First report of Candida auris infections from Saudi Arabia

Implementation of effective strategies to prevent Candida auris transmission in a Quaternary Care Center, Riyadh, Saudi Arabia

This study outlines the results of an investigation of a large C. auris outbreak at King Saud Medical City (KSMC), a quaternary hospital in Saudi Arabia. We identified 122 cases of C. auris (colonization, 74; infection, 48) from June 2021 to June 2022. The mean patient age was 48.4 years, and the median duration of stay before diagnosis was 32.7 days. A significant proportion of patients (87.70%) were diagnosed with C. auris more than 3 days after admission to KSMC. The source of exposure was either nosocomial (from KSMC, 28.68%; from other hospitals, 16.39%) or unknown (54.91%). The hospitalization mortality rate was 45.90%. This report highlights the challenges in investigating and managing C. auris outbreaks, emphasizing the need for a comprehensive approach incorporating strategies for screening and early identification, effective environmental cleaning, and the implementation of stringent infection control measures such as hand hygiene, isolation of patient, standard and contact precaution and decolonization.

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.

Risk factors, antifungal susceptibility, complications, and outcome of Candida auris bloodstream infection in a tertiary care center in the western region of Saudi Arabia

BACKGROUND

Candida auris, an emerging multidrug-resistant fungus species that grows as yeast, causes bloodstream infection, and is associated with high mortality rates. In this study, we identified risk factors associated with C. auris bloodstream infection, antifungal susceptibility pattern, complications, and outcome of the infection.

METHODS

This single-center cross-sectional retrospective study was conducted at King Abdulaziz Medical City, a tertiary care facility in Jeddah, Saudi Arabia, which included all patients 18 years or above who have had one or more blood cultures for C. auris between January 2021 and December 2022. We aimed to identify the risk factors associated with C. auris bloodstream infection, antifungal susceptibility patterns, complications, and outcomes at our center.

RESULTS

Forty-six patients with C. auris-positive blood cultures were included. All the patients had healthcare-associated infections. The mean age was 64.67 years, and the majority of patients were male (73.9 %). The most common concomitant hospital-acquired infections were skin and soft tissue infections (37 %), followed by hospital-acquired pneumonia (34.8 %) and intra-abdominal infections (26.1 %). The mean total white blood cell count, procalcitonin, and C-reactive protein was 10.5 ± 5.99 × 109/L, 2.63 ± 4.82 μg/L, and 90.3 ± 64.1 mg/L, respectively. Hypertension (73.9 %) was the most common comorbidity, followed by diabetes mellitus (58.7 %) and renal dysfunction (54.3 %). Risk factors associated with C. auris candidemia included antibiotic use (91.3 %), especially for > 14 days (78.3 %), C. auris colonization (60.9 %), use of central venous catheters, especially when the catheter was in place for >30 days (80.4 %), ICU admission in the last 30 days before C. auris-positive blood culture (93.5 %), especially for more than two weeks (76.1 %), mechanical ventilation (89.1 %), total parenteral nutrition (13 %), previous intra-abdominal surgery (30.4 %), and immunosuppressive therapy (56.5 %). A total of 97.8 % of C. auris isolates were resistant to fluconazole and 17.4 % were resistant to amphotericin B. Endocarditis and endophthalmitis were reported in one (2.2 %) patient each. The all-cause mortality at 30 days was 47.8 %.

CONCLUSION

Our study is one of the few studies available globally on C. auris bloodstream infection that investigated risk factors, antifungal susceptibility, complications, and outcomes. A thorough screening and risk assessment strategy should aid infection control, preventing it from becoming a major concern in the future.

Description of Candida auris Occurrence in a Tertiary Health Institution in Riyadh, Saudi Arabia

BACKGROUND

Candida auris is an emerging multidrug-resistant fungal pathogen that represents a current serious threat to healthcare settings.

OBJECTIVE

The objective was to determine the prevalence of C. auris in a Riyadh hospital since its initial detection in late 2019.

METHODS

Using an adapted risk assessment tool, we reviewed the charts and medical files of all suspected and confirmed cases of C. auris infections reported at King Khalid University Hospital, Riyadh, between November 2019 and December 2022. Anonymized data were retrieved in a pre-established datasheet and analyzed to determine the epidemiological characteristics of C. auris infections in our facility. We analyzed prevalence by age, gender, risk factors, and according to sampling source.

