Candidemia in the Intensive Care Unit

Evaluating antimicrobial stewardship strategies in candidemia: a novel desirability of outcome ranking (DOOR) analysis comparing blood culture versus T2Candida diagnostic approaches

The T2Candida Panel (T2 Biosystems, Lexington, MA) is a rapid diagnostic test that detects Candida from whole blood within 3-5 hours. We developed and applied a desirability of outcome ranking (DOOR) analysis to investigate if an antimicrobial stewardship program (ASP) strategy centered on T2Candida diagnosis is associated with improved outcomes compared to an ASP strategy that relies on conventional blood culture diagnosis in critically ill patients with candidemia. This is a retrospective, observational cohort of patients with candidemia identified ≤72 h of intensive care unit admission at two medical centers in Detroit, MI (one T2Candida site and one blood culture site) from 2016 to 2023. Management strategies for candidemia were compared using an original DOOR analysis with inverse probability of treatment weighting (IPTW) to account for confounding. Two hundred patients were included, 100 from each site. Baseline illness severity, race, and Candida species varied between groups; however, source control procedures, echocardiogram, and ophthalmologic exam occurred at similar frequencies. T2Candida/ASP was associated with faster median (interquartile range [IQR]) detection of candidemia (7.0 [5.0-10.75] h vs 45.5 h [34.25-68.75], P < 0.001) and timelier median (IQR) initiation of directed antifungal therapy (6.0 [0-11.0] h vs 49.0 [34.0-77.0] h, P < 0.001). T2Candida/ASP patients had a 58.0% probability of achieving an overall better outcome compared to those managed with blood culture/ASP (95% confidence interval: 50.4-65.2%) in IPTW-adjusted DOOR analysis. An ASP strategy incorporating T2Candida was associated with an overall better patient outcome compared to patients managed via conventional blood culture diagnosis.IMPORTANCECandida species are a significant cause of bloodstream infections in critically ill patients. Conventional diagnostic methods, such as blood cultures, have poor sensitivity and delayed results. The T2Candida Panel is a diagnostic tool that rapidly detects Candida directly from the blood in 3-5 h, enabling faster initiation of antifungal therapy. Antimicrobial stewardship programs (ASPs) optimize the management of bloodstream infections and may benefit from incorporating T2Candida to improve patient outcomes. This study examined whether an ASP intervention based on T2Candida diagnosis, compared to one relying on traditional blood culture methods, could improve outcomes in candidemia using a desirability of outcome ranking (DOOR) analysis. The DOOR method provides a comprehensive evaluation by integrating multiple outcomes into a single end point, which is ideal given the complexity of patients with candidemia. The T2Candida/ASP intervention resulted in an overall better patient outcome, considering infectious complications, treatment failure, and all-cause mortality.

Fungal microbiota in COPD patients during exacerbations

Acute exacerbations of chronic obstructive pulmonary disease (COPD) results in increased mortality and can be triggered by a range of factors, including microorganisms. Very little studies have examined the role of fungi and fungal diversity in COPD patients. The aim of the study was to determine the role of Candida in COPD during an exacerbation. Oral swabs, sputum, feces and whole blood samples were collected from the AECOPD patients and control group. Mycological and serological analysis were performed. Yeast were statistically significantly more often isolated from the AECOPD group (97.06%) than from the control group (26.32%). 7 species were isolated from the AECOPD, and 3 from the control group. Dominated Candida albicans followed by C. tropicalis. α-diversity was much greater in AECOPD patients than in controls. β-diversity was also assessed. A much higher level of antimycotic resistance was observed in isolates from the AECOPD group, which affects the effectiveness of therapy. Serological tests showed twice the frequency of positive results in the AECOPD group. The mycobiota of AECOPD patients is numerically and taxonomically richer than controls, including species less frequently recorded in humans. Our research confirms that fungal mycobiota may be a potential factor influencing the development of exacerbations and progression of COPD.

Global burden of reported lower respiratory system fungal infection

Background

The epidemiological trend of lower respiratory tract fungal infections remains unclear. This study aims to quantify the global burden of these infections from 1990 to 2021 using data from the Global Burden of Disease Study 2021.

Methods

Data were analyzed at global, regional, and national levels, considering factors such as age, gender, region, and socio-demographic index (SDI). Key indicators included age-standardized disability-adjusted life-year (ASDR) and age-standardized mortality rates (ASMR).

Results

On a global scale, the burden of lower respiratory fungal infections decreased significantly from 1990 to 2021, with a decline in mortality rates. Regionally, substantial disparities were observed among the 21 geographic super-regions. Nationally, Argentina experienced the greatest increase in ASDR and ASMR, while Finland showed the largest decrease, with average annual percentage changes (AAPC) below -5 for both indicators. Sex-based analysis revealed a notably higher burden in males compared to females. ASDR and ASMR were negatively correlated with SDI in most regions.

