Emergence of multidrug-resistant Candida auris in Taiwan

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.

The First Invasive Candida auris Infection in Taiwan

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

A global view on fungal infections in humans and animals: opportunistic infections and microsporidioses

After cardiovascular diseases, infectious diseases are the second most common cause of death worldwide. Although these infections are caused mainly by viruses or bacteria, a systematically growing prevalence of human and animal opportunistic fungal infections is noticeable worldwide. More attention is being paid to this problem, especially due to the growing frequency of recalcitrant and recurrent mycoses. The latter are classically divided into superficial, which are the most common type, subcutaneous, and systemic. This work discusses opportunistic fungal pathogens without proven horizontal transmission between different animal species including humans and microsporidia as spore-forming unicellular parasites related to fungi; however, with a yet undetermined taxonomic position. The review also mentions aetiological agents, risk factors, epidemiology, geographical distribution, and finally symptoms characteristic for individual disease entities. This paper provides insight into fungal infections from a global perspective and simultaneously draws attention to emerging pathogens, whose prevalence is continuously increasing. Finally, this work also takes into consideration the correct nomenclature of fungal disease entities and the importance of secondary metabolites in the pathogenesis of fungal infections.

Genomic epidemiology of Candida auris in a general hospital in Shenyang, China: a three-year surveillance study

Candida auris is an emerging pathogenic fungal species found worldwide. Since April 2016, C. auris colonization/infection cases have been found in a general hospital in Shenyang, China. The genome-based phylogenetic studies of these isolates remain undefined. In the current study, the microbiological characteristics and antifungal susceptibility of these C. auris isolates, which were collected in Shenyang during the three-year period (2016–2018), were investigated. Whole-genome sequencing was applied to investigate the genetic variation and molecular epidemiological characteristics. A total of 93 C. auris isolates, including 92 clinical isolates and 1 environmental screening isolate were identified. Among the investigated wards, the C. auris cases were the most prevalent (97.4%, 37/38) in four intensive care units (ICUs). The Shenyang isolates carrying the VF125AL mutation in the key drug-resistance gene ERG11 were mainly fluconazole resistant and formed a distinct subclade under the South African clade according to the phylogenetic and population structural analyses. In addition, the Shenyang subclade was found to be closely related to the British subclade in the aspect of genetic distance. As a conclusion, this study provides an important clue for revealing the origin of C. auris found in Shenyang and could also contribute to improve the understanding of the epidemiological characteristics of C. auris worldwide.

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.

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.

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.