Five-year profile of candidaemia at an Indian trauma centre: High rates of Candida auris blood stream infections

First report of Candida auris in Guangdong, China: clinical and microbiological characteristics of 7 episodes of candidemia

Candida auris is an emerging multidrug-resistant fungal pathogen worldwide. To date, it has not been reported in Guangdong, China. For the first time, we reported 7 cases of C. auris candidemia from two hospitals in Guangdong. The clinical and microbiological characteristics of these cases were investigated carefully. Two geographic clades, i.e. III and I, were found popular in different hospitals by whole genome sequencing analyses. All C. auris isolates from bloodstream were resistant to fluconazole, 5 of which belonged to Clade III harbouring VF125AL mutation in the ERG11 gene. The isolates with Clade I presented Y132F mutation in the ERG11 gene as well as resistance to amphotericin B. All isolates exhibited strong biofilm-forming capacity and non-aggregative phenotype. The mean time from admission to onset of C. auris candidemia was 39.4 days (range: 12 - 80 days). Despite performing appropriate therapeutic regimen, 42.9% (3/7) of patients experienced occurrences of C. auris candidemia and colonization after the first positive bloodstream. C. auris colonization was still observed after the first C. auris candidemia for 81 days in some patient. Microbiologic eradication from bloodstream was achieved in 85.7% (6/7) of patients at discharge. In conclusion, this study offers a crucial insight into unravelling the multiple origins of C. auris in Guangdong, highlighting great challenges in clinical prevention and control.

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.

Evaluation of the Vitek 2 system for antifungal susceptibility testing of Candida auris using a representative international panel of clinical isolates: overestimation of amphotericin B resistance and underestimation of fluconazole resistance

Although the Vitek 2 system is broadly used for antifungal susceptibility testing of Candida spp., its performance against Candida auris has been assessed using limited number of isolates recovered from restricted geographic areas. We therefore compared Vitek 2 system with the reference Clinical and Laboratory Standards Institute (CLSI) broth microdilution method using an international collection of 100 C. auris isolates belonging to different clades. The agreement ±1 twofold dilution between the two methods and the categorical agreement (CA) based on the Centers for Disease Control and Prevention's (CDC's) tentative resistance breakpoints and Vitek 2-specific wild-type upper limit values (WT-ULVs) were determined. The CLSI-Vitek 2 agreement was poor for 5-flucytosine (0%), fluconazole (16%), and amphotericin B (29%), and moderate for voriconazole (61%), micafungin (67%), and caspofungin (81%). Significant interpretation errors were recorded using the CDC breakpoints for amphotericin B (31% CA, 69% major errors; MaEs) and fluconazole (69% CA, 31% very major errors; VmEs), but not for echinocandins (99% CA, 1% MaEs for both micafungin and caspofungin) for which the Vitek 2 allowed correct categorization of echinocandin-resistant FKS1 mutant isolates. Discrepancies were reduced when the Vitek 2 WT-ULV of 16 mg/L for amphotericin B (98% CA, 2% MaEs) and of 4 mg/L for fluconazole (96% CA, 1% MaEs, 3% VmEs) were used. In conclusion, the Vitek 2 system performed well for echinocandin susceptibility testing of C .auris. Resistance to fluconazole was underestimated whereas resistance to amphotericin B was overestimated using the CDC breakpoints of ≥32 and ≥2 mg/L, respectively. Vitek 2 minimun inhibitory concentrations (MICs) >4 mg/L indicated resistance to fluconazole and Vitek 2 MICs ≤16 mg/L indicated non-resistance to amphotericin B.

Challenges in management of Candida auris meningitis secondary to infected ventriculoperitoneal shunt - A case report

Meningitis in patients with ventriculo-peritoneal shunt (VP shunt) caused by various species of Candida have been widely described in literature. However, reports describing Candida auris as a cause of meningitis is limited. In this case report we describe a case of multidrug resistant Candida auris meningitis secondary to VP shunt infection successfully treated with intrathecal amphotericin B deoxycholate and intravenous liposomal amphotericin B. This is the second case report of successful treatment of Candida auris meningitis from India. More literature regarding the use of intrathecal/intraventricular echinocandins including optimal dosing and duration of therapy is needed.

Tools and techniques to identify, study, and control Candida auris

Candida auris, is an emerging fungal pathogen that can cause life-threatening infections in humans. Unlike many other Candida species that colonize the intestine, C. auris most efficiently colonizes the skin. Such colonization contaminates the patient's environment and can result in rapid nosocomial transmission. In addition, this transmission can lead to outbreaks of systemic infections that have mortality rates between 40% and 60%. C. auris isolates resistant to all known classes of antifungals have been identified and as such, understanding the underlying biochemical mechanisms of how skin colonization initiates and progresses is critical to developing better therapeutic options. With this review, we briefly summarize what is known about horizontal transmission and current tools used to identify, understand, and control C. auris infections.

Host defense mechanisms against Candida auris

INTRODUCTION

Candida auris is a pathogen of growing public health concern given its rapid spread across the globe, its propensity for long-term skin colonization and healthcare-related outbreaks, its resistance to a variety of antifungal medications, and the high morbidity and mortality associated with invasive disease. Despite that, the host immune response mechanisms that operate during C. auris skin colonization and invasive infection remains poorly understood.

AREAS COVERED

In this manuscript, we review the available literature in the growing research field pertaining to C. auris host defenses and we discuss what is known about the ability of C. auris to thrive on mammalian skin, the role of lymphoid cell-mediated, IL-17-dependent defenses in controlling cutaneous colonization, and the contribution of myeloid phagocytes in curtailing systemic infection.

EXPERT OPINION

Understanding the mechanisms by which the host immune system responds to and controls colonization and infection with C. auris and developing a deeper knowledge of tissue-specific host-C. auris interactions and of C. auris immune-evading mechanisms may help devise improved strategies for decolonization, prognostication, prevention, vaccination, and/or directed antifungal treatment in vulnerable patient populations.

