Emergence of Candida auris in Brazil in a COVID-19 Intensive Care Unit

Screening of the global health priority BoxⓇ reveals potential new disinfectants against the emerging multidrug-resistant pathogen Candida auris

BACKGROUND

Candida auris has been identified by the World Health Organization as a critical pathogen due to its invasive nature, resistance to multiple drugs, and high mortality rates in hospital outbreaks. This fungus can persist on surfaces and human skin for extended periods, complicating infection control efforts. The need for effective disinfection strategies is urgent, as current disinfectants are often ineffective against C. auris biofilms.

OBJECTIVE

The study aimed to identify potential disinfectants from a collection of 240 compounds in the Global Health Priority Box® that are effective against C. auris, particularly strains resistant to existing options.

METHODS

The research employed a screening protocol using a fluconazole-resistant strain of C. auris (149/23). Antifungal activity was assessed using the microdilution method to determine Minimum Inhibitory Concentrations (MICs) and Minimum Fungicidal Concentrations (MFCs). Additional assays were conducted to evaluate biofilm inhibition, biofilm eradication, cell membrane integrity, nucleotide leakage, sorbitol protection assay, efflux pump inhibition, and hemolysis assay.

RESULTS

Two compounds, Hydramethylnon (MMV1577471) and Flufenerim (MMV1794206), demonstrated significant inhibitory effects against C. auris. Hydramethylnon exhibited potent antifungal activity, inhibiting up to 93 % of fungal growth with an MFC of 16 μg/mL. Flufenerim inhibited up to 58 % of fungal growth, showing fungistatic action with an MFC greater than 4 μg/mL. Biofilm inhibition tests showed that both compounds significantly inhibited biofilm formation, with increased efficacy at higher concentrations. Both compounds showed eradication rates in both stages. Furthermore, Hydramethylnon and Flufenerim did not affect cell membrane integrity or nucleotide leakage, suggesting a mode of action not reliant on disrupting these cellular components. The sorbitol protection assay revealed that neither compound caused cell wall damage. In the efflux pump inhibition assay, Hydramethylnon did not activate efflux pumps, while Flufenerim activated efflux pumps, reducing its effectiveness. Hemocompatibility assay showed safety.

CONCLUSION

The study highlights Hydramethylnon and Flufenerim as promising candidates for further development as disinfectants, offering potential solutions to the urgent need for effective disinfection agents against C. auris. The findings underscore the value of screening compound collections to identify novel antifungal agents and understand their mechanisms of action, thereby contributing to the advancement of new disinfection strategies in healthcare settings.

Liposomal Fba and Met6 peptide vaccination protects mice from disseminated candidiasis

Epitopes from the Candida cell surface proteins Fba and Met6 are putative vaccine targets for invasive candidiasis. Here, we describe a Candida vaccine approach in which short peptides derived from Fba and Met6 are used in spontaneous nanoliposome antigen particle (SNAP) format. SNAP was enabled by the interaction of cobalt porphyrin phospholipid in liposomes with three histidine residues on the N-terminus of synthetic short peptide immunogens from Fba (F-SNAP), Met6 (M-SNAP), or bivalent Fba and Met6 (FM-SNAP). Liposomes were adjuvanted with synthetic monophosphoryl lipid and QS-21. In mice, immunization with F-SNAP, M-SNAP, or FM-SNAP induced antigen-specific IgG responses and mixed Th1/Th2 immunity. The duplex FM-SNAP vaccine elicited stronger antibody responses against each peptide, even at order-of-magnitude lower peptide dosing than a comparable adjuvanted, conjugate vaccine. Enzyme-linked immunosorbent spot analysis revealed the induction of antigen-specific, cytokine-producing T cells. Compared to F-SNAP or M-SNAP, higher production of TNFα, IL-2, and IFNγ was observed with re-stimulation of splenocytes from bivalent FM-SNAP-immunized mice. When vaccinated BALB/c mice were challenged with Candida auris, analysis of the fungal burden in the kidneys showed that SNAP vaccination protected from disseminated candidiasis. In a lethal fungal exposure model in A/J mice, F-SNAP, M-SNAP, and FM-SNAP vaccination protected mice from candidiasis challenge. Together, these results show that further investigation into the SNAP adjuvant platform is warranted using Fba and Met6 epitopes for a pan-Candida peptide vaccine that provides multifaceted protective immune responses.

IMPORTANCE

This study introduces a promising vaccine strategy against invasive candidiasis, a severe fungal infection, by targeting specific peptides on the surface of Candida. Using a novel approach called spontaneous nanoliposome antigen particle (SNAP), we combined peptides from two key Candida proteins, Fba and Met6, into a vaccine. This vaccine induced robust immune responses in mice, including the production of protective antibodies and the activation of immune cells. Importantly, mice vaccinated with SNAP were shielded from disseminated candidiasis in experiments. These findings highlight a potential avenue for developing a broad-spectrum vaccine against Candida infections, which could significantly improve outcomes for patients at risk of these often deadly fungal diseases.

Near-infrared spectroscopy and multivariate analysis as effective, fast, and cost-effective methods to discriminate Candida auris from Candida haemulonii

Candida auris and Candida haemulonii are two emerging opportunistic pathogens that have caused an increase in clinical cases in the recent years worldwide. The differentiation of some Candida species is highly laborious, difficult, costly, and time-consuming depending on the similarity between the species. Thus, this study aimed to develop a new, faster, and less expensive methodology for differentiating between C. auris and C. haemulonii based on near-infrared (NIR) spectroscopy and multivariate analysis. C. auris CBS10913 and C. haemulonii CH02 were separated in 15 plates per species, and three isolated colonies of each plate were selected for Fourier transform near-infrared (FT-NIR) analysis, totaling 90 spectra. Subsequently, principal component analysis (PCA) and variable selection algorithms, including the successive projections algorithm (SPA) and genetic algorithm (GA) coupled with linear discriminant analysis (LDA), were employed to discern distinctive patterns among the samples. The use of PCA, SPA, and GA algorithms associated with LDA achieved 100% sensitivity and specificity for the discriminations. The SPA-LDA and GA-LDA algorithms were essential in selecting the variables (infrared wavelengths) of most importance for the models, which could be attributed to binding of cell wall structures such as polysaccharides, peptides, proteins, or molecules resulting from yeasts' metabolism. These results show the high potential of combined FT-NIR and multivariate analysis techniques for the classification of Candida-like fungi, which can contribute to faster and more effective diagnosis and treatment of patients affected by these microorganisms.

What are the 100 most cited fungal genera?

