PHOTODYNAMIC INACTIVATION OFSTAPHYLOCOCUS AUREUS BY THE AMINOPORPHYIN A4

MORA, JIMENA; GHIO LARA CAROLINA; MARTINEZ MARIA DEL CARMEN; DURANTINI EDUARDO

Milan

Congreso; International Congress on Porphyrins and Porphyrias; 2019

Universitá Digli Studi di Milano

Photodynamic inactivation (IFD) can be an alternative therapy to antibiotics and antiseptics for localized infections treatment, particularly those caused by resistant organisms to conventional antimicrobial agents. The IFD is based on the preferential accumulation of a photosensitizer (FS) in the microbial cells; the subsequent illumination induces the photodynamic activity producing a lethal damage in the cell. Porphyrins are effectives against parasitosis and Gram positive bacterias. In this work we evaluate the effect of a synthetic porphyrin 5,10,15,20-tetrakis [4- (3-N, N-imethylaminopropoxy) phenyl] porphyrin (A4) and its protonated form A4 + as FS to inactivate Staphylococus aureus. Bacterial viability was determined by counting the CFU / ml on plates with Tryptic Soy agar. The illumination was performed with white light, 0.5 mW / cm2. After 30 minutes of incubation in darkness, IC50 values were 6.2 ± 0.7μM for A4 and 1.7 ± 0.2μM for A4 +. When the treatment conditions were 15 minutes in darkness and 15 minutes under light, the IC50 values were significantly low, 3.7 ± 0.4μM for A4 and 1.2 ± 0.2μM for A4 +. For both porphyrins, the cytotoxicity of A4 tested on Vero cells, and evaluated with the MTT assay, was about 7 times higher for the no irradiated cells than for those irradiated.The selectivity index 43.5 and 5.97 (p