Immune responses to human fungal pathogens and therapeutic prospects

Pathogenic fungi have emerged as significant causes of infectious morbidity and death in patients with acquired immunodeficiency conditions such as HIV/AIDS and following receipt of chemotherapy, immunosuppressive agents or targeted biologics for neoplastic or autoimmune diseases, or transplants for end organ failure. Furthermore, in recent years, the spread of multidrug-resistant Candida auris has caused life-threatening outbreaks in health-care facilities worldwide and raised serious concerns for global public health. Rapid progress in the discovery and functional characterization of inborn errors of immunity that predispose to fungal disease and the development of clinically relevant animal models have enhanced our understanding of fungal recognition and effector pathways and adaptive immune responses. In this Review, we synthesize our current understanding of the cellular and molecular determinants of mammalian antifungal immunity, focusing on observations that show promise for informing risk stratification, prognosis, prophylaxis and therapies to combat life-threatening fungal infections in vulnerable patient populations.

Protective Efficacy of Anti-Hyr1p Monoclonal Antibody against Systemic Candidiasis Due to Multi-Drug-Resistant Candida auris

Candida auris is a multi-drug-resistant fungal pathogen that can survive outside the host and can easily spread and colonize the healthcare environment, medical devices, and human skin. C. auris causes serious life-threatening infections (up to 60% mortality) in immunosuppressed patients staying in such contaminated healthcare facilities. Some isolates of C. auris are resistant to virtually all clinically available antifungal drugs. Therefore, alternative therapeutic approaches are urgently needed. Using in silico protein modeling and analysis, we identified a highly immunogenic and surface-exposed epitope that is conserved between C. albicans hyphal-regulated protein (Cal-Hyr1p) and Hyr1p/Iff-like proteins in C. auris (Cau-HILp). We generated monoclonal antibodies (MAb) against this Cal-Hyr1p epitope, which recognized several clinical isolates of C. auris representing all four clades. An anti-Hyr1p MAb prevented biofilm formation and enhanced opsonophagocytic killing of C. auris by macrophages. When tested for in vivo efficacy, anti-Hyr1p MAb protected 55% of mice against lethal systemic C. auris infection and showed significantly less fungal burden. Our study is highly clinically relevant and provides an effective alternative therapeutic option to treat infections due to MDR C. auris.

Strategies to Prevent Transmission of Candida auris in Healthcare Settings

Purpose of Review

Candida auris, a recently recognized yeast pathogen, has become a major public health threat due to the problems associated with its accurate identification, intrinsic and acquired resistance to antifungal drugs, and its potential to easily contaminate the environment causing clonal outbreaks in healthcare facilities. These outbreaks are associated with high mortality rates particularly among older patients with multiple comorbidities under intensive care settings. The purpose of this review is to highlight strategies that are being adapted to prevent transmission of C. auris in healthcare settings.

Recent Findings

Colonized patients shed C. auris into their environment which contaminates surrounding equipment. It resists elimination even by robust decontamination procedures and is easily transmitted to new patients during close contact resulting in outbreaks. Efforts are being made to rapidly identify C. auris-infected/C. auris-colonized patients, to determine its susceptibility to antifungals, and to perform effective cleaning and decontamination of the environment and isolation of colonized patients to prevent further transmission.

Summary

Rapid and accurate identification of hospitalized patients infected/colonized with C. auris, rapid detection of its susceptibility patterns, and appropriate use of infection control measures can help to contain the spread of this highly pathogenic yeast in healthcare settings and prevent/control outbreaks.

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.

The Dominance of Candida auris: A Single-center Experience of 79 Episodes of Candidemia from Western India

Introduction

Invasive candidiasis is a serious infection seen in hospitalized or immunocompromised patients. Mortality rates for candidemia can be as high as 30–60%. Candida auris is an emerging species of Candida and is increasingly becoming a global public health problem.

Methods

This was a retrospective observational study, in which we analyzed 79 episodes of candidemia. Blood cultures were done using the Bactec™ FX blood culturing instrument (Becton, Dickinson and Company Sparks, Maryland, USA). Species identification was done using VITEK® 2 YST panels (bioMérieux Inc., Durham, North Carolina, USA). Antifungal susceptibility testing was performed using VITEK® 2 AST-YSO8 panels (bioMérieux Inc., Durham, North Carolina, USA).

Results

Among the 79 episodes, the most common species was found to be C. auris (43.03% of all the episodes). Candida tropicalis was found to be the second most common species in patients admitted to our hospital with candidemia. All the isolates of C. auris were resistant to fluconazole, while 32.35 % of the isolates were also resistant to amphotericin B. Crude mortality in patients with C. auris candidemia was higher than the crude mortality for the other species.

Conclusion

This is the first study from India where C. auris was seen as the most predominant species among patients admitted with candidemia. This is a serious issue given the high rates of fluconazole resistance, mortality, and cost of therapy associated with C. auris bloodstream infections. Urgent attention needs to be diverted to infection control practices and antimicrobial stewardship programs.

How to cite this article

Prayag PS, Patwardhan S, Panchakshari S, Rajhans PA, Prayag A. The Dominance of Candida auris: A Single-center Experience of 79 Episodes of Candidemia from Western India. Indian J Crit Care Med 2022;26(5):560–563.

Fatal Breakthrough Candidemia in an Immunocompromised Patient in Kuwait Due to Candida auris Exhibiting Reduced Susceptibility to Echinocandins and Carrying a Novel Mutation in Hotspot-1 of FKS1

Candida auris is an emerging yeast pathogen that has recently caused major outbreaks in healthcare facilities worldwide. Clinical C. auris isolates are usually resistant to fluconazole and readily develop resistance to echinocandins and amphotericin B (AMB) during treatment. We describe here an interesting case of C. auris infection in an immunocompromised patient who had previously received AMB and caspofungin treatment. Subsequently, C. auris was isolated from tracheal (tracheostomy) secretions and twice from urine and all three isolates were susceptible to AMB and micafungin. The patient received a combination therapy with AMB and caspofungin. Although the C. auris was cleared from the urine, the patient subsequently developed breakthrough candidemia and the bloodstream isolate exhibited a reduced susceptibility to micafungin and also showed the presence of a novel (S639T) mutation in hotspot-1 of FKS1. Interestingly, C. auris from the tracheal (tracheostomy) secretions recovered one and four days later exhibited a reduced susceptibility to micafungin and S639Y and S639T mutations in hotspot-1 of FKS1, respectively. Although the treatment was changed to voriconazole, the patient expired. Our case highlights a novel FKS1 mutation and the problems clinicians are facing to treat invasive C. auris infections due to inherent or developing resistance to multiple antifungal drugs and limited antifungal armamentarium.

