Overexpression of aldo-keto-reductase in azole-resistant clinical isolates of Candida glabrata determined by cDNA-AFLP

Abstract

BackgroundCandida glabrata causes significant medical problems in immunocompromised patients. Many strains of this yeast are intrinsically resistant to azole antifungal agents, and treatment is problematic, leading to high morbidity and mortality rates in immunosuppressed individuals. The primary goal of this study was to investigate the genes involved in the drug resistance of clinical isolates of C. glabrata.MethodsThe clinical isolates of C. glabrata were collected in an epidemiological survey of candidal infection in immunocompromised patients and consisted of four fluconazole and itraconazole resistant isolates, two fluconazole and itraconazole sensitive isolates, and C. glabrata CBS 138 as reference strain. Antifungal susceptibility patterns of the organisms were determined beforehand by the Clinical and Laboratory Standards Institute (CLSI). The potential gene(s) implicated in antifungal resistance were investigated using complementary DNA- Amplified Fragment Length Polymorphism (cDNA-AFLP). Semi-quantitative RT-PCR was carried out to evaluate the expression of gene(s) in resistant isolates as compared to sensitive and reference strains.Results and conclusionsThe aldo-keto-reductase superfamily (AKR gene) was upregulated in the resistant clinical isolates as assessed by cDNA-AFLP. Semi-quantitative RT-PCR revealed AKR mRNA expression approximately twice that seen in the sensitive isolates. Overexpression of the AKR gene was associated with increased fluconazole and itraconazole resistance in C. glabrata. The data suggest that upregulation of the AKR gene might give a new insight into the mechanism of azole resistance.

Enhanced Cellular Cytotoxicity and Antibacterial Activity of 18-β-Glycyrrhetinic Acid by Albumin-conjugated PLGA Nanoparticles

“…PLGA NPs were fabricated using a sonication/ solvent evaporation method (9). In the first step, PVA (0.5% w/w) was dissolved in deionized water forming the aqueous phase and different ratios of GLA to PLGA were dissolved in acetone at room temperature (25 °C) To prepare organic phase (oil phase).…”

“…A small amount of freeze dried powder of NPs was fixed on a double-sided tape attached to a metallic sample stand, and was gold coated before SEM (9). …”

“…Drug loading was calculated as the GLA content in NPs divided by the total weight of NPs. The encapsulation efficiency was obtained by calculating the ratio of GLA amount incorporated inside the NPs to the GLA amount which was used for NPs preparation (9). Each experiment was repeated three times.…”

“…These advantages include their structural stability, narrow size distribution and the possibility of their functionalization for targeted drug delivery (9). Various polymers may be utilized for polymeric NPs preparation, among which PLGA or poly (lactic-co-glycolic acid) has a special place.…”

Inhaled sildenafil as an alternative to oral sildenafil in the treatment of pulmonary arterial hypertension (PAH)

“…In fact, as an alternative to the oral form of the drug, poly-lactic-co-glycolic acid (PLGA) particles of sildenafil have been prepared with a goal to treat PAH and other diseases [18, 19]. Nebulized sildenafil has been reported to potentiate the vasodilatory effects of nitric oxide in a sheep model of PAH [20].…”