Mechanistic aspects of the photodynamic inactivation of Candida albicans induced by cationic porphyrin derivatives

Photodynamic Inactivation of Candida Albicans by Hematoporphyrin Monomethyl Ether

“…Transmission electron microscopy (TEM) TEM samples were prepared according to a previously described method [26]. After PDI treatment, yeast cells were centrifuged at 4000 rpm for 10 min and fixed in 2.5% glutaraldehyde at 4°C for 2 h. The pellets were washed with PBS three times and fixed in 1% osmium tetroxide at 4°C for 2 h. Thereafter, the pellets were dehydrated with ethanol gradients and embedded in Epon 812 epoxy resin (SPI-Chem, USA) at 60°C for 24 h. Thin-section samples of 50-70 nm were prepared using a LKB-V ultratome (LKB, Sweden).…”

“…This finding suggests that HMME would be a good PS to use in PACT of drug-resistant strains.PDI of microorganisms has been proposed to occur through inactivation of a number of biomolecules. For example, DNA damage would interfere with chromosome segregation, DNA replication, and transcription.Quiroga et al investigated the mechanism of the PDI of C. albicans mediated by cationic porphyrin derivatives[26] and found no significant cleavage of genomic DNA after treatment despite efficient yeast cell photoinactivation. The authors hypothesized that either damage to genomic DNA was not involved in the PDI process or that any damage to the DNA resulting from a few lesions was not sufficient to induce DNA strand breaks that could be detected by gel electrophoresis.…”

Phototreatment of Water by Organic Photosensitizers and Comparison with Inorganic Semiconductors

“…It has been known for almost a century that light and photosensitizer can cause destruction of microorganisms [5], and during these years many have discussed and some have put forward their results to explain the mechanism of cell killing [9,16,25,[30][31][32][33][34][35][36][37][38]. The photoprocess successfully causes reduction in survival of bacteria (Gram-positive and Gramnegative), yeast, fungi, and viruses [32].…”

“…Cationic porphyrins interact strongly with DNA and cause photocleavage in solution [35]. Quiroga et al [36] used TFAP 3+ , TMAP 4+ , and TMPyP to study the photoinactivation of C. albicans. All the cationic porphyrin exhibited a photosensitizing activity causing about 3.5-log decrease in cell survival.…”

Chemical Composition and Antimicrobial Activity of Essential Oils from Xylopia aromatica (Annonaceae) Flowers and Leaves

“…Only a few antifungal agents are in clinical use and therapies are limited by drugsafety considerations. 20,21 This paper offers the first report of the composition and antimicrobial effect of EO of X. aromatica flowers. Previous studies have investigated the antimicrobial activity of EO of X. aromatica leaves against S. aureus, Mycobacterium smegmatis, Escherichia coli, P. aeruginosa and C. albicans; 10 here, we report the activity of this EO against B. cepacia, S. pyogenes, P. acnes and C. tropicalis for the first time.…”