The global diversity of fungi has been estimated between 2 to 11 million species, of which only about 155 000 have been named. Most fungi are invisible to the unaided eye, but they represent a major component of biodiversity on our planet, and play essential ecological roles, supporting life as we know it. Although approximately 20 000 fungal genera are presently recognised, the ecology of most remains undetermined. Despite all this diversity, the mycological community actively researches some fungal genera more commonly than others. This poses an interesting question: why have some fungal genera impacted mycology and related fields more than others? To address this issue, we conducted a bibliometric analysis to identify the top 100 most cited fungal genera. A thorough database search of the Web of Science, Google Scholar, and PubMed was performed to establish which genera are most cited. The most cited 10 genera are Saccharomyces, Candida, Aspergillus, Fusarium, Penicillium, Trichoderma, Botrytis, Pichia, Cryptococcus and Alternaria. Case studies are presented for the 100 most cited genera with general background, notes on their ecology and economic significance and important research advances. This paper provides a historic overview of scientific research of these genera and the prospect for further research. Citation: Bhunjun CS, Chen YJ, Phukhamsakda C, Boekhout T, Groenewald JZ, McKenzie EHC, Francisco EC, Frisvad JC, Groenewald M, Hurdeal VG, Luangsa-ard J, Perrone G, Visagie CM, Bai FY, Błaszkowski J, Braun U, de Souza FA, de Queiroz MB, Dutta AK, Gonkhom D, Goto BT, Guarnaccia V, Hagen F, Houbraken J, Lachance MA, Li JJ, Luo KY, Magurno F, Mongkolsamrit S, Robert V, Roy N, Tibpromma S, Wanasinghe DN, Wang DQ, Wei DP, Zhao CL, Aiphuk W, Ajayi-Oyetunde O, Arantes TD, Araujo JC, Begerow D, Bakhshi M, Barbosa RN, Behrens FH, Bensch K, Bezerra JDP, Bilański P, Bradley CA, Bubner B, Burgess TI, Buyck B, Čadež N, Cai L, Calaça FJS, Campbell LJ, Chaverri P, Chen YY, Chethana KWT, Coetzee B, Costa MM, Chen Q, Custódio FA, Dai YC, Damm U, de Azevedo Santiago ALCM, De Miccolis Angelini RM, Dijksterhuis J, Dissanayake AJ, Doilom M, Dong W, Alvarez-Duarte E, Fischer M, Gajanayake AJ, Gené J, Gomdola D, Gomes AAM, Hausner G, He MQ, Hou L, Iturrieta-González I, Jami F, Jankowiak R, Jayawardena RS, Kandemir H, Kiss L, Kobmoo N, Kowalski T, Landi L, Lin CG, Liu JK, Liu XB, Loizides M, Luangharn T, Maharachchikumbura SSN, Makhathini Mkhwanazi GJ, Manawasinghe IS, Marin-Felix Y, McTaggart AR, Moreau PA, Morozova OV, Mostert L, Osiewacz HD, Pem D, Phookamsak R, Pollastro S, Pordel A, Poyntner C, Phillips AJL, Phonemany M, Promputtha I, Rathnayaka AR, Rodrigues AM, Romanazzi G, Rothmann L, Salgado-Salazar C, Sandoval-Denis M, Saupe SJ, Scholler M, Scott P, Shivas RG, Silar P, Souza-Motta CM, Silva-Filho AGS, Spies CFJ, Stchigel AM, Sterflinger K, Summerbell RC, Svetasheva TY, Takamatsu S, Theelen B, Theodoro RC, Thines M, Thongklang N, Torres R, Turchetti B, van den Brule T, Wang XW, Wartchow F, Welti S, Wijesinghe SN, Wu F, Xu R, Yang ZL, Yilmaz N, Yurkov A, Zhao L, Zhao RL, Zhou N, Hyde KD, Crous PW (2024). What are the 100 most cited fungal genera? Studies in Mycology 108: 1-411. doi: 10.3114/sim.2024.108.01.

Mechanism of azole resistance in Candida vulturna, an emerging multidrug resistant pathogen related with Candida haeumulonii and Candida auris

BACKGROUND

Candida vulturna is an emerging pathogen belonging to the Metshnikowiaceae family together with Candida auris and Candida haemulonii species complex. Some strains of this species were reported to be resistant to several antifungal agents.

OBJECTIVES

This study aims to address identification difficulties, evaluate antiungal susceptibilities and explore the molecular mechanisms of azole resistance of Candida vulturna.

METHODS

We studied five C. vulturna clinical strains isolated in three Colombian cities. Identification was performed by phenotypical, proteomic and molecular methods. Antifungal susceptibility testing was performed following CLSI protocol. Its ERG11 genes were sequenced and a substitution was encountered in azole resistant isolates. To confirm the role of this substitution in the resistance phenotype, Saccharomyces cerevisiae strains with a chimeric ERG11 gene were created.

RESULTS

Discrepancies in identification methods are highlighted. Sequencing confirmed the identification as C. vulturna. Antifungal susceptibility varied among strains, with four strains exhibiting reduced susceptibility to azoles and amphotericin B. ERG11 sequencing showed a point mutation (producing a P135S substitution) that was associated with the azole-resistant phenotype.

CONCLUSIONS

This study contributes to the understanding of C. vulturna's identification challenges, its susceptibility patterns, and sheds light on its molecular mechanisms of azole resistance.

Systematic Review of Candidemia in Brazil: Unlocking Historical Trends and Challenges in Conducting Surveys in Middle-Income Countries

INTRODUCTION

Candidemia, a bloodstream infection predominantly affecting critically ill patients, poses a significant global health threat especially with the emergence of non-albicans Candida species, including drug-resistant strains. In Brazil, limited access to advanced diagnostic tools and trained microbiologists hampers accurate identification of Candida species and susceptibility to antifungals testing hindering surveillance efforts.

METHODS

We conducted a systematic review spanning publications from 2017 to 2023 addressing Candida species distribution and antifungal susceptibility among Brazilian patients with candidemia.

RESULTS

Despite initially identifying 7075 records, only 16 met inclusion criteria providing accurate information of 2305 episodes of candidemia. The predominant species were C. albicans, C. parapsilosis, and C. tropicalis, followed by notable proportions of Nakaseomyces glabratus. Limited access to diagnostic tests was evident as only 5 out of 16 studies on candidemia were able to report antifungal susceptibility testing results. In vitro resistance to echinocandins was rare (only 6/396 isolates, 1,5%). In counterpart, fluconazole exhibited resistance rates ranging from 0 to 43%, with great heterogeneity among different studies and species of Candida considered.

CONCLUSION

Our review underscores the critical need for enhanced surveillance and research efforts to address the evolving landscape of candidemia and antifungal resistance in Brazil. Despite some limitations, available data suggest that while resistance to echinocandins and amphotericin B remains rare, there is a growing concern regarding resistance to fluconazole among Candida species.

Multicenter Candida auris outbreak caused by azole-susceptible clade IV in Pernambuco, Brazil

BACKGROUND

Candida auris is an emerging multidrug-resistant yeast, frequently causing outbreaks in health care facilities. The pathogen persistently colonises human skin and inanimate surfaces such as catheters, aiding to its spread. Moreover, colonisation is a risk factor to develop invasive infection.

OBJECTIVES

We investigated 61 C. auris strains isolated from non-sterile human body sites (n = 53) and the hospital environment (n = 8), originating from four different centres in a single Brazilian state.

MATERIALS AND METHODS

Antifungal susceptibility testing (AFST) against common antifungals was performed, and resistance-associated genes were evaluated. Genetic relatedness was investigated with short tandem repeat (STR) genotyping and validated with whole-genome sequencing (WGS) single nucleotide polymorphism (SNP) analysis.

RESULTS

Antifungal susceptibility testing demonstrated that all isolates were susceptible to azoles, echinocandins and amphotericin B. No mutations were detected in ERG11 and FKS1 genes. With STR typing, isolates were allocated to clade IV and appeared closely related. This was confirmed by WGS SNP analysis of 6 isolates, which demonstrated a maximal difference of only 41 SNPs between these strains. Furthermore, the Brazilian isolates formed a distinct autochthonous branch within clade IV, excluding recent introductions from outside the country. A molecular clock analysis of clade IV isolates from various countries suggests that early in the previous century there was a unique event causing environmental spread of a C. auris ancestor throughout the Latin-American continent, followed by human introduction during the last decades.

CONCLUSION

We report the emergence of C. auris patient colonisation in multiple centres by fluconazole-susceptible clade IV close-related strains in Pernambuco State, Brazil.

Rapid Environmental Contamination With Candida auris and Multidrug-Resistant Bacterial Pathogens Near Colonized Patients

BACKGROUND

Environmental contamination is suspected to play an important role in Candida auris transmission. Understanding speed and risks of contamination after room disinfection could inform environmental cleaning recommendations.

METHODS

We conducted a prospective multicenter study of environmental contamination associated with C. auris colonization at 6 ventilator-capable skilled nursing facilities and 1 acute care hospital in Illinois and California. Known C. auris carriers were sampled at 5 body sites followed by sampling of nearby room surfaces before disinfection and at 0, 4, 8, and 12 hours after disinfection. Samples were cultured for C. auris and bacterial multidrug-resistant organisms (MDROs). Odds of surface contamination after disinfection were analyzed using multilevel generalized estimating equations.

RESULTS

Among 41 known C. auris carriers, colonization was detected most frequently on palms/fingertips (76%) and nares (71%). C. auris contamination was detected on 32.2% (66/205) of room surfaces before disinfection and 20.5% (39/190) of room surfaces by 4 hours after disinfection. A higher number of C. auris-colonized body sites was associated with higher odds of environmental contamination at every time point following disinfection, adjusting for facility of residence. In the rooms of 38 (93%) C. auris carriers co-colonized with a bacterial MDRO, 2%-24% of surfaces were additionally contaminated with the same MDRO by 4 hours after disinfection.

