Objectives. Antimicrobial activities of non-thermal atmospheric
plasma-treated liquids on various bacterial and fungal strains in their
planktonic and biofilm forms have been widely reported. Since most of the
plasma-treated liquids are water based, they might be washed off certain
surfaces and they cannot be applied for the infections of respiratory tract. In
the present study we have tested antimicrobial activities of plasma-treated
N-acetyl cysteine solution (NAC), phosphate buffered saline (PBS) solution and
deionized water when nebulized over planktonic forms of E. coli and S. aureus. Methods. Antimicrobial activities of
nebulized plasma-treated liquids were evaluated with zone of inhibition test
and colony counting assay. Moreover pH of NAC, PBS solution and deionized water
were measured before, after plasma treatment and during nebulization since low
pH is well known consequence observed in plasma-treated liquids. Results.
Our results have revealed that pH of plasma-treated NAC, PBS solution and DIW
decreases after plasma treatment consistent with previous reports and does not
change during nebulization. Moreover, antimicrobial activity assessment
indicates that nebulized plasma-treated NAC shows the strongest antimicrobial
activity, which leads complete inactivation of bacteria for 103 to
106 CFU/ml initial bacterial load and 5-log reduction for 107
CFU/ml initial bacterial load on both E.
coli and S. aureus. Conclusions. Plasma-treated liquids
could retain their antimicrobial activity during nebulization and nebulization
could be considered as a future alternative method for delivery of
plasma-treated liquids for respiratory tract infections.
Non-thermal plasma, plasma medicine, nebulization, antimicrobial, biomedical engineering