Conclusion

Although the global burden of lower respiratory tract fungal infections has decreased, it remains a substantial public health issue, particularly in low-SDI regions. There is an urgent need to implement targeted preventive measures to address this ongoing challenge.

Candidemia chronicles: Retrospective analysis of candidemia epidemiology, species distribution, and antifungal susceptibility patterns in Bahrain

BACKGROUND

Invasive fungal infections, particularly candidemia, pose significant clinical challenges globally. Understanding local epidemiology, species distribution, and antifungal susceptibility patterns is crucial for effective management despite regional variations.

AIM

To investigate the epidemiology, species distribution, antifungal susceptibility patterns, and associated risk factors of candidemia among patients in Bahrain from 2021 to 2023.

METHODS

This retrospective study analyzed demographic data, Candida species distribution, antifungal susceptibility profiles, and risk factors among candidemia patients treated at a tertiary care hospital in Bahrain over three years. Data was collected from medical records and analyzed using descriptive statistics.

RESULTS

A total of 430 candidemia cases were identified. The mean age of patients was 65.7 years, with a mortality rate of 85.5%. Candida albicans (C. albicans) was the most common species, followed by Candida parapsilosis, Candida tropicalis (C. tropicalis), and emerging multidrug-resistant Candida auris (C. auris). Antifungal susceptibility varied across species, with declining susceptibility to azoles observed, particularly among C. albicans and C. tropicalis. Major risk factors included central venous catheters, broad-spectrum antibiotics, and surgical procedures.

CONCLUSION

This study highlights the substantial burden of candidemia among older adults in Bahrain, characterized by diverse Candida species. It also concerns levels of antifungal resistance, notably in C. auris. The findings underscore the importance of local epidemiological surveillance and tailored treatment strategies to improve outcomes and mitigate the spread of multidrug-resistant Candida species. Future research should focus on molecular resistance mechanisms and optimizing therapeutic approaches to address this growing public health concern.

Emerging trends of invasive yeast infections and azole resistance in Beijing intensive care units

BACKGROUND

Invasive fungal infections pose a substantial threat to patients in healthcare settings globally. Recent changes in the prevalence of fungal species and challenges in conducting reference antifungal susceptibility testing emphasize the importance of monitoring fungi and their antifungal resistance.

METHODS

A two-phase surveillance project was conducted in Beijing, China, involving 37 centres across 12 districts, from January 2012 to December 2013 and from January 2016 to December 2017.

FINDINGS

We found that the proportion of Candida albicans in intensive care units (ICUs) during 2016-2017 exhibited a significant decline compared with the 2012-2013 period, although it remained the most predominant pathogen. In contrast, the prevalence of Nakaseomyces glabratus (formerly Candida glabrata) and Candida tropicalis notably increased during the two-phase surveillance. The high prevalence of C. tropicalis and its resistance to azole drugs posed a serious threat to patients in ICUs. The pathogens causing invasive fungal infections in Beijing were relatively sensitive to echinocandins. While C. albicans continued to exhibit susceptibility to azoles, the resistance and growth rates of C. tropicalis towards azoles were particularly prominent. Concerns were raised due to the emergence of multiple, short-term isolates of Clavispora lusitaniae and Candida parapsilosis complex in neonatal ICUs, given their similarity in antifungal susceptibilities. Such occurrences point towards the potential for transmission and persisting presence of these pathogens within the ICU environment.

CONCLUSIONS

Our study complements existing data on the epidemiology of invasive fungal infections. It is imperative to exercise cautious medication management for ICU patients in Beijing, paying particular attention to azole resistance in C. tropicalis.

Clinical significance of inflammatory markers for evaluating disease severity of mixed-pathogen bloodstream infections of both Enterococcus spp. and Candida spp

Objective

In recent decades, there has been a notable increase in the morbidity and mortality rates linked to bacteremia and candidemia. This study aimed to investigate the clinical significance of inflammatory markers in assessing the disease severity in critically ill patients suffering from mixed-bloodstream infections (BSIs) due to Enterococcus spp. and Candida spp.

Methods

In this retrospective research, patients diagnosed with BSIs who were admitted to the intensive care unit (ICU) during the period of January 2019 to December 2022 were analyzed. The patients were divided into two groups: a mixed-pathogen BSI group with both Enterococcus spp. and Candida spp., and a single-pathogen BSI group with only Enterococcus spp. The study examined the differences in inflammatory marker levels and disease severity, including Acute Physiology and Chronic Health Evaluation (APACHE) II scores, duration of ICU stay, and 30-day mortality, between the two groups. Furthermore, we sought to scrutinize the potential associations among these aforementioned parameters.

