TY - GEN

T1 - Comparison of UVB and UVC irradiation disinfection efficacies on Pseudomonas Aeruginosa (P. aeruginosa) biofilm

AU - Argyraki, A.

AU - Markvart, M.

AU - Nielsen, Anne

AU - Bjarnsholt, T.

AU - Bjørndal, L.

AU - Petersen, P. M.

PY - 2016

Y1 - 2016

N2 - Disinfection routines are important in all clinical applications. The uprising problem of antibiotic resistance has driven major research efforts towards alternative disinfection approaches, involving light-based solutions. Pseudomonas aeruginosa (P. aeruginosa) is a common bacterium that can cause skin, soft tissue, lungs, kidney and urinary tract infections. Moreover, it can be found on and in medical equipment causing often cross infections in hospitals. The objective of this study was to test the efficiency, of two different light-based disinfection treatments, namely UVB and UVC irradiation, on P. aeruginosa biofilms at different growth stages. In our experiments a new type of UV light emitting diodes (LEDs) were used to deliver UV irradiation on the biofilms, in the UVB (296nm) and UVC (266nm) region. The killing rate was studied as a function of dose for 24h grown biofilms. The dose was ramped from 72J/m2 to 10000J/m2. It was shown that UVB irradiation was more effective than UVC irradiation in inactivating P. aeruginosa biofilms. No colony forming units (CFU) were observed for the UVB treated biofilms when the dose was 10000 J/m2 (CFU in control sample: 7.5 x 104). UVB irradiation at a dose of 20000J/m2 on mature biofilms (72h grown) resulted in a 3.9 log killing efficacy. The fact that the wavelength of 296nm exists in daylight and has such disinfection ability on biofilms gives new perspectives for applications within disinfection at hospitals.

AB - Disinfection routines are important in all clinical applications. The uprising problem of antibiotic resistance has driven major research efforts towards alternative disinfection approaches, involving light-based solutions. Pseudomonas aeruginosa (P. aeruginosa) is a common bacterium that can cause skin, soft tissue, lungs, kidney and urinary tract infections. Moreover, it can be found on and in medical equipment causing often cross infections in hospitals. The objective of this study was to test the efficiency, of two different light-based disinfection treatments, namely UVB and UVC irradiation, on P. aeruginosa biofilms at different growth stages. In our experiments a new type of UV light emitting diodes (LEDs) were used to deliver UV irradiation on the biofilms, in the UVB (296nm) and UVC (266nm) region. The killing rate was studied as a function of dose for 24h grown biofilms. The dose was ramped from 72J/m2 to 10000J/m2. It was shown that UVB irradiation was more effective than UVC irradiation in inactivating P. aeruginosa biofilms. No colony forming units (CFU) were observed for the UVB treated biofilms when the dose was 10000 J/m2 (CFU in control sample: 7.5 x 104). UVB irradiation at a dose of 20000J/m2 on mature biofilms (72h grown) resulted in a 3.9 log killing efficacy. The fact that the wavelength of 296nm exists in daylight and has such disinfection ability on biofilms gives new perspectives for applications within disinfection at hospitals.

KW - Disinfection

KW - Light emitting diodes (LEDs)

KW - Pseudomonas aeruginosa (P. aeruginosa)

KW - Sterilization

KW - Ultraviolet light

KW - UVB

KW - UVC

U2 - 10.1117/12.2225597

DO - 10.1117/12.2225597

M3 - Article in proceedings

AN - SCOPUS:84982298830

VL - 9887

T3 - Proceedings of S P I E - International Society for Optical Engineering

BT - Biophotonics

PB - SPIE - International Society for Optical Engineering

T2 - Biophotonics: Photonic Solutions for Better Health Care V

Y2 - 4 April 2016 through 7 April 2016

ER -