RESULTS

Of the 53 confirmed C. auris-positive cases during the study period, 33 (62%) were males. Their ages ranged between 15 and 98, with most positive cases occurring in those aged 50 and above. Only one of the confirmed cases was hospital-acquired. All patients had at least one risk factor, and urine samples yielded the greatest number of positive cases, while admission to healthcare facilities constituted the highest risk in our study.

CONCLUSION

Establishing a local prevalence pattern could serve as a baseline/benchmark to compare with regional and international benchmarks.

Psychogenetic, genetic and epigenetic mechanisms in Candida auris: Role in drug resistance

In recent years, we are facing the challenge of drug resistance emergence in fungi. The availability of limited antifungals and development of multi-drug resistance in fungal pathogens has become a serious concern in the past years in the health sector. Although several cellular, molecular, and genetic mechanisms have been proposed to explain the drug resistance mechanism in fungi, but a complete understanding of the molecular and genetic mechanisms is still lacking. Besides the genetic mechanism, epigenetic mechanisms are pivotal in the fungal lifecycle and disease biology. However, very little is understood about the role of epigenetic mechanisms in the emergence of multi-drug resistance in fungi, especially in Candida auris (C. auris). The current narrative review summaries the clinical characteristics, genomic organization, and molecular/genetic/epigenetic mechanisms underlying the emergence of drug resistance in C. auris. A very few studies have attempted to evaluate the role of epigenetic mechanisms in C. auris. Furthermore, advanced genetic tools such as the CRISP-Cas9 system can be utilized to elucidate the epigenetic mechanisms and their role in the emergence of multi-drug resistance in C. auris.

Candida auris: A Mini Review on Epidemiology in Healthcare Facilities in Asia

Candida auris, a newly emerging healthcare-associated yeast pathogen from the Metschnikowiaceae family, was first described in the ear canal of an elderly Japanese patient in 2009. The yeast is one of the causative agents of candidemia, which has been linked with nosocomial outbreaks and high mortality rates in healthcare facilities worldwide. Since its first isolation, the occurrence of C. auris in six continents has becomes a grave concern for the healthcare professionals and scientific community. Recent reports showed the identification of five geographically distinct clades and high rates of antifungal resistance associated with C. auris. Till date, there are no effective treatment options, and standardized measures for prevention and control of C. auris infection in healthcare facilities. This leads to frequent therapeutic failures and complicates the eradication of C. auris infection in healthcare facilities. Thus, this review focuses on the recent understanding of the epidemiology, risk factors, diagnosis, transmission and prevention and control strategies of C. auris infection in healthcare facilities in Asia.

Silver Nanoparticles: A Promising Antifungal Agent against the Growth and Biofilm Formation of the Emergent Candida auris

Candida auris is a globally-emerging pathogen that is correlated to nosocomial infections and high mortality rates, causing major outbreaks in hospitals and serious public health concerns worldwide. This study investigated the antifungal activity of silver nanoparticles (AgNPs) on clinical isolates of C. auris. A total of eight clinical isolates were collected from blood, urine, ear swab, and groin. C. auris was confirmed by MALDI-TOF MS, and gene sequencing. All isolates confirmed as C. auris were subjected to antimicrobial agents, including amphotericin B, fluconazole, caspofungin, voriconazole, micafungin, and flucytosine. A serial dilution of a silver nanoparticles solution was prepared to test antifungal susceptibility testing under planktonic conditions. Moreover, an antibiofilm activity assay was determined using a colony-forming assay and a cell viability assay by a live−dead yeast kit. Significant antifungal and antibiofilm activity of AgNPs was detected against all isolates; MIC was <6.25 μg/mL, the range of MFC was from 6.25 to 12.5 μg/mL for all isolates, and the highest value of IC50 was 3.2 μg/mL. Silver nanomaterials could represent a possible antimicrobial agent to prevent outbreaks caused by C. auris infections.

Clinical characteristics and outcome of candidemia: Experience from a tertiary referral center in Saudi Arabia

Background:

Candida bloodstream infections cause significant excess morbidity and mortality in the health-care setting. There is limited evidence regarding Candida species causing invasive infections in Saudi Arabia.

Objective:

To identify Candida species causing bloodstream infection and determine the clinical outcome and factors associated with mortality in a tertiary center in Saudi Arabia.

