Axillary Digital Thermometers uplifted a multidrug-susceptible Candida auris outbreak among COVID-19 patients in Brazil

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.

Antifungal activity of β-lapachone against a fluconazole-resistant Candida auris strain

Candida spp. can be found in the human microbiome. However, immunocompromised patients are likely to develop invasive Candida infections, with mortality rates higher than 50%. The discovery of C. auris, a species that rapidly acquire antifungal resistance, increased the concern about Candida infections. The limited number of antifungal agents and the high incidence of resistance to them make imperative the development of new antifungal drugs. β-lapachone is a biological active naphthoquinone that displays antifungal activity against C. albicans and C. glabrata. The aim of this study was to evaluate if this substance affects C. auris growth and elucidate its mechanism of action. A fluconazole-resistant C. auris isolate was used in this study. The antifungal activity of β-lapachone was determined through microbroth dilution assays, and its mechanism of action was evaluated using fluorescent probes. Interaction with fluconazole and amphotericin B was assessed by disk diffusion assay and checkerboard. β-lapachone inhibited planktonic C. auris cell growth by 92.7%, biofilm formation by 84.9%, and decrease the metabolism of preformed biofilms by 87.1% at 100 µg/ml. At 100 µg/ml, reductions of 30% and 59% of Calcofluor White and Nile red fluorescences were observed, indicating that β-lapachone affects cell wall chitin and neutral lipids content, respectively. Also, the ratio 590 nm/529 nm of JC-1 decreased 52%, showing that the compound affects mitochondria. No synergism was observed between β-lapachone and fluconazole or amphotericin B. Data show that β-lapachone may be a promising candidate to be used as monotherapy to treat C. auris resistant infections.

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.

Candida auris Outbreak in a Multidisciplinary Hospital in Romania during the Post-Pandemic Era: Potential Solutions and Challenges in Surveillance and Epidemiological Control

Candida auris is a newly emerging yeast, which is raising public health concerns due to its outbreak potential, lack of protocols for decontamination and isolation of patients or contacts, increased resistance to common antifungals, and associated high mortality. This research aimed to describe the challenges related to identifying the outbreak, limiting further contamination, and treating affected individuals. We retrospectively analyzed all cases of C. auris detected between October 2022 and August 2023, but our investigation focused on a three-month-long outbreak in the department of cardio-vascular surgery and the related intensive care unit. Along with isolated cases in different wards, we identified 13 patients who became infected or colonized in the same area and time, even though the epidemiological link could only be traced in 10 patients, according to the epidemiologic investigation. In conclusion, our study emphasizes the substantial challenge encountered in clinical practice when attempting to diagnose and limit the spread of an outbreak. Therefore, it is crucial to promptly apply contact precaution measures and appropriate environmental cleaning, from the first positive case detected.

The many faces of Candida auris: Phenotypic and strain variation in an emerging pathogen

Candida auris is an emerging fungal pathogen with unusual evolutionary history-there are multiple distinct phylogeographic clades showing a near simultaneous transition from a currently unknown reservoir to nosocomial pathogen. Each of these clades has experienced different selective pressures over time, likely resulting in selection for genotypes with differential fitness or phenotypic consequences when introduced to new environments. We also observe diversification within clades, providing additional opportunities for phenotypic differences. These differences can have large impacts on pathogenic potential, drug resistance profile, evolutionary trajectory, and transmissibility. In recent years, there have been significant advances in our understanding of strain-specific behavior in other microbes, including bacterial and fungal pathogens, and we have an opportunity to take this strain variation into account when describing aspects of C. auris biology. Here, we critically review the literature to gain insight into differences at both the strain and clade levels in C. auris, focusing on phenotypes associated with clinical disease or transmission. Our goal is to integrate clinical and epidemiological perspectives with molecular perspectives in a way that would be valuable for both audiences. Identifying differences between strains and understanding which phenotypes are strain specific will be crucial for understanding this emerging pathogen, and an important caveat when describing the analysis of a singular isolate.

Emergence of highly resistant Candida auris in the United Arab Emirates: a retrospective analysis of evolving national trends

Introduction

The Centers for Disease Prevention and Control lists Candida auris, given its global emergence, multidrug resistance, high mortality, and persistent transmissions in health care settings as one of five urgent threats. As a new threat, the need for surveillance of C. auris is critical. This is particularly important for a cosmopolitan setting and global hub such as the United Arab Emirates (UAE) where continued introduction and emergence of resistant variant strains is a major concern.

Methods

The United Arab Emirates has carried out a 12 years of antimicrobial resistance surveillance (2010-2021) across the country, spanning all seven Emirates. A retrospective analysis of C. auris emergence from 2018-2021 was undertaken, utilising the demographic and microbiological data collected via a unified WHONET platform for AMR surveillance.