Results

The neutrophil-to-lymphocyte ratios (NLRs) and levels of plasma C-reactive protein (CRP), interleukin (IL)-6, IL-8, and tumor necrosis factor-α (TNF-α) in the mixed-pathogen BSI group were higher than those in the single-pathogen BSI group. Spearman's rank correlation analysis showed that NLRs and plasma CRP and IL-6 levels were positively correlated with disease severity in the mixed-pathogen BSI group. Further, the levels of plasma IL-8 and TNF-α were also positively correlated with ICU stay duration and 30-day mortality. In multivariate analysis, plasma CRP and IL-6 levels were independently associated with 30-day mortality.

Conclusion

Mixed-pathogen BSIs caused by Enterococcus spp. and Candida spp. may give rise to increased NLRs and plasma CRP, IL-6, IL-8, and TNF-α levels in comparison to BSI caused by Enterococcus spp. only, thus leading to elevated disease severity in critically ill patients.

Effect of Amphotericin B on the Thermodynamic Properties and Surface Morphology of the Pulmonary Surfactant Model Monolayer during Respiration

During the COVID-19 pandemic, the treatment of pulmonary fungal infection faced noteworthy challenges. Amphotericin B has shown promising therapeutic effects as an inhalation treatment for pulmonary fungal infections, especially those associated with the COVID-19 virus, due to its rare resistance. However, because the drug frequently produces renal toxicity, its effective dose is limited in clinical use. In this work, the DPPC/DPPG mixed monolayer was used as the pulmonary surfactant monolayer to study the interaction between amphotericin B and the pulmonary surfactant monolayer during inhalation therapy using the Langmuir technique and atomic force microscopy. The effects of different molar ratios of AmB on the thermodynamic properties and surface morphology of the pulmonary surfactant monolayer at different surface pressures was evaluated. The results showed that when the molar ratio of AmB to lipids in the pulmonary surfactant was less than 1:1, the main intermolecular force was attractive at a surface pressure greater than 10 mN/m. This drug had little effect on the phase transition point of the DPPC/DPPG monolayer, but decreased the height of the monolayer at 15 mN/m and 25 mN/m. When the molar ratio of AmB to lipids was greater than 1:1, the intermolecular force was mainly repulsive at a surface pressure greater than 15 mN/m, and AmB increased the height of the DPPC/DPPG monolayer at both 15 mN/m and 25 mN/m. These results are helpful in understanding the interaction between the pulmonary surfactant model monolayer and different doses of drugs at various surface tensions during respiration.

Automatic classification of Candida species using Raman spectroscopy and machine learning

One of the problems that most affect hospitals is infections by pathogenic microorganisms. Rapid identification and adequate, timely treatment can avoid fatal consequences and the development of antibiotic resistance, so it is crucial to use fast, reliable, and not too laborious techniques to obtain quick results. Raman spectroscopy has proven to be a powerful tool for molecular analysis, meeting these requirements better than traditional techniques. In this work, we have used Raman spectroscopy combined with machine learning algorithms to explore the automatic identification of eleven species of the genus Candida, the most common cause of fungal infections worldwide. The Raman spectra were obtained from more than 220 different measurements of dried drops from pure cultures of each Candida species using a Raman Confocal Microscope with a 532 nm laser excitation source. After developing a spectral preprocessing methodology, a study of the quality and variability of the measured spectra at the isolate and species level, and the spectral features contributing to inter-class variations, showed the potential to discriminate between those pathogenic yeasts. Several machine learning and deep learning algorithms were trained using hyperparameter optimization techniques to find the best possible classifier for this spectral data, in terms of accuracy and lowest possible overfitting. We found that a one-dimensional Convolutional Neural Network (1-D CNN) could achieve above 80 % overall accuracy for the eleven classes spectral dataset, with good generalization capabilities.