Materials and Methods:

This retrospective study included all cases of positive blood culture for Candida in patients admitted to King Abdulaziz Medical City, a tertiary care center in Riyadh, Saudi Arabia, between January 1, 2013 and June 30, 2019.

Results:

A total of 532 patients with candidemia were identified (male: 55.4%; mean age: 54 ± 26.2 years). The most common Candida species isolated was Candida albicans (26.7%), followed by Candida glabrata (22.7%), Candida parapsilosis (22.2%), and Candida tropicalis (18.4%). Non-albicans candidemia was more common in patients with diabetes (76.7%; P = 0.0560), neutropenia (89.8%; P = 0.0062), recent exposure to fluconazole (85.7%; P = 0.0394), and active chemotherapy (83.1%; P = 0.0128). In non-albicans, susceptibility to fluconazole varied from 95.9% with C. tropicalis to 41.5% with C. parapsilosis; nonetheless, all species were highly susceptible to echinocandins. The overall 30- and 90-day mortality rates were 39.9% and 56.4%, respectively. The mortality rate was nonsignificantly higher with non-albicans species at 30 days (41.2% vs. 35.9%; P = 0.2634) and 90 days (58.2% vs. 51.4%; P = 0.1620).

Conclusion:

This study found a changing pattern in the Candida species causing bloodstream infections and an epidemiological shift toward more non-albicans Candida species in Saudi Arabia.

Emerging Status of Multidrug-Resistant Bacteria and Fungi in the Arabian Peninsula

Simple Summary

The incidence and developing status of multidrug-resistant bacteria and fungi, as well as their related mortality, is reviewed by a systematic published literature search from nine countries in the Arabian Peninsula. In order to analyse the emerging status and mortality, a total of 382 research articles were selected from a comprehensive screening of 1705 papers. More than 850 deaths reported since 2010 in the Arabian Peninsula due to the infection of multidrug-resistant bacteria and fungi. Multidrug-resistant bacteria Acinetobacter baumannii, Mycobacterium tuberculosis, Staphylococcus aureus, and fungi Candida auris are the most prevalent and causing high deaths. To control these infections and associated deaths in the Arabian Peninsula, continuous preventive measures, accurate methods for early diagnosis of infection, active surveillance, constant monitoring, developing vaccines, eradicating multidrug resistance modulators, and data sharing among countries are required.

Abstract

We aimed to identify the prevalence and emerging status of multidrug-resistant bacteria and fungi and their associated mortality in nine countries in the Arabian Peninsula. Original research articles and case studies regarding multidrug-resistant bacteria and fungi in the Arabian Peninsula, published during the last 10 years, were retrieved from PubMed and Scopus. A total of 382 studies were included as per the inclusion and exclusion criteria, as well as the PRISMA guidelines, from a thorough screening of 1705 articles, in order to analyse the emerging status and mortality. The emerging nature of >120 multidrug-resistant (MDR) bacteria and fungi in the Arabian Peninsula is a serious concern that requires continuous monitoring and immediate preventive measures. More than 50% (n = 453) of multidrug-resistant, microbe-associated mortality (n = 871) in the Arabian Peninsula was due to MDR Acinetobacter baumannii, Mycobacterium tuberculosis and Staphylococcus aureus infection. Overall, a 16.51% mortality was reported among MDR-infected patients in the Arabian Peninsula from the 382 articles of this registered systematic review. MDR A. baumannii (5600 isolates) prevailed in all the nine countries of the Arabian Peninsula and was one of the fastest emerging MDR bacteria with the highest mortality (n = 210). A total of 13,087 Mycobacterium tuberculosis isolates were reported in the region. Candida auris (580 strains) is the most prevalent among the MDR fungal pathogen in the Arabian Peninsula, having caused 54 mortalities. Active surveillance, constant monitoring, the development of a candidate vaccine, an early diagnosis of MDR infection, the elimination of multidrug resistance modulators and uninterrupted preventive measures with enhanced data sharing are mandatory to control MDR infection and associated diseases of the Arabian Peninsula. Accurate and rapid detection methods are needed to differentiate MDR strain from other strains of the species. This review summarises the logical relation, prevalence, emerging status and associated mortality of MDR microbes in the Arabian Peninsula.

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.

