In vitro inhibition of biofilm and virulence factor production in azole-resistant strains of Candida albicans isolated from diabetic foot by Artemisia vulgaris stabilized tin (IV) oxide nanoparticles

The advent of nanotechnology has been instrumental in the development of new drugs with novel targets. Recently, metallic nanoparticles have emerged as potential candidates to combat the threat of drug-resistant infections. Diabetic foot ulcers (DFUs) are one of the dreadful complications of diabetes mellitus due to the colonization of numerous drug-resistant pathogenic microbes leading to biofilm formation. Biofilms are difficult to treat due to limited penetration and non-specificity of drugs. Therefore, in the current investigation, SnO2 nanoparticles were biosynthesized using Artemisia vulgaris (AvTO-NPs) as a stabilizing agent and were characterized using ultraviolet–visible (UV–vis) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Furthermore, the efficacy of AvTO-NPs against biofilms and virulence factors of drug-resistant Candida albicans strains isolated from DFUs was assessed. AvTO-NPs displayed minimum inhibitory concentrations (MICs) ranging from 1 mg/mL to 2 mg/mL against four strains of C. albicans. AvTO-NPs significantly inhibited biofilm formation by 54.8%–87%, germ tube formation by 72%–90%, cell surface hydrophobicity by 68.2%–82.8%, and exopolysaccharide (EPS) production by 69%–86.3% in the test strains at respective 1/2xMIC. Biosynthesized NPs were effective in disrupting established mature biofilms of test strains significantly. Elevated levels of reactive oxygen species (ROS) generation in the AvTO-NPs-treated C. albicans could be the possible cause of cell death leading to biofilm inhibition. The useful insights of the present study could be exploited in the current line of treatment to mitigate the threat of biofilm-related persistent DFUs and expedite wound healing

<i>Candida albicans</i> Strains Adapted to Caspofungin Due to Aneuploidy Become Highly Tolerant under Continued Drug Pressure

Candida albicans is a prevalent fungal pathogen of humans. Understanding the development of decreased susceptibility to ECN drugs of this microbe is of substantial interest, as it is viewed as an intermediate step allowing the formation of FKS1 resistance mutations. We used six previously characterized mutants that decreased caspofungin susceptibility either by acquiring aneuploidy of chromosome 5 (Ch5) or by aneuploidy-independent mechanisms. When we exposed these caspofungin-adapted mutants to caspofungin again, we obtained 60 evolved mutants with further decreases in caspofungin susceptibility, as determined with CLSI method. We show that the initial adaptation to caspofungin is coupled with the adaptation to other ECNs, such as micafungin and anidulafungin, in mutants with no ploidy change, but not in aneuploid mutants, which become more susceptible to micafungin and anidulafungin. Furthermore, we find that the initial mechanism of caspofungin adaptation determines the pattern of further adaptation as parentals with no ploidy change further adapt to all ECNs by relatively small decreases in susceptibility, whereas aneuploid parentals adapt to all ECNs, primarily by large decrease in susceptibilities. Our data suggest that either distinct or common mechanisms can govern adaptation to different ECNs

Research and Reviews: Journal of Pharmaceutical Quality Assurance A Comprehensive Drug Review on Macitentan: A Preeminent Inclusion to Pulmonary Arterial Hypertension Therapy

ABSTRACT Macitentan is a radically novice oral orphan drug which was approved by FDA in Oct 2013 (under trade name Opsumit ® ). It belongs to the class of the endothelin receptor antagonist (ETRA) and is indicated for the treatment of pulmonary arterial hypertension (PAH). PAH is a chronic disorder of raising blood pressure in the artery between the aisle of heart and lung. Till the date, the disease remains incurable and possesses a poor prognosis. A ray of hope in this direction is shown by Macitentan, which has been proved beneficial in decreasing disease progression symptoms and reducing hospitalization. Phase III SERAPHIN trials clearly indicate that it improves morbidity, mortality and 6MWD data compared with other drugs of the same class. Furthermore, its use is seemingly increasing for the treatment of other cardiovascular disorders related to ET system. However, the pharmacokinetics dose adjustments of Macitentan in patients with renal or hepatic impairment are extraneous. Drug-drug interactions are occult, and one circulating pharmacologically active metabolite (ACT-132577) is omnipresent. The safety profile of Macitentan is superior to other drugs of same ETRA&apos;s class with prolonged receptor binding properties, greater tissue penetration, hepatic safety, edema/ fluid retention and easy dosing, but it is similar when the decrease in hemoglobin concentration is taken into account. Macitentan attributes, hence, are appended and revolutionary important in the therapeutic longterm treatment and a better alternative remedy for PAH. The present review thus delineates the complete drug profile of Macitentan from the data of studies carried out till date and alleges it as a sanguine future for an overall improved CVS healthcare contributor

Distinct roles of the 7-transmembrane receptor protein Rta3 in regulating the asymmetric distribution of phosphatidylcholine across the plasma membrane and biofilm formation in Candida albicans.

