title: Use of a Real Time PCR Assay to Assess the Effect of Pulsed Light Inactivation on Bacterial Cell Membranes and Associated Cell Viability.
abstract: Research into more rapid and effective means of disinfecting water has become necessary due to the recognition that not all pathogenic species are being removed by chemical means. There is an extent of research highlighting the benefits of pulsed light for the disinfection of water. This study aims to determine the ability of a real time polymerase chain reaction assay to evaluate microbial inactivation of pulsed light treated cells. Findings show that pulsed light is a more rapid means of inactivating test species than standard UV lamp systems. A linear relationship between cell number and polymerase chain reaction amplification was obtained. A difference in threshold value (Ct) of approximately 4 (p ≤ 0.05) was obtained for DNA amplification following the addition of the dye for pulsed ultrviolet (PUV)-treated Bacillus cells. Membrane protein leakage proved an effective means of determining membrane damage for both Bacillus and E. coli test species following PUV treatment. This membrane damage was not evident for cells exposed to low pressure ultraviolet (LPUV). Findings describe suggest that PUV treatment induced a viable but nonculturable state in treated cells.
authors.affiliation: Department of Life Sciences, Institute of Technology Sligo, Ash Lane, Sligo, Ireland.
authors.forename: Mary
authors.initials: M
authors.lastname: Garvey
authors.forename: Alessia
authors.initials: A
authors.lastname: Stocca
authors.forename: Neil
authors.initials: N
authors.lastname: Rowan
mesh_terms: D001386:Azides; D001409:Bacillus cereus; D001410:Bacillus megaterium; D002462:Cell Membrane / Q000528:radiation effects*; D004203:Disinfection; D004926:Escherichia coli; D050296:Microbial Viability; D011419:Propidium / Q000031:analogs & derivatives; D060888:Real-Time Polymerase Chain Reaction; D014466:Ultraviolet Rays; D014871:Water Microbiology
chemical_list: D001386:Azides; C533957:propidium monoazide; D011419:Propidium