CONCLUSIONS

C. auris can contaminate the healthcare environment rapidly after disinfection, highlighting the challenges associated with environmental disinfection. Future research should investigate long-acting disinfectants, antimicrobial surfaces, and more effective patient skin antisepsis to reduce the environmental reservoir of C. auris and bacterial MDROs in healthcare settings.

The laboratory investigation, management, and infection prevention and control of Candida auris: a narrative review to inform the 2024 national guidance update in England

The emergent fungal pathogen Candida auris is increasingly recognised as an important cause of healthcare-associated infections globally. It is highly transmissible, adaptable, and persistent, resulting in an organism with significant outbreak potential that risks devastating consequences. Progress in the ability to identify C. auris in clinical specimens is encouraging, but laboratory diagnostic capacity and surveillance systems are lacking in many countries. Intrinsic resistance to commonly used antifungals, combined with the ability to rapidly acquire resistance to therapy, substantially restricts treatment options and novel agents are desperately needed. Despite this, outbreaks can be interrupted, and mortality avoided or minimised, through the application of rigorous infection prevention and control measures with an increasing evidence base. This review provides an update on epidemiology, the impact of the COVID-19 pandemic, risk factors, identification and typing, resistance profiles, treatment, detection of colonisation, and infection prevention and control measures for C. auris. This review has informed a planned 2024 update to the United Kingdom Health Security Agency (UKHSA) guidance on the laboratory investigation, management, and infection prevention and control of Candida auris. A multidisciplinary response is needed to control C. auris transmission in a healthcare setting and should emphasise outbreak preparedness and response, rapid contact tracing and isolation or cohorting of patients and staff, strict hand hygiene and other infection prevention and control measures, dedicated or single-use equipment, appropriate disinfection, and effective communication concerning patient transfers and discharge.

Overview of invasive fungal infections in children in South America - the threat of resistant Candida species and the role of climate change in the new geographic distribution of endemic systemic mycosis

PURPOSE OF REVIEW

Invasive fungal infection (IFI) in children is a growing problem with crescent morbidity and mortality, well recognized in developed countries, affecting mainly immunocompromised children, including neonates and children in intensive care units. The burden of IFI in South American children is less well comprehended. In addition, the current epidemiology of endemic systemic mycoses in children may have changed over time.

RECENT FINDINGS

Candida spp. infections are very prevalent in South America hospitalized children, especially in neonates, in a rate far superior compared to developed countries. C. auris, has already been responsible for outbreaks in neonates and children in Venezuela and Colombia. Sporotrichosis is well established as an urban zoonosis in impoverish families. Paracoccidioidomycosis and histoplasmosis are affecting new areas of Brazil, probably due to climate change, deforestation, and human migration.

SUMMARY

This review aims to unveil the real dimension of these infections in South American children. Hopefully, the awareness brought by this review will help healthcare professionals to recognize IFI more easily and it will provide support for getting more resources for IFI treatment and prevention.

COVID-19 associated candidemia: From a shift in fungal epidemiology to a rise in azole drug resistance

Our understanding of fungal epidemiology and the burden of antifungal drug resistance in COVID-19-associated candidemia (CAC) patients is limited. Therefore, we conducted a retrospective multicenter study in Iran to explore clinical and microbiological profiles of CAC patients. Yeast isolated from blood, were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and subjected to antifungal susceptibility testing (AFST) using the broth microdilution method M27-A3 protocol. A total of 0.6% of the COVID-19 patients acquired CAC (43/6174). Fluconazole was the most widely used antifungal, and 37% of patients were not treated. Contrary to historic candidemia patients, Candida albicans and C. tropicalis were the most common species. In vitro resistance was high and only noted for azoles; 50%, 20%, and 13.6% of patients were infected with azole-non-susceptible (ANS) C. tropicalis, C. parapsilosis, and C. albicans isolates, respectively. ERG11 mutations conferring azole resistance were detected for C. parapsilosis isolates (Y132F), recovered from an azole-naïve patient. Our study revealed an unprecedented rise in ANS Candida isolates, including the first C. parapsilosis isolate carrying Y132F, among CAC patients in Iran, which potentially threatens the efficacy of fluconazole, the most widely used drug in our centers. Considering the high mortality rate and 37% of untreated CAC cases, our study underscores the importance of infection control strategies and antifungal stewardship to minimize the emergence of ANS Candida isolates during COVID-19.

Frequency of Detection of Candida auris Colonization Outside a Highly Endemic Setting: What Is the Optimal Strategy for Screening of Carriage?

Candida auris outbreaks are increasingly frequent worldwide. In our 1000-bed hospital, an endemic transmission of C. auris was established in two of five intensive care units (ICUs). Aims of our study were to describe the occurrence of new cases of C. auris colonization and infection outside the endemic ICUs, in order to add evidence for future policies on screening in patients discharged as negative from an endemic setting, as well as to propose a new algorithm for screening of such high-risk patients. From 26 March 2021 to 26 January 2023, among 392 patients who were diagnosed as colonized or infected with C. auris in our hospital, 84 (21.4%) received the first diagnosis of colonization or infection outside the endemic ICUs. A total of 68 patients out of 84 (81.0%) had a history of prior admission to the endemic ICUs. All were screened and tested negative during their ICU stay with a median time from last screening to discharge of 3 days. In 57/68 (83.8%) of patients, C. auris was detected through screening performed after ICU discharge, and 90% had C. auris colonization detected within 9 days from ICU discharge. In 13 cases (13/57 screened, 22.8%), the first post-ICU discharge screening was negative. In those not screened, candidemia was the most frequent event of the first C. auris detection (6/11 patients not screened). In settings where the transmission of C. auris is limited to certain wards, we suggest screening both at discharge from the endemic ward(s) even in case of a recent negative result, and at least twice after admission to nonendemic settings.

Study of Candidemia and its Antifungal Susceptibility Profile at the University Hospital of Montevideo, Uruguay

Systemic candidiasis are high mortality infections caused by yeasts of the genus Candida, affecting patients with numerous risk factors. Nowadays, candidemia produced by "non-albicans" species has increased considerably. Timely diagnosis and subsequent treatment substantially improve patients' survival. Our objectives are to study the frequency, distribution, and antifungal susceptibility profiles of candidemia isolates in our hospital. We conducted a descriptive, cross-sectional study. Positive blood cultures were recorded from January 2018 to December 2021. Positive Candida genus blood cultures were selected, classified, and analyzed on their susceptibility profile for amphotericin B, fluconazole and caspofungin using AST-YS08® card for VITEK 2 Compact® to determine minimum inhibitory concentration (MIC) and CLSI M60 2020 2nd Edition to determine breakpoints. 3862 positive blood cultures were obtained, 113 (2.93%) presented growth of Candida spp., corresponding to 58 patients. 55.2% came from the Hospitalization Ward and Emergency Services and 44.8% from the Intensive Care Unit. The species were distributed as follows: Nakaseomyces glabratus (Candida glabrata) (32.74%), Candida albicans (27.43%), Candida parapsilosis (23.01%), Candida tropicalis (7.08%) and others (9.73%). Most species were found to be susceptible to most antifungals, except for C. parapsilosis, presenting 4 isolates with resistance to fluconazole and N. glabratus (C. glabrata), whose clinical susceptibility data remains insufficient to provide accurate breakpoints. The percentage of recorded positive blood cultures of Candida spp. was 2.93%, these results were consistent with those reported at a regional level. A predominance of "non-albicans" species was observed. It is essential to know the prevalence, epidemiology, and susceptibility profiles of candidemia in our country, as well as being updated on its subsequent changes, maintaining epidemiological surveillance. This allows professionals to map out early and effective therapeutic strategies, staying alert of possible multi-resistant strains.

