Please use this identifier to cite or link to this item:
Title: Sewage bacteriophage inactivation by cationic porphyrins: influence of light parameters
Author: Costa, Liliana
Carvalho, Carla M. B.
Faustino, Maria A. F.
Neves, Maria G. P. M. S.
Tomé, João P. C.
Tomé, Augusto C.
Cavaleiro, José A. S.
Cunha, Ângela
Almeida, Adelaide
Issue Date: Aug-2010
Publisher: Royal Society of Chemistry
Abstract: Photodynamic therapy has been used to inactivate microorganisms through the use of targeted photosensitizers. Although the photoinactivation of microorganisms has already been studied under different conditions, a systematic evaluation of irradiation characteristics is still limited. The goal of this study was to test how the light dose, fluence rate and irradiation source affect the viral photoinactivation of a T4-like sewage bacteriophage. The experiments were carried out using white PAR light delivered by fluorescent PAR lamps (40 W m(-2)), sun light (600 W m(-2)) and an halogen lamp (40-1690 W m(-2)). Phage suspensions and two cationic photosensitizers (Tetra-Py(+)-Me, Tri-Py(+)-Me-PF) at concentrations of 0.5, 1.0 and 5.0 microM were used. The results showed that the efficacy of the bacteriophage photoinactivation is correlated not only with the sensitizer and its concentration but also with the light source, energy dose and fluence rate applied. Both photosensitizers at 5.0 microM were able to inactivate the T4-like phage to the limit of detection for each light source and fluence rate. However, depending of the light parameters, different irradiation times are required. The efficiency of photoinactivation is dependent on the spectral emission distribution of the light sources used. Considering the same light source and a fixed light dose applied at different fluence rates, phage inactivation was significantly higher when low fluence rates were used. In this way, the light source, fluence rate and total light dose play an important role in the effectiveness of the antimicrobial photodynamic therapy and should always be considered when establishing an optimal antimicrobial protocol.
Peer review: yes
DOI: 10.1039/c0pp00051e
ISSN: 1474-905X
Appears in Collections:CESAM - Artigos
DBio - Artigos
DQ - Artigos
QOPNA - Artigos

Files in This Item:
File Description SizeFormat 
Costa et al. - 2010 - Sewage bacteriophage inactivation by cationic porp.pdf231.87 kBAdobe PDFrestrictedAccess

Formato BibTex MendeleyEndnote Degois 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.