Nanotechnology-Based Approaches for Voriconazole Delivery Applied to Invasive Fungal Infections

Invasive fungal infections increase mortality and morbidity rates worldwide. The treatment of these infections is still limited due to the low bioavailability and toxicity, requiring therapeutic monitoring, especially in the most severe cases. Voriconazole is an azole widely used to treat invasive aspergillosis, other hyaline molds, many dematiaceous molds, Candida spp., including those resistant to fluconazole, and for infections caused by endemic mycoses, in addition to those that occur in the central nervous system. However, despite its broad activity, using voriconazole has limitations related to its non-linear pharmacokinetics, leading to supratherapeutic doses and increased toxicity according to individual polymorphisms during its metabolism. In this sense, nanotechnology-based drug delivery systems have successfully improved the physicochemical and biological aspects of different classes of drugs, including antifungals. In this review, we highlighted recent work that has applied nanotechnology to deliver voriconazole. These systems allowed increased permeation and deposition of voriconazole in target tissues from a controlled and sustained release in different routes of administration such as ocular, pulmonary, oral, topical, and parenteral. Thus, nanotechnology application aiming to delivery voriconazole becomes a more effective and safer therapeutic alternative in the treatment of fungal infections.

Development and validation of COVID-19 associated candidemia score (CAC-Score) in ICU patients

BACKGROUND

The development of candidemia is a highly fatal condition in severe COVID-19 infection.

OBJECTIVES

This study aimed to develop a candidemia prediction score in COVID-19 patient based on the patient's clinical characteristics, and healthcare-related factors during intensive care units (ICU) follow-up.

PATIENTS/METHODS

Severe COVID-19 patients hospitalised in ICU in Ankara City Hospital during the one-year period (August 15, 2020, and August 15, 2021) were included. After univariate analysis, multivariate analysis was applied using variable selection approach to investigate the effects of variables together and to create a score model for candidemia. Statistically significant factors were included in the development process of candida prediction score.

RESULTS

Of 1305 COVID-19 ICU patients, 139 had a candidemia episode. According to the final model, four variables, presence of central venous catheter (CVC) (OR 19.07, CI 8.12-44.8, p < .0001), multifocal colonisation (OR 2.28, CI 1.39-3.72, p 0.001), length of ICU stays ≥14 days (OR 3.62, CI 2.42-5.44, p < .0001) and corticosteroids (OR 0.51, CI 0.34-0.76, p 0.0011) were the only statistically significant independent risk factors for candidemia. Score model was demonstrated by a nomogram, and the risk for candidemia was calculated to be high in patients who scored ≥56 points by using the criteria [CVC = 51, multifocal colonisation = 14, prolonged hospitalisation = 23, no steroid use = 12 points]. The AUC of the score is 0.84 (CI 0.81-0.87).

CONCLUSION

We developed and validated an easy-to-use clinical prediction score for candidemia in severe COVID-19 infection. In COVID-19 ICU patients, the risk of candidemia is high if one of the other risk factors is present together with CVC.

A low serum uric acid concentration predicts a poor prognosis in adult patients with candidemia

This study aimed to determine the relation of serum uric acid (UA) level with outcomes in adults with candidemia. Medical records of patients with candidemia treated from 2014 to 2017 were retrospectively reviewed. Patients were age- and sex-matched with healthy control subjects. The associations of UA and cystatin C (CysC) levels with diagnosis and prognosis of candidemia were determined. Sixty-four patients with candidemia (13 females and 51 males; mean age 48.5 years) and 64 matched control subjects were included. The median UA level of patients with candidemia was 255 μmol/L (range, 158–395 μmol/L), and of healthy controls was 398 μmol/L (range, 345–450 μmol/L) (P < 0.001). The median CysC level of patients with candidemia was 1.07 mg/L (range, 0.89–1.59 mg/L), and of the healthy controls was 0.82 mg/L (range, 0.74–0.95 mg/L) (P < 0.001). Patients with a favorable prognosis had significantly higher serum UA levels than those with a poor prognosis (181 μmol/L vs 344 μmol/L; P = 0.001). It was indicated that the estimated OR for UA was significantly > 1 (P = 0.009), and the AUC was 0.734. In summary, a lower serum UA level is associated with a diagnosis of candidemia, and a poor outcome.

Incidence and risk factors for COVID-19 associated candidemia (CAC) in ICU patients

BACKGROUND

Critically ill COVID-19 patients have a high risk for the development of candidemia due to being exposed to both well-defined classical risk factors and COVID-19-specific risk factors in ICU.

OBJECTIVES

In this study, we investigated the incidence of candidemia in critically COVID-19 patients, and the independent risk factors for candidemia.

PATIENTS/METHODS

COVID-19 patients hospitalised in ICU during 1-year period (August 2020 to August 2021) were included. Clinical and laboratory characteristics of all COVID-19 patients, applied treatments, and invasive procedures that may predispose to candidemia were recorded.

