Dynamics and Predictors of Mortality Due to Candidemia Caused by Different Candida Species: Comparison of Intensive Care Unit-Associated Candidemia (ICUAC) and Non-ICUAC

Clinical characteristics and outcomes of patients with candidemia during the COVID-19 pandemic: Insights from experience in the Omicron era

BACKGROUND

In Taiwan, COVID-19 outbreaks caused by the Omicron variant occurred in 2022. We investigated the incidence of candidemia during COVID-19 pandemic and the mortality of candidemia patients with COVID-19 in Taiwan.

METHODS

The incidence of candidemia and fluconazole susceptibility of Candida species before (2015-2019) and during COVID-19 pandemic (2020-2023) at Kaohsiung Chang Gung Memorial Hospital were investigated. The associated factors with mortality in candidemia patients during COVID-19 pandemic were analyzed. Candidemia patients who had COVID-19 within the prior 90 days (case group, n = 34) were propensity-score matched for age, ICU admission, and abdominal surgery in a 1:4 ratio with candidemia patients without COVID-19 (control group, n = 136).

RESULTS

Age (adjusted odds ratio [AOR] = 1.02, 95% CI: 1.01-1.03), ICU stay (AOR = 1.84, 95% CI: 1.29-2.62), higher Charlson comorbidity index (AOR = 1.08, 95% CI: 1.03-1.13), corticosteroid use (AOR = 1.50, 95% CI: 1.04-2.17) were associated with increased risk of mortality; abdominal surgery (AOR = 0.47, 95% CI: 0.29-0.74) and infected by Candida parapsilosis (AOR = 0.61, 95% CI: 0.38-0.98) were associated with decreased risk of mortality. After matching, there was no significant difference in mortality rates between the case and control groups. The incidence of candidemia increased from 196 to 278 patients/100,000 admissions during COVID-19 pandemic, while the causative species of candidemia and fluconazole susceptibility rates were similar.

CONCLUSION

While the incidence of candidemia increased during COVID-19 pandemic, there was no significant difference in mortality between candidemia patients with and without COVID-19 in the Omicron era.

Epidemiology, clinical characteristics, outcome and biofilm forming properties in candidaemia: A single-centre retrospective 4-year analysis from Hungary

BACKGROUND

Candidaemia is a life-threatening disease that is associated with high mortality, especially in intensive care units (ICUs). The number of comprehensive studies dealing with the epidemiologic characteristics of biofilm-related properties is limited.

OBJECTIVE

This study evaluated the clinical characteristics of candidaemia, to assess the biofilm-forming properties of isolates, and to identify the risk factors of mortality.

PATIENTS AND METHODS

A total of 149 candidaemia episodes from the University of Debrecen, Clinical Centre, between January 2020 and December 2023 were investigated retrospectively. The susceptibility of Candida isolates to fluconazole, amphotericin B, anidulafungin, caspofungin, and micafungin was evaluated and compared to the susceptibility of 1-day-old biofilms. Multivariate logistic regression analysis was applied to identify the independent predictors of 30-day mortality rate.

RESULTS

The most common Candida species was Candida albicans (41%), followed by C. parapsilosis (20%), C. glabrata (14%), C. tropicalis (13%), rare Candida species (7%), and C. krusei (5%). Sixty-six percent of Candida isolates were biofilm formers and 44% had high metabolic activity. The 30-day mortality rate was 52%, which was higher in ICUs (65%). The logistic regression analysis revealed several factors significantly influencing mortality including ICU admission (odds ratio [OR] 2.99, 95% confidence interval [CI] 1.17-8.04, p = 0.025), fluconazole treatment (OR 4.12, 95% CI 1.62-11.42, p = .004), and pneumonia (OR 0.261, 95% CI 0.1-0.67, p = .006).

CONCLUSIONS

This comprehensive analysis supports the better characterisation of candidaemia in healthcare settings, which ultimately may reduce mortality among patients.

Novel evidence on sepsis-inducing pathogens: from laboratory to bedside

Sepsis is a life-threatening condition and a significant cause of preventable morbidity and mortality globally. Among the leading causative agents of sepsis are bacterial pathogens Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus pyogenes, along with fungal pathogens of the Candida species. Here, we focus on evidence from human studies but also include in vitro and in vivo cellular and molecular evidence, exploring how bacterial and fungal pathogens are associated with bloodstream infection and sepsis. This review presents a narrative update on pathogen epidemiology, virulence factors, host factors of susceptibility, mechanisms of immunomodulation, current therapies, antibiotic resistance, and opportunities for diagnosis, prognosis, and therapeutics, through the perspective of bloodstream infection and sepsis. A list of curated novel host and pathogen factors, diagnostic and prognostic markers, and potential therapeutical targets to tackle sepsis from the research laboratory is presented. Further, we discuss the complex nature of sepsis depending on the sepsis-inducing pathogen and host susceptibility, the more common strains associated with severe pathology and how these aspects may impact in the management of the clinical presentation of sepsis.

