فهرست نشریات علمی دسترسی آزاد ایران

The present study was designed to explore the effect of gold nanoparticles on the hmgA gene expression and pyomelanin pigment production from local Pseudomonas aeruginosa isolates. Out of 162 patients suffering from ear infections, urinary tract infections, burns, wounds, cerebrospinal fluid (CSF), respiratory tract infections (RTI), and blood infection (sepsis), eight isolates identified to produce pyomelanin pigment (8.42%). All isolates were characterized using microscopical, morphological, and biochemical methods, VITEK-2 compact systems, and 16SrRNA gene, which showed that all these isolates belong to P. aeruginosa. Screening producing pyomelanin pigment was carried out by using a specific media to promote the production of pyomelanin pigment. The extracted pyomelanin pigment was purified using simple acid sedimentation followed by centrifugation to extract the crude product and purify it with HPLC. The purified pigment was positive for all major physical and chemical tests that characterize pyomelanin pigment, including UV-visible spectroscopy and Fourier transform infrared spectroscopy (FT-IR). The study also covered the preparation of gold nanoparticles using the green chemistry method, which used black tea-leaf extract. The resulting nanoparticles were positive for all significant qualitative tests used to characterize them, including UV-visible spectroscopy (FT-IR), X-ray diffraction (XRD), and SEM. The results of the SEM image showed spherical particles with a size of approximately 19nm nanoparticles. In conclusion, the effect of the prepared gold nanoparticles on the gene expression of the hmgA gene was studied at different concentrations compared to the control sample using a real-time one-step polymerization reaction, also the gene expression results showed that the gold nanoparticles significantly increased the gene expression of the hmgA gene.