RESULTS

Of 1229 COVID-19 patients, 63 developed candidemia. Candidemia incidence rate was 4.4 episodes per 1000 ICU days. The most common species was Candida albicans (52.3%). Only 37 patients (58.7%) received antifungal therapy. The presence of central venous catheter (OR 4.7, 95% CI 1.8-12.2, p < .005), multifocal candida colonisation (OR 2.7, 95% CI 1.4-5.2, p < .005), a prolonged ICU stay (≥14 days) (OR 1.9, 95% CI 1.08-3-37, p < .05), the absence of chronic lung disease (OR 0.4, 95% CI 0.1-0.9, p < .05) and the absence of corticosteroid use (OR 0.3, 95% CI 0.14-0.52, p < .0001) were significantly associated with candidemia.

CONCLUSIONS

Our study filled the knowledge gap in the literature about the impact of COVID-19-associated risk factors for the development of candidemia. The classical risk factors for candidemia had a significant effect on candidemia, and contrary to expectations, corticosteroids had a protective effect against the development of candidemia. The results of these studies showing interesting effects of corticosteroids in critically ill COVID-19 patients should be confirmed by further studies.

Clinical impact of Candida respiratory tract colonization and acute lung infections in critically ill patients with COVID-19 pneumonia

Coronavirus disease 2019 (COVID-19), which is attributable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been causing a worldwide health issue. Airways colonization by Candida spp. is prevalent among patients on automatic ventilation in intensive care units (ICUs). This research aimed to ascertain the risk factors and roles of Candida spp. respiratory tract colonization, and Candida lung infection during the progression of COVID-19 pneumonia in critically ill patients. In total, Candida spp. were recovered in 69 from 100 immunosuppressed patients with COVID-19. Bronchoscopy was used to collect the Bronchoalveolar lavage (BAL) specimens. For the identification of Candida spp. PCR sequencing was done using the ITS1 and ITS4 primers. The amplification of the HWP1 gene was conducted to identify the Candida albicans complex. The antifungal activities of fluconazole, itraconazole, voriconazole, amphotericin B and caspofungin against Candida spp. were evaluated using the Clinical and Laboratory Standards Institute M60. In 63.77% of the patients, Candida respiratory colonization at D0 and D14 had no impact on the severity of COVID-19. In comparison to C. albicans strains, Candida respiratory disorder with C. glabrata had influenced the severity of COVID-19 for critically ill patients following adjustment for the risk factors of COVID-19 (P < 0.05). Amphotericin B and caspofungin showed superior activity against all Candida spp. All antifungal agents showed 100% sensitivity against the two C. africana strains. Our observation on patients who used automatic ventilation, respiratory colonization by Candida spp. was not seen to influence the infection or death caused by COVID-19. Amphotericin B and caspofungin showed superior activity against all Candida spp. and were recommended for the treatment regime of pulmonary candidiasis associated with COVID-19 infection. Although “Candida pneumonia” is rarely being reported in critically ill patients, Candida airway colonization mainly by Candida albicans is common especially among patients with diabetes, malignancies, and kidney disorders.

Fungal Infection Testing in Pediatric Intensive Care Units-A Single Center Experience

Mycoses are diseases caused by fungi that involve different parts of the body and can generate dangerous treatment complications. This study aims to analyze fungal infection epidemiology in intensive care units (Pediatric and Cardiac Surgery Intensive Care Units—PCICU) and the Neonatal Intensive Care Unit (NICU) in one large pediatric center in the period 2015–2020 compared with 2005. The year 2005 was randomly selected as a historical time reference to notice possible changes. In 2005 and 2015–2020, 23,334 mycological tests were performed in intensive care units. A total of 4628 tests (19.8%) were performed in the intensive care units. Microbiological diagnostics involved mycological and serological testing. Of the 458 children hospitalized in the NICU, positive results in the mycological tests in the studied years were found in 21–27% of the children and out of 1056 PCICU patients, positive results were noticed in 18–29%. In both departments, the main detected pathogen was Candida albicans which is comparable with data published in other centers. Our experience indicates that blood cultures as well as the detection of antifungal antibodies do not add important information to mycological diagnostics. For the years of observation, only a few positive results were detected, even in patients with invasive fungal diseases. To our knowledge, this is one of a few similar studies over recent years and it provides contemporary reports of mycoses in pediatric ICU patients.