Chromophore-Targeting Precision Antimicrobial Phototherapy

Phototherapy, encompassing the utilization of both natural and artificial light, has emerged as a dependable and non-invasive strategy for addressing a diverse range of illnesses, diseases, and infections. This therapeutic approach, primarily known for its efficacy in treating skin infections, such as herpes and acne lesions, involves the synergistic use of specific light wavelengths and photosensitizers, like methylene blue. Photodynamic therapy, as it is termed, relies on the generation of antimicrobial reactive oxygen species (ROS) through the interaction between light and externally applied photosensitizers. Recent research, however, has highlighted the intrinsic antimicrobial properties of light itself, marking a paradigm shift in focus from exogenous agents to the inherent photosensitivity of molecules found naturally within pathogens. Chemical analyses have identified specific organic molecular structures and systems, including protoporphyrins and conjugated C=C bonds, as pivotal components in molecular photosensitivity. Given the prevalence of these systems in organic life forms, there is an urgent need to investigate the potential impact of phototherapy on individual molecules expressed within pathogens and discern their contributions to the antimicrobial effects of light. This review delves into the recently unveiled key molecular targets of phototherapy, offering insights into their potential downstream implications and therapeutic applications. By shedding light on these fundamental molecular mechanisms, we aim to advance our understanding of phototherapy's broader therapeutic potential and contribute to the development of innovative treatments for a wide array of microbial infections and diseases.

A Bibliometric Review on Candida auris of the First Fifteen Years of Research (2009-2023)

Introduction

Candida auris is a relatively novel pathogen first described in 2009 in Japan. It has increased its presence worldwide, becoming a public health concern due to its innate resistance to antifungals and outbreak potential.

Methods

We performed a query using the word "Candida auris" from the Scopus database, further performing a bibliometric analysis with the open-source R package Bibliometrix.

Results

907 original articles were retrieved, allowing us to map the principal authors, papers, journals, and countries involved in this yeast research, as well as analyze current and future trends and the number of published articles.

Conclusion

C. auris will continue to be a pivotal point in fungal resistance research, either for a better understanding of its resistance and pathogenic mechanisms or for developing novel drugs.

Candida auris: a global pathogen that has taken root in Colombia

Candida auris has been recognized as an emerging multidrug-resistant pathogen with a significant public health burden, causing cases of invasive infection and colonization due to its persistence on inanimate surfaces, ability to colonize skin of some patients, and high transmissibility in healthcare settings. The first sporadic report of the isolation of this species from the ear canal of a patient in Asia was in 2009 and reports from other regions of the world soon followed. However, it was not until 2015 that global epidemiological alerts were communicated as a result of an increasing number of reports of invasive infections caused by C. auris in several countries. Colombia was soon added to this list in 2016 after an unusual increase in the number of C. haemulonii isolates was reported, later confirmed as C. auris. Since the issuing of a national alert by the Colombian National Institute of Health together with the Ministry of Health in 2016, the number of cases reported reached over 2,000 by 2022. Colombian isolates have not shown pan resistance to available antifungals, unlike C. auris strains reported in other regions of the world, which leaves patients in Colombia with therapeutic options for these infections. However, increasing fluconazole resistance is being observed. Whole-genome sequencing of Colombian C. auris isolates has enhanced molecular epidemiological data, grouping Colombian isolates in clade IV together with other South American isolates.

COVID-19-associated candidiasis and the emerging concern of Candida auris infections

The incidence of COVID-19-associated candidiasis (CAC) is increasing, resulting in a grave outcome among hospitalized patients with COVID-19. The most alarming condition is the increasing incidence of multi-drug resistant Candida auris infections among patients with COVID-19 worldwide. The therapeutic strategy towards CAC caused by common Candida species, such as Candida albicans, Candida tropicalis, and Candida glabrata, is similar to the pre-pandemic era. For non-critically ill patients or those with a low risk of azole resistance, fluconazole remains the drug of choice for candidemia. For critically ill patients, those with a history of recent azole exposure or with a high risk of fluconazole resistance, echinocandins are recommended as the first-line therapy. Several novel therapeutic agents alone or in combination with traditional antifungal agents for candidiasis are potential options in the future. However, for multidrug-resistant C. auris infection, only echinocandins are effective. Infection prevention and control policies, including strict isolation of the patients carrying C. auris and regular screening of non-affected patients, are suggested to prevent the spread of C. auris among patients with COVID-19. Whole-genome sequencing may be used to understand the epidemiology of healthcare-associated candidiasis and to better control and prevent these infections.

Coinfections and Superinfections Associated with COVID-19 in Colombia: A Narrative Review

The COVID-19 pandemic has had significant impacts on healthcare systems around the world, including in Latin America. In Colombia, there have been over 23,000 confirmed cases and 100 deaths since 2022, with the highest number of cases occurring in females and the highest number of deaths in males. The elderly and those with comorbidities, such as arterial hypertension, diabetes mellitus, and respiratory diseases, have been particularly affected. Coinfections with other microorganisms, including dengue virus, Klebsiella pneumoniae, and Mycobacterium tuberculosis, have also been a significant factor in increasing morbidity and mortality rates in COVID-19 patients. It is important for surveillance systems to be improved and protocols to be established for the early detection and management of coinfections in COVID-19. In addition to traditional treatments, alternatives such as zinc supplementation and nanomedicine may have potential in the fight against COVID-19. It is also crucial to consider the social, labor, educational, psychological, and emotional costs of the pandemic and to address issues such as poverty and limited access to potable water in order to better prepare for future pandemics.

Evaluation of a Novel FKS1 R1354H Mutation Associated with Caspofungin Resistance in Candida auris Using the CRISPR-Cas9 System

Outbreaks of invasive infections, with high mortality rates, caused by multidrug-resistant Candida auris have been reported worldwide. Although hotspot mutations in FKS1 are an established cause of echinocandin resistance, the actual contribution of these mutations to echinocandin resistance remains unknown. Here, we sequenced the FKS1 gene of a caspofungin-resistant clinical isolate (clade I) and identified a novel resistance mutation (G4061A inducing R1354H). We applied the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system to generate a recovered strain (H1354R) in which only this single nucleotide mutation was reverted to its wild-type sequence. We also generated mutant strains with only the R1354H mutation introduced into C. auris wild-type strains (clade I and II) and analyzed their antifungal susceptibility. Compared to their parental strains, the R1354H mutants exhibited a 4- to 16-fold increase in caspofungin minimum inhibitory concentration (MIC) while the H1354R reverted strain exhibited a 4-fold decrease in caspofungin MIC. In a mouse model of disseminated candidiasis, the in vivo therapeutic effect of caspofungin was more closely related to the FKS1 R1354H mutation and the virulence of the strain than its in vitro MIC. The CRISPR-Cas9 system could thus aid in elucidating the mechanism underlying drug resistance in C. auris.

Worsening Spread of Candida auris in the United States, 2019 to 2021

BACKGROUND

Candida auris is an emerging fungal threat that has been spreading in the United States since it was first reported in 2016.

OBJECTIVE

To describe recent changes in the U.S. epidemiology of C auris occurring from 2019 to 2021.

DESIGN

Description of national surveillance data.

SETTING

United States.

PATIENTS

Persons with any specimen that was positive for C auris.

MEASUREMENTS

Case counts reported to the Centers for Disease Control and Prevention by health departments, volume of colonization screening, and antifungal susceptibility results were aggregated and compared over time and by geographic region.

RESULTS

A total of 3270 clinical cases and 7413 screening cases of C auris were reported in the United States through 31 December 2021. The percentage increase in clinical cases grew each year, from a 44% increase in 2019 to a 95% increase in 2021. Colonization screening volume and screening cases increased in 2021 by more than 80% and more than 200%, respectively. From 2019 to 2021, 17 states identified their first C auris case. The number of C auris cases that were resistant to echinocandins in 2021 was about 3 times that in each of the previous 2 years.

LIMITATION

Identification of screening cases depends on screening that is done on the basis of need and available resources. Screening is not conducted uniformly across the United States, so the true burden of C auris cases may be underestimated.

CONCLUSION

C auris cases and transmission have risen in recent years, with a dramatic increase in 2021. The rise in echinocandin-resistant cases and evidence of transmission is particularly concerning because echinocandins are first-line therapy for invasive Candida infections, including C auris. These findings highlight the need for improved detection and infection control practices to prevent spread of C auris.