OUP accepted manuscript

Candida auris is an emerging, multi drug resistant fungal pathogen that has caused infectious outbreaks in over 45 countries since its first isolation over a decade ago, leading to in-hospital crude mortality rates as high as 72%. The fungus is also acclimated to disinfection procedures and persists for weeks in nosocomial ecosystems. Alarmingly, the outbreaks of C. auris infections in Coronavirus Disease-2019 (COVID-19) patients have also been reported. The pathogenicity, drug resistance and global spread of C. auris have led to an urgent exploration of novel, candidate antifungal agents for C. auris therapeutics. This narrative review codifies the emerging data on the following new/emerging antifungal compounds and strategies: antimicrobial peptides, combinational therapy, immunotherapy, metals and nano particles, natural compounds, and repurposed drugs. Encouragingly, a vast majority of these exhibit excellent anti- C. auris properties, with promising drugs now in the pipeline in various stages of development. Nevertheless, further research on the modes of action, toxicity, and the dosage of the new formulations are warranted. Studies are needed with representation from all five C. auris clades, so as to produce data of grater relevance, and broader significance and validity.

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.

Antifungal Susceptibility Testing: A Primer for Clinicians

Clinicians treating patients with fungal infections may turn to susceptibility testing to obtain information regarding the activity of different antifungals against a specific fungus that has been cultured. These results may then be used to make decisions regarding a patient's therapy. However, for many fungal species that are capable of causing invasive infections, clinical breakpoints have not been established. Thus, interpretations of susceptible or resistant cannot be provided by clinical laboratories, and this is especially true for many molds capable of causing severe mycoses. The purpose of this review is to provide an overview of susceptibility testing for clinicians, including the methods used to perform these assays, their limitations, how clinical breakpoints are established, and how the results may be put into context in the absence of interpretive criteria. Examples of when susceptibility testing is not warranted are also provided.

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.

Augmenting the Activity of Chlorhexidine for Decolonization of Candida auris from Porcine skin

Candida auris readily colonizes skin and efficiently spreads among patients in healthcare settings worldwide. Given the capacity of this drug-resistant fungal pathogen to cause invasive disease with high mortality, hospitals frequently employ chlorhexidine bathing to reduce skin colonization. Using an ex vivo skin model, we show only a mild reduction in C. auris following chlorhexidine application. This finding helps explain why chlorhexidine bathing may have failures clinically, despite potent in vitro activity. We further show that isopropanol augments the activity of chlorhexidine against C. auris on skin. Additionally, we find both tea tree (Melaleuca alternifolia) oil and lemongrass (Cymbopogon flexuosus) oil to further enhance the activity of chlorhexidine/isopropanol for decolonization. We link this antifungal activity to individual oil components and show how some of these components act synergistically with chlorhexidine/isopropanol. Together, the studies provide strategies to improve C. auris skin decolonization through the incorporation of commonly used topical compounds.

Epidemiology of Candidemia in Kuwait: A Nationwide, Population-Based Study

The Candida species cause a majority of invasive fungal infections. In this article, we describe the nationwide epidemiology of candidemia in Kuwait in 2018. Yeast bloodstream isolates submitted from all major hospitals and identified by phenotypic MALDI-TOF MS and/or by molecular methods were studied. Susceptibility testing was performed by Etest. Out of 313 bloodstream yeasts, 239 Candida spp. isolates (excluding duplicate isolates) were obtained during 234 candidemic episodes among 223 patients. Mixed-species candidemia and re-infection occurred in 5 and 11 patients, respectively. C. albicans (n = 74), C. parapsilosis (n = 54), C. tropicalis (n = 35), C. auris (n = 33), C. glabrata (n = 32), other Candida spp. (n = 11), and other yeasts (n = 9) caused fungemia. Nearly 50% of patients were in intensive care units. Candida spp. isolates (except C. glabrata) were susceptible to caspofungin and 27% of C. auris were amphotericin B-resistant. Resistance to fluconazole was 100% in C. auris, 17% in C. parapsilosis, 12% in C. glabrata, and 1% in C. albicans. Mortality was 47% for other Candida/yeast infections. Nationwide candidemia incidence in 2018 was 5.29 cases/100,000 inhabitants. Changes in species spectrum, increasing fluconazole resistance in C. parapsilosis, and the emergence of C. auris as a major pathogen in Kuwait are noteworthy findings. The data could be of help in informing decisions regarding planning, in the allocation of resources, and in antimicrobial stewardship.

Clinical profile, antifungal susceptibility, and molecular characterization of Candida auris isolated from patients in a South Indian surgical ICU

BACKGROUND

Candida auris is an emerging multidrug resistant yeast which causes blood stream infection especially among critically ill patients. This yeast can also colonize patients and are isolated from hospital environment causing outbreaks in hospital settings.

OBJECTIVE

To describe possible outbreak of C. auris infection in surgical ICU and characterize the isolates by molecular typing and azole resistance mechanism.

METHODS

After isolation of Candida auris from cluster of patients from surgical ICU, environment survey was done to identify the source in the hospital. The identity of the isolates was confirmed by Matrix Assisted Laser Desorption Ionisation Time of Flight mass spectroscopy and sequencing 26S and ITS region of rDNA. Molecular typing was done by fluorescent amplified fragment length polymorphism technique. Antifungal susceptibility testing was performed by CLSI broth dilution technique. ERG11 gene was sequenced to screen for mutations responsible for azole resistance.

RESULTS AND CONCLUSION

A total of eight C. auris was isolated during the four months (December 2018-March 2019) suggesting possible of outbreak in surgical ICU of tertiary care center in South India. C. auris (n = 8) was isolated from urine (n = 4), blood (n = 3) and ear discharge (n = 1) samples. Based on 26S sequence analysis all our isolates belonged to South Asian clade. All the isolates had minimum inhibitory concentration (MIC) of ≥16 µg/ml to fluconazole. ERG11 sequence exhibited amino acid substitution Y132F in all the isolates. The two environmental isolates clustered closely with an isolate from urine sample. Adherence to strict infection control practices prevented further spread of infection.

