Evaluation of UV-C induced changes in Escherichia coli DNA using Repetitive Extragenic Palindromic-Polymerase Chain Reaction (REP-PCR)

A. TROMBERT, H. IRAZOQUI, C. MARTÍN Y F. ZALAZAR

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY

Elsevier B.V

Lugar: Amsterdam; Año: 2007 vol. 89 p. 44 - 49

1010-6030

Ultraviolet radiation is an efficient inactivation method for a broad range of bacteria, viruses and parasites. Inactivation of microorganismsby UV-B and UV-C radiation is driven through modifications in their genomic DNA, being the most stable DNA-lesions differentkinds of pyrimidine dimers (PDs) (e.g., cyclobutane pyrimidine dimers (CPDs) and other photoproducts). Taking into accountthat these modifications inhibit the DNA polymerization in vivo as well as in vitro, in the present work the usefulness of the REP?PCR assay to detect UV-induced changes in the Escherichia coli DNA was evaluated. In vitro amplification of DNA extracted at different times after UV treatment showed a disappearance of amplicons of higher size as time of treatment increases. When the bacteria were letto progress through their dark repair process, modifications in the electrophoretic patterns by REP?PCR were observed again. Amplifiedbacterial DNA tended to recover the profile showed at the beginning of treatment. In addition, the reappearance of bands of highermolecular size was associated to an increase in their signal intensity probably due to a higher amplification rate. Results of REP?PCR were correlated to the colony-forming ability of E. coli. It was concluded that REP?PCR appears as a rapid, robust, useful complementary methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.times after UV treatment showed a disappearance of amplicons of higher size as time of treatment increases. When the bacteria were letto progress through their dark repair process, modifications in the electrophoretic patterns by REP?PCR were observed again. Amplifiedbacterial DNA tended to recover the profile showed at the beginning of treatment. In addition, the reappearance of bands of highermolecular size was associated to an increase in their signal intensity probably due to a higher amplification rate. Results of REP?PCR were correlated to the colony-forming ability of E. coli. It was concluded that REP?PCR appears as a rapid, robust, useful complementary methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.times after UV treatment showed a disappearance of amplicons of higher size as time of treatment increases. When the bacteria were letto progress through their dark repair process, modifications in the electrophoretic patterns by REP?PCR were observed again. Amplifiedbacterial DNA tended to recover the profile showed at the beginning of treatment. In addition, the reappearance of bands of highermolecular size was associated to an increase in their signal intensity probably due to a higher amplification rate. Results of REP?PCR were correlated to the colony-forming ability of E. coli. It was concluded that REP?PCR appears as a rapid, robust, useful complementary methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.Escherichia coli DNA was evaluated. In vitro amplification of DNA extracted at different times after UV treatment showed a disappearance of amplicons of higher size as time of treatment increases. When the bacteria were letto progress through their dark repair process, modifications in the electrophoretic patterns by REP?PCR were observed again. Amplifiedbacterial DNA tended to recover the profile showed at the beginning of treatment. In addition, the reappearance of bands of highermolecular size was associated to an increase in their signal intensity probably due to a higher amplification rate. Results of REP?PCR were correlated to the colony-forming ability of E. coli. It was concluded that REP?PCR appears as a rapid, robust, useful complementary methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.E. coli. It was concluded that REP?PCR appears as a rapid, robust, useful complementary methodology to monitor the impact of UV irradiation ? at a molecular level ? on the inactivation and the mechanisms ofrepair, applicable on a broad spectrum of microorganisms.