Share Email Print

Proceedings Paper

Investigation into the susceptibility of Burkholderia cepacia complex isolates to photodynamic antimicrobial chemotherapy (PACT)
Author(s): C. M. Cassidy; A. L. Watters; R. F. Donnelly; M. M. Tunney
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

The main cause of morbidity and mortality in cystic fibrosis (CF) sufferers is progressive pulmonary damage caused by recurrent and often unremitting respiratory tract infection. Causative organisms include Pseudomonas aeruginosa and Haemophilus influenzae, but in recent years the Burkholderia cepacia complex has come to the fore. This group of highly drug-resistant Gram-negative bacteria are associated with a rapid decline in lung function and the often fatal cepacia syndrome, with treatment limited to patient segregation and marginally effective antibacterial regimens. Thus, development of an effective treatment is of the upmost importance. PACT, a non-target specific therapy, has proven successful in killing both Gram-positive and Gram-negative bacteria. In this study, planktonic cultures of six strains of the B. cepacia complex were irradiated (635 nm, 200 J cm-2,10 minutes irradiation) following 30 seconds incubation with methylene blue (MB) or meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate (TMP). Rates of kill of > 99 % were achieved with MB- and TMP-PACT. A MB concentration of 50 μg ml-1 and TMP concentration of 500 μg ml-1 were associated with highest percentage kills for each photosensitizer. PACT is an attractive option for treatment of B.cepacia complex infection. Further study, involving biofilm culture susceptibility, delivery of light to the target and in vivo testing will be necessary before it PACT becomes a viable treatment option for CF patients who are colonised or infected with B. cepacia complex.

Paper Details

Date Published: 13 July 2009
PDF: 7 pages
Proc. SPIE 7380, Photodynamic Therapy: Back to the Future, 738039 (13 July 2009); doi: 10.1117/12.822874
Show Author Affiliations
C. M. Cassidy, Queen's Univ. Belfast (United Kingdom)
A. L. Watters, Queen's Univ. Belfast (United Kingdom)
R. F. Donnelly, Queen's Univ. Belfast (United Kingdom)
M. M. Tunney, Queen's Univ. Belfast (United Kingdom)

Published in SPIE Proceedings Vol. 7380:
Photodynamic Therapy: Back to the Future
David H. Kessel, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?