Candida auris Cell Wall Mannosylation Contributes to Neutrophil Evasion through Pathways Divergent from Candida albicans and Candida glabrata

Candida auris, a recently emergent fungal pathogen, has caused invasive infections in health care settings worldwide. Mortality rates approach 60% and hospital spread poses a public health threat. Compared to other Candida spp., C. auris avoids triggering the antifungal activity of neutrophils, innate immune cells that are critical for responding to many invasive fungal infections, including candidiasis. However, the mechanism underpinning this immune evasion has been largely unknown. Here, we show that C. auris cell wall mannosylation contributes to the evasion of neutrophils ex vivo and in a zebrafish infection model. Genetic disruption of mannosylation pathways (PMR1 and VAN1) diminishes the outer cell wall mannan, unmasks immunostimulatory components, and promotes neutrophil engagement, phagocytosis, and killing. Upon examination of these pathways in other Candida spp. (Candida albicans and Candida glabrata), we did not find an impact on neutrophil interactions. These studies show how C. auris mannosylation contributes to neutrophil evasion though pathways distinct from other common Candida spp. The findings shed light on innate immune evasion for this emerging pathogen.

IMPORTANCE The emerging fungal pathogen Candida auris presents a global public health threat. Therapeutic options are often limited for this frequently drug-resistant pathogen, and mortality rates for invasive disease are high. Previous study has demonstrated that neutrophils, leukocytes critical for the antifungal host defense, do not efficiently recognize and kill C. auris. Here, we show how the outer cell wall of C. auris promotes immune evasion. Disruption of this mannan polysaccharide layer renders C. auris susceptible to neutrophil killing ex vivo and in a zebrafish model of invasive candidiasis. The role of these mannosylation pathways for neutrophil evasion appears divergent from other common Candida species.

A Case Report of a Candida auris Infection in Saudi Arabia

Candida auris is a relatively new species of the Candida genus that is rapidly spreading in healthcare institutions across the globe. It is exceedingly difficult to identify with standard laboratory procedures and is challenging to treat due to its resistance to most antifungals. Moreover, it quickly colonizes on the surfaces in hospitals and ICUs and causes repeated infections, despite regular hospital disinfection. This grim occurrence of multidrug-resistant yeast has now become imperative to report, as its true prevalence remains unclear. Only some reports have been published in Saudi Arabia and here we present a case of C. auris candidemia identified in our hospital.

Candida auris: Epidemiology, Diagnosis, Pathogenesis, Antifungal Susceptibility, and Infection Control Measures to Combat the Spread of Infections in Healthcare Facilities

Candida auris, a recently recognized, often multidrug-resistant yeast, has become a significant fungal pathogen due to its ability to cause invasive infections and outbreaks in healthcare facilities which have been difficult to control and treat. The extraordinary abilities of C. auris to easily contaminate the environment around colonized patients and persist for long periods have recently resulted in major outbreaks in many countries. C. auris resists elimination by robust cleaning and other decontamination procedures, likely due to the formation of 'dry' biofilms. Susceptible hospitalized patients, particularly those with multiple comorbidities in intensive care settings, acquire C. auris rather easily from close contact with C. auris-infected patients, their environment, or the equipment used on colonized patients, often with fatal consequences. This review highlights the lessons learned from recent studies on the epidemiology, diagnosis, pathogenesis, susceptibility, and molecular basis of resistance to antifungal drugs and infection control measures to combat the spread of C. auris infections in healthcare facilities. Particular emphasis is given to interventions aiming to prevent new infections in healthcare facilities, including the screening of susceptible patients for colonization; the cleaning and decontamination of the environment, equipment, and colonized patients; and successful approaches to identify and treat infected patients, particularly during outbreaks.

Drug-Resistant Fungi: An Emerging Challenge Threatening Our Limited Antifungal Armamentarium

The high clinical mortality and economic burden posed by invasive fungal infections (IFIs), along with significant agricultural crop loss caused by various fungal species, has resulted in the widespread use of antifungal agents. Selective drug pressure, fungal attributes, and host- and drug-related factors have counteracted the efficacy of the limited systemic antifungal drugs and changed the epidemiological landscape of IFIs. Species belonging to Candida, Aspergillus, Cryptococcus, and Pneumocystis are among the fungal pathogens showing notable rates of antifungal resistance. Drug-resistant fungi from the environment are increasingly identified in clinical settings. Furthermore, we have a limited understanding of drug class-specific resistance mechanisms in emerging Candida species. The establishment of antifungal stewardship programs in both clinical and agricultural fields and the inclusion of species identification, antifungal susceptibility testing, and therapeutic drug monitoring practices in the clinic can minimize the emergence of drug-resistant fungi. New antifungal drugs featuring promising therapeutic profiles have great promise to treat drug-resistant fungi in the clinical setting. Mitigating antifungal tolerance, a prelude to the emergence of resistance, also requires the development of effective and fungal-specific adjuvants to be used in combination with systemic antifungals.

Molecular Epidemiology of Candida Auris Outbreak in a Major Secondary-Care Hospital in Kuwait

The emerging, often multidrug-resistant Candida auris is increasingly being associated with outbreaks in healthcare facilities. Here we describe the molecular epidemiology of a C. auris outbreak during 18 months, which started in 2018 in the high dependency unit (HDU) of a secondary-care hospital in Kuwait. Demographic and clinical data for candidemia and colonized patients were prospectively recorded. Clinical and environmental isolates were subjected to phenotypic and molecular identification; antifungal susceptibility testing by broth microdilution method; PCR-sequencing of ERG11 and FKS1 for resistance mechanisms to triazoles and echinocandins, respectively; and molecular fingerprinting by short tandem repeat (STR) analyses. Seventy-one (17 candidemic and 54 colonized) patients including 26 with candiduria and seven environmental samples yielded C. auris. All isolates were identified as C. auris by Vitek2, MALDI-TOF MS, PCR amplification and/or PCR-sequencing of rDNA. Twelve candidemia and 26 colonized patients were admitted or exposed to HDU. Following outbreak recognition, an intensive screening program was instituted for new patients. Despite treatment of all candidemia and 36 colonized patients, 9 of 17 candidemia and 27 of 54 colonized patients died with an overall crude mortality rate of ~50%. Nearly all isolates were resistant to fluconazole and contained the Y132F mutation in ERG11 except one patient's isolates, which were also distinct by STR typing. Only urine isolates from two patients developed echinocandin resistance with concomitant FKS1 mutations. The transmission of C. auris in this outbreak was linked to infected/colonized patients and the hospital environment. However, despite continuous surveillance and enforcement of infection control measures, sporadic new cases continued to occur, challenging the containment efforts.

