Queen’s University ‘cold’ plasma jet kills superbugs

Published: 5-Oct-2012

Has the ability to decontaminate surfaces rapidly and curb the spread of these bacteria


Scientists at Queen’s University Belfast have developed a new technique with the potential to kill hospital superbugs such as Pseudomonas aeruginosa, C. difficile and MRSA.

As outlined in the journal, PloS One, the method uses a cold plasma jet to penetrate the dense bacterial structures known as biofilms that bind bacteria together and make them resistant to conventional chemical cleaning.

Scientists in the School of Mathematics and Physics and the School of Pharmacy at Queen’s passed electrical currents through flowing gas mixtures to create a wide variety of reactive species. These then effectively penetrated biofilms of Pseudomonas aeruginosa and MRSA and rapidly killed the bacteria within.

Antibiotics and disinfectants are currently used to kill hospital bugs and while they are effective at killing individual bacteria, they are often ineffective against complex organised communities of bacteria.

Professor Bill Graham, from the Centre for Plasma Physics at Queen’s, said: “When bacteria congregate on surfaces they produce a kind of glue which joins them together in complex communities, known as biofilms. Instead of individual bacteria, they form a resistant film or layer and bind themselves together. This often makes it impossible for antibiotics to penetrate through and kill the bacteria deep within this protective layer. Bacteria growing like this, as is often seen with superbugs in hospitals, are often more than 1000 times more tolerant to antimicrobial agents such as antibiotics and disinfectants compared with free-floating bacteria.

“The technique we’ve used, known as a cold plasma jet, creates a number of agents that rapidly kill bacteria, even within mature biofilms. Not only does it attack the bacteria but this synergistic approach also attacks the biofilm structure killing the bacteria deep within.”

Dr Brendan Gilmore, from the School of Pharmacy, added: “In the present study we have looked at Pseudomonas aeruginosa. Other applications could include MRSA and other drug resistant superbugs such as C. difficile and its spores. We are currently investigating these and some types of viruses.”

These ‘cold’ plasmas could be used widely in hospitals, surgeries and in the community as hand held devices for rapid decontamination of surfaces, including the skin, or be incorporated into bigger devices for decontamination of larger areas. Their ability to rapidly decontaminate surfaces has the potential to curb the spread of harmful bacteria, including multidrug resistant bacteria such as MRSA.

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