New Technologies to Diagnose and Treat a Multidrug-Resistant Candida auris: A Patent Review

Synergistic Antifungal Activity of Pentamidine and Auranofin Against Multidrug-Resistant Candida auris

BACKGROUND

Candida auris is a significant clinical concern due to its ability to cause outbreaks in healthcare settings and its common resistance to current treatments. This highlights the need for alternative therapies. Drug repurposing offers a promising approach, and the combination of pentamidine (antiprotozoal) and auranofin (anti-rheumatic) has shown potential antifungal activity against Candida species, including C. auris. This study aimed to evaluate the antifungal activity of pentamidine and auranofin, both individually and in combination, against C. auris.

METHODS

Minimum Inhibitory Concentrations (MICs) were determined following CLSI guidelines, and drug interactions were assessed using the checkerboard microdilution method. Additional evaluations included growth inhibition, antibiofilm activity, cell damage, sorbitol protection, and efflux pump inhibition. Nucleotide leakage and cell membrane permeability were analyzed using biochemical assays. In vivo efficacy was tested using a Tenebrio molitor larvae model infected with C. auris.

RESULTS

The MICs of pentamidine against C. auris ranged from 16 to 128 μg/mL, showing fungicidal activity. The combination with auranofin had a synergistic effect (FICI: 0.37) and exhibited a fungistatic effect in growth inhibition assays. Auranofin was most effective at inhibiting biofilm formation. Pentamidine impaired mitochondrial function, leading to cellular respiration issues and membrane damage. Efflux pump assays indicated activation by both drugs, potentially influencing resistance. In vivo tests showed both drugs significantly improved survival rates in infected larvae compared to fluconazole.

CONCLUSION

In conclusion, pentamidine and auranofin, either individually or in combination, are promising treatments for C. auris and warrant further research into optimal dosing and combination strategies.

Characterization of susceptibility patterns and adaptability of the newly emerged Candida auris

The emergence of Candida auris has caused a major concern in the public health worldwide. This novel fungus is characterized by its multidrug resistance profile, ability to thrive in harsh and stressful conditions, as well as high temperatures and salt concentrations, persistence on hospital surfaces, causing nosocomial infections and outbreaks, and unique fitness properties. Here, we study the antifungal susceptibility patterns, thermotolerance, and halotolerance of 15 putative C. auris clinical isolates from Inkosi Albert Academic Hospital, Durban, South Africa. Five of the C. auris isolates showed resistance to all three antifungals (fluconazole, amphotericin B, and micafungin) and were selected for characterization of their adaptability mechanisms. Four of the tested multidrug-resistant C. auris isolates (C. auris strain F25, C. auris strain F276, C. auris F283, and C. auris M153) showed good growth when exposed to high temperature (42 °C) and salinity (10% NaCl) conditions whereas one isolate (C. auris F65) showed moderate growth under these conditions. Candida parapsilosis showed poor growth whereas C. albicans no growth under these conditions. The five C. auris strains were positive for all the adaptive features.

Current global status of Candida auris an emerging multidrug-resistant fungal pathogen: bibliometric analysis and network visualization

BACKGROUND

Candida auris is an emerging multidrug-resistant fungal pathogen associated with nosocomial infections and hospital outbreaks worldwide, presenting a serious global health threat. There has been a rapid emergence of scientific research publications focusing on therapeutic compounds, diagnostic techniques, control strategies, prevention, and understanding the epidemiology related to C. auris.

OBJECTIVE

This study aims to provide the most up-to-date comprehensive and integrated examination of C. auris research subject and demonstrate that C. auris is indeed a topic of increasing interest.

METHODS

The search query "candida-auris" was used as a topic term to find and retrieve relevant data published between 2009 and 15 June 2023, from the Web of Science Core Collection (WoSCC) database. In this work, the bibliometric analysis and network visualization were conducted using VOSviewer software, and Biblioshiny interface accessible through the Bibliometrix R-package on RStudio software.

RESULTS

The yearly growth rate percentage (37.91%), along with the strong positive correlations between publications and citations (r = 0.981; p < 0.001), suggests heightened scholarly engagement in this topic. The USA, India, China, and the UK have emerged as pivotal contributors, with the Centers for Disease Control and Prevention (CDC) in the USA being the most productive institution. Current research hotspots in this field mainly focused on identifying and limiting transmission of the clonal strains, epidemiology, antifungal resistance, and in vitro antifungal susceptibility testing.

CONCLUSION

This detailed bibliometric analysis in C. auris topic shows that this fungal pathogen has garnered growing attention and attracted progressively more scholars. This paper will help researchers to find without difficulty the relevant articles, research hotspots, influential authors, institutions, and countries related to the topic.

Candidiasis and Other Emerging Yeasts

Purpose of Review

The review presents a comprehensive and updated information on the contemporary status of invasive candidiasis (IC), other emerging yeast infections, and the challenges they present in terms of at-risk population, specific virulence attributes, and antifungal susceptibility profile.

Recent Findings

With the advancement in medical field, there has been parallel expansion of vulnerable populations over the past two decades. This had led to the emergence of a variety of rare yeasts in healthcare settings, both Candida and non-Candida yeast causing sporadic cases and outbreaks. The advancements in diagnostic modalities have enabled accurate identification of rare Candida species and non-Candida yeast (NCY) of clinical importance. Their distribution and susceptibility profile vary across different geographical regions, thus necessitating surveillance of local epidemiology of these infections to improve patient outcomes.

Summary

The challenges in management of IC have been complicated with emergence of newer species and resistance traits. C. tropicalis has already overtaken C. albicans in many Asian ICUs, while C. auris is rising rapidly worldwide. Recent genomic research has reclassified several yeasts into newer genera, and an updated version of MALDI-TOF MS or ITS sequencing is necessary for accurate identification. Having a knowledge of the differences in predisposing factors, epidemiology and susceptibility profile of already established pathogenic yeasts, as well as new emerging yeasts, are imperative for better patient management.