PRIMARY FUNDING SOURCE

None.

Addressing Microbial Resistance Worldwide: Challenges over Controlling Life-Threatening Fungal Infections

Fungal infections are a serious global concern because of their ability to spread and colonize host tissues in immunocompromised individuals. Such infections have been frequently reported worldwide and are currently gaining clinical research relevance owing to their resistant character, representing a bottleneck in treating affected people. Resistant fungi are an emergent public health threat. The upsurge of such pathogens has led to new research toward unraveling the destructive potential evoked by these species. Some fungi-grouped into Candida, Aspergillus, and Cryptococcus-are causative agents of severe and systemic infections. They are associated with high mortality rates and have recently been described as sources of coinfection in COVID-hospitalized patients. Despite the efforts to elucidate the challenges of colonization, dissemination, and infection severity, the immunopathogenesis of fungal diseases remains a pivotal characteristic in fungal burden elimination. The struggle between the host immune system and the physiological strategies of the fungi to maintain cellular viability is complex. In this brief review, we highlight the relevance of drug resistance phenotypes in fungi of clinical significance, taking into consideration their physiopathology and how the scientific community could orchestrate their efforts to avoid fungal infection dissemination and deaths.

Colonized patients by Candida auris: Third and largest outbreak in Brazil and impact of biofilm formation

Objective

To describe the clinical-epidemiological features of patients colonized by Candida auris in the largest outbreak in Brazil and to show the biofilm formation capacity of yeast strains.

Methods

Clinical yeasts suspected of C. auris isolated from urine and surveillance samples were seeded on chromogenic media at 30°C and Sabouraud agar at 42°C. matrix-assisted laser desorption/ionization-time of flight mass spectometry was used for reliable identification. After proteomic confirmation, the genomic approach and culture on Chromagar Candida Plus media were carried out. Biofilm formation was investigated based on metabolic activity, and the clinical-epidemiological profile of patients was described.

Results

A total of 11 C. auris clinical yeasts from nine patients were identified between the end of December 2021 and March 2022. Two clinical yeasts were isolates from urine and nine clinical yeasts were isolates from axillary and inguinal surveillance swabs. No case is related to previous Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, all the yeasts showed a high ability of biofilm formation.

Conclusion

C. auris requires great vigilance as its high capacity to colonize and form biofilms contributes to its dissemination. The rapid and precise identification of this species is essential for the management, control, and prevention of infections.

Nanotechnology-Based Approaches for Voriconazole Delivery Applied to Invasive Fungal Infections

Invasive fungal infections increase mortality and morbidity rates worldwide. The treatment of these infections is still limited due to the low bioavailability and toxicity, requiring therapeutic monitoring, especially in the most severe cases. Voriconazole is an azole widely used to treat invasive aspergillosis, other hyaline molds, many dematiaceous molds, Candida spp., including those resistant to fluconazole, and for infections caused by endemic mycoses, in addition to those that occur in the central nervous system. However, despite its broad activity, using voriconazole has limitations related to its non-linear pharmacokinetics, leading to supratherapeutic doses and increased toxicity according to individual polymorphisms during its metabolism. In this sense, nanotechnology-based drug delivery systems have successfully improved the physicochemical and biological aspects of different classes of drugs, including antifungals. In this review, we highlighted recent work that has applied nanotechnology to deliver voriconazole. These systems allowed increased permeation and deposition of voriconazole in target tissues from a controlled and sustained release in different routes of administration such as ocular, pulmonary, oral, topical, and parenteral. Thus, nanotechnology application aiming to delivery voriconazole becomes a more effective and safer therapeutic alternative in the treatment of fungal infections.

Assessment of Risk Factors and Clinical Outcomes in Hospitalized COVID-19 Patients with Candida spp. Co-infections: Species Distribution and Antifungal Susceptibility Patterns of Isolates

INTRODUCTION

Fungal co-infections are considered an important complication in hospitalized patients with SARS-CoV-2 that can be attributed to disease aggravation, increased mortality, and poor outcomes. This study was conducted to determine the species distribution and antifungal susceptibility patterns of Candida isolates from hospitalized COVID-19 patients in Shiraz, Iran, in addition to associated risk factors and outcomes of co-infections with Candida species.

MATERIALS AND METHODS

In this single-center study, a total of 106 hospitalized COVID-19 patients were evaluated for clinical characteristics and outcomes. Species identification was performed by ITS1-5.8S-ITS2 gene sequencing. Antifungal susceptibility testing to fluconazole, itraconazole, voriconazole, posaconazole, caspofungin, amphotericin B, and nystatin was determined according to the M27-A3/S4 CLSI protocol.

RESULTS

Candida species were recovered from 48% (51/106) of hospitalized COVID-19 patients. Statistical analysis showed that patients who had heart failure, bacterial co-infection, and were receiving empirical antifungal therapy had a higher risk of developing Candida co-infection. In total, 71 Candida isolates were recovered, of which C. albicans (69%) was the most prevalent isolate. The majority of the Candida isolates were susceptible to all classes of tested antifungal drugs.

DISCUSSION

Our results elucidate a high rate of Candida co-infections among hospitalized COVID-19 patients. Comorbidities such as heart failure, HTN, COPD, bacterial infections as well as therapeutic interventions including catheterization, mechanical ventilation, and ICU admission increased the risk of Candida spp. isolation from the bloodstream, respiratory tract and urine samples, which led to a higher in-hospital mortality rate. Additionally, obtained data clarified that empirical antifungal therapy was not as successful as anticipated.

The Menace of Candida auris Epidemic Amidst the COVID-19 Pandemic: A Systematic Review

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), the causative agent for the Coronavirus Disease 2019 (COVID-19) pandemic, has sparked a medical emergency worldwide. With the rise in COVID-19 infections and an eventual increase in hospitalized critically ill patients, a trend of bacterial, fungal, and viral superinfection has been noted. One important agent of co-infection identified is Candida auris. Due to its multidrug-resistant nature and easy transmissibility, C. auris is difficult to manage in COVID-positive patients. Patients with comorbidities, immunosuppressive states, intubated and on ventilators are more likely to contract the fungal infection. Therefore, it is essential to the first screen, diagnose, and isolate patients with C. auris infection and manage and treat them while preventing the spread of the disease. Failure to recognize and prevent its spread may lead to an eventual epidemic or even a pandemic during the current COVID-pandemic, which the exhausted healthcare system can most definitely not handle. This systematic review investigates the prevalence of C. auris, its pathophysiology, diagnosis, prevention, and treatment during the COVID-19 pandemic.

Fungal Infection in Co-infected Patients With COVID-19: An Overview of Case Reports/Case Series and Systematic Review

Fungal co-infections are frequent in patients with coronavirus disease 2019 (COVID-19) and can affect patient outcomes and hamper therapeutic efforts. Nonetheless, few studies have investigated fungal co-infections in this population. This study was performed to assess the rate of fungal co-infection in patients with COVID-19 as a systematic review. EMBASE, MEDLINE, and Web of Science were searched considering broad-based search criteria associated with COVID-19 and fungal co-infection. We included case reports and case series studies, published in the English language from January 1, 2020 to November 30, 2021, that reported clinical features, diagnosis, and outcomes of fungal co-infection in patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Totally, 54 case reports and 17 case series were identified, and 181 patients (132 men, 47 women, and 2 not mentioned) co-infected with COVID-19 and fungal infection enrolled. The frequency of fungal co-infection among patients with COVID-19 was 49.7, 23.2, 19.8, 6.6, and 0.5% in Asia, America, Europe, Africa, and Australia, respectively. Diabetes (59.6%) and hypertension (35.9%) were found as the most considered comorbidities in COVID-19 patients with fungal infections. These patients mainly suffered from fever (40.8%), cough (30.3%), and dyspnea (23.7%). The most frequent findings in the laboratory results of patients and increase in C-reactive protein (CRP) (33.1%) and ferritin (18.2%), and lymphopenia (16%) were reported. The most common etiological agents of fungal infections were Aspergillus spp., Mucor spp., Rhizopus spp., and Candida spp. reported in study patients. The mortality rate was 54.6%, and the rate of discharged patients was 45.3%. Remdesivir and voriconazole were the most commonly used antiviral and antifungal agents for the treatment of patients. The global prevalence of COVID-19-related deaths is 6.6%. Our results showed that 54.6% of COVID-19 patients with fungal co-infections died. Thus, this study indicated that fungal co-infection and COVID-19 could increase mortality. Targeted policies should be considered to address this raised risk in the current pandemic. In addition, fungal infections are sometimes diagnosed late in patients with COVID-19, and the severity of the disease worsens, especially in patients with underlying conditions. Therefore, patients with fungal infections should be screened regularly during the COVID-19 pandemic to prevent the spread of the COVID-19 patients with fungal co-infection.