Results

Nine hundred eight non-duplicate C. auris isolates were reported from 2018-2021. An exponential upward trend of cases was found. Most isolates were isolated from urine, blood, skin and soft tissue, and the respiratory tract. UAE nationals nationals comprised 29% (n = 186 of 632) of all patients; the remainder were from 34 other nations. Almost all isolates were from inpatient settings (89.0%, n = 809). The cases show widespread distribution across all reporting sites in the country. C. auris resistance levels remained consistently high across all classes of antifungals used. C. auris in this population remains highly resistant to azoles (fluconazole, 72.6% in 2021) and amphotericin. Echinocandin resistance has now emerged and is increasing annually. There was no statistically significant difference in mortality between Candida auris and Candida spp. (non-auris) patients (p-value: 0.8179), however Candida auris patients had a higher intensive care unit (ICU) admission rate (p-value <0.0001) and longer hospital stay (p < 0.0001) compared to Candida spp. (non-auris) patients.

Conclusion

The increasing trend of C. auris detection and associated multidrug resistant phenotypes in the UAE is alarming. Continued C. auris circulation in hospitals requires enhanced infection control measures to prevent continued dissemination.

Intrahospital transmission and infection control of Candida auris originating from a severely infected COVID-19 patient transferred abroad

BACKGROUND

Intrahospital spread of Candida auris, which survives tenaciously in many environments, can cause sustained colonization and infection. A large outbreak of C. auris was experienced in the intensive care units (ICUs) at the study hospital during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

The index patient with severe COVID-19, who was transferred from Vietnam in January 2022, developed C. auris candidaemia 10 days after hospitalization. From mid-June 2022 to January 2023, strengthened infection prevention and control (IPC) measures were implemented in three ICUs: (1) contact precautions and isolation (CPI) for C. auris-positive cases; (2) surveillance cultures including point-prevalence (N=718) for patients or close contacts or ICU-resident healthcare workers (HCWs); (3) intensive environmental disinfection with 10-fold diluted bleach; and (4) 2% chlorhexidine bathing for all ICU patients. Environmental cultures (ECx) on surfaces and shared objects (N=276) were conducted until early September 2022, when all ECx were negative.

RESULTS

Among 53 C. auris-positive patients between February 2022 and January 2023, invasive infections resulted in seven cases of candidaemia and one case of pneumonia. C. auris was isolated from reusable tympanic thermometers (TTMs) contaminated with earwax. The isolation rate of C. auris in ECx decreased from 6.8% in June 2022 to 2.0% in August 2022, and was no longer detected in TTMs. Colonization in HCWs was remarkably rare (0.5%). The number of C. auris-positive patients peaked in July (N=10) then decreased gradually. By January 2023, no C. auris were isolated in the ICU.

CONCLUSION

Aggressive IPC measures with CPI, ECx and surveillance, decontamination of TTMs, and bathing were effective in successfully controlling this C. auris outbreak.

The Gordian Knot of C. auris: If You Cannot Cut It, Prevent It

Since its first description in 2009, Candida auris has, so far, resulted in large hospital outbreaks worldwide and is considered an emerging global public health threat. Exceptionally for yeast, it is gifted with a profoundly worrying invasive potential and high inter-patient transmissibility. At the same time, it is capable of colonizing and persisting in both patients and hospital settings for prolonged periods of time, thus creating a vicious cycle of acquisition, spreading, and infection. It exhibits various virulence qualities and thermotolerance, osmotolerance, filamentation, biofilm formation and hydrolytic enzyme production, which are mainly implicated in its pathogenesis. Owing to its unfavorable profile of resistance to diverse antifungal agents and the lack of effective treatment options, the implementation of robust infection prevention and control (IPC) practices is crucial for controlling and minimizing intra-hospital transmission of C. auris. Rapid and accurate microbiological identification, adherence to hand hygiene, use of adequate personal protective equipment (PPE), proper handling of catheters and implantable devices, contact isolation, periodical environmental decontamination, targeted screening, implementation of antimicrobial stewardship (AMS) programs and communication between healthcare facilities about residents' C. auris colonization status are recognized as coherent strategies for preventing its spread. Current knowledge on C. auris epidemiology, clinical characteristics, and its mechanisms of pathogenicity are summarized in the present review and a comprehensive overview of IPC practices ensuring yeast prevention is also provided.