Cell Surface Expression of Nrg1 Protein in Candida auris

Candida auris is an emerging antifungal resistant human fungal pathogen increasingly reported in healthcare facilities. It persists in hospital environments, and on skin surfaces, and can form biofilms readily. Here, we investigated the cell surface proteins from C. auris biofilms grown in a synthetic sweat medium mimicking human skin conditions. Cell surface proteins from both biofilm and planktonic control cells were extracted with a buffer containing β-mercaptoethanol and resolved by 2-D gel electrophoresis. Some of the differentially expressed proteins were excised and identified by mass spectrometry. C. albicans orthologs Spe3p, Tdh3p, Sod2p, Ywp1p, and Mdh1p were overexpressed in biofilm cells when compared to the planktonic cells of C. auris. Interestingly, several proteins with zinc ion binding activity were detected. Nrg1p is a zinc-binding transcription factor that negatively regulates hyphal growth in C. albicans. C. auris does not produce true hypha under standard in vitro growth conditions, and the role of Nrg1p in C. auris is currently unknown. Western blot analyses of cell surface and cytosolic proteins of C. auris against anti-CalNrg1 antibody revealed the Nrg1p in both locations. Cell surface localization of Nrg1p in C. auris, an unexpected finding, was further confirmed by immunofluorescence microscopy. Nrg1p expression is uniform across all four clades of C. auris and is dependent on growth conditions. Taken together, the data indicate that C. auris produces several unique proteins during its biofilm growth, which may assist in the skin-colonizing lifestyle of the fungus during its pathogenesis.

On the emergence, spread and resistance of Candida auris: host, pathogen and environmental tipping points

Over a decade ago, a multidrug-resistant nosocomial fungus Candida auris emerged worldwide and has since become a significant challenge for clinicians and microbiologists across the globe. A resilient pathogen, C. auris survives harsh disinfectants, desiccation and high-saline environments. It readily colonizes the inanimate environment, susceptible patients and causes invasive infections that exact a high toll. Prone to misidentification by conventional microbiology techniques, C. auris rapidly acquires multiple genetic determinants that confer multidrug resistance. Whole-genome sequencing has identified four distinct clades of C. auris, and possibly a fifth one, in circulation. Even as our understanding of this formidable pathogen grows, the nearly simultaneous emergence of its distinct clades in different parts of the world, followed by their rapid global spread, remains largely unexplained. We contend that certain host-pathogen-environmental factors have been evolving along adverse trajectories for the last few decades, especially in regions where C. auris originally appeared, until these factors possibly reached a tipping point to compel the evolution, emergence and spread of C. auris. Comparative genomics has helped identify several resistance mechanisms in C. auris that are analogous to those seen in other Candida species, but they fail to fully explain how high-level resistance rapidly develops in this yeast. A better understanding of these unresolved aspects is essential not only for the effective management of C. auris patients, hospital outbreaks and its global spread but also for forecasting and tackling novel resistant pathogens that might emerge in the future. In this review, we discuss the emergence, spread and resistance of C. auris, and propose future investigations to tackle this resilient pathogen.

First Candida auris Outbreak during a COVID-19 Pandemic in a Tertiary-Care Center in Lebanon

Candida auris is an emerging fungal pathogen considered as a global health threat. Recently there has been growing concern regarding drug resistance, difficulty in identification, as well as problems with eradication. Although outbreaks have been reported throughout the globe including from several Arab countries, there were no previous reports from Lebanon. We herein report the first cases of C. auris infection from the American University of Beirut Medical Center, a tertiary care center in Lebanon describing the clinical features of the affected patients in addition to the infection control investigation and applied interventions to control the outbreak. Fourteen patients with C. auris infection/colonization identified using MALDI-TOF and VITEK 2- Compact system were reported over a period of 13 weeks. Patients were admitted to four separate critical care units. All of them came through the emergency room and had comorbid conditions. Half of the patients were infected with COVID-19 prior to isolation of the C. auris. C. auris was isolated from blood (two isolates), urine (three isolates), respiratory tract (10 isolates) and skin (one isolate). All the patients had received broad spectrum antibiotics prior to isolation of C. auris. Six patients received antifungal treatment, while the remaining eight patients were considered colonized. Environmental cultures were taken from all four units and failed to isolate the organism from any cultured surfaces. A series of interventions were initiated by the Infection Prevention and Control team to contain the outbreak. Rapid detection and reporting of cases are essential to prevent further hospital transmission. A national standardized infection control registry needs to be established to identify widespread colonization.