Multidrug-Resistant Candida auris Infections in Critically Ill Coronavirus Disease Patients, India, April-July 2020

In New Delhi, India, candidemia affected 15 critically ill coronavirus disease patients admitted to an intensive care unit during April–July 2020. Candida auris accounted for two thirds of cases; case-fatality rate was high (60%). Hospital-acquired C. auris infections in coronavirus disease patients may lead to adverse outcomes and additional strain on healthcare resources.

The Quiet and Underappreciated Rise of Drug-Resistant Invasive Fungal Pathogens

Human fungal pathogens are attributable to a significant economic burden and mortality worldwide. Antifungal treatments, although limited in number, play a pivotal role in decreasing mortality and morbidities posed by invasive fungal infections (IFIs). However, the recent emergence of multidrug-resistant Candida auris and Candida glabrata and acquiring invasive infections due to azole-resistant C. parapsilosis, C. tropicalis, and Aspergillus spp. in azole-naïve patients pose a serious health threat considering the limited number of systemic antifungals available to treat IFIs. Although advancing for major fungal pathogens, the understanding of fungal attributes contributing to antifungal resistance is just emerging for several clinically important MDR fungal pathogens. Further complicating the matter are the distinct differences in antifungal resistance mechanisms among various fungal species in which one or more mechanisms may contribute to the resistance phenotype. In this review, we attempt to summarize the burden of antifungal resistance for selected non-albicansCandida and clinically important Aspergillus species together with their phylogenetic placement on the tree of life. Moreover, we highlight the different molecular mechanisms between antifungal tolerance and resistance, and comprehensively discuss the molecular mechanisms of antifungal resistance in a species level.

A clinical predictive model of candidaemia by Candida auris in previously colonized critically ill patients

OBJECTIVES

Candida auris is an emerging multidrug-resistant fungus that has been associated with nosocomial outbreaks with high rates of mortality and transmission. The aim of this study was to perform a retrospective cohort analysis of risk factors and to build a scoring method for estimating the risk of candidaemia in colonized critically ill patients.

METHODS

We performed a retrospective observational cohort study of patients aged ≥15 years colonized by C. auris in the 3-year period between March 2016 and March 2019. Epidemiological, clinical, laboratory and microbiological data were collected. We developed a predictive model for candidaemia using elastic net multivariable logistic regression techniques, assessed its discriminative capacity, and internally validated it using bootstrap resampling.

RESULTS

Two-hundred and six patients were enrolled in the cohort for derivation and internal validation. Thirty-seven out of 206 patients developed candidaemia. Total parenteral nutrition was the foremost risk factor (adjusted OR 3.73); previous surgery (adjusted OR 1.03), sepsis (adjusted OR 1.75), previous exposure to antifungal agents (adjusted OR 1.17), arterial catheters (adjusted OR 1.46), central venous catheters (adjusted OR 1.21), presence of advanced chronic kidney disease (adjusted OR 1.35) and multifocal colonization (adjusted OR of unifocal colonization 0.46) were proven to be independent predictors of candidaemia in our cohort. The corresponding area under the curve (AUC) of the elastic net regularized predictive model was 0.89 (95%CI 0.826; 0.951). After performing the internal validation by generating 500 bootstrap replications, the model still showed great accuracy, with a resulting AUC of 0.84.

CONCLUSION

Our study provides evidence on the independent predisposing factors for candidaemia. It may help predict its estimated risk and may identify a high-risk population that could benefit from early or prophylactic antifungal treatment after external validation in other cohorts.

Candida auris: A Decade of Understanding of an Enigmatic Pathogenic Yeast

Candida auris is an enigmatic yeast that continues to stimulate interest within the mycology community due its rapid and simultaneous emergence of distinct clades. In the last decade, almost 400 manuscripts have contributed to our understanding of this pathogenic yeast. With dynamic epidemiology, elevated resistance levels and an indication of conserved and unique pathogenic traits, it is unsurprising that it continues to cause clinical concern. This mini-review aims to summarise some of the key attributes of his remarkable pathogenic yeast.

Increasing Trends of Reduced Susceptibility to Antifungal Drugs Among Clinical Candida glabrata Isolates in Kuwait

Among non-albicans Candida species, Candida glabrata is the leading cause of invasive infections in critically ill patients. It is intrinsically less susceptible to fluconazole/other azoles that limits therapeutic options. This study determined distribution of C. glabrata in clinical specimens and determined their susceptibility to fluconazole, caspofungin, and amphotericin B by E test. During 8-year period (2011-2018), 1,410 isolates were obtained from 1,410 patients including 600, 409, and 131 isolates from respiratory, urine, and bloodstream specimens, respectively. Proportion of C. glabrata isolates was nearly the same during the two 4-year periods. Demographic details were available from 731 patients and susceptibility data for 1,225 isolates. C. glabrata isolation from bloodstream, respiratory, and urine specimens was higher from elderly (>60 years) versus younger patients. More bloodstream and urine isolates were obtained from female patients, however, more respiratory isolates were recovered from male patients (p = <0.05). Resistance to all three drugs increased during 2015-2018 compared with 2011-2014 but was more pronounced for fluconazole (p = 0.001). More isolates with reduced susceptibility to fluconazole/amphotericin B were obtained from elderly patients versus younger subjects and urine versus respiratory samples (p = <0.05). Our data show increasing trends of reduced susceptibility to antifungals, particularly fluconazole, among clinical C. glabrata isolates in Kuwait. Most isolates with reduced susceptibility to fluconazole/amphotericin B were obtained from elderly patients and urine/respiratory samples with urinary tract appearing as the most favorable niche for antifungal drug resistance development. The study also highlights the need for continued surveillance and better antifungal drug stewardship to control resistance development in C. glabrata.