A Brazilian Inter-Hospital Candidemia Outbreak Caused by Fluconazole-Resistant Candida parapsilosis in the COVID-19 Era

Horizontal transmission of fluconazole-resistant Candida parapsilosis (FRCP) through healthcare workers’ hands has contributed to the occurrence of candidemia outbreaks worldwide. Since the first COVID-19 case in Brazil was detected in early 2020, hospitals have reinforced hand hygiene and disinfection practices to minimize SARS-CoV-2 contamination. However, a Brazilian cardiology center, which shares ICU patients with a cancer center under a FRCP outbreak since 2019, reported an increased FRCP candidemia incidence in May 2020. Therefore, the purpose of this study was to investigate an inter-hospital candidemia outbreak caused by FRCP isolates during the first year of the COVID-19 pandemic in Brazil. C. parapsilosis bloodstream isolates obtained from the cancer (n = 35) and cardiology (n = 30) centers in 2020 were submitted to microsatellite genotyping and fluconazole susceptibility testing. The ERG11 gene of all isolates from the cardiology center was sequenced and compared to the corresponding sequences of the FRCP genotype responsible for the cancer center outbreak in 2019. Unprecedentedly, most of the FRCP isolates from the cardiology center presented the same genetic profile and Erg11-Y132F mutation detected in the strain that has been causing the persistent outbreak in the cancer center, highlighting the uninterrupted horizontal transmission of clonal isolates in our hospitals during the COVID-19 pandemic.

Inflammasome-mediated GSDMD activation facilitates escape of Candida albicans from macrophages

Candida albicans is the most common cause of fungal sepsis. Inhibition of inflammasome activity confers resistance to polymicrobial and LPS-induced sepsis; however, inflammasome signaling appears to protect against C. albicans infection, so inflammasome inhibitors are not clinically useful for candidiasis. Here we show disruption of GSDMD, a known inflammasome target and key pyroptotic cell death mediator, paradoxically alleviates candidiasis, improving outcomes and survival of Candida-infected mice. Mechanistically, C. albicans hijacked the canonical inflammasome-GSDMD axis-mediated pyroptosis to promote their escape from macrophages, deploying hyphae and candidalysin, a pore-forming toxin expressed by hyphae. GSDMD inhibition alleviated candidiasis by preventing C. albicans escape from macrophages while maintaining inflammasome-dependent but GSDMD-independent IL-1β production for anti-fungal host defenses. This study demonstrates key functions for GSDMD in Candida's escape from host immunity in vitro and in vivo and suggests that GSDMD may be a potential therapeutic target in C. albicans-induced sepsis.

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

We investigated mortality and predictors of mortality due to intensive care unit-associated candidemia (ICUAC) versus non-ICUAC by Candida species. This study included all candidemia cases in 11 hospitals from 2017 to 2018 in South Korea. The all-cause mortality rates in all 370 patients with ICUAC were approximately twofold higher than those in all 437 patients with non-ICUAC at 7 days (2.3-fold, 31.1%/13.3%), 30 days (1.9-fold, 49.5%/25.4%), and 90 days (1.9-fold, 57.8%/30.9%). Significant species-specific associations with 7- and 30-day ICUAC-associated mortality were not observed. Multivariate analysis revealed that ICU admission was an independent predictor of Candida glabrata (OR, 2.07–2.48) and Candida parapsilosis-associated mortality (OR, 6.06–11.54). Fluconazole resistance was a predictor of C. glabrata-associated mortality (OR, 2.80–5.14). Lack (less than 3 days) of antifungal therapy was the strongest predictor of 7-day mortality due to ICUAC caused by Candida albicans (OR, 18.33), Candida tropicalis (OR, 10.52), and C. glabrata (OR, 21.30) compared with 30- and 90-day mortality (OR, 2.72–6.90). C. glabrata ICUAC had a stronger association with lack of antifungal therapy (55.2%) than ICUAC caused by other species (30.6–36.7%, all p < 0.05). Most predictors of mortality associated with ICUAC were distinct from those associated with non-ICUAC and were mediated by Candida species.

8-hydroxyquinoline-5-(N-4-chlorophenyl) sulfonamide and fluconazole combination as a preventive strategy for Candida biofilm in haemodialysis devices

Introduction. The presence of Candida biofilms in medical devices is a concerning and important clinical issue for haemodialysis patients who require constant use of prosthetic fistulae and catheters.Hypothesis/Gap Statement. This prolonged use increases the risk of candidaemia due to biofilm formation. PH151 and clioquinol are 8-hydroxyquinoline derivatives that have been studied by our group and showed interesting anti-Candida activity.Aim. This study evaluated the biofilm formation capacity of Candida species on polytetrafluoroethylene (PTFE) and polyurethane (PUR) and investigated the synergistic effects between the compounds PH151 and clioquinol and fluconazole, amphotericin B and caspofungin against biofilm cells removed from those materials. Further, the synergistic combination was evaluated in terms of preventing biofilm formation on PTFE and PUR discs.Methodology. Susceptibility testing was performed for planktonic and biofilm cells using the broth microdilution method. The checkerboard method and the time-kill assay were used to evaluate the interactions between antifungal agents. Antibiofilm activity on PTFE and PUR materials was assessed to quantify the prevention of biofilm formation.Results. Candida albicans, Candida glabrata and Candida tropicalis showed ability to form biofilms on both materials. By contrast, Candida parapsilosis did not demonstrate this ability. Synergistic interaction was observed when PH151 was combined with fluconazole in 77.8 % of isolates and this treatment was shown to be concentration- and time-dependent. On the other hand, indifferent interactions were predominantly observed with the other combinations. A reduction in biofilm formation on PUR material of more than 50 % was observed when using PH151 combined with fluconazole.Conclusion. PH151 demonstrated potential as a local treatment for use in a combination therapy approach against Candida biofilm formation on haemodialysis devices.