Drug Resistance-Associated Mutations in ERG11 of Multidrug-Resistant Candida auris in a Tertiary Care Hospital of Eastern Saudi Arabia

Candida auris is an emerging multi-drug resistant pathogen with high mortality rate; nosocomial infections have been reported worldwide, causing a major challenge for clinicians and microbiological laboratories. The study aims to describe new cases of C. auris and detect drug resistance-associated mutations of C. auris by the sequencing of ERG11 and FKS1 genes. A total of six specimens were collected from blood, urine, ear swab, and groin screening samples. Isolates were incubated for 48 h on Sabouraud Dextrose agar (SDA) at 42 °C, then confirmed by MALDI-TOF MS. Furthermore, antifungal susceptibility testing was performed using the Vitek 2 system to detect Minimum Inhibitory Concentrations (MICs) of six antifungals. Sequences of 18S rRNA gene and ITS regions from isolates and phylogenetic analysis were performed. Gene sequencing was analysed to detect drug resistance-associated mutations by FKS1 and ERG11 genes sequencing. All C. auris isolates were confirmed by MALDI-TOF MS, and evolutionary analyses using sequences of 18S rRNA gene and ITS region. Antifungal susceptibility testing showed that all isolates were resistant to fluconazole. Sequencing of ERG11 and FKS1 genes from the isolates revealed the presence of two (F132Y and K143R) drug resistance-associated mutations in ERG11, however, FKS1 gene was devoid of mutations. The study sheds light on a public health threat of an emerging pathogen, and the hospital implemented strict contact screening and infection control precautions to prevent C. auris infection. Finally, there is a critical need to monitor the antifungal resistance in different geographical areas and implementation of efficient guidelines for treatment.

Two Cases of the Emerging Candida auris in a university hospital from Saudi Arabia

Candida auris is an opportunistic multidrug-resistant pathogen that was first isolated in 2009 and has since been reported from about 30 countries. In Saudi Arabia, only four cases of C. auris have previously been reported; here, we report two new cases of this infection. Both patients were polymorbid and had long hospitalization periods with recurrent intensive care unit (ICU) admissions. The findings of the tissue/blood cultures and antimicrobial therapy protocols are explained in the case report. Urine culture in both cases was positive for C. auris, and the colonies grew well at 42°C. The fungal isolates were confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The first patient was treated with the recommended dose of caspofungin, but he passed away. The second patient was also planned to be treated with caspofungin, but he passed away before the treatment could be initiated. The present cases further corroborate signs of a growing number of reports of C. auris in patients with high-risk factors, such as hospitalization in ICU, multiple chronic conditions and prolonged antimicrobial treatment exposure. It also highlights the need for hospitals to further improve their infection control practices to prevent nosocomial infections such as C. auris.

Is the superbug fungus really so scary? A systematic review and meta-analysis of global epidemiology and mortality of Candida auris

BACKGROUND

Candida auris is a new pathogen called "superbug fungus" which caused panic worldwide. There are no large-scale epidemiology studies by now, therefore a systematic review and meta-analysis was undertaken to determine the epidemic situation, drug resistance patterns and mortality of C. auris.

METHODS

We systematically searched studies on the clinical report of Candida auris in Pubmed, Embase and Cochrane databases until October 6, 2019. A standardized form was used for data collection, and then statics was performed with STATA11.0.

RESULTS

It showed that more than 4733 cases of C. auris were reported in over 33 countries, with more cases in South Africa, United States of America, India, Spain, United Kingdom, South Korea, Colombia and Pakistan. C. auirs exhibited a decrease in case count after 2016. Clade I and III were the most prevalent clades with more cases reported and wider geographical distribution. Blood stream infection was observed in 32% of the cases, which varied depending on the clades. Resistance to fluconazole, amphotericin B, caspofungin, micafungin and anidulafungin in C. auris were 91, 12, 12.1, 0.8 and 1.1%. The overall mortality of C. auris infection was 39%. Furthermore, subgroup analyses showed that mortality was higher in bloodstream infections (45%), and lower in Europe (20%).

CONCLUSIONS

Over 4000 cases of C. auris were reported in at least 33 countries, which showed high resistance to fluconazole, moderate resistance to amphotericin B and caspofungin, high sensitivity to micafungin and anidulafungin. The crude mortality for BSI of C. auris was 45% which was similar to some drug-resistant bacteria previously reported. In conclusion, C. auris displayed similar characteristics to some drug resistance organisms. This study depicts several issues of C. auris that are most concerned, and is of great significance for the clinical management.

