Comparative evaluation of the antimicrobial effect of electric plasma in textile between a standard strain of Klebsiella pneumoniae and a resistant clinical strain (KPC)

To evaluate the antimicrobial effect of high-frequency electric plasma on a cotton textile article containing planktonic cells and biofilm formation of a standard strain and a multi-resistant clinical strain of Klebsiella pneumoniae carbapenemase (KPC), and to evaluate the integrity of the post textile fiber treatment, suggesting an alternative method to control this bacterium in hospital fabrics. Based on the American Association of Textile Chemists and Colorists – 100 methodology, inoculants of the standard strain of K. pneumoniae ATCC 4352 and a clinical strain of KPC isolated from hospital infection were prepared. These were used to contaminate 100% cotton fabric samples, and the antibacterial effect of electric plasma was evaluated at 2, 3, 4, and 5 min in planktonic cells and 4, 6, 8, and 10 min in a 48-h biofilm, assessing the antimicrobial effect by colony-forming units per milliliter count and the cell viability by MTT assay, respectively. The results were statistically analyzed using the GraphPad Prism 5 program, considering P <0.05 significant. The presence of biofilm in the fibers and the effect of electric plasma on their integrity was assessed by scanning electron microscopy (SEM). For both strains, the percentage of reduction in planktonic cells ranged from 23.53 to 100%, with a significant reduction in all treatment times for both strains, except for the KPC strain in 2 min, with total elimination in 5 min. In addition, significant anti-biofilm activity was obtained after 8 and 10 min of treatment exclusively for the standard strain. There was no damage to the integrity of the textile fiber after the treatment. Electric plasma is a promising physical agent, as long as the application time and intensity are respected, against planktonic cells and K. pneumoniae biofilm in cotton textiles, used in hospital garments.