Antifungal stewardship: the Latin American experience

Antifungal stewardship is a critical component of healthcare management that focuses on optimizing the use of antifungal medications to improve patient outcomes, minimize resistance, and reduce healthcare costs.  In resource-limited settings, the prevalence of fungal infections remains a significant health concern, often exacerbated by factors such as compromised immune systems, inadequate diagnostic capabilities, and limited access to antifungal agents. This paper reviews the current state of antifungal stewardship practices in developing countries, addressing the unique socioeconomic and healthcare landscape.

An Autochthonous Susceptible Candida auris Clade I Otomycosis Case in Iran

Candida auris is a newly emerging multidrug-resistant fungal pathogen considered to be a serious global health threat. Due to diagnostic challenges, there is no precise estimate for the prevalence rate of this pathogen in Iran. Since 2019, only six culture-proven C. auris cases have been reported from Iran, of which, five belonged to clade V and one to clade I. Herein, we report a case of otomycosis due to C. auris from 2017 in a 78-year-old man with diabetes mellitus type II without an epidemiological link to other cases or travel history. Short tandem repeat genotyping and whole genome sequencing (WGS) analysis revealed that this isolate belonged to clade I of C. auris (South Asian Clade). The WGS single nucleotide polymorphism calling demonstrated that the C. auris isolate from 2017 is not related to a previously reported clade I isolate from Iran. The presence of this retrospectively recognized clade I isolate also suggests an early introduction from other regions or an autochthonous presence. Although the majority of reported C. auris isolates worldwide are resistant to fluconazole and, to a lesser extent, to echinocandins and amphotericin B, the reported clade I isolate from Iran was susceptible to all antifungal drugs.

Severe Candida infections in critically ill patients with COVID-19

The frequency of co-infections with bacterial or fungal pathogens has constantly increased among critically ill patients with coronavirus disease 2019 (COVID-19) during the pandemic. Candidemia was the most frequently reported invasive fungal co-infection. The onset of candidemia in COVID-19 patients was often delayed compared to non-COVID-19 patients. Additionally, Candida invasive infections in COVID-19 patients were more often linked to invasive procedures (e.g., invasive mechanical ventilation or renal replacement therapy) during the intensive care stay and the severity of illness rather than more "classic" risk factors present in patients without COVID-19 (e.g., underlying diseases and prior hospitalization). Moreover, apart from the increased incidence of candidemia during the pandemic, a worrying rise in fluconazole-resistant strains was reported, including a rise in the multidrug-resistant Candida auris. Regarding outcomes, the development of invasive Candida co-infection had a negative impact, increasing morbidity and mortality compared to non-co-infected COVID-19 patients. In this narrative review, we present and critically discuss information on the diagnosis and management of invasive fungal infections caused by Candida spp. in critically ill COVID-19 patients.

Outbreaks of Fungal Infections in Hospitals: Epidemiology, Detection, and Management

Nosocomial clusters of fungal infections, whilst uncommon, cannot be predicted and are associated with significant morbidity and mortality. Here, we review reports of nosocomial outbreaks of invasive fungal disease to glean insight into their epidemiology, risks for infection, methods employed in outbreak detection including genomic testing to confirm the outbreak, and approaches to clinical and infection control management. Both yeasts and filamentous fungi cause outbreaks, with each having general and specific risks. The early detection and confirmation of the outbreak are essential for diagnosis, treatment of affected patients, and termination of the outbreak. Environmental sampling, including the air in mould outbreaks, for the pathogen may be indicated. The genetic analysis of epidemiologically linked isolates is strongly recommended through a sufficiently discriminatory approach such as whole genome sequencing or a method that is acceptably discriminatory for that pathogen. An analysis of both linked isolates and epidemiologically unrelated strains is required to enable genetic similarity comparisons. The management of the outbreak encompasses input from a multi-disciplinary team with epidemiological investigation and infection control measures, including screening for additional cases, patient cohorting, and strict hygiene and cleaning procedures. Automated methods for fungal infection surveillance would greatly aid earlier outbreak detection and should be a focus of research.

A Candida auris-specific adhesin, Scf1, governs surface association, colonization, and virulence

Candida auris is an emerging fungal pathogen responsible for health care-associated outbreaks that arise from persistent surface and skin colonization. We characterized the arsenal of adhesins used by C. auris and discovered an uncharacterized adhesin, Surface Colonization Factor (Scf1), and a conserved adhesin, Iff4109, that are essential for the colonization of inert surfaces and mammalian hosts. SCF1 is apparently specific to C. auris, and its expression mediates adhesion to inert and biological surfaces across isolates from all five clades. Unlike canonical fungal adhesins, which function through hydrophobic interactions, Scf1 relies on exposed cationic residues for surface association. SCF1 is required for C. auris biofilm formation, skin colonization, virulence in systemic infection, and colonization of inserted medical devices.

