Augmented survival of Neisseria gonorrhoeae within biofilms: exposure to atmospheric pressure non-thermal plasmas.
Bacteria embedded within biofilms present a challenge to surface decontamination by conventional means. Atmospheric pressure non-thermal plasma processes have emerged as a promising approach to overcoming this problem. We used atmospheric pressure non-equilibrium plasmas (APNPs) to assess planktonic versus biofilm-resident bacterial (Neisseria gonorrhoeae) susceptibility to treatment. The decontamination efficiency of the process was evaluated against bacteria embedded within a biofilm, as well as planktonic cells placed on a glass surface. Bacterial survival was assessed using a combination of colony forming unit (CFU) ability and vital staining with a combination of SYTO9 plus propidium iodide. Both methods revealed an increased resistance of biofilm-resident bacteria compared with planktonic cells, after a 20-min exposure to the APNPs. Transmission electron microscopy revealed disruption and damage to the cell wall, resulting in the release of cytoplasmic compounds, alterations in morphology, and a decrease in cell volume, indicating that APNPs may affect the cell wall. Present results show that biofilm-resident bacteria demonstrate augmented survival when exposed to APNP treatment and therefore that decontamination procedures should take into account this survival when evaluating surface decontamination measures.
Xu
L
L
Department of Dermatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Tu
Y
Y
Yu
Y
Y
Tan
M
M
Li
J
J
Chen
H
H
D001274:Atmospheric Pressure; D018441:Biofilms; D002473:Cell Wall / Q000648:ultrastructure; D015169:Colony Count, Microbial; D004202:Disinfectants / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D006801:Humans; D050296:Microbial Viability; D046529:Microscopy, Electron, Transmission; D009344:Neisseria gonorrhoeae / Q000254:growth & development / Q000302:isolation & purification / Q000502:physiology* / Q000648:ultrastructure; D058626:Plasma Gases / Q000494:pharmacology*; D013194:Staining and Labeling / Q000379:methods
D004202:Disinfectants; D058626:Plasma Gases