Echinocandins as Biotechnological Tools for Treating Candida auris Infections

Candida auris has been reported in the past few years as an invasive fungal pathogen of high interest. Its recent emergence in healthcare-associated infections triggered the efforts of researchers worldwide, seeking additional alternatives to the use of traditional antifungals such as azoles. Lipopeptides, specially the echinocandins, have been reported as an effective approach to control pathogenic fungi. However, despite its efficiency against C. auris, some isolates presented echinocandin resistance. Thus, therapies focused on echinocandins’ synergism with other antifungal drugs were widely explored, representing a novel possibility for the treatment of C. auris infections.

Management of Candida auris outbreak in a tertiary-care setting in Saudi Arabia

OBJECTIVE

To describe local experience in managing an outbreak of Candida auris in a tertiary-care setting.

METHODS

In response to emerging Candida auris, an outbreak investigation was conducted at our hospital between March 2018 and June 2019. Once a patient was confirmed to have Candida auris, screening of exposed patients and healthcare workers (HCWs) was conducted. Postexposure screening included those who had had direct contact with or shared the same unit or ward with a laboratory-confirmed case. In response to the increasing number of cases, new infection control measures were implemented.

RESULTS

In total, 23 primary patients were detected over 15 months. Postexposure screening identified 11 more cases, and all were patients. Furthermore, ~28.6% of patients probably caught infection in another hospital or in the community. Infection control measures were strictly implemented including hand hygiene, personal protective equipment, patient hygiene, environmental cleaning, cohorting of patients and HCWs, and avoiding the sharing of equipment. The wave reached a peak in April 2019, followed by a sharp decrease in May 2019 and complete clearance in June 2019. The case patients were equally distributed between intensive care units (51.4%) and wards (48.6%). More infections (62.9%) occurred than colonizations (37.1%). Urinary tract infection (42.9%) and candidemia (17.1%) were the main infections. In total, 7 patients (20.0%) died during hospitalization; among them, 6 (17.1%) died within 30 days of diagnosis.

CONCLUSIONS

Active screening of exposed patients followed by strict infection control measures, including environmental cleaning, was successful in ending the outbreak. Preventing future outbreaks is challenging due to outside sources of infection and environmental resistance.

Evaluation of Microsatellite Typing, ITS Sequencing, AFLP Fingerprinting, MALDI-TOF MS, and Fourier-Transform Infrared Spectroscopy Analysis of Candida auris

Candida auris is an emerging opportunistic yeast species causing nosocomial outbreaks at a global scale. A few studies have focused on the C. auris genotypic structure. Here, we compared five epidemiological typing tools using a set of 96 C. auris isolates from 14 geographical areas. Isolates were analyzed by microsatellite typing, ITS sequencing, amplified fragment length polymorphism (AFLP) fingerprint analysis, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), and Fourier-transform infrared (FTIR) spectroscopy methods. Microsatellite typing grouped the isolates into four main clusters, corresponding to the four known clades in concordance with whole genome sequencing studies. The other investigated typing tools showed poor performance compared with microsatellite typing. A comparison between the five methods showed the highest agreement between microsatellite typing and ITS sequencing with 45% similarity, followed by microsatellite typing and the FTIR method with 33% similarity. The lowest agreement was observed between FTIR spectroscopy, MALDI-TOF MS, and ITS sequencing. This study indicates that microsatellite typing is the tool of choice for C. auris outbreak investigations. Additionally, FTIR spectroscopy requires further optimization and evaluation before it can be used as an epidemiological typing method, comparable with microsatellite typing, as a rapid method for tracing nosocomial fungal outbreaks.

Update on invasive fungal infections in the Middle Eastern and North African region

In the recent years, the epidemiology of invasive fungal infections (IFIs) has changed worldwide. This is remarkably noticed with the significant increase in high-risk populations. Although surveillance of such infections is essential, data in the Middle Eastern and North African (MENA) region remain scarce. In this paper, we reviewed the existing data on the epidemiology of different IFIs in the MENA region. Epidemiological surveillance is crucial to guide optimal healthcare practices. This study can help to guide appropriate interventions and to implement antimicrobial stewardship and infection prevention and control programs in countries.