Candida auris: a novel emerging nosocomial pathogen - properties, epidemiological situation and infection control

Immunosuppression and critical illnesses in combination with ecological imbalance open the door for novel opportunistic fungal infections, as in case of Candida (C). auris. C. auris has emerged globally as a multidrug-resistant yeast, causing infections and outbreaks in health care facilities. This narrative review discusses the properties of the yeast, the development of the epidemiological situation, the nosocomial spread and causes for nosocomial outbreaks triggered by C. auris in the hospital environment, and summarizes international recommendations for infection control, supplemented by suggestions on diagnostic, screening and antibiotic stewardship.

Secondary fungal infections in SARS-CoV-2 patients: pathological whereabouts, cautionary measures, and steadfast treatments

The earliest documented COVID-19 case caused by the SARS-CoV-2 coronavirus occurred in Wuhan, China, in December 2019. Since then, several SARS-CoV-2 mutants have rapidly disseminated as exemplified by the community spread of the recent omicron variant. The disease already attained a pandemic status with ever-dwindling mortality even after two and half years of identification and considerable vaccination. Aspergillosis, candidiasis, cryptococcosis and mucormycosis are the prominent fungal infections experienced by the majority of SARS-CoV-2 high-risk patients. In its entirety, COVID-19's nexus with these fungal infections may worsen the intricacies in the already beleaguered high-risk patients, making this a topic of substantial clinical concern. Thus, thorough knowledge of the subject is necessary. This article focuses on the concomitant fungal infection(s) in COVID-19 patients, taking into account their underlying causes, the screening methods, manifested drug resistance, and long-term effects. The information and knowledge shared herein could be crucial for the management of critically ill, aged, and immunocompromised SARS-CoV-2 patients who have had secondary fungal infections (SFIs).

Clorgyline Analogs Synergize with Azoles against Drug Efflux in Candida auris

Concern about the global emergence of multidrug-resistant fungal pathogens led us to explore the use of combination therapy to combat azole resistance in Candida auris. Clorgyline had previously been shown to be a multi-target inhibitor of Cdr1 and Mdr1 efflux pumps of Candida albicans and Candida glabrata. A screen for antifungal sensitizers among synthetic analogs of Clorgyline detected interactions with the C. auris efflux pump azole substrates Posaconazole and Voriconazole. Of six Clorgyline analogs, M19 and M25 were identified as potential sensitizers of azole resistance. M19 and M25 were found to act synergistically with azoles against resistant C. auris clade I isolates and recombinant Saccharomyces cerevisiae strains overexpressing C. auris efflux pumps. Nile Red assays with the recombinant strains showed M19 and M25 inhibited the activity of Cdr1 and Mdr1 efflux pumps that are known to play key roles in azole resistance in C. auris clades I, III, and IV. While Clorgyline, M19 and M25 uncoupled the Oligomycin-sensitive ATPase activity of Cdr1 from C. albicans and C. auris, their mode of action is yet to be fully elucidated. The experimental combinations described herein provides a starting point to combat azole resistance dominated by overexpression of CauCdr1 in C. auris clades I and IV and CauMdr1 in C. auris clade III.

Fast and Accurate Identification of Candida auris by High Resolution Mass Spectrometry

The emerging pathogen Candida auris has been associated with nosocomial outbreaks on six continents. Genetic analysis indicates simultaneous and independent emergence of separate clades of the species in different geographical locations. Both invasive infection and colonization have been observed, warranting attention due to variable antifungal resistance profiles and hospital transmission. MALDI-TOF based identification methods have become routine in hospitals and research institutes. However, identification of the newly emerging lineages of C. auris yet remains a diagnostic challenge. In this study an innovative liquid chromatography (LC)-high resolution Orbitrap^TM mass spectrometry method was used for identification of C. auris from axenic microbial cultures. A set of 102 strains from all five clades and different body locations were investigated. The results revealed correct identification of all C. auris strains within the sample cohort, with an identification accuracy of 99.6% from plate culture, in a time-efficient manner. Furthermore, application of the applied mass spectrometry technology provided the species identification down to clade level, thus potentially providing the possibility for epidemiological surveillance to track pathogen spread. Identification beyond species level is required specially to differentiate between nosocomial transmission and repeated introduction to a hospital.

Increasing number of cases and outbreaks caused by Candida auris in the EU/EEA, 2020 to 2021

The number of cases of Candida auris infection or carriage and of countries reporting cases and outbreaks increased in the European Union and European Economic Area during 2020 and 2021. Eight countries reported 335 such cases in 2020 and 13 countries 655 cases in 2021. Five countries experienced outbreaks while one country reported regional endemicity. These findings highlight the need for adequate laboratory capacity and surveillance for early detection of C. auris and rapid implementation of control measures.