The First Invasive Candida auris Infection in Taiwan

Candida auris, a multidrug resistant pathogenic yeast, has spread worldwide and caused several outbreaks in healthcare settings. Here, we report the first case of C. auris candidemia in Taiwan in a patient with a two-month history of hospitalization in Vietnam. We performed further investigation on the isolate from the present case as well as the previously reported C. auris isolate identified from a wound in 2018 in Taiwan, which was the first case reported in Taiwan. Both C. auris isolates were found to be susceptible to fluconazole, amphotericin B, and echinocandins. Additionally, mutations in ERG11 or FKS1 were not detected in either isolate. Microsatellite genotyping revealed that both isolates belonged to the South Asian clade. In recent years, C. auris has emerged as a global concern, and differences in clades and susceptibility patterns mandate further awareness and systematic surveillance.

COVID-19-Associated Fungal Infections: An Urgent Need for Alternative Therapeutic Approach?

Secondary fungal infections may complicate the clinical course of patients affected by viral respiratory diseases, especially those admitted to intensive care unit. Hospitalized COVID-19 patients are at increased risk of fungal co-infections exacerbating the prognosis of disease due to misdiagnosis that often result in treatment failure and high mortality rate. COVID-19-associated fungal infections caused by predominantly Aspergillus and Candida species, and fungi of the order Mucorales have been reported from several countries to become significant challenge for healthcare system. Early diagnosis and adequate antifungal therapy is essential to improve clinical outcomes, however, drug resistance shows a rising trend highlighting the need for alternative therapeutic agents. The purpose of this review is to summarize the current knowledge on COVID-19-associated mycoses, treatment strategies and the most recent advancements in antifungal drug development focusing on peptides with antifungal activity.

An overview of COVID-19 related to fungal infections: what do we know after the first year of pandemic?

In 2019, severe acute respiratory syndrome caused by CoV-2 virus became a pandemic worldwide, being the fast spread of the disease due to the movement of infected people from one country to another, from one continent to another, or within the same country. Associated comorbidities are important factors that predispose to any fungal coinfections. Because of the importance of fungal infections in COVID-19 patients, the aim of this work was to collect data of the more encountered mycoses related to patients undergoing this disease. Aspergillosis was the first COVID-19-related fungal infection reported, being A. fumigatus the most frequent species for CAPA. Other fungal infections related include mainly candidiasis and mucormycosis, being Rhizopus spp. the more prevalent species found. Influenza-associated pulmonary aspergillosis is well documented; thus, similar complications are expected in severe forms of COVID-19 pneumonia. Therefore, in patients with COVID-19, it is important to take special attention to the surveillance and suspicion of fungal coinfections that might worsen the patient's prognosis.

Global Prevalence and Subgroup Analyses of Coronavirus Disease (COVID-19) Associated Candida auris infections (CACa): A Systematic Review and Meta-Analysis

Background

Increased hospitalisation rates in the Coronavirus disease 19 (COVID‐19) era lead to a new wave of hospital‐acquired infections such as emerging multidrug‐resistant Candida auris. We aimed to evaluate and estimate the global prevalence of coronavirus‐associated C. auris infection (CACa).

Methods

We searched related databases between December 2019 and April 2022 for studies that reported data about CACa. Meta‐analysis was performed using MedCalc software version 20.104 according to the DerSimonian and Laird method applying the random‐effects model. We evaluated heterogeneity using the χ²‐based Q statistic (significant for p‐value < .1) and the I² statistic (>75% indicative of ‘notable’ heterogeneity). Moreover, if possible, an odds ratio (OR) analysis was performed for eligible data.

Results

Our meta‐analysis includes ten eligible studies, including 1942 patients hospitalised with COVID‐19; 129 were C. auris cases. The overall pooled prevalence of CACa was estimated at 5.7%. The mortality rate of CACa was estimated at 67.849%. Hypertension was the most prevalent comorbidity (59.374%), followed by diabetes mellitus (52.898%) and cardiovascular diseases (31.392%). Men with a prevalence rate of 80.012% were 3.27 (OR) times more prone to getting infected by C. auris.

Conclusion

We concluded that the prevalence of C. auris infections decreased during the COVID‐19 pandemic and the prevalence gradient changed from Asia to America. Unfortunately, there are many descriptive studies with duplicate content in the field of epidemiology of C. auris infections which are increasing every day. We suggest further non‐descriptive studies to accurately establish the cause‐and‐effect relationships between C. auris and COVID‐19 infections.

Disruption of Iron Homeostasis and Mitochondrial Metabolism Are Promising Targets to Inhibit Candida auris

Fungal infections are a global threat, but treatments are limited due to a paucity in antifungal drug targets and the emergence of drug-resistant fungi such as Candida auris. Metabolic adaptations enable microbial growth in nutrient-scarce host niches, and they further control immune responses to pathogens, thereby offering opportunities for therapeutic targeting. Because it is a relatively new pathogen, little is known about the metabolic requirements for C. auris growth and its adaptations to counter host defenses. Here, we establish that triggering metabolic dysfunction is a promising strategy against C. auris. Treatment with pyrvinium pamoate (PP) induced metabolic reprogramming and mitochondrial dysfunction evident in disrupted mitochondrial morphology and reduced tricarboxylic acid (TCA) cycle enzyme activity. PP also induced changes consistent with disrupted iron homeostasis. Nutrient supplementation experiments support the proposition that PP-induced metabolic dysfunction is driven by disrupted iron homeostasis, which compromises carbon and lipid metabolism and mitochondria. PP inhibited C. auris replication in macrophages, which is a relevant host niche for this yeast pathogen. We propose that PP causes a multipronged metabolic hit to C. auris: it restricts the micronutrient iron to potentiate nutritional immunity imposed by immune cells, and it further causes metabolic dysfunction that compromises the utilization of macronutrients, thereby curbing the metabolic plasticity needed for growth in host environments. Our study offers a new avenue for therapeutic development against drug-resistant C. auris, shows how complex metabolic dysfunction can be caused by a single compound triggering antifungal inhibition, and provides insights into the metabolic needs of C. auris in immune cell environments. IMPORTANCE Over the last decade, Candida auris has emerged as a human pathogen around the world causing life-threatening infections with wide-spread antifungal drug resistance, including pandrug resistance in some cases. In this study, we addressed the mechanism of action of the antiparasitic drug pyrvinium pamoate against C. auris and show how metabolism could be inhibited to curb C. auris proliferation. We show that pyrvinium pamoate triggers sweeping metabolic and mitochondrial changes and disrupts iron homeostasis. PP-induced metabolic dysfunction compromises the utilization of both micro- and macronutrients by C. auris and reduces its growth in vitro and in immune phagocytes. Our findings provide insights into the metabolic requirements for C. auris growth and define the mechanisms of action of pyrvinium pamoate against C. auris, demonstrating how this compound works by inhibiting the metabolic flexibility of the pathogen. As such, our study characterizes credible avenues for new antifungal approaches against C. auris.

Prevalence, Risk Factors, Treatment and Outcome of multidrug resistance Candida auris Infections in Coronavirus Disease (COVID-19) Patients: A Systematic Review

BACKGROUND

Candida auris is an emerging multidrug-resistant pathogen in intensive care settings (ICU). During the coronavirus disease 19 (COVID-19) pandemic, ICU admissions were overwhelmed, possibly contributing to the C. auris outbreak in COVID-19 patients.

OBJECTIVES

The present systematic review addresses the prevalence, underlying diseases, iatrogenic risk factors, treatment and outcome of C. auris infections in COVID-19 patients.

