Tatiana Vassu

Treatment with some anti-inflammatory drugs reduces germ tube formation in Candida albicans strains

Candida albicans is an opportunistic dimorphic fungus that inhabits various host mucosal sites. It can cause both superficial and serious systemic disease. Conversion from the yeast to the hyphal form has been associated with increased virulence and mucosal invasiveness. The aim of this study was to investigate the effect of sodium diclofenac and aspirin on germs tube formation of different Candida albicans strains. Prostaglandins may play an important role in fungal colonization. Nonsteroidal anti-inflammatory drugs are inhibitors of the cyclooxygenase isoenzymes. These drugs specifically block the biosynthesis of mammalian prostaglandins by inhibiting one or both of cyclooxygenase isoenzymes. In tests for germ tube formation sodium diclofenac reduced the filamentation to the 12.5%- 5.1%. In the presence of aspirin the filamentation was reduced up to 85–45% depending on the tested strain. Our results suggest that cyclooxygenase-depending synthesis of fungal prostaglandins is important for morphogenesis and fungal virulence. Inhibitors of cyclooxygenase isoensymes (aspirin and diclofenac) are effective in decreasing germ tube formation of Candida albicans.

Innovative array-based assay for omics pattern in melanoma

ABSTRACT Cutaneous melanoma remains a major health issue and still an important challenge for research. Thus, omics complex evaluation can provide a more specific molecular classification for this heterogeneous disease. Complex omics analysis based on genomic and proteomic microarrays can identify disease markers that prognosticate disease evolution or can monitor therapies efficacy. Among the technologies that gained momentum in the last years, array-based comparative genomic hybridization offered the possibility to analyze chromosomal numerical aberrations within cutaneous melanomas providing important support for molecular classification of melanoma tumors. This technology can identify new chromosomal alterations and discover new deregulated melanoma genes that can be further used as therapy targets. Integrating genetic profiling with clinical and pathological parameters would lead to seminal improvements in diagnosis, prognosis, and therapy.

Fatty Acids Effect on Lipase and Biosurfactant Induction in Rhodotorula Glutinis CMGB-RG5

Abstract Fatty acids represent important substrates for obtaining microbial lipases and biosurfactants. The yeast strain CMGBRG5 was identified as Rhodotorula glutinis using the BIOLOG MicroLog System. The opacity screening tests showed that R. glutinis CMGB-RG5 was able to produce lipases in presence of 1% Tween 80 after three days of incubation. Lipase induction was estimated as cell growth in presence of Tween 80, Tween 20, olive oil and tributyrin. After 48 hours, best results were obtained in presence of butyric acid, respectively, oleic acid: 2.2 × 107 cells/ml on tributyrin and 1.0 × 107 cells/ml on olive oil. Biosurfactant production was evaluated as emulsification index (E24%). After one week, high E24 values were obtained on fried sunflower oil (53%) and olive oil (35%). Crude and concentrated biosurfactants were tested against nine Candida strains. Best antimicrobial activity was observed for [20X] biosurfactants against C. tropicalis, C. guilliermondii and C. krusei. In conclusion, R. glutinis CGB-RG5 shows high potential for using fatty acids from various sources as unique carbon substrates for synthesis of biocompounds with high economic and biotechnological value.

Microbial Community Dynamics in Field-Scale Biopile Bioremediation

Understanding the microbial communities responses to biopile procedures is an essential step in the field of microbial ecology and in bioremediation applications. In order to estimate metabolic dynamics at a microbial community level, we used Biolog Ecoplates. Assays showed that the bacterial communities from all samples were capable of utilizing a great variety from the 31 carbon substrates. Shannon’s diversity index values were between 2.711±0.303 in August and 3.262±0.062 in April, recording a general variation of 0.5 that is similar to other studies. Statistical analysis showed a good correlation coeficient for 2-hydroxybenzoic acid, a compound that is metabolized through the nafhthalene degradation pathway. Results showed a metabolic shift of the microbial community determined by temperature and the decrease of aromatic hydrocarbon concentrations. The shift was observed in the dynamics of MPN from 9x106 to 1x109 cell/g of soil. Even if the initial total petroleum hydrocarbon concentration from the biopile matrix was much higher than in other studies (10.25 g/kg), at the end of the evaluation the pollutant content of the biopile matrix had a removal rate between 92-98% for monoaromatic hydrocarbons and 57-75% for poliaromatic hydrocarbons.

Phenotypic and genotypic assessment of Lactobacillus plantarum influence on Candida albicans fluconazole resistance

Lactobacilli are the most common genera of vaginal microbiota in healthy women, being involved in maintaining the microbial barrier against the development of pathogenic microorganisms in the urogenital tract. Recent studies have shown that the disturbance of microbial environmental balance in the vagina is associated with an increasing risk to develop infections. Over the last years, Candida albicans has continued to be the most frequent species isolated from vaginal yeast infections. The main goal of our studies was to determine the potential influence of lactic acid bacteria strains on the expression of C. albicans CMGBy 13 fluconazole resistance. The present study included 153 lactic acid bacteria strains isolated from fermented food products and human gastrointestinal tracts and one strain of C. albicans CMGBy13 isolated from a patient with vaginal infection. Preliminary analysis included the qualitative screening by disk diffusion assay of lactic acid bacteria strains capacity to increase the fluconazole susceptibility of yeast cells. Two lactic acid bacteria strains, Lactobacillus plantarum CMGB 1 and L. rhamnosus CMGB 38, were selected for further fluorescence microscopy and flow cytometry assays in order to establish their influence on C. albicans efflux pumps activity and, respectively, on the fluconazole resistance genes expression by RT-PCR.