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.

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.

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.

COVID-19 and C. auris: A Case-Control Study from a Tertiary Care Center in Lebanon

Many healthcare centers around the world have reported the surge of Candida auris (C. auris) outbreaks during the COVID-19 pandemic, especially among intensive care unit (ICU) patients. This is a retrospective study conducted at the American University of Beirut Medical Center (AUBMC) between 1 October 2020 and 15 June 2021, to identify risk factors for acquiring C. auris in patients with severe COVID-19 infection and to evaluate the impact of C. auris on mortality in patients admitted to the ICU during that period. Twenty-four non-COVID-19 (COV−) patients were admitted to ICUs at AUBMC during that period and acquired C. auris (C. auris+/COV−). Thirty-two patients admitted with severe COVID-19 (COV+) acquired C. auris (C. auris+/COV+), and 130 patients had severe COVID-19 without C. auris (C. auris−/COV+). Bivariable analysis between the groups of (C. auris+/COV+) and (C. auris−/COV+) showed that higher quick sequential organ failure assessment (qSOFA) score (p < 0.001), prolonged length of stay (LOS) (p = 0.02), and the presence of a urinary catheter (p = 0.015) or of a central venous catheter (CVC) (p = 0.01) were associated with positive culture for C. auris in patients with severe COVID-19. The multivariable analysis showed that prolonged LOS (p = 0.008) and a high qSOFA score (p < 0.001) were the only risk factors independently associated with positive culture for C. auris. Increased LOS (p = 0.02), high “Candida score” (p = 0.01), and septic shock (p < 0.001) were associated with increased mortality within 30 days of positive culture for C. auris. Antifungal therapy for at least 7 days (p = 0.03) appeared to decrease mortality within 30 days of positive culture for C. auris. Only septic shock was associated with increased mortality in patients with C. auris (p = 0.006) in the multivariable analysis. C. auris is an emerging pathogen that constitutes a threat to the healthcare sector.

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.

Successful control of Candida auris transmission in a German COVID-19 intensive care unit

BACKGROUND

Candida auris is a frequently multi-drug resistant yeast species that poses a global health threat due to its high potential for hospital outbreaks. While C. auris has become endemic in parts of Asia and Africa, transmissions have so far rarely been reported in Western Europe except for Great Britain and Spain. We describe the first documented patient-to-patient transmission of C. auris in Germany in a COVID-19 intensive care unit (ICU) and infection control measures implemented to prevent further spread of the pathogen.

METHODS

Identification of C. auris was performed by MALDI-TOF and confirmed by internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing was carried out. We conducted repeated cross-sectional examinations for the presence of C. auris in the patients of the affected ICU and investigated possible routes of transmission.

RESULTS

The index patient had been transferred to Germany from a hospital in Northern Africa and was found to be colonised with C. auris. The contact patient developed C. auris sepsis. Infection prevention and control (IPC) measures included strict isolation of the two C. auris patients and regular screening of non-affected patients. No further case occurred during the subsequent weeks. Reusable blades used in video laryngoscope-guided intubation were considered as the most likely vehicle of transmission.

CONCLUSIONS

In view of its high risk of transmission, vigilance regarding C. auris colonisation in patients referred from endemic countries is crucial. Strict and immediate IPC measures may have the potential to prevent C. auris outbreaks.

It is complicated: Potential short- and long-term impact of coronavirus disease 2019 (COVID-19) on antimicrobial resistance—An expert review

As of December 2021, the coronavirus disease 2019 (COVID-19) pandemic has claimed millions of deaths and caused disruptions in health systems around the world. The short- and long-term effects of COVID-19 on antimicrobial resistance (AMR), which was already a global threat before the pandemic, are manifold and complex. In this expert review, we summarize how COVID-19 might be affecting AMR in the short term (by influencing the key determinants antibiotic use, infection control practices and international/local mobility) and which additional factors might play a role in the long term. Whereas reduced outpatient antibiotic use in high-income countries, increased awareness for hand hygiene, and reduced mobility have likely mitigated the emergence and spread of AMR in the short term, factors such as overuse of antibiotics in COVID-19 patients, shortage of personal protective equipment, lack of qualified healthcare staff, and patient overcrowding have presumably facilitated its propagation. Unsurprisingly, international and national AMR surveillance data for 2020 show ambiguous trends. Although disruptions in antibiotic stewardship programs, AMR surveillance and research might promote the spread of AMR, other developments could prove beneficial to the cause in the long term. These factors include the increased public awareness for infectious diseases and infection control issues, the strengthening of the One Health perspective as outlined by the Centers for Disease Control and Prevention, and the unprecedented number of international research collaborations and platforms. These factors could even serve as leverage and provide opportunities to better combat AMR in the future.