METHODS

MEDLINE, Scopus, Embase, Web of Science and LitCovid databases were systematically searched with appropriate keywords from 1^st January 2020 to 31^st December 2021.

RESULTS

A total of 97 cases of C. auris were identified in COVID-19 patients. The prevalence of C. auris infections in COVID-19 patients was 14%. The major underlying diseases were diabetes mellitus (42.7%), hypertension (32.9%), and obesity (14.6%), followed by the iatrogenic risk factors such as a central venous catheter (76.8%%) intensive care unit (ICU) stay (75.6%), and broad-spectrum antibiotic usage (74.3%). There were no significant differences in underlying disease and iatrogenic risk factors among C. auris non-candidemia/colonisation and C. auris candidemia cases. The mortality rate of the total cohort is 44.4%, whereas, in C. auris candidemia patients, the mortality was 64.7%.

CONCLUSION

This study shows that the prevalence of C. auris infections remains unchanged in the COVID-19 pandemic. Hospital-acquired risk factors may contribute to the clinical illness. Proper infection control practices and hospital surveillance may stop future hospital outbreaks during the pandemic.

Expert recommendations for prevention and management of Candida auris transmission

Candida auris was first described as a yeast pathogen in 2009. Since then, the new species has emerged worldwide. In contrast to most other Candida spp., C. auris frequently exhibits multi-drug resistance and is readily transmitted in hospital settings. While most isolations so far are from colonized patients, C. auris does cause life-threatening invasive infections. During management of the first documented C. auris transmission in a German hospital, experts from the National Reference Centers for Invasive Fungal Infections (NRZMyk) and the National Reference Center for Surveillance of Nosocomial Infections screened available literature and integrated available knowledge on infection prevention and C. auris epidemiology and biology to enable optimal containment. Relevant recommendations developed during this process are summarized in this guidance document, intended to assist in management of C. auris transmission and potential outbreak situations. Rapid and effective measures to contain C. auris spread require a multidisciplinary approach that includes clinical specialists of the affected unit, nursing staff, hospital hygiene, diagnostic microbiology, cleaning staff, hospital management and experts in diagnostic mycology / fungal infections. Action should be initiated in a step-wise process and relevant interventions differ between management of singular C. auris colonized / infected patients and detection of potential C. auris transmission or nosocomial outbreaks. [word count 205].

Fungal Infections in Critically Ill COVID-19 Patients: Inevitabile Malum

Patients with severe COVID-19 belong to a population at high risk of invasive fungal infections (IFIs), with a reported incidence of IFIs in critically ill COVID-19 patients ranging between 5% and 26.7%. Common factors in these patients, such as multiple organ failure, immunomodulating/immunocompromising treatments, the longer time on mechanical ventilation, renal replacement therapy or extracorporeal membrane oxygenation, make them vulnerable candidates for fungal infections. In addition to that, SARS-CoV2 itself is associated with significant dysfunction in the patient's immune system involving both innate and acquired immunity, with reduction in both CD4+ T and CD8+ T lymphocyte counts and cytokine storm. The emerging question is whether SARS-CoV-2 inherently predisposes critically ill patients to fungal infections or the immunosuppressive therapy constitutes the igniting factor for invasive mycoses. To approach the dilemma, one must consider the unique pathogenicity of SARS-CoV-2 with the deranged immune response it provokes, review the well-known effects of immunosuppressants and finally refer to current literature to probe possible causal relationships, synergistic effects or independent risk factors. In this review, we aimed to identify the prevalence, risk factors and mortality associated with IFIs in mechanically ventilated patients with COVID-19.

COVID-19-Associated Candidiasis: Possible Patho-Mechanism, Predisposing Factors, and Prevention Strategies

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is threatening public health. A large number of affected people need to be hospitalized. Immunocompromised patients and ICU-admitted patients are predisposed to further bacterial and fungal infections, making patient outcomes more critical. Among them, COVID-19-associated candidiasis is becoming more widely recognized as a part of severe COVID-19 sequelae. While the molecular pathophysiology is not fully understood, some factors, including a compromised immune system, iron and zinc deficiencies, and nosocomial and iatrogenic transmissions, predispose COVID-19 patients to candidiasis. In this review, we discuss the existing knowledge of the virulence characteristics of Candida spp. and summarize the key concepts in the possible molecular pathogenesis. We analyze the predisposing factors that make COVID-19 patients more susceptible to candidiasis and the preventive measures which will provide valuable insights to guide the effective prevention of candidiasis in COVID-19 patients.

The Continuing Emergence of Candida blankii as a Pathogenic Fungus: A New Case of Fungemia in a Patient Infected with SARS-CoV-2

Candida blankii is a recently recognized human pathogen, with most cases of the infection being reported in the immunocompromised. We here describe the case of a critically ill elderly woman with COVID-19 who developed a C. blankii bloodstream infection from a femoral central venous catheter. Aspergillus niger was also isolated from her respiratory secretions. The patient was started on voriconazole for empiric coverage of both A. niger, and at that time, unidentified yeast was found in the blood. Fevers persisted, and the patient expired six days after the yeast was first isolated. Almost one month after her death, C. blankii was identified as the cause of fungemia by sequencing of the internal transcribed spacer (ITS) region of the ribosomal gene and BLAST searching against two databases (performed by a reference laboratory). The isolate demonstrated high minimum inhibitory concentrations (MICs) to azoles and low MICs to amphotericin B, similar to previously described isolates. Timely identification of C. blankii would have prompted different empiric antifungal choices and possibly changed the final outcome. Clinicians should be aware of the pathological potential of C. blankii, the challenges of correctly identifying the organism, and its susceptibility patterns to common antifungals. There is an urgent need to improve assays for C. blankii identification, which will aid in accurate and timely pathogen identification, and appropriate therapeutic management.

A Brazilian Inter-Hospital Candidemia Outbreak Caused by Fluconazole-Resistant Candida parapsilosis in the COVID-19 Era

Horizontal transmission of fluconazole-resistant Candida parapsilosis (FRCP) through healthcare workers’ hands has contributed to the occurrence of candidemia outbreaks worldwide. Since the first COVID-19 case in Brazil was detected in early 2020, hospitals have reinforced hand hygiene and disinfection practices to minimize SARS-CoV-2 contamination. However, a Brazilian cardiology center, which shares ICU patients with a cancer center under a FRCP outbreak since 2019, reported an increased FRCP candidemia incidence in May 2020. Therefore, the purpose of this study was to investigate an inter-hospital candidemia outbreak caused by FRCP isolates during the first year of the COVID-19 pandemic in Brazil. C. parapsilosis bloodstream isolates obtained from the cancer (n = 35) and cardiology (n = 30) centers in 2020 were submitted to microsatellite genotyping and fluconazole susceptibility testing. The ERG11 gene of all isolates from the cardiology center was sequenced and compared to the corresponding sequences of the FRCP genotype responsible for the cancer center outbreak in 2019. Unprecedentedly, most of the FRCP isolates from the cardiology center presented the same genetic profile and Erg11-Y132F mutation detected in the strain that has been causing the persistent outbreak in the cancer center, highlighting the uninterrupted horizontal transmission of clonal isolates in our hospitals during the COVID-19 pandemic.

Pathogenesis of Respiratory Viral and Fungal Coinfections

Individuals suffering from severe viral respiratory tract infections have recently emerged as "at risk" groups for developing invasive fungal infections. Influenza virus is one of the most common causes of acute lower respiratory tract infections worldwide. Fungal infections complicating influenza pneumonia are associated with increased disease severity and mortality, with invasive pulmonary aspergillosis being the most common manifestation. Strikingly, similar observations have been made during the current coronavirus disease 2019 (COVID-19) pandemic. The copathogenesis of respiratory viral and fungal coinfections is complex and involves a dynamic interplay between the host immune defenses and the virulence of the microbes involved that often results in failure to return to homeostasis. In this review, we discuss the main mechanisms underlying susceptibility to invasive fungal disease following respiratory viral infections. A comprehensive understanding of these interactions will aid the development of therapeutic modalities against newly identified targets to prevent and treat these emerging coinfections.