Nine Things Genomics Can Tell Us About Candida auris

Candida auris is a recently emerged multidrug-resistant fungal pathogen causing severe illness in hospitalized patients. C. auris is most closely related to a few environmental or rarely observed but cosmopolitan Candida species. However, C. auris is unique in the concern it is generating among public health agencies for its rapid emergence, difficulty to treat, and the likelihood for further and more extensive outbreaks and spread. To date, five geographically distributed and genetically divergent lineages have been identified, none of which includes isolates that were collected prior to 1996. Indeed, C. auris' ecological niche(s) and emergence remain enigmatic, although a number of hypotheses have been proposed. Recent genomic and transcriptomic work has also identified a variety of gene and chromosomal features that may have conferred C. auris with several important clinical phenotypes including its drug-resistance and growth at high temperatures. In this review we discuss nine major lines of enquiry into C. auris that big-data technologies and analytical approaches are beginning to answer.

Broad-spectrum antifungal activities and mechanism of drimane sesquiterpenoids

Eight drimane sesquiterpenoids including (-)-drimenol and (+)-albicanol were synthesized from (+)-sclareolide and evaluated for their antifungal activities. Three compounds, (-)-drimenol, (+)-albicanol, and (1R,2R,4aS,8aS)-2-hydroxy-2,5,5,8a-tetramethyl-decahydronaphthalene-1-carbaldehyde (4) showed strong activity against C. albicans. (-)-Drimenol, the strongest inhibitor of the three, (at concentrations of 8 – 64 µg/ml, causing 100% death of various fungi), acts not only against C. albicans in a fungicidal manner, but also inhibits other fungi such as Aspergillus, Cryptococcus, Pneumocystis, Blastomyces, Saksenaea and fluconazole resistant strains of C. albicans, C. glabrata, C. krusei, C. parapsilosis and C. auris. These observations suggest that drimenol is a broad-spectrum antifungal agent. At a high concentration (100 μg/ml) drimenol caused rupture of the fungal cell wall/membrane. In a nematode model of C. albicans infection, drimenol rescued the worms from C. albicans-mediated death, indicating drimenol is tolerable and bioactive in metazoans. Genome-wide fitness profiling assays of both S. cerevisiae (nonessential homozygous and essential heterozygous) and C. albicans (Tn-insertion mutants) collections revealed putative genes and pathways affected by drimenol. Using a C. albicans mutant spot assay, the Crk1 kinase associated gene products, Ret2, Cdc37, and orf19.759, orf19.1672, and orf19.4382 were revealed to be involved in drimenol's mechanism of action. The three orfs identified in this study are novel and appear to be linked with Crk1 function. Further, computational modeling results suggest possible modifications of the structure of drimenol, including the A ring, for improving the antifungal activity.

Molecular characterisation and clinical outcomes of Candida auris infection: Single-centre experience in Saudi Arabia

BACKGROUND

Candida auris is a difficult-to-diagnose multidrug-resistant yeast that can cause invasive infections with high mortality. Since emerging in 2009, this pathogen has been associated with numerous outbreaks around the world. Whole genome sequencing (WGS) is instrumental for understanding the emergence and local transmission of this pathogen.

OBJECTIVES

To describe the clinical, molecular characteristics of Candida auris infection and clinical outcome in our centre.

PATIENTS AND METHODS

Patients with positive cultures for Candida auris were identified in a microbiology database. Clinical characteristics and antifungal susceptibility were obtained. Isolates were sent to the US CDC for whole genome sequencing.

RESULTS

Seven unique patients with eight different isolates were identified. Seven isolates were sent to the US CDC for whole genome sequencing. None of the patients had bloodstream infection. Thirty-day mortality was higher in infected patients compared with those who were colonised. Seven of the eight isolates were resistant to both fluconazole, and five were resistant to amphotericin B. WGS analysis demonstrated that the seven isolates belonged to the South Asian clade but formed two distinct subclades suggesting two independent introductions and ongoing transmission within the facility.

CONCLUSIONS

Candida auris is associated with a high mortality rate in infected patients. Strict infection control measures and surveillance for asymptomatic cases are warranted to halt ongoing transmission.