Candida auris candidaemia in an intensive care unit - Prospective observational study to evaluate epidemiology, risk factors, and outcome

PURPOSE

To determine the prevalence of Candida auris candidaemia in our ICU patients and its molecular epidemiology.

METHODS

A prospective observational study was conducted on candidaemia in our ICU patients over 18 months during 2016-2017. Demographics, underlying disease, risk factors, antifungal therapy and outcome were studied. Risk factors of C. auris and non-auris candidaemia were compared.

RESULTS

During the study period, among 108 candidaemia cases recorded, the incidence was 6.75/1000 ICU bed days. C. auris topped the list (n = 42, 39.9%), followed by C. tropicalis (34.3%), and C. parapsilosis (15.7%). On bivariate analysis prior antibiotic therapy, long central line days, mechanical ventilation and length of ICU stay were significant risk factors for C. auris candidaemia compared to non-auris candidaemia. Multivariate analysis showed underlying respiratory and neurological diseases as significantly associated with risk of C. auris candidaemia. Fluconazole, amphotericin B, and caspofungin resistance were noted in 97.0%, 93.7% and 3% of C. auris isolates respectively.

CONCLUSION

Longer duration of central line days, prior antibiotic use, mechanical ventilation and prolonged ICU stay were important risk factors associated with C. auris candidaemia along with underlying respiratory or neurological disease. The isolates are non-clonal in origin, but they belong to a single clade.

Candida auris in various hospitals across Kuwait and their susceptibility and molecular basis of resistance to antifungal drugs

BACKGROUND

Candida auris, a multidrug-resistant species, has the propensity of nosocomial transmission despite normal decontamination procedures. Here, we describe the isolation of C auris from patients in various hospitals in Kuwait during 2014-2018. Susceptibility to antifungal drugs and molecular basis of resistance to fluconazole, voriconazole and micafungin were also studied.

METHODS

Candida auris (n = 314) obtained from 126 patients in eight hospitals were studied. All isolates were identified by PCR amplification and/or PCR-sequencing of ribosomal DNA (rDNA). Antifungal susceptibility was determined by Etest. Molecular basis of resistance to fluconazole and micafungin was studied by PCR-sequencing of ERG11 and FKS1 genes, respectively.

FINDINGS

Bloodstream (n = 58), urine (n = 124), respiratory (n = 98) and other (n = 34) specimens yielded 314 C auris isolates. The proportion of bloodstream C auris among all yeast isolates was higher (42 of 307, 13.7%) in 2018 as compared to 2014-2017 (16 of 964, 1.7%) (P = .001). More bloodstream isolates (42 of 139) were cultured in 2018 than during 2014-2017 (16 of 175) (P = .001). Resistance to amphotericin B, fluconazole, voriconazole and micafungin was detected in 27.1%, 100%, 41.1% and 1.7% isolates, respectively. Fluconazole-resistant isolates contained either Y132F or K143R mutation in ERG11. Isolates with K143R mutation were additionally resistant to voriconazole. Micafungin-resistant isolates contained S639F mutation in hot spot 1 of FKS1.

CONCLUSIONS

Our study highlights spreading of C auris in major hospitals across Kuwait and its increasing role as a bloodstream pathogen in 2018. Cross-resistance to voriconazole was also seen in isolates with K143R mutation in ERG11, while micafungin-resistant isolates harboured S639F mutation in hot spot 1 of FKS1.

Indifferent effect of nonsteroidal anti-inflammatory drugs (NSAIDs) combined with fluconazole against multidrug-resistant Candida auris

Background and Purpose:

Emergence and development of antifungal drug resistance in Candida species constitute a serious concern. Candida auris as an emerging multidrug-resistant fungus is the most important public health threat with high levels of mortality and morbidity. Almost all C. auris isolates are resistant to fluconazole, and there have been reports of elevated minimum inhibitory concentrations (MICs) to amphotericin B and echinocandins. To overcome the growing challenge of antifungal resistance, a valuable alternative option would be the use of drug combination.

Materials and Methods:

The present study evaluated the in vitro combination of nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, diclofenac and aspirin with fluconazole against fluconazole-resistant C. auris in comparison to other fluconazole-resistant Candida species, including C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, and C. krusei originating from patients with candidiasis.

Results:

The MIC ranges of fluconazole-ibuprofen and fluconazole-diclofenac decreased from 32-256 to 32-128 and 16-256 µg/ml, respectively and remained the same for fluconazole-aspirin against C. auris. However, the combination of fluconazole with ibuprofen resulted in a synergistic effect for 5 strains, including C. albicans (n=2), C. tropicalis (n=1), C. glabrata (n=1), and C. krusei (n=1), by decreasing the MIC of fluconazole by 2-3 log₂ dilutions.

Conclusion:

Although the interaction of NSAIDs with fluconazole was not synergistic against fluconazole-resistant C. auris isolates, no antagonism was observed for any combinations. Therefore, combination with newer azole agents needs to be conducted.

External Quality Assessment Evaluating the Ability of Dutch Clinical Microbiological Laboratories to Identify Candida auris

Background: Candida auris is a yeast that is causing nosocomial outbreaks in healthcare facilities around the world. There is a risk of the misidentification of C. auris with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)—when libraries are used that lack C. auris spectra, or when conventional biochemical methods are used. Methods: We conducted an external quality assessment to evaluate the ability of Dutch clinical microbiological laboratories to identify C. auris, and to raise awareness about the risk of misidentification. Results: 35/47 participating laboratories were able to identify C. auris correctly. Only 2/14 labs that potentially misidentified C. auris with their primary identification methods specified that they would perform additional tests to exclude C. auris when appropriate. 45/47 labs used MALDI-TOF MS systems to identify Candida species. Conclusions: There was a lack of awareness about the potential misidentification of C. auris in many labs that used MALDI-TOF MS with libraries that lacked C. auris spectra, and labs that used Vitek 2. However, as the currently available MALDI-TOF MS libraries in The Netherlands contain several C. auris spectra, we expect that currently almost all participating laboratories are able to identify C. auris correctly, as 45/47 participating laboratories use MALDI-TOF MS as their primary yeast identification method.

