectant out of its system.
The findings are critical for the design of new chemicals to combat the germ.
Professor Peter Henderson of the University of Leeds' School of Biomedical Sciences said: "The Australians saw that, in response to chlorhexidine, a gene becomes active and produces a protein they called Acinetobacter Chlorhexidine Efflux, or 'Ace' for short. Working together, we demonstrated that Ace binds to the disinfectant and effectively pumps the chlorhexidine that has leaked through the cell wall out again."
Acinetobacter baumannii was once treatable with normal antibiotics but is now one of the most worrying superbugs threatening the medical system. It has been particularly associated with infections of military personnel injured in Iraq and Afghanistan. Its ability to survive on disinfected artificial surfaces for long periods has allowed it to thrive and spread through the military and into the civilian medical system.
Sally Davies, the Chief Medical Officer for England, said in March that antibiotic resistance posed a "catastrophic threat" that could mean that even minor surgeries might carry deadly risks by the 2030s.
Professor Henderson said: "Identifying the resistance protein now allows us to look for a compound that will inhibit the protein's activity and form the basis of a new treatment against infection."
The early indications are that the protein specifically binds with chlorhexidine rather than other antibiotic molecules. Although some multi-drug resistant proteins have been found, the fight against superbugs has generally been characterised by a painstaking search for several proteins associated with resistance to particular drugs and chemicals.
Members of the University of Leeds' Astbury Centre for Structural Molecular Biology are at the forefront of work on "pump" proteins.
Professor Henderson said: "There are very similar genes in other pathogenic organisms. Our next step will be to explore what these proteins do in those other organisms. In some cases, it is strongly suggested that they make the germ resistant to chlorhexidine, but in others it appears to be something else. We need to find out what that is."
He added: "The bad news is that the bugs are winning. We can't devise new antibiotics nearly fast enough to find a new way of dealing with them and there is not enough funding to pursue the research. This project is typical of the sort of work that we have to do to win the fight against superbugs."
Professor Ian Paulsen at Macquarie University said: "Antiseptics and disinfectants are a key defence used to control the spread of these bacteria in hospitals particularly. 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 is published in the journal Proceedings of the National Academy of Sciences. The work was funded under a European International Research Staff Exchange Scheme (IRSES) project involving the University of Oslo, University of Leeds and Macquarie University. Researchers from Flinders University, Australia also contributed to the research.
Ralf Richter, David Brockwell, Eric Hewitt, Jessica Kwok, Emanuele Paci and MAPS/FMH, BBSRC (Jun 2017), £600,000
Eric Blair, Adrian Whitehouse, Nicola Stonehouse, Alison Baker, Richard Bayliss, Joan Boyes, Ryan Seipke, Sally Boxall and MAPS/FMH, BBSRC (Jun 2017), £376,000
Stefan Kepinski, Yoselin Benitez-Alfonso, Tom Bennett, Michelle Peckham, BBSRC (Jun 2017), £331,000
Roman Tuma, Lars Jeuken, Paul Millner, Sheena Radford, Peter Stockley and MAPS/FMH, BBSRC (Jun 2017), £222,000
Vas Ponnambalam, Darren Tomlinson, Stephen Wheatcroft, BHF (May 2017), £107,878
Graham Askew in collaboration with Bangor University, BBSRC (Mar 2017), £477,383
Stephen Muench, BBSRC (Mar 2017), £132,945
Nic Stonehouse, MRC (Mar 2017), £906,341
Bill Kunin, Steve Sait, BBSRC (Mar 2017), £602,831
Adrian Goldman, EU (Mar 2017), £546,576
Sheena Radford, Wellcome Trust (Mar 2017), £1,836,482
Tom Bennett, Royal Society (Mar 2017), £15,000
Jamie Johnston, Royal Society (Mar 2017), £15,000
Beatrice Filippi, Royal Society (Mar 2017), £15,000
Ryan Seipke, BBSRC (Feb 2017), £52,116
Mary O'Connell, BBSRC (Feb 2017), £46,986
Hannah Dugdale, NERC (Feb 2017), £504,138
Anastasia Zhuravleva, EPSRC (Jan 2017), £100,792
Richard Bayliss, Cancer Research UK (Jan 2017), £1,600,000
John Barr, EU (Jan 2017), £339,000
Mark Harris, Royal Society (Jan 2017), £250,000
Alison Dunn, NERC (Jan 2017), £105,000
Alex Breeze, Pancreatic Cancer Research Fund (Jan 2017), £180,000
Alison Dunn, NERC (Dec 2016), £18,000
Lisa Collins, BBSRC (Dec 2016), £1,681,835
Brendan Davies, Leverhulme Trust (Dec 2016), £247,555
Alan Benson, Mark Drinkhill, Ed White, British Heart Foundaion (Dec 2016), £217,223
Adrian Goldman, Royal Society (Dec 2016), £82,999
Lisa Roberts, Alex Breeze, Brendan Davies, Timothy Devinney, Oliver Harlen, Joseph Holden, Anthea Hucklesby, Pamela Jones, Philip Mellor, RCUK (Nov 2016), £484,172
Lisa Roberts, Alex Breeze, Brendan Davies, Timothy Devinney, Oliver Harlen, Joseph Holden, Anthea Hucklesby, Pamela Jones, Philip Mellor, Wellcome Trust (Nov 2016), £119,343
Katie Field, Rank Prize Funds (Nov 2016), £20,000
Jessica Kwok, Royal Society (Nov 2016), £14,948
John Ladbury, Cancer Research UK (Oct 2016), £4,250
Miriam Wittmann, Martin Stacey, Edward Vital, Lupus UK
(Oct 2016), £34,010
Valerie Speirs, NC3Rs
(Oct 2016), £90,000
Nicola Stonehouse, Morgan Herod, David Rowlands, BBSRC
(Sep 2016), £436,424
Joseph Cockburn, Wellcome Trust
(Sep 2016), £100,000
John Barr, Public Health England
(Sep 2016), £94,471
Helen Miller, DSM Nutritional Products A/S
(Sep 2016), £54,680
Steven Clapcote, Vitaflo International Ltd
(Sep 2016), £39,285
Juan Fontana Jordan De Urries
, Royal Society
(Sep 2016), £21,793
Jing Li, Sarah Calaghan, Mark Drinkhill, British Heart Foundation
(Sep 2016), £117,585
Sheena Radford, Alison Ashcroft, BBSRC (Sep 2016), £457,216
Patricija Van Oosten-Hawle, An-Jung Chen, David Westhead, NC3Rs
(Sep 2016), £354,456
Glyn Hemsworth, BBSRC (Sep 2016), £1,024,034
David Jayne, Paul Millner, MRC (Aug 2016), £207,860
Sheena Radford, Alison Ashcroft, BBSRC (Aug 2016), £457,215
Patricija Van Oosten-Hawle, Dave Westhead, An-Jung Chen, NC3Rs (Aug 2016), £354,456
Peter Henderson, EU - European Union
EU - European Union
(Jul 2016), £123,897
Adrian Goldman, EU - European Union
(Jul 2016), £116,290
Urwin, Howard Atkinson, NERC
(Jul 2016), £105,053
Eileen Ingham and colleagues in Engineering and M&H, EPSRC (Jul 2016), £3,867,449
Michael Colman, MRC (Jul 2016), £200,956
Tim Benton, Fresca Group Ltd
(Jul 2016), £52,082