Shining light on multi-drug resistant Candida auris: Ultraviolet-C disinfection, wavelength sensitivity, and prevention of biofilm formation of an emerging yeast pathogen

Candida auris is an emerging fungal superbug of worldwide interest. It is associated with high mortality rates and exhibits increased resistance to antifungals. Ultraviolet subtype C (UVC) light can be used to disinfect surfaces to mitigate its spread. The objectives of this study were (1) To investigate UVC disinfection performances and wavelength sensitivity of C. auris. (2) To evaluate the UVC dose required for the prevention of biofilm formation on stainless-steel, plastic (polystyrene), and poly-cotton fabric surfaces. C. auris was grown following standard procedures. The study utilized six different UVC LED arrays with wavelengths between 252 and 280 nm. Arrays were set at similar intensities, to obtain doses of 5-40 mJ cm-2 and similar irradiation time. Disinfection performance for each array was determined using log reduction value (LRV) and percentage reduction by comparing the controls against the irradiated treatments. Evaluation of the ability of 267 nm UVC LEDs to prevent C. auris biofilm formation was investigated using stainless-steel, plastic coupons, and poly-cotton fabric. Peak sensitivity to UVC disinfection was between 267 and 270 nm. With 20 mJ cm-2 , the study obtained ≥LRV3. On stainless-steel coupons, 30 mJ cm-2 was sufficient to prevent biofilm formation, while on plastic, this required 10 mJ cm-2 . A dose of 60 mJ cm-2 reduced biofilms on poly-cotton fabric significantly (R2  = 0.9750, p = 0.0002). The study may allow for the design and implementation of disinfection systems.

The challenge of preventing and containing outbreaks of multidrug-resistant organisms and Candida auris during the coronavirus disease 2019 pandemic: report of a carbapenem-resistant Acinetobacter baumannii outbreak and a systematic review of the literature

BACKGROUND

Despite the adoption of strict infection prevention and control measures, many hospitals have reported outbreaks of multidrug-resistant organisms (MDRO) during the Coronavirus 2019 (COVID-19) pandemic. Following an outbreak of carbapenem-resistant Acinetobacter baumannii (CRAB) in our institution, we sought to systematically analyse characteristics of MDRO outbreaks in times of COVID-19, focussing on contributing factors and specific challenges in controlling these outbreaks.

METHODS

We describe results of our own CRAB outbreak investigation and performed a systematic literature review for MDRO (including Candida auris) outbreaks which occurred during the COVID-19 pandemic (between December 2019 and March 2021). Search terms were related to pathogens/resistance mechanisms AND COVID-19. We summarized outbreak characteristics in a narrative synthesis and contrasted contributing factors with implemented control measures.

RESULTS

The CRAB outbreak occurred in our intensive care units between September and December 2020 and comprised 10 patients (thereof seven with COVID-19) within two distinct genetic clusters (both ST2 carrying OXA-23). Both clusters presumably originated from COVID-19 patients transferred from the Balkans. Including our outbreak, we identified 17 reports, mostly caused by Candida auris (n = 6) or CRAB (n = 5), with an overall patient mortality of 35% (68/193). All outbreaks involved intensive care settings. Non-adherence to personal protective equipment (PPE) or hand hygiene (n = 11), PPE shortage (n = 8) and high antibiotic use (n = 8) were most commonly reported as contributing factors, followed by environmental contamination (n = 7), prolonged critical illness (n = 7) and lack of trained HCW (n = 7). Implemented measures mainly focussed on PPE/hand hygiene audits (n = 9), environmental cleaning/disinfection (n = 9) and enhanced patient screening (n = 8). Comparing potentially modifiable risk factors and control measures, we found the largest discrepancies in the areas of PPE shortage (risk factor in 8 studies, addressed in 2 studies) and patient overcrowding (risk factor in 5 studies, addressed in 0 studies).

CONCLUSIONS

Reported MDRO outbreaks during the COVID-19 pandemic were most often caused by CRAB (including our outbreak) and C. auris. Inadequate PPE/hand hygiene adherence, PPE shortage, and high antibiotic use were the most commonly reported potentially modifiable factors contributing to the outbreaks. These findings should be considered for the prevention of MDRO outbreaks during future COVID-19 waves.

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.