COVID-19-associated opportunistic infections: a snapshot on the current reports

Treatment of the novel Coronavirus Disease 2019 (COVID-19) remains a complicated challenge, especially among patients with severe disease. In recent studies, immunosuppressive therapy has shown promising results for control of the cytokine storm syndrome (CSS) in severe cases of COVID-19. However, it is well documented that immunosuppressive agents (e.g., corticosteroids and cytokine blockers) increase the risk of opportunistic infections. On the other hand, several opportunistic infections were reported in COVID-19 patients, including Aspergillus spp., Candida spp., Cryptococcus neoformans, Pneumocystis jiroveci (carinii), mucormycosis, Cytomegalovirus (CMV), Herpes simplex virus (HSV), Strongyloides stercoralis, Mycobacterium tuberculosis, and Toxoplasma gondii. This review is a snapshot about the main opportunistic infections that reported among COVID-19 patients. As such, we summarized information about the main immunosuppressive agents that were used in recent clinical trials for COVID-19 patients and the risk of opportunistic infections following these treatments. We also discussed about the main challenges regarding diagnosis and treatment of COVID-19-associated opportunistic infections (CAOIs).

A Markerless CRISPR-Mediated System for Genome Editing in Candida auris Reveals a Conserved Role for Cas5 in the Caspofungin Response

Candida auris is a multidrug-resistant human fungal pathogen that has recently emerged worldwide. It can cause life-threatening disseminated infections in humans, with mortality rates upwards of 50%. The molecular mechanisms underlying its multidrug resistance and pathogenic properties are largely unknown. Few methods exist for genome editing in C. auris, all of which rely on selectable markers that limit the number of modifications that can be made. Here, we present a markerless CRISPR/Cas9-mediated genome editing system in C. auris. Using this system, we successfully deleted genes of interest and subsequently reconstituted them at their native loci in isolates across all five C. auris clades. This system also enabled us to introduce precision genome edits to create translational fusions and single point mutations. Using Cas5 as a test case for this system, we discovered a conserved role for Cas5 in the caspofungin response between Candida albicans and C. auris. Overall, the development of a system for precise and facile genome editing in C. auris that can allow edits to be made in a high-throughput manner is a major step forward in improving our understanding of this important human fungal pathogen. IMPORTANCE Candida auris is a recently emerged multidrug-resistant fungal pathogen capable of causing life-threatening systemic infections in humans. Few tools are available for genome editing in C. auris. Here, we present a markerless genome editing system for C. auris that relies on CRISPR/Cas9 technology and works to modify the genomes of all known C. auris clades. Using this system, we discovered a conserved role for Cas5 in the caspofungin response between C. albicans and C. auris. Overall, the development of a system for facile genome editing in C. auris is a major step forward in improving our understanding of this important human fungal pathogen.

Candida auris and other phylogenetically related species - a mini-review of the literature

The lesser-known non-albicans Candida species are often overlooked and difficult to diagnose in most microbiology laboratories. Candida auris, a relatively newly discovered species, is responsible for outbreaks in various geographical regions. Because of its increased resistance to antifungal drugs, C. auris is responsible for hard-to-treat infections and its pathogenicity is still incompletely elucidated. Non-albicans species phylogenetically related to C. auris, like the C. haemulonii complex might also play a role in human pathology. The current summary of the literature presents the emergence, virulence, laboratory identification, and molecular mechanisms responsible for antifungal resistance of emergent rare non-albicans Candida species.

Nanopore Genome Sequencing and Variant Analysis of the Susceptible Candida auris Strain L1537/2020, Salvador, Brazil

Candida auris has been reported worldwide, but only in December 2020, the first strain from a COVID-19 patient in Brazil was isolated. Here, we describe the genome sequence of this susceptible C. auris strain and performed variant analysis of the genetic relatedness with strains from other geographic localities.

What Do We Know about Candida auris? State of the Art, Knowledge Gaps, and Future Directions

Candida auris has unprecedently emerged as a multidrug resistant fungal pathogen, considered a serious global threat due to its potential to cause nosocomial outbreaks and deep-seated infections with staggering transmissibility and mortality, that has put health authorities and institutions worldwide in check for more than a decade now. Due to its unique features not observed in other yeasts, it has been categorised as an urgent threat by the Centers for Disease Control and Prevention and other international agencies. Moreover, epidemiological alerts have been released in view of the increase of healthcare-associated C. auris outbreaks in the context of the COVID-19 pandemic. This review summarises the current evidence on C. auris since its first description, from virulence to treatment and outbreak control, and highlights the knowledge gaps and future directions for research efforts.

Photodynamic Therapy Is Effective Against Candida auris Biofilms

Fungal infections are increasing in prevalence worldwide. The paucity of available antifungal drug classes, combined with the increased occurrence of multidrug resistance in fungi, has led to new clinical challenges in the treatment of fungal infections. Candida auris is a recently emerged multidrug resistant human fungal pathogen that has become a worldwide public health threat. C. auris clinical isolates are often resistant to one or more antifungal drug classes, and thus, there is a high unmet medical need for the development of new therapeutic strategies effective against C. auris. Additionally, C. auris possesses several virulence traits, including the ability to form biofilms, further contributing to its drug resistance, and complicating the treatment of C. auris infections. Here we assessed red, green, and blue visible lights alone and in combination with photosensitizing compounds for their efficacies against C. auris biofilms. We found that (1) blue light inhibited and disrupted C. auris biofilms on its own and that the addition of photosensitizing compounds improved its antibiofilm potential; (2) red light inhibited and disrupted C. auris biofilms, but only in combination with photosensitizing compounds; and (3) green light inhibited C. auris biofilms in combination with photosensitizing compounds, but had no effects on disrupting C. auris biofilms. Taken together, our findings suggest that photodynamic therapy could be an effective non-drug therapeutic strategy against multidrug resistant C. auris biofilm infections.

Public health issues with Candida auris in COVID-19 patients

The ongoing pandemic of coronavirus disease 2019 (COVID‐19) has overwhelmed a number of medical facilities as well as a few entire health‐care systems. A novel issue co‐incident with the expeditious deployment of specialty care units for COVID‐19 inpatients is the worldwide epidemic of Candida auris infections. Since its first identification and classification in Japan in 2009, it has spread globally. This threat was predicted as C. auris has a high mortality rate, cryptic fomite spread, frequent misidentification since conventional methods do not detect it, and multidrug‐resistance. Since the April 2020 warning at the start of the COVID‐19 pandemic in the United States, C. auris has been delineated as an increasingly consequential source of significant nosocomial infections, emphasizing the added hazard of C. auris to COVID‐19 inpatients, particularly those in intensive care units.

Candida auris was a worldwide nosocomial epidemic prior to COVID‐19; it remains so!

This 21st century worldwide fungal epidemic complicates the COVID‐19 pandemic to jointly menace mankind

C. auris is multi‐drug resistant, requires expensive mass spectrometry equipment to diagnose, and has a high mortality rate in intensive care units

This nosocomial infection may persist on dry linen, sheets, floors, cell phones, and medical equipment for weeks

We propose a policy that documents the presence or absence of this invasive Candidal species in intensive care units during this COVID‐19 pandemic to aggressively eliminate it.

Risk Factors for Fungal Co-Infections in Critically Ill COVID-19 Patients, with a Focus on Immunosuppressants

Severe cases of coronavirus disease 2019 (COVID-19) managed in the intensive care unit are prone to complications, including secondary infections with opportunistic fungal pathogens. Systemic fungal co-infections in hospitalized COVID-19 patients may exacerbate COVID-19 disease severity, hamper treatment effectiveness and increase mortality. Here, we reiterate the role of fungal co-infections in exacerbating COVID-19 disease severity as well as highlight emerging trends related to fungal disease burden in COVID-19 patients. Furthermore, we provide perspectives on the risk factors for fungal co-infections in hospitalized COVID-19 patients and highlight the potential role of prolonged immunomodulatory treatments in driving fungal co-infections, including COVID-19-associated pulmonary aspergillosis (CAPA), COVID-19-associated candidiasis (CAC) and mucormycosis. We reiterate the need for early diagnosis of suspected COVID-19-associated systemic mycoses in the hospital setting.