Fungal pathogens such as Candida albicans exhibit several survival mechanisms to evade attack by antifungals and colonise host tissues. Rta3, a member of the Rta1-like family of lipid-translocating exporters has a 7-transmembrane domain topology, similar to the G-protein-coupled receptors and is unique to the fungal kingdom. Our findings point towards a role for the plasma membrane localised Rta3 in providing tolerance to miltefosine, an analogue of alkylphosphocholine, by maintaining mitochondrial energetics. Concurrent with miltefosine susceptibility, the rta3Δ/Δ strain displays increased inward translocation (flip) of fluorophore-labelled phosphatidylcholine (PC) across the plasma membrane attributed to enhanced PC-specific flippase activity. We also assign a novel role to Rta3 in the Bcr1-regulated pathway for in vivo biofilm development. Transcriptome analysis reveals that Rta3 regulates expression of Bcr1 target genes involved in cell surface properties, adhesion, and hyphal growth. We show that rta3Δ/Δ mutant is biofilm-defective in a rat venous catheter model of infection and that BCR1 overexpression rescues this defect, indicating that Bcr1 functions downstream of Rta3 to mediate biofilm formation in C.&nbsp;albicans. The identification of this novel Rta3-dependent regulatory network that governs biofilm formation and PC asymmetry across the plasma membrane will provide important insights into C.&nbsp;albicans pathogenesis

Distinct roles of the 7-transmembrane receptor protein Rta3 in regulating the asymmetric distribution of phosphatidylcholine across the plasma membrane and biofilm formation in Candida albicans.

Fungal pathogens such as Candida albicans exhibit several survival mechanisms to evade attack by antifungals and colonise host tissues. Rta3, a member of the Rta1-like family of lipid-translocating exporters has a 7-transmembrane domain topology, similar to the G-protein-coupled receptors and is unique to the fungal kingdom. Our findings point towards a role for the plasma membrane localised Rta3 in providing tolerance to miltefosine, an analogue of alkylphosphocholine, by maintaining mitochondrial energetics. Concurrent with miltefosine susceptibility, the rta3Δ/Δ strain displays increased inward translocation (flip) of fluorophore-labelled phosphatidylcholine (PC) across the plasma membrane attributed to enhanced PC-specific flippase activity. We also assign a novel role to Rta3 in the Bcr1-regulated pathway for in vivo biofilm development. Transcriptome analysis reveals that Rta3 regulates expression of Bcr1 target genes involved in cell surface properties, adhesion, and hyphal growth. We show that rta3Δ/Δ mutant is biofilm-defective in a rat venous catheter model of infection and that BCR1 overexpression rescues this defect, indicating that Bcr1 functions downstream of Rta3 to mediate biofilm formation in C.&nbsp;albicans. The identification of this novel Rta3-dependent regulatory network that governs biofilm formation and PC asymmetry across the plasma membrane will provide important insights into C.&nbsp;albicans pathogenesis

Dataset for: Distinct roles of the 7-transmembrane receptor protein Rta3 in regulating the asymmetric distribution of phosphatidylcholine across the plasma membrane and biofilm formation in <i>Candida albicans</i>

Fungal pathogens like <i>Candida albicans</i> exhibit several survival mechanisms to evade attack by antifungals and colonize host tissues. Rta3, a member of the Rta1-like family of lipid-translocating exporters has a 7-transmembrane domain (7TMD) topology, similar to the G-protein-coupled receptors (GPCR) and is unique to the fungal kingdom. Our findings point towards a role for plasma membrane localized Rta3 in providing tolerance to miltefosine, an analogue of alkylphosphocholine, by maintaining mitochondrial energetics. Concurrent with miltefosine susceptibility, the <i>rta3Δ/Δ</i> strain displays increased inward translocation (flip) of fluorophore-labelled phosphatidylcholine (PC) across the plasma membrane attributed to enhanced PC-specific flippase activity. We also assign a novel role to Rta3 in the Bcr1- regulated pathway during in vivo biofilm development. Transcriptome analysis reveals that Rta3 regulates expression of Bcr1 target genes involved in cell surface properties, adhesion, and hyphal growth. We show that the <i>rta3Δ/Δ</i> mutant is biofilm-defective in a rat venous catheter model of infection and that <i>BCR1</i> overexpression rescues this defect, indicating that Bcr1 functions downstream of Rta3 to mediate biofilm formation in <i>C. albicans</i>. The identification of this novel Rta3-dependent regulatory network that governs biofilm formation and PC asymmetry across the plasma membrane will provide important insights into <i>C. albicans</i> pathogenesis by providing insight into how <i>C. albicans</i> adapts to the host environment

Table_1_In vitro inhibition of biofilm and virulence factor production in azole-resistant strains of Candida albicans isolated from diabetic foot by Artemisia vulgaris stabilized tin (IV) oxide nanoparticles.docx

The advent of nanotechnology has been instrumental in the development of new drugs with novel targets. Recently, metallic nanoparticles have emerged as potential candidates to combat the threat of drug-resistant infections. Diabetic foot ulcers (DFUs) are one of the dreadful complications of diabetes mellitus due to the colonization of numerous drug-resistant pathogenic microbes leading to biofilm formation. Biofilms are difficult to treat due to limited penetration and non-specificity of drugs. Therefore, in the current investigation, SnO2 nanoparticles were biosynthesized using Artemisia vulgaris (AvTO-NPs) as a stabilizing agent and were characterized using ultraviolet–visible (UV–vis) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Furthermore, the efficacy of AvTO-NPs against biofilms and virulence factors of drug-resistant Candida albicans strains isolated from DFUs was assessed. AvTO-NPs displayed minimum inhibitory concentrations (MICs) ranging from 1 mg/mL to 2 mg/mL against four strains of C. albicans. AvTO-NPs significantly inhibited biofilm formation by 54.8%–87%, germ tube formation by 72%–90%, cell surface hydrophobicity by 68.2%–82.8%, and exopolysaccharide (EPS) production by 69%–86.3% in the test strains at respective 1/2xMIC. Biosynthesized NPs were effective in disrupting established mature biofilms of test strains significantly. Elevated levels of reactive oxygen species (ROS) generation in the AvTO-NPs-treated C. albicans could be the possible cause of cell death leading to biofilm inhibition. The useful insights of the present study could be exploited in the current line of treatment to mitigate the threat of biofilm-related persistent DFUs and expedite wound healing.</p