Detection and Characterization of Two Phenotypes of Candida parapsilosis in South Korea: Clinical Features and Microbiological Findings

We newly detected two (sinking and floating) phenotypes of Candida parapsilosis among bloodstream infection (BSI) isolates from Korean hospitals and assessed their microbiological and clinical characteristics. During the performance of a Clinical and Laboratory Standards Institute (CLSI) broth microdilution antifungal susceptibility testing, the sinking phenotype had a characteristic smaller button-like appearance because all yeast cells sank to the bottoms of the CLSI U-shaped round-bottom wells, whereas the floating phenotype comprised dispersed cells. Phenotypic analysis, antifungal susceptibility testing, ERG11 sequencing, microsatellite genotyping, and clinical analysis were performed on C. parapsilosis isolates from 197 patients with BSI at a university hospital during 2006 to 2018. The sinking phenotype was detected in 86.7% (65/75) of the fluconazole-nonsusceptible (FNS) isolates, 92.9% (65/70) of the isolates harboring the Y132F ERG11 gene substitution, and 49.7% (98/197) of all isolates. Clonality was more frequently observed for the Y132F-sinking isolates (84.6% [55/65]) than for all other isolates (26.5% [35/132]; P < 0.0001). Annual incidence of Y132F-sinking isolates increased 4.5-fold after 2014, and two dominant genotypes, persistently recovered for 6 and 10 years, accounted for 69.2% of all Y132F-sinking isolates. Azole breakthrough fungemia (odds ratio [OR], 6.540), admission to the intensive care unit (OR, 5.044), and urinary catheter placement (OR, 6.918) were independent risk factors for BSIs with Y132F-sinking isolates. The Y132F-sinking isolates exhibited fewer pseudohyphae, a higher chitin content, and lower virulence in the Galleria mellonella model than the floating isolates. These long-term results illustrate the increasing BSIs caused by clonal transmission of the Y132F-sinking isolates of C. parapsilosis. IMPORTANCE We believe that this is the first study describe the microbiological and molecular characteristics of bloodstream isolates of C. parapsilosis in Korea exhibiting two phenotypes (sinking and floating). An important aspect of our findings is that the sinking phenotype was observed predominantly in isolates harboring a Y132F substitution in the ERG11 gene (92.9%), fluconazole-nonsusceptible (FNS) isolates (86.7%), and clonal BSI isolates (74.4%) of C. parapsilosis. Although the increase in the prevalence of FNS C. parapsilosis isolates has been a major threat in developing countries, in which the vast majority of candidemia cases are treated with fluconazole, our long-term results show increasing numbers of BSIs caused by clonal transmission of Y132F-sinking isolates of C. parapsilosis in the period with an increased echinocandin use for candidemia treatment in Korea, which suggests that C. parapsilosis isolates with the sinking phenotype continue to be a nosocomial threat in the era of echinocandin therapy.

Invasive candidiasis: current clinical challenges and unmet needs in adult populations

Invasive candidiasis (IC) is a serious infection caused by several Candida species, and the most common fungal disease in hospitals in high-income countries. Despite overall improvements in health systems and ICU care in the last few decades, as well as the development of different antifungals and microbiological techniques, mortality rates in IC have not substantially improved. The aim of this review is to summarize the main issues underlying the management of adults affected by IC, focusing on specific forms of the infection: IC developed by ICU patients, IC observed in haematological patients, breakthrough candidaemia, sanctuary site candidiasis, intra-abdominal infections and other challenging infections. Several key challenges need to be tackled to improve the clinical management and outcomes of IC patients. These include the lack of global epidemiological data for IC, the limitations of the diagnostic tests and risk scoring tools currently available, the absence of standardized effectiveness outcomes and long-term data for IC, the timing for the initiation of antifungal therapy and the limited recommendations on the optimal step-down therapy from echinocandins to azoles or the total duration of therapy. The availability of new compounds may overcome some of the challenges identified and increase the existing options for management of chronic Candida infections and ambulant patient treatments. However, early identification of patients that require antifungal therapy and treatment of sanctuary site infections remain a challenge and will require further innovations.

Whole-Genome Sequence Analysis of Candida glabrata Isolates from a Patient with Persistent Fungemia and Determination of the Molecular Mechanisms of Multidrug Resistance

Whole-genome sequencing (WGS) was used to determine the molecular mechanisms of multidrug resistance for 10 serial Candida glabrata bloodstream isolates obtained from a neutropenic patient during 82 days of amphotericin B (AMB) or echinocandin therapy. For WGS, a library was prepared and sequenced using a Nextera DNA Flex Kit (Illumina) and the MiseqDx (Illumina) instrument. All isolates harbored the same Msh2p substitution, V239L, associated with multilocus sequence type 7 and a Pdr1p substitution, L825P, that caused azole resistance. Of six isolates with increased AMB MICs (≥2 mg/L), three harboring the Erg6p A158fs mutation had AMB MICs ≥ 8 mg/L, and three harboring the Erg6p R314K, Erg3p G236D, or Erg3p F226fs mutation had AMB MICs of 2-3 mg/L. Four isolates harboring the Erg6p A158fs or R314K mutation had fluconazole MICs of 4-8 mg/L while the remaining six had fluconazole MICs ≥ 256 mg/L. Two isolates with micafungin MICs > 8 mg/L harbored Fks2p (I661_L662insF) and Fks1p (C499fs) mutations, while six isolates with micafungin MICs of 0.25-2 mg/L harbored an Fks2p K1357E substitution. Using WGS, we detected novel mechanisms of AMB and echinocandin resistance; we explored mechanisms that may explain the complex relationship between AMB and azole resistance.

