Bactericidal activity of biofilm in flexible cystoscope under combined exposure of glutaraldehyde, 808-nm, and 405-nm laser

Abstract

Flexible cystoscopy is a widely used diagnostic and therapeutic procedure in urology. However, some dangerous bacteria are resistant to traditional antibiotics. Thus, the current study introduced a combination of glutaraldehyde (GTA), 808- nm, and 405-nm laser to disinfect Staphylococcus aureus bacterial biofilms inside flexible cystoscopes based upon a Teflon tubing model. Based upon the pilot study, the samples were exposed either under GTA (0.5% in 180 s), 808-nm (1.6 W/cm2 in 180 s), and 405-nm laser (1.6 W/cm2 in 180 s) alone or their combinations. An infrared (IR) camera was deployed to provide the real-time monitoring of temperature development on the biofilm surface while colony forming unit (CFU) analysis was employed to count viable cells before and after the treatment. The preliminary results showed that GTA, 808-nm, and 405-nm laser alone could induce a 2.2-, 1.4-, and 2-log10 CFU/cm2 reduction of S. aureus bacterial biofilm, respectively. However, their triple combination could eradicate around 6.5-log10 CFU/cm2 reduction in microorganism population. Therefore, the triple combination may be a useful modality for cystoscope reprocessing to prevent any secondary infection in the urinary tract during the cystoscopy.