Candida auris Blood stream infection- a descriptive study from Qatar

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.

Uniqueness of Candida auris cell wall in morphogenesis, virulence, resistance, and immune evasion

Candida auris has drawn global attention due to its alarming multidrug resistance and the emergence of pan resistant strains. C. auris poses a significant risk in nosocomial candidemia especially among immunocompromised patients. C. auris showed unique virulence characteristics associated with cell wall including cell polymorphism, adaptation, endurance on inanimate surfaces, tolerance to external conditions, and immune evasion. Notably, it possesses a distinctive cell wall composition, with an outer mannan layer shielding the inner 1,3-β glucan from immune recognition, thereby enabling immune evasion and drug resistance. This review aimed to comprehend the association between unique characteristics of C. auris's cell wall and virulence, resistance mechanisms, and immune evasion. This is particularly relevant since the fungal cell wall has no human homology, providing a potential therapeutic target. Understanding the complex interactions between the cell wall and the host immune system is essential for devising effective treatment strategies, such as the use of repurposed medications, novel therapeutic agents, and immunotherapy like monoclonal antibodies. This therapeutic targeting strategy of C. auris holds promise for effective eradication of this resilient pathogen.

In vitro activity of taurolidine against clinical Candida auris isolates: relevance to catheter-related bloodstream infections

Candida auris is an evolving and concerning global threat. Of particular concern are bloodstream infections related to central venous catheters. We evaluated the activity of taurolidine, a broad-spectrum antimicrobial in catheter lock solutions, against 106 C. auris isolates. Taurolidine was highly active with a MIC50/MIC90 of 512/512 mg/L, over 20-fold lower than lock solution concentrations of ≥13,500 mg/L. Our data demonstrate a theoretical basis for taurolidine-based lock solutions for prevention of C. auris catheter-associated infections.

Clinical and microbiological characteristics of a hospital outbreak of Candida auris in a referral hospital in Lima, Peru

BACKGROUND

Candida auris, a multidrug-resistant fungal pathogen, has received considerable attention owing to its recent surge, especially in South America, which coincides with the ongoing global COVID-19 pandemic. Understanding the clinical and microbiological characteristics of outbreaks is crucial for their effective management and control.

OBJECTIVE

This retrospective observational study aimed to characterize a C. auris outbreak at a Peruvian referral hospital between January 2021 and July 2023.

METHODS

Data were collected from hospitalized patients with positive C. auris culture results. Microbiological data and antifungal susceptibility test results were analysed. Additionally, infection prevention and control measures have been described. Statistical analysis was used to compare the characteristics between the infected and colonized patients.

RESULTS

Thirty-three patients were identified, mostly male (66.7%), with a median age of 53 years. Among them, 18 (54.5%) were colonized, and 15 (45.5%) were infected. Fungemia was the predominant presentation (80%), with notable cases of fungemia in tuberculosis patients with long-stay devices for parenteral anti-tuberculosis therapy. Seventy-five percent of the isolates exhibited fluconazole resistance. Echinocandins were the primary treatment, preventing fungemia recurrence within 30 days. Infected patients had significantly longer hospital stays than colonized patients (100 vs. 45 days; p = .023). Hospital mortality rates were 46.7% and 25% in the infected and fungemia patients, respectively. Simultaneous outbreaks of multidrug-resistant bacteria were documented.

CONCLUSIONS

This study underscores the severity of a C. auris outbreak at a referral hospital in Peru, highlighting its significant impact on patient outcomes and healthcare resources. The high prevalence of fluconazole-resistant isolates, leading to prolonged hospital stay and high mortality rates, particularly in cases of fungemia, underscores the critical need for effective infection prevention and control strategies.

Malik A, Nafady-Hego H, Hanana F, Abraham J, G. Garcell H, Hudaib G, Al-Wali W, Eltayeb F, Shams S, G. Thomas A, Saleem S, Abou-Samra AB, Butt AA. Spectrum of infection and outcomes in individuals with Candida auris infection in Qatar

BACKGROUND

We investigated the spectrum of infection and risk factors for invasive fungal disease due to Candida auris (CA) in Qatar.

METHODS

We performed structured chart reviews on individuals with any positive CA culture between May 2019 and December 2022 at three tertiary care hospitals in Qatar. Invasive CA disease (ICAD) was defined as a positive sterile site culture, or any positive culture for CA with appropriate antifungal prescription. Main outcomes included proportion of individuals who developed ICAD among those with positive cultures, and 30-day/in-hospital mortality.

RESULTS

Among 331 eligible individuals, median age was 56 years, 83.1% were male, 70.7% were non-Qataris, and 37.5% had ≥ 3 comorbidities at baseline. Overall, 86.4% were deemed to have colonization and 13.6% developed ICAD. Those with ICAD were more likely to have invasive central venous or urinary catheterization and mechanical ventilation. Individuals with ICAD had longer prior ICU stay (16 vs 26 days, P = 0.002), and longer hospital length of stay (63 vs. 43 days; P = 0.003), and higher 30-day mortality (38% vs. 14%; P<0.001). In multivariable regression analysis, only mechanical ventilation was associated with a higher risk of ICAD (OR 3.33, 95% CI 1.09-10.17).

CONCLUSION

Invasive Candida auris Disease is associated with longer hospital stay and higher mortality. Severely ill persons on mechanical ventilation should be especially monitored for development of ICAD.

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.

Antifungal Use and Resistance in a Lower-Middle-Income Country: The Case of Lebanon

Antimicrobial resistance is a serious threat, particularly in low- and middle-income countries (LMICs). Antifungal resistance is often underestimated in both healthcare and non-clinical settings. In LMICs, it is believed that the inappropriate use of antifungals, limited surveillance systems, and low diagnostic capacities are significant drivers of resistance. Like other LMICs, Lebanon lacks antifungal use and resistance surveillance programs, and the impact of antifungal resistance in the country remains unclear, especially during the unfolding economic crisis that has severely affected medical care and access to safe food and water. Interestingly, the widespread use of antifungals in medicine and agriculture has raised concerns about the development of antifungal resistance in Lebanon. In this light, we aimed to survey available antifungal drugs in the country and evaluate susceptibility patterns of prevalent fungal species to guide empiric treatments and develop antifungal stewardship programs in Lebanon. We noted that the economic crisis resulted in significant increases in antifungal drug prices. Additionally, a comprehensive literature search across PubMed, ScienceDirect, and Google Scholar databases identified 15 studies on fungal infections and antifungal resistance conducted from 1998 to 2023 in Lebanon. While data on antifungal resistance are limited, 87% of available studies in Lebanon focused on candidiasis, while the remaining 13% were on aspergillosis. Overall, we observed a marked antimicrobial resistance among Candida and Aspergillus species. Additionally, incidences of Candida auris infections have increased in Lebanese hospitals during the COVID-19 pandemic, with a uniform resistance to fluconazole and amphotericin-B. Taken together, a One Health approach, reliable diagnostics, and prudent antifungal use are required to control the spread of resistant fungal pathogens in healthcare and agricultural settings.