Population genomic analyses reveal evidence for limited recombination in the superbug Candida auris in nature

Candida auris is a recently emerged, multidrug-resistant pathogenic yeast capable of causing a diversity of human infections worldwide. Genetic analyses based on whole-genome sequences have clustered strains in this species into five divergent clades, with each clade containing limited genetic variation and one of two mating types, MTLa or MTLα. The patterns of genetic variations suggest simultaneous emergence and clonal expansion of multiple clades of this pathogen across the world. At present, it is unclear whether recombination has played any role during the evolution of C. auris. In this study, we analyzed patterns of associations among single nucleotide polymorphisms in both the nuclear and the mitochondrial genomes of 1,285 strains to investigate potential signatures of recombination in natural C. auris populations. Overall, we found that polymorphisms in the nuclear and mitochondrial genomes clustered the strains similarly into the five clades, consistent with a lack of evidence for recombination among the clades after their divergence. However, variable percentages of SNP pairs showed evidence of phylogenetic incompatibility and linkage equilibrium among samples in both the nuclear and the mitochondrial genomes, with the percentages higher in the total population than those within individual clades. Our results are consistent with limited but greater frequency of recombination before the divergence of the clades than afterwards. SNPs at loci related to antifungal resistance showed frequencies of recombination similar to or lower than those observed for SNPs in other parts of the genome. Together, though very limited, evidence for the observed recombination for both before and after the divergence of the clades suggests the possibility for continuous genetic exchange in natural populations of this important yeast pathogen.

Molecular characterisation of Candida auris isolates from immunocompromised patients in a tertiary-care hospital in Kuwait reveals a novel mutation in FKS1 conferring reduced susceptibility to echinocandins

BACKGROUND

Candida auris is an emerging, potentially multidrug-resistant pathogen that exhibits clade-specific resistance to fluconazole and also develops resistance to echinocandins and amphotericin B easily. This study analysed 49 C auris isolates for alterations in hotspot-1 and hotspot-2 of FKS1 for the detection of mutations conferring reduced susceptibility to echinocandins.

METHODS

C auris isolates (n = 49) obtained from 18 immunocompromised patients during June 2016-December 2018 were analysed. Antifungal susceptibility testing was performed by Etest and broth microdilution-based MICRONAUT-AM assay. Mutations in hotspot-1 and hotspot-2 regions of FKS1 were detected by PCR sequencing and fingerprinting of the isolates was done by short tandem repeat typing.

RESULTS

The patients had multiple comorbidities/risk factors for Candida spp. infection including cancer/leukaemia/lymphoma/myeloma (n = 16), arterial/central line (n = 17), urinary catheter (n = 17), mechanical ventilation (n = 14) and major surgery (n = 9) and received antifungal drugs as prophylaxis and/or empiric treatment. Seven patients developed C auris candidemia/breakthrough candidemia, nine patients had candiduria with/without candidemia and four patients developed surgical site/respiratory infection. Resistance to fluconazole and amphotericin B was detected in 44 and four isolates, respectively. Twelve C auris isolates from eight patients showed reduced susceptibility to echinocandins. Seven isolates contained hostspot-1 mutations and three isolates from a candidemia patient contained R1354H mutation in hotspot-2 of FKS1. Ten patients died, five were cured, two were lost to follow-up and treatment details for one patient were not available.

CONCLUSIONS

Our findings describe development of a novel mutation in FKS1 conferring reduced susceptibility to echinocandins in one patient during treatment and unfavourable clinical outcome for many C auris-infected patients.

A Chronic Autochthonous Fifth Clade Case of Candida auris Otomycosis in Iran

Candida auris, a multidrug-resistant nosocomial pathogen, has emerged globally with high morbidity and mortality among immunocompromised individuals and COVID19 hospitalized patients. Five major clades of C. auris have been previously described. The fifth clade is exclusively found in Iran where C. auris isolates are genetically distinct from other clades by > 200,000 single-nucleotide polymorphisms. The origin of C. auris remains unclear, and limited clinical data are available at present regarding clade V infection or colonization. Herein, another case of otomycosis in Iran caused by an isolate of C. auris belonging to the fifth clade is reported. Genotyping revealed that the obtained C. auris isolate from Isfahan clustered with earlier clade V isolates from Babol, cities around 600 km separated, which indicates that C. auris clade V is established in Iran. C. auris is thought to exist more commonly in Iran, given that limited diagnostic capacity in the country has probably curbed the identification of more C. auris cases. Therefore, surveillance of the environment, patients and healthcare facilities in different geographical regions in Iran is urgently required.

