Investigation of arginine A-specific cysteine proteinase gene expression profiling in clinical Porphyromonas gingivalis isolates against photokilling action of the photo-activated disinfection

AbstractPorphyromonas gingivalis is a significant root canal pathogen capable of causing endodontic infections, which during their treatment may receive sub-lethal doses of photo-activated disinfection (sPAD). As sPAD can influence microbial virulence, this study was designed to evaluate the effect of sPAD on gene expression level of arginine A-specific cysteine proteinase (rgpA), as one of the underlying virulence factors involved in the development of endodontic infection viaP. gingivalis strains. To find out the sPAD against 16 clinical isolates of PAD-resistantP. gingivalis that were isolated in vivo, we used toluidine blue O (TBO), methylene blue (MB), and indocyanine green (ICG) as the photosensitizers, which were excited with specific wavelength of light in vitro. Quantitative real-time PCR (qRT-PCR) was then applied to monitor gene expression ofrgpA inP. gingivalis isolates to characterize its virulence agent and understand the effect of sPAD on its pathogenicity. Maximal sPAD that could not decrease the count ofP. gingivalis isolates were 6.25, 15.6, and 25  μg/mL at fluencies of 171.87, 15.6, and 93.75 J/cm2 for TBO, ICG, and MB, respectively. ICG-sPAD could suppress thergpA gene expression about 14-fold, while MB and TBO-mediated sPAD could cause the attenuation ofrgpA expression about 4.9- and 11.6-fold, respectively. ICG-sPAD with the maximum ability to reducergpA gene expression compared with other photosensitizers can be an appropriate candidate for the trea...
Source: Lasers in Medical Science - Category: Laser Surgery Source Type: research