ECMM CandiReg-A ready to use platform for outbreaks and epidemiological studies

BACKGROUND

Recent outbreaks of Candida auris further exemplify that invasive Candida infections are a substantial threat to patients and healthcare systems. Even short treatment delays are associated with higher mortality rates. Epidemiological shifts towards more resistant Candida spp. require careful surveillance.

OBJECTIVES

Triggered by the emergence of C auris and by increasing antifungal resistance rates the European Confederation of Medical Mycology developed an international Candida Registry (FungiScope™ CandiReg) to allow contemporary multinational surveillance.

METHODS

CandiReg serves as platform for international cooperation to enhance research regarding invasive Candida infections. CandiReg uses the General Data Protection Regulation compliant data platform ClinicalSurveys.net that holds the electronic case report forms (eCRF). Data entry is supported via an interactive macro created by the software that can be accessed via any Internet browser.

RESULTS

CandiReg provides an eCRF for invasive Candida infections that can be used for a variety of studies from cohort studies on attributable mortality to evaluations of guideline adherence, offering to the investigators of the 28 ECMM member countries the opportunity to document their cases of invasive Candida infection. CandiReg allows the monitoring of epidemiology of invasive Candida infections, including monitoring of multinational outbreaks. Here, we describe the structure and management of the CandiReg platform.

CONCLUSION

CandiReg supports the collection of clinical information and isolates to improve the knowledge on epidemiology and eventually to improve management of invasive Candida infections. CandiReg promotes international collaboration, improving the availability and quality of evidence on invasive Candida infection and contributes to improved patient management.

The First Two Cases of Candida auris in The Netherlands

Candida auris is a rapidly emerging multidrug-resistant pathogenic yeast. In recent years, an increasing number of C. auris invasive infections and colonized patients have been reported, and C. auris has been associated with hospital outbreaks worldwide, mainly in intensive care units (ICUs). Here, we describe the first two cases of C. auris in The Netherlands. Both cases were treated in a healthcare facility in India prior to admission. The patients were routinely placed in contact precautions in a single room after admission, which is common practice in The Netherlands for patients with hospitalization outside The Netherlands. No transmission of C. auris was noticed in both hospitals. Routine admission screening both for multidrug-resistant (MDR) bacteria and MDR yeasts should be considered for patients admitted from foreign hospitals or countries with reported C. auris transmission.

Multidrug-Resistant Candida auris Fungemia in Critical Care Units: Experience from a Tertiary Care Hospital in India

Candida auris, a recently identified multiresistant Candida species, was first reported in Japan in 2009. It is different from other pathogenic yeast species because of its propensity to cause outbreaks and transmits between patients within health care settings. The invasive infections caused by C. auris are associated with high mortality rates, approaching 70% particularly in intensive care unit patients. Conventional biochemical methods are inaccurate in identifying this species of Candida. Although C. auris is frequently reported as multi-, extended-, or pan drug resistant to antifungal drugs, there is a wide variability in the susceptibility among reports worldwide. In this study we report a case series of five hospitalized patients with multidrug-resistant candidemia caused by C. auris in a tertiary hospital in India. Our finding suggests that correct identification followed by therapeutic intervention is necessary for favorable outcome in patients with C. auris fungemia.

Identification of Drug Resistant Candida auris

Candida auris is a multidrug resistant yeast, recognized as a cause of invasive infections and health care associated outbreaks around the world. C. auris is of great public health concern, due to its propensity for drug resistance, mode and pace of its transmission, and the possibility that biologic and epidemiologic factors could exacerbate worldwide emergence of C. auris infections. Currently, outbreak response is complicated by limited treatment options and inadequate disinfection strategies, as well as by issues (misidentification, long turnaround time) associated with application of commonly used diagnostic tools. Misdiagnosis of C. auris is common since many diagnostic platforms available in clinical and public health laboratories depend on reference databases that have not fully incorporated C. auris. Moreover, the correlation between minimal inhibitory concentration values (MICs) and clinical outcomes is poorly understood resulting in the absence of C. auris-specific breakpoints. New, accurate and fast diagnostic methods have emerged to facilitate effective patient management and improve infection control measures, ultimately reducing the potential for C. auris transmission. This review provides an overview of available C. auris detection/identification and antifungal susceptibility determination methods and discusses their advantages and limitations. A special emphasis has been placed on culture-independent methods that have recently been developed and offer faster turnaround times.

Control of Candida auris in healthcare institutions: Outcome of an International Society for Antimicrobial Chemotherapy expert meeting

Candida auris (C. auris) is an emerging fungal pathogen causing invasive infections and outbreaks that have been difficult to control in healthcare facilities worldwide. There is a lack of current evidence for pragmatic infection prevention and control recommendations. The aim of this paper was to review the epidemiology of C. auris and identify best practices with a panel of experts, in order to provide guidance and recommendations for infection prevention and control measures based on available scientific evidence, existing guidelines and expert opinion. The Infection Prevention and Control working group of the International Society of Antimicrobial Chemotherapy organised an expert meeting with infection prevention and mycology experts to review recommendations for healthcare workers on infection prevention and control measures for C. auris at inpatient healthcare facilities. The most common interventions included: screening, standard precautions, cleaning and disinfection, inpatient transfer, outbreak management, decolonisation, and treatment.

Candida auris and multidrug resistance: Defining the new normal

Candida auris is an emerging species of yeast characterized by colonization of skin, persistence in the healthcare environment, and antifungal resistance. C. auris was first described in 2009 from a single isolate but has since been reported in more than 25 countries worldwide. Resistance to fluconazole and amphotericin B is common, and resistance to the echinocandins is emerging in some countries. Antifungal resistance has been shown to be acquired rather than intrinsic and the primary mechanisms of resistance to the echinocandins and azoles have been determined. There are a number of new antifungal agents in phase 2 and phase 3 clinical trials and many have activity against C. auris. This review will discuss what is currently known about antifungal resistance in C. auris, limitations to antifungal susceptibility testing, the mechanisms of resistance, and the new antifungals that are on the horizon.