Molecular genotyping of Candida albicans isolated from different sites may trace the etiological infection routes: Observation in China

BACKGROUND

Invasive candidiasis is a growing concern worldwide, especially in immunocompromised patients, including ICU patients.

OBJECTIVES

As Candida albicans is the leading cause of candidaemia, it is important to investigate the evolution of C. albicans in patients with candidaemia.

METHODS

We analysed 238 strains of C. albicans isolated from different body sites. Antifungal susceptibility testing, CAI loci genotyping and multilocus sequence typing (MLST) of all isolates were performed. The relationships among the total isolates that differed in sequence at only one of the seven housekeeping gene loci were analysed using eBURST.

RESULTS

Multilocus sequence typing analysis in 238 isolates by combining seven housekeeping alleles revealed 175 diploid sequence types, in which 84 were newly identified. eBURST analysis for these data recognised 19 clonal complexes (CCs) and 79 singletons. Besides, seventy-three CAI genotypes were identified. Blood isolates showed maximum genotypes (49), and the dominant genotypes were CAI 17-21 and CAI 21-21. Oral isolates possessed 25 CAI genotypes, and the dominant genotypes were CAI 17-21 and CAI 21-21 as well. Since isolates with CAI allele numbers <30 showed easier transmission, CAI 17-21 and CAI 21-21 were the most frequently transmitted. Finally, the CAI genotypes were classified into six groups.

CONCLUSIONS

This work revealed the oral and blood strains isolated from the patients with candidaemia in ICU shared the identical dominant CAI genotypes. Our data expanded the C. albicans MLST database and helped with understanding the evolution and spread of invasive candidiasis.

Caspofungin: a review of its characteristics, activity, and use in intensive care units

INTRODUCTION

Candidemia is the fourth frequent reason of healthcare-related bloodstream infections in critically ill patients. For initial management of (suspected) invasive candidiasis in critically ill patients, usage of an echinocandin, e.g. caspofungin, has been recommended.

AREAS COVERED

In this study, characteristics of caspofungin and its use in intensive care unit (ICU) patients are reviewed based on an electronic search using PubMed and Google scholar.

EXPERT OPINION

Caspofungin is a semisynthetic derivative from pneumocandin B and the first member of the echinocandins that was approved by the U.S. Food and Drug Administration (FDA) to fight fungal infection. Caspofungin inhibits the enzyme β(1,3)-D-glucan synthase of the fungal cell wall resulted in inhibition of the synthesis of β(1,3)-D-glucan. For critically ill patients, inter- and intraindividual variations affect the caspofungin concentration. The incidence rates and densities of candidemia in surgical ICUs may be higher than medical ICUs resulting in a higher burden of candidemia in surgical ICUs. However, the mortality rate in surgical ICU patients with candidemia is higher than that medical ICU patients due to differences in their underlying conditions.

Prevalence and Antifungal Susceptibility of Pathogenic Yeasts in China: A 10-Year Retrospective Study in a Teaching Hospital

