Characteristics of the Pseudomonas aeruginosa PA01 Intercellular Signaling Pathway (Quorum Sensing) Functioning in Presence of Porphyrins Bismuth Complexes.

The influence of synthetic and natural porphyrins bismuth complexes on P. aeruginosa quorum sensing system was carried out by detection of the pyocyanin, rhamnolipids and autoinducers biosynthesis level. The highest ability to reduce pyocyanin biosynthesis showed Bi(III)-TPP. Rhamnolipids production level also decreased in the presence of studied compounds. This effect was the most expressed in presence of 40 and 80 µM of the synthetic meso-substituted porphyrins. Autoinducers biosynthesis, especially 3-oxo-C12-HSL was suppressed in presence of the bismuth complexes. That suggest that the mechanisms of action of this substances is an inhibition of signaling molecules or/and receptor for them.

Inhibition of lactophage activity by quinolinilporphyrin and its zinc compex.

The influence of free base of quinolinilporphyrin and its Zn complex on infectivity of lactophages E3, E5 and E17 has been studied. The results of our investigations show that inhibition of lactophage activity by Zn complex of quinolinilporphyrin at concentration 10 microM and 20 microM was in the range 53-62% and 65-85%, respectively. The presence of this porphyrin in nutrient medium prevents the propagation of bacteriophage infection in Lactococcus lactis, but does not affect the phage adsorption process. The free base of quinolinilporphyrin slightly inhibits the activity of lactophages.