Evolutionary clade affects resistance of Clostridium difficile spores to Cold Atmospheric Plasma.
Clostridium difficile is a spore forming bacterium and the leading cause of colitis and antibiotic associated diarrhoea in the developed world. Spores produced by C. difficile are robust and can remain viable for months, leading to prolonged healthcare-associated outbreaks with high mortality. Exposure of C. difficile spores to a novel, non-thermal atmospheric pressure gas plasma was assessed. Factors affecting sporicidal efficacy, including percentage of oxygen in the helium carrier gas admixture, and the effect on spores from different strains representing the five evolutionary C. difficile clades was investigated. Strains from different clades displayed varying resistance to cold plasma. Strain R20291, representing the globally epidemic ribotype 027 type, was the most resistant. However all tested strains displayed a ~3 log reduction in viable spore counts after plasma treatment for 5 minutes. Inactivation of a ribotype 078 strain, the most prevalent clinical type seen in Northern Ireland, was further assessed with respect to surface decontamination, pH, and hydrogen peroxide concentration. Environmental factors affected plasma activity, with dry spores without the presence of organic matter being most susceptible. This study demonstrates that cold atmospheric plasma can effectively inactivate C. difficile spores, and highlights factors that can affect sporicidal activity.
School of Biological Sciences and the Institute for Global Food Security, Medical Biology Centre, Queens University Belfast, Northern Ireland.
Mairéad
M
Connor
School of Pharmacy, Medical Biology Centre, Queens University Belfast, Northern Ireland.|School of Mathematics and Physics, Queens University Belfast, Northern Ireland.
Padrig B
PB
Flynn
Department of Microbiology, Belfast Health &Social Care Trust, Belfast, Northern Ireland.
Derek J
DJ
Fairley
School of Biological Sciences and the Institute for Global Food Security, Medical Biology Centre, Queens University Belfast, Northern Ireland.
Nikki
N
Marks
School of Chemistry and Chemical Engineering, Queens University Belfast, Northern Ireland.
Panagiotis
P
Manesiotis
School of Mathematics and Physics, Queens University Belfast, Northern Ireland.
William G
WG
Graham
School of Pharmacy, Medical Biology Centre, Queens University Belfast, Northern Ireland.
Brendan F
BF
Gilmore
School of Biological Sciences and the Institute for Global Food Security, Medical Biology Centre, Queens University Belfast, Northern Ireland.
John W
JW
McGrath
D016360:Clostridioides difficile / Q000187:drug effects* / Q000502:physiology*; D003666:Decontamination / Q000379:methods; D004202:Disinfectants / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D004777:Environment; D019143:Evolution, Molecular; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D050296:Microbial Viability; D010100:Oxygen / Q000378:metabolism; D058626:Plasma Gases / Q000494:pharmacology*; D013171:Spores, Bacterial / Q000187:drug effects* / Q000235:genetics*; D013997:Time Factors
D004202:Disinfectants; D058626:Plasma Gases; D006861:Hydrogen Peroxide; D010100:Oxygen