Short Course of Antifungal Therapy in Patients With Uncomplicated Candida Bloodstream Infection: Another Case of Less Is More in the Clinical Setting?

Background

The objective of this study was to compare the clinical outcomes of patients receiving a short course (SC) vs a prolonged course (PC) of antifungal therapy for uncomplicated Candida bloodstream infections (BSIs).

Methods

All episodes of uncomplicated Candida BSI from September 1, 2018, to August 31, 2020, were reviewed. We compared the primary (all-cause 90-day mortality) and secondary study end points (1-year recurrent Candida BSI and all-cause 1-year mortality) among patients who underwent SC (5-11 days) or PC (12-24 days) therapy using propensity score analysis with the inverse probability of treatment weighting (IPTW) method.

Results

A total of 114 patients with uncomplicated Candida BSI were included: 35 (30.7%) were classified into the SC group (median [interquartile range {IQR}], 9 [7-11] days) and 79 (69.3%) into the PC group (median [IQR], 14 [14-16] days). Patients in the SC group compared with the PC group had a higher rate of hospitalization in the surgical ward (40.0% vs 19.0%; P = .02) or septic shock at the time of Candida BSI onset (11.4% vs 1.3%; P = .03). The risk of 90-day mortality was not different between the SC and PC groups (n = 8 [22.9%] vs 17 [21.5%], respectively; IPTW-adjusted subdistribution hazard ratio [sHR], 0.67; 95% CI, 0.31-1.47; P = .20). The risk for recurrent Candida BSI within 1 year of completing therapy (IPTW-adjusted sHR, 1.07; 95% CI, 0.20-5.80; P = .94) or for all-cause 1-year mortality (IPTW-adjusted HR, 0.72; 95% CI, 0.35-1.50; P = .38) did not differ between groups.

Conclusions

Receiving a short vs prolonged course of antifungal therapy did not affect mortality or BSI recurrence in patients with uncomplicated candidemia.

Nationwide Surveillance of Antifungal Resistance of Candida Bloodstream Isolates in South Korean Hospitals: Two Year Report from Kor-GLASS

We incorporated nationwide Candida antifungal surveillance into the Korea Global Antimicrobial Resistance Surveillance System (Kor-GLASS) for bacterial pathogens. We prospectively collected and analyzed complete non-duplicate blood isolates and information from nine sentinel hospitals during 2020−2021, based on GLASS early implementation protocol for the inclusion of Candida species. Candida species ranked fourth among 10,758 target blood pathogens and second among 4050 hospital-origin blood pathogens. Among 766 Candida blood isolates, 87.6% were of hospital origin, and 41.3% occurred in intensive care unit patients. Adults > 60 years of age accounted for 75.7% of cases. Based on species-specific clinical breakpoints, non-susceptibility to fluconazole, voriconazole, caspofungin, micafungin, and anidulafungin was found in 21.1% (154/729), 4.0% (24/596), 0.1% (1/741), 0.0% (0/741), and 0.1% (1/741) of the isolates, respectively. Fluconazole resistance was determined in 0% (0/348), 2.2% (3/135, 1 Erg11 mutant), 5.3% (7/133, 6 Pdr1 mutants), and 5.6% (6/108, 4 Erg11 and 1 Cdr1 mutants) of C. albicans, C. tropicalis, C. glabrata, and C. parapsilosis isolates, respectively. An echinocandin-resistant C. glabrata isolate harbored an F659Y mutation in Fks2p. The inclusion of Candida species in the Kor-GLASS system generated well-curated surveillance data and may encourage global Candida surveillance efforts using a harmonized GLASS system.

Advances in prophylaxis and treatment of invasive fungal infections: perspectives on hematologic diseases

Invasive fungal infections (IFIs) are common causes of mortality and morbidity in patients with hematologic diseases. Delayed initiation of antifungal treatment is related to mortality. Aspergillus sp. is the leading cause of IFI followed by Candida sp. Diagnosis is often challenging owing to variable conditions related to underlying diseases. Clinical suspect and prompt management is important. Imaging, biopsy, and non-culture-based tests must be considered together. New diagnostic procedures have been improved, including antigen-based assays and molecular detection of fungal DNA. Among hematologic diseases, patients with acute myeloid leukemia, myelodysplastic syndrome, recipients of hematopoietic stem cell transplantation are at high risk for IFIs. Antifungal prophylaxis is recommended for these high-risk patients. There are continuous attempts to achieve ideal management of IFIs. Scoring system for quality control has been developed with important recommendations of current guidelines. Higher adherence to guidelines is related to decreased mortality in IFIs.