Acute renal failure associated with Candida albicans infection

Amino Acid Sensing and Assimilation by the Fungal Pathogen Candida albicans in the Human Host

Nutrient uptake is essential for cellular life and the capacity to perceive extracellular nutrients is critical for coordinating their uptake and metabolism. Commensal fungal pathogens, e.g., Candida albicans, have evolved in close association with human hosts and are well-adapted to using diverse nutrients found in discrete host niches. Human cells that cannot synthesize all amino acids require the uptake of the “essential amino acids” to remain viable. Consistently, high levels of amino acids circulate in the blood. Host proteins are rich sources of amino acids but their use depends on proteases to cleave them into smaller peptides and free amino acids. C. albicans responds to extracellular amino acids by pleiotropically enhancing their uptake and derive energy from their catabolism to power opportunistic virulent growth. Studies using Saccharomyces cerevisiae have established paradigms to understand metabolic processes in C. albicans; however, fundamental differences exist. The advent of CRISPR/Cas9-based methods facilitate genetic analysis in C. albicans, and state-of-the-art molecular biological techniques are being applied to directly examine growth requirements in vivo and in situ in infected hosts. The combination of divergent approaches can illuminate the biological roles of individual cellular components. Here we discuss recent findings regarding nutrient sensing with a focus on amino acid uptake and metabolism, processes that underlie the virulence of C. albicans.

Antimicrobial activity and acetylcholinestrase inhibition of novel synthesized pyrimidine derivatives versus Candida albicans trafficking to brain and kidney

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The current study interested by treatment of Candida albicans in case of invading the fungi into brain and kidney.

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Investigating novel synthesized compounds as antifungal agents then determining their efficiency and safety margin.

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Assessment molecular biochemical parameters specific for inflammation.

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Comparing their antifungal effect to Diflucan in case of invading the fungi to kidney and brain tissue.

The expedient fungi Candida albicans (C. albicans) is able to thrive in many host niches including blood stream, skin, mucosal surfaces, and different body organs. Herein, the assessment of novel synthesized pyrimidine derivatives as anti fungal agent was investigated. Female albino mice were injected intraperitoneally by C. albicans (1.5 × 10⁶ CFU). infected Mice then subjected to treatment with two different doses which was low (50 mg/kg) and high one (200 mg/kg) of diflucan in addition to the newly synthestic compounds (2-(4- (Pyridine- 2- yl) aminosulfonyle phenylamino) - 6 -(naphthalene-2- yl)-4-(pyridine-2- yl) n - 3 carbonitril) and (2-(4-(Pyrimidine-2- yl) aminosulfonyle phenylamino)- 6 -(naphthalene-2- yl)- 4 -(pyridine-2- yl) pyridine-3- carbonitril) donated as (C1 & C2, respectively). Three weeks later gene expression of renal alpha smooth muscle actin (α-SMA) and of cyclooxygenase-2 (COX-2) protein expression were assessed as well as serum malondialdehyde (MDA) and total antioxidant capacity in both kidney and brain tissues. Furthermore, acetylcholinestrase activity was assessed. Candida albicans significantly elevated serum MDA. On the other hand, C. albicans injection revealed a significantly reduction in total antioxidant capacity in kidney as well as in brain tissue. Furthermore, acetylcholine assessment declared a significant elevation. All biochemical parametersۥ upset were modulated upon new synthesized compounds treatment. Molecular analyses declared a significant down - regulation in renal α -smooth muscle actin gene expression in addition to, a significant down- regulation in COX-2 protein expression. From data recorded, it could be concluded that, C2 in a dose 200 mg ∕kg noticeably declared a significant effect comparing with the other treated groups revealing its promising effect as anti-fungal agent.

Evaluation of intravenous voriconazole in patients with compromised renal function

Background

Incorporation of the solubilizing excipient, sulfobutylether-β-cyclodextrin (SBECD), in the intravenous (IV) formulation of voriconazole has resulted in the recommendation that this formulation be used with caution in patients with creatinine clearances (Cl_cr) < 50 mL/min. This study evaluated the safety of IV voriconazole compared with two other IV antifungals not containing SBECD in patients with compromised renal function.

Methods

A total of 128 patients aged 11–93 years who had a baseline Cl_cr < 50 mL/min between January 1, 2007 and December 31, 2010 were identified from a database of a university-affiliated inpatient healthcare system; of these, 55 patients received caspofungin, 54 patients received fluconazole, and 19 patients received voriconazole. Changes in serum creatinine (S_cr) and Cl_cr levels while on therapy were compared with baseline values and between groups.

Results

The groups had similar characteristics apart from the larger proportion of females that received fluconazole. Baseline S_cr was higher in those receiving caspofungin, but maximal increases of S_cr and decreases in Cl_cr were greatest for the fluconazole group. Acute kidney injury (AKI), assessed by RIFLE criteria, was more frequent in the fluconazole vs. the caspofungin group (p < 0.01); incidence of AKI in the voriconazole group was not significantly different than found in the other two groups. The infecting organism was a predictor of AKI and formulation with SBECD was not.

Conclusions

Treatment of fungal infections in patients with compromised renal function with an SBECD-containing antifungal agent was not associated with AKI in clinical practice. Since the infecting organism was associated with AKI, decision on which antifungal to use should be determined by susceptibilities to the organism and not the incorporation of SBECD in the IV formulation.

Glomerular endothelial injury associated with free radical production induced by a fungal cell wall component, (1-->3) beta-D glucan

Clinical evidence suggests that microangiopathy may be induced by fungal infection. The present study evaluated the toxic effect of (1-->3) beta-D glucan, a major component of fungal cell wall, on cultured transformed glomerular endothelial cells (TF-GEN). When TF-GEN were exposed to increasing concentrations of (1-->3) beta-D glucan (beta-DG; 115 to 430 pg/ml) for 1 to 3 hours, concentration- and time-dependent increases in hydroxyl radical production were demonstrated by electron paramagnetic resonance spectrometry using 5, 5-dimethyl-1-pyrrolyne-N-oxide as a spin trap agent. The amount of radicals induced by 230 or 430 pg/ml beta-DG was comparable to that induced by E. coli LPS (1 or 10 microg/ml). The beta-DG-induced free radical production was associated with a subsequent increase in LDH release from TF-GEN. When TF-GEN pretreated with U78517F (0.1 or 1.0 microM), a lipophilic antioxidant, were stimulated with LPS (1 or 10 microg/ml) or beta-DG (230 pg/ml) for 3 hours, free radical production by TF-GEN was significantly reduced in cells pretreated with the higher concentration of U78517F. Thus, fungal (1-->3) beta-D glucan induces glomerular endothelial injury by stimulating cellular free radical production. Such a mechanism may underlie microangiopathy in systemic fungal infections.