On the Synergism of Biogenic Gold Nanoparticles and Hydroxyaluminum Phthalocyanines in the Photoeradication of Staphylococcus aureus

Due to the unusual properties of gold nanoparticles, these structures are widely used in medicine and biology. This paper describes for the first time the synthesis of colloidal gold nanoparticles by the cell-free filtrate obtained from the Coriolus versicolor biomass and the use of these biogenic nanostructures to increase the photosensitizing efficiency of di- (AlPcS2) and tetrasulfonated (AlPcS4) hydroxyaluminum phthalocyanines in antibacterial photodynamic therapy. The obtained monodisperse particles were extremely stable, and this remarkable stability was due to the presence of phosphoprotein as a capping agent. The studied gold nanoparticles had a spherical shape, were uniformly distributed, and were characterized by a single plasmon band at wavelength of 514–517 nm. Almost 60% of the gold particles were found to be in the range of 13 to 15 nm. In accordance with the regulations of the American Microbiological Society, indicating that any antimicrobial technique must kill at least 3 log CFU (99.9%) to be accepted as “antimicrobial”, this mortality of Staphylococcus aureus was shown to be achieved in the presence of AlPcS4 + AuNPs mixture and 4.8 J cm−2 light dose compared to AlPcS4 alone, which required a light dose of 24 J cm−2. The best effect of increasing the effectiveness of combating this pathogen was observed in the case of AlPcS2 + AuNPs as a photosensitizing mixture. The light dose of 24 J cm−2 caused a lethal effect of the studied coccus in the planktonic culture.

Vertical Transmission from Russia

The Russian Microbiological Society has had a long and complicated history, reflecting the recent history of our country. It was established in 1957, in the Soviet Union, as the All-Union Microbiological Society and in the mid-80s comprised more than 5000 members. Several distinguished Russian microbiologists were its Presidents: the last one was Professor Elena Kondrat'eva, famous for her investigations of bacterial photosynthesis. However, the Society did not survive all the changes of the 90s, and, in spite of an attempt to revive it in 1992, did not exist until 2003.