Clinical and laboratory evaluation of anti-microbial efficacy of photocatalysts

Abstract

Aim This study aims at investigating and testing the tentative antimicrobial efficacy; in vitro and in- hospital applications of apatite coated ferrum titanate which is one of the new generation photocatalysts. Material and Methods 30 sterile petri dishes were kept under florescent light for 4 days following the application of 20 ppm apatite coated ferrum titanate aerosol. 0.5 McFarland (1.5X108 CFU/mL -CFU=colony forming unit) Pseudomonas aeruginosa and 0.5 McFarland Acinetobacter baumannii were cultured on 10 separate dishes. 10 unprocessed dishes were used as controls. Samples were evaluated for bacterial survival rate (CFUX100/CFU) after application. In the second step, same photocatalyst aerosol was applied as 0.012 L/m2 with the specific kit on the surfaces of different units within the hospital. Particle count was measured and compared before and one-month after the photocatalyst application by lumimeter. Results Bacterial survival rate was significantly lower on photocatalyst applied surfaces versus control for Pseudomonas aeruginosa after second day of application (p<0.001) (60±8% / 95±9%). This difference continued up to the 4th day gradually (3. day: 35±5% / 90±9%; 4. day:22±5% / 85±8%). Bacterial survival rate was significantly lower on photocatalyst applied surfaces versus control for Acinetobacter baumannii after the second day of application (55±7% / 87±8%) (p<0.01). This difference continued up to the 4th day gradually (3. day:40±5% / 80±8%; 4. day:15±5% / 78±7%). Particle count on photocatalyst applied surfaces diminished 97.15% in operating room, 95.61% in ICU, 98.30 in physicians' room, 94.13% in wards and 97.04% in hospital kitchen. Conclusions As a result of our pioneering study on the evaluation of photocatalyst, we think that it may be one of the economic and safe alternative methods of hospital sterilization based on bactericidal and bacteriostatic efficacy confirmed in both laboratory and clinical applications.