Review on Antifungal Resistance Mechanisms in the Emerging Pathogen Candida auris

Candida auris is an emerging multi-drug resistant yeast, that causes major issues regarding patient treatment and surface disinfection in hospitals. Indeed, an important proportion of C. auris strains isolated worldwide present a decreased sensitivity to multiple and sometimes even all available antifungals. Based on recent tentative breakpoints by the CDC, it appears that in the USA about 90, 30, and < 5% of isolates have been resistant to fluconazole, amphotericin B, and echinocandins, respectively. To date, this has lead to a low therapeutic success. Furthermore, C. auris is prone to cause outbreaks, especially since it can persist for weeks in a nosocomial environment and survive high-end disinfection procedures. In this review, we describe the molecular resistance mechanisms to antifungal drugs identified so far in C. auris and compare them to those previously discovered in other Candida species. Additionally, we examine the role that biofilm formation plays in the reduced antifungal sensitivity of this organism. Finally, we summarize the few insights on how this yeast survives on hospital surfaces and discuss the challenge it presents regarding nosocomial environment disinfection.

The epidemiology of Candida species in the Middle East and North Africa

In recent decades, the epidemiology of invasive candidiasis (IC) has progressively changed worldwide. This notably includes emergence of several Candida species. Although some surveillance programs provided global trends in IC epidemiology, data from countries from the Middle East and North Africa (MENA) remain scarce. In this manuscript, we reviewed the existing available data on the epidemiology of Candida species associated with IC, particularly candidemia, in MENA region regarding species distribution. As witnessed worldwide, an evident shift of Candidaalbicans towards non-albicansCandida (NAC) has been observed in the MENA region. The worrying emergence of multi-drug resistant Candida species in MENA calls for a better understanding of their epidemiology. This represents an essential prerequisite for the implementation of effective infection control strategies and surveillance systems to prevent IC among high-risk patients.

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-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.

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.

Candida auris otomycosis in Iran and review of recent literature

Candida auris is a multidrug-resistant yeast emerging in immunocompromised and in otherwise healthy individuals. Due to difficulties in microbiological identification of C. auris because of the lack of available laboratory technology in developing countries, the number of patients affected is most likely underestimated. We report the first case of C. auris otitis which now adds Iran as the fifth country around the Persian Gulf, in addition to Kuwait, Oman, United Arab Emirates and Saudi Arabia. Candida auris is an unknown pathogen in routine laboratories in Iran because most Candida isolates are probably misdiagnosed. Otomycosis seems to be a different clinical presentation of C. auris mainly involving isolates from the East-Asian clade. We compared the mycological and clinical details of the Iranian patient with other cases of otitis reported since the last review of C. auris otomycosis in 2017.

Antifungal Resistance: Specific Focus on Multidrug Resistance in Candida auris and Secondary Azole Resistance in Aspergillus fumigatus

Antifungal resistance is a topic of concern, particularly for specific fungal species and drugs. Among these are the multidrug-resistant Candida auris and azole-resistant Aspergillus fumigatus. While the knowledge on molecular mechanisms of resistance is now accumulating, further data are also available for the clinical implications and the extent of correlation of in vitro resistance to clinical outcomes. This review article summarizes the epidemiology of C. auris infections, animal models focusing on the activity of novel antifungal compounds in C. auris infections, virulence factors, and the mechanisms of antifungal resistance for this multi-resistant Candida species. Regarding A. fumigatus, the significance of azoles in the treatment of A. fumigatus infections, reference methods available for the detection of resistance in vitro, molecular mechanisms of secondary azole resistance, routes of acquisition, and clinical implications of in vitro resistance are covered to provide guidance for the current status of azole resistance in A. fumigatus.

Epidemiology, clinical characteristics, resistance, and treatment of infections by Candida auris

Candida spp. infections are a major cause of morbidity and mortality in critically ill patients. Candida auris is an emerging multi-drug-resistant fungus that is rapidly spreading worldwide. Since the first reports in 2009, many isolates across five continents have been identified as agents of hospital-associated infections. Independent and simultaneous outbreaks of C. auris are becoming a major concern for healthcare and scientific community. Moreover, laboratory misidentification and multi-drug-resistant profiles, rarely observed for other non-albicans Candida species, result in difficult eradication and frequent therapeutic failures of C. auris infections. The aim of this review was to provide an updated and comprehensive report of the global spread of C. auris, focusing on clinical and microbiological characteristics, mechanisms of virulence and antifungal resistance, and efficacy of available control, preventive, and therapeutic strategies.