South Asian (Clade I) Candida auris meningitis in a paediatric patient in Iran with a review of the literature

Candida meningitis is a rare life-threatening yeast infection mostly involving immunocompromised or paediatric patients undergoing neurosurgical procedures or shunt placement. Due to difficulties in diagnosis because of diverse clinical manifestations, the number of patients affected is most likely underestimated. Therefore, the correct diagnosis may be delayed for months, and accurate species identification is highly recommended for administering appropriate antifungal therapy. We report the first case of fluconazole-resistant Candida auris meningitis in a paediatric patient in Iran. This strain was probably imported, as it genotypically belonged to Clade I from South Asia. Furthermore, we include a literature review of C auris meningitis cases, as the number of cases with C auris meningitis has increased with reports from the United Kingdom, India and Iran. This problem might increase further in the era of COVID-19 due to attrition of experienced healthcare personnel and a high workload of hospital healthcare workers. To understand the precise prevalence of this emerging multidrug resistance pathogen, epidemiological surveillance studies are urgently warranted.

Invasive Fungal Infections Complicating COVID-19: A Narrative Review

Invasive fungal infections (IFIs) can complicate the clinical course of COVID-19 and are associated with a significant increase in mortality, especially in critically ill patients admitted to an intensive care unit (ICU). This narrative review concerns 4099 cases of IFIs in 58,784 COVID-19 patients involved in 168 studies. COVID-19-associated invasive pulmonary aspergillosis (CAPA) is a diagnostic challenge because its non-specific clinical/imaging features and the fact that the proposed clinically diagnostic algorithms do not really apply to COVID-19 patients. Forty-seven observational studies and 41 case reports have described a total of 478 CAPA cases that were mainly diagnosed on the basis of cultured respiratory specimens and/or biomarkers/molecular biology, usually without histopathological confirmation. Candidemia is a widely described secondary infection in critically ill patients undergoing prolonged hospitalisation, and the case reports and observational studies of 401 cases indicate high crude mortality rates of 56.1% and 74.8%, respectively. COVID-19 patients are often characterised by the presence of known risk factors for candidemia such as in-dwelling vascular catheters, mechanical ventilation, and broad-spectrum antibiotics. We also describe 3185 cases of mucormycosis (including 1549 cases of rhino-orbital mucormycosis (48.6%)), for which the main risk factor is a history of poorly controlled diabetes mellitus (>76%). Its diagnosis involves a histopathological examination of tissue biopsies, and its treatment requires anti-fungal therapy combined with aggressive surgical resection/debridement, but crude mortality rates are again high: 50.8% in case reports and 16% in observational studies. The presence of other secondary IFIs usually diagnosed in severely immunocompromised patients show that SARS-CoV-2 is capable of stunning the host immune system: 20 cases of Pneumocystis jirovecii pneumonia, 5 cases of cryptococcosis, 4 cases of histoplasmosis, 1 case of coccidioides infection, 1 case of pulmonary infection due to Fusarium spp., and 1 case of pulmonary infection due to Scedosporium.

Impact of SARS-CoV-2 Epidemic on Antimicrobial Resistance: A Literature Review

Antimicrobial resistance is an urgent threat to public health and global development; in this scenario, the SARS-CoV2 pandemic has caused a major disruption of healthcare systems and practices. A narrative review was conducted on articles focusing on the impact of COVID-19 on multidrug-resistant gram-negative, gram-positive bacteria, and fungi. We found that, worldwide, multiple studies reported an unexpected high incidence of infections due to methicillin-resistant S. aureus, carbapenem-resistant A. baumannii, carbapenem-resistant Enterobacteriaceae, and C. auris among COVID-19 patients admitted to the intensive care unit. In this setting, inappropriate antimicrobial exposure, environmental contamination, and discontinuation of infection control measures may have driven selection and diffusion of drug-resistant pathogens.

Overview on the Prevalence of Fungal Infections, Immune Response, and Microbiome Role in COVID-19 Patients

Patients with severe COVID-19, such as individuals in intensive care units (ICU), are exceptionally susceptible to bacterial and fungal infections. The most prevalent fungal infections are aspergillosis and candidemia. Nonetheless, other fungal species (for instance, Histoplasma spp., Rhizopus spp., Mucor spp., Cryptococcus spp.) have recently been increasingly linked to opportunistic fungal diseases in COVID-19 patients. These fungal co-infections are described with rising incidence, severe illness, and death that is associated with host immune response. Awareness of the high risks of the occurrence of fungal co-infections is crucial to downgrade any arrear in diagnosis and treatment to support the prevention of severe illness and death directly related to these infections. This review analyses the fungal infections, treatments, outcome, and immune response, considering the possible role of the microbiome in these patients. The search was performed in Medline (PubMed), using the words "fungal infections COVID-19", between 2020-2021.