Candida auris-the growing menace to global health

A paradigm shift of candidiasis from Candida albicans to non-albicans Candida species has fundamentally increased with the advent of C. auris. C. auris, despite being a newly emerged multidrug-resistant fungal pathogen, is associated with severe invasive infections and outbreaks with high mortality rates. Initially reported from Japan in 2009, C. auris have now been found in different countries on all the continents except Antarctica. Due to its capability of nosocomial transmission and forming adherent biofilms on clinically important substrates, a high number of related hospital outbreaks have been reported worldwide. As C. auris is a multidrug-resistant pathogen and is prone to misidentification by available conventional methods, it becomes difficult to detect and manage C. auris infection and also limits the therapeutic options against this deadly pathogen. The emergence of multidrug-resistant C. auris advocates and amplifies the vigilance of early diagnosis and appropriate treatment of fungal infections. In this review, we discussed the nine-year-old history of C. auris-its trends in global emergence, epidemiological relatedness, isolation, mortality, associated risk factors, virulence factors, drug resistance and susceptibility testing, diagnostic challenges, microbiological characteristics, therapeutic options and infection prevention and control associated with this pathogen.

The Epidemiology and Prevention of Candida auris

PURPOSE OF REVIEW

Candida auris has recently emerged as a pathogen with the potential for nosocomial transmission and outbreaks. The aim of this review is to summarize the global dissemination of this pathogen, characterize patient and facility characteristics associated with infection and outbreaks, and outline evidence to support interventions to prevent of transmission in the healthcare setting.

RECENT FINDINGS

C. auris has emerged separately in four clades, with international spread within a decade of its first identification and report. Acquisition and infection have predominantly been identified as healthcare-associated events. The presence of invasive devices, intensive care, and broad-spectrum antibiotic and antifungal use may be important risk factors for the development of infection due to C. auris. Nosocomial transmission is likely associated with colonization density and suboptimal infection prevention practices. The optimal strategy for reducing transmission from the environment requires further study. Candida auris is a recently emerging fungal pathogen that may cause nosocomial infections and outbreaks. Based on observed transmission patterns and interventions, key prevention measures outlined in the review include case finding and surveillance, hand hygiene, and environmental disinfection.

In vitro virulence determinants, comparative pathogenicity of Diutina (Candida) mesorugosa clinical isolates and literature review of the D. rugosa complex

Opportunistic mycoses by yeasts have increased considerably in the last three decades. Although Candida albicans is considered one of the most important causes of nosocomial infections, there is a recent shift to non-albicans Candida species as the most frequently isolated yeasts in particular risk groups. Diutina rugosa (formerly Candida rugosa) is a complex that includes four species: D. rugosa sensu stricto, D. neorugosa, D. pseudorugosa, and D. mesorugosa, and they are estimated to represent 0.2% of all Candida clinical isolates. In this study, we analyze nine clinical isolates of D. mesorugosa with focus on the virulence determinants and pathogenicity of the species by means of a Galleria mellonella survival model. Overall, we detected very strong aspartyl-protease and esterase activities. In contrast, both DNase and hemolysin activities were evident in only two of the isolates. None of the isolates was positive for phospholipase activity. All isolates studied were able to form biofilm after 72 h of incubation in a robust manner when compared with the C. albicans strain used as control. Susceptibility testing showed minimum inhibitory concentrations (MICs) ≤1 µg/mL for amphotericin B in all isolates tested. Eight out of nine of the isolates had MICs ≤2 µg/mL for fluconazole. All isolates were resistant to both anidulafungin and caspofungin (MICs ≥1 µg/mL). We found a significant difference (P < 0.0001) amongst the survival curves for the different D. mesorugosa isolates in the Galleria mellonella survival model. Strains HPM309 and H259 produced an acute infection and exhibited the highest virulence, whereas the D. mesorugosa isolates 99-480 and DM17 proved to be the less virulent strains.

The emerging pathogen Candida auris: A focus on the Middle-Eastern countries

Recent emergence of Candida auris as a multidrug resistant fungal pathogen, associated with difficult-to-control nosocomial transmission and high mortality, raises serious concerns for public health. Since it was first reported from Japan in 2009, C. auris infections have been diagnosed in several countries from all over the world. However, there is a paucity of reported cases from the Middle East. Literature search resulted in finding only six countries (Kuwait, Israel, Oman, KSA, UAE and Iran) reporting C. auris infections in the past three years. All patients were adults with several underlying comorbidities. Majority of the cases presented with bloodstream infection with crude mortality rate of 60%. All isolates were misidentified as C. haemulonii by commercial systems requiring specialized methods for identification. In vitro antifungal susceptibility testing showed 100% strains to be resistant to fluconazole (MIC 32 ≥ 256 mg/L) while variable resistance against other antifungal agents.

Detection and treatment of Candida auris in an outbreak situation: risk factors for developing colonization and candidemia by this new species in critically ill patients

BACKGROUND

Candida auris is an emerging, multidrug-resistant yeast causing hospital outbreaks. This study describes the first 24 months of the ongoing C. auris outbreak in our hospital and analyzes predisposing factors to C. auris candidemia/colonization.

RESEARCH DESIGN AND METHODS

A 12-month prospective, case-controlled study was performed including a total of 228 patients (114 colonized/candidemia and 114 controls). Data from the first 79 candidemia episodes and 738 environmental samples were also analyzed. Definitive C. auris identification was performed by ITS sequencing. Antifungal susceptibility was carried out by EUCAST methodology.

RESULTS

Polytrauma (32%), cardiovascular disease (25%), and cancer (17%) were the most common underlying condition in colonized/candidemia patients. Indwelling CVC (odds ratio {OR}, 13.48), parenteral nutrition (OR, 3.49), and mechanical ventilation (OR, 2.43) remained significant predictors of C. auris colonization/candidemia. C. auris was most often isolated on sphygmomanometer cuffs (25%) patient tables (10.2%), keyboards (10.2%), and infusion pumps (8.2%). All isolates were fully resistant to fluconazole (MICs >64 mg/L) and had significantly reduced susceptibility to voriconazole (GM, 1.8 mg/L).

CONCLUSIONS

Predictor conditions to C. auris colonization/candidemia are similar to other Candida species. C. auris colonizes multiple patient's environment surfaces. All isolates are resistant to fluconazole and had significant reduced susceptibility to voriconazole.