To determine the dynamic changes of pathogenic yeast prevalence and antifungal susceptibility patterns in tertiary hospitals in China, we analyzed 527 yeast isolates preserved in the Research Center for Medical Mycology at Peking University, Beijing, China, between Jan 2010 and Dec 2019 and correctly identified 19 yeast species by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and ribosomal DNA sequencing. Antifungal susceptibility testing was performed following a Sensititre YeastOne colorimetric microdilution panel with nine clinically available antifungals. The Clinical and Laboratory Standards Institute (CLSI)-approved standard M27-A3 (S4) and newly revised clinical breakpoints or species-specific and method-specific epidemiological cutoff values were used for the interpretation of susceptibility test data. In this study, although Candida albicans was the predominant single species, non-C. albicans species constituted >50% of isolates in 6 out of 10 years, and more rare species were present in the recent 5 years. The non-C. albicans species identified most frequently were Candida parapsilosis sensu stricto, Candida tropicalis, and Candida glabrata. The prevalence of fluconazole and voriconazole resistance in the C. parapsilosis sensu stricto population was <3%, but C. tropicalis exhibited decreased susceptibility to fluconazole (42, 57.5%) and voriconazole (31, 42.5%), and 22 (30.1%) C. tropicalis isolates exhibited wild-type minimum inhibitory concentrations (MICs) to posaconazole. Furthermore, fluconazole and voriconazole cross-resistance prevalence in C. tropicalis was 19 (26.1%). The overall prevalence of fluconazole resistance in the C. glabrata population was 14 (26.9%), and prevalence of isolates exhibiting voriconazole non-wild-type MICs was 33 (63.5%). High-level echinocandin resistance was mainly observed in C. glabrata, and the prevalence rates of isolate resistance to anidulafungin, micafungin, and caspofungin were 5 (9.6%), 5 (9.6%), and 4 (7.7%), respectively. Moreover, one C. glabrata isolate showed multidrug resistant to azoles, echinocandins, and flucytosine. Overall, the 10-year surveillance study showed the increasing prevalence of non-C. albicans species over time; the emergence of azole resistance in C. tropicalis and multidrug resistance in C. glabrata over the years reinforced the need for epidemiological surveillance and monitoring.

Clinical Usefulness of Susceptibility Breakpoints for Yeasts in the Treatment of Candidemia: A Noninterventional Study

This prospective noninterventional study evaluated whether antifungal susceptibility data (MIC) provided for Candida clinical isolates on the basis of recently established breakpoints are taken into account by clinicians to guide their treatment decision making process, and assessed the response in MIC- and non-MIC-based treatment groups. During a six month period, the usage of systemic antifungals was recorded in detail and compared with mycological data (Candida species and MICs) in candidemia patients. Patients were assigned to a susceptible or resistant infection group based on European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints; treatment decisions were under the professional discretion of the treating physicians. 123 patients were evaluated with Candida albicans accounting for 59%, Candida glabrata for 19%, Candida parapsilosis for 15%, Candida tropicalis for 4% and Candida krusei for 3%. Antifungal treatment correlated with species and MICs in 80% (n = 99 patients), high MICs and species-dependent guideline recommendations were ignored in 20% (n = 24 patients); the overall outcome of candidemia cases in our study population was excellent, as by day 14, all patients were cleared from fungal blood stream infection (mean 5.6 days, range 2–12). The current variability in antifungal usage and the delay in initiating appropriate therapy indicate a need for antifungal stewardship to improve the management of invasive fungal infections.

Post-sepsis immunosuppression depends on NKT cell regulation of mTOR/IFN-γ in NK cells

As treatment of the early, inflammatory phase of sepsis improves, post-sepsis immunosuppression and secondary infection have increased in importance. How early inflammation drives immunosuppression remains unclear. Although IFN-γ typically helps microbial clearance, we found that increased plasma IFN-γ in early clinical sepsis was associated with the later development of secondary Candida infection. Consistent with this observation, we found that exogenous IFN-γ suppressed macrophage phagocytosis of zymosan in vivo, and antibody blockade of IFN-γ after endotoxemia improved survival of secondary candidemia. Transcriptomic analysis of innate lymphocytes during endotoxemia suggested that NKT cells drove IFN-γ production by NK cells via mTORC1. Activation of invariant NKT (iNKT) cells with glycolipid antigen drove immunosuppression. Deletion of iNKT cells in Cd1d-/- mice or inhibition of mTOR by rapamycin reduced immunosuppression and susceptibility to secondary Candida infection. Thus, although rapamycin is typically an immunosuppressive medication, in the context of sepsis, rapamycin has the opposite effect. These results implicated an NKT cell/mTOR/IFN-γ axis in immunosuppression following endotoxemia or sepsis. In summary, in vivo iNKT cells activated mTORC1 in NK cells to produce IFN-γ, which worsened macrophage phagocytosis, clearance of secondary Candida infection, and mortality.

Functional networks of co-expressed genes to explore iron homeostasis processes in the pathogenic yeast Candida glabrata

Candida glabrata is a cause of life-threatening invasive infections especially in elderly and immunocompromised patients. Part of human digestive and urogenital microbiota, C. glabrata faces varying iron availability, low during infection or high in digestive and urogenital tracts. To maintain its homeostasis, C. glabrata must get enough iron for essential cellular processes and resist toxic iron excess. The response of this pathogen to both depletion and lethal excess of iron at 30°C have been described in the literature using different strains and iron sources. However, adaptation to iron variations at 37°C, the human body temperature and to gentle overload, is poorly known. In this study, we performed transcriptomic experiments at 30°C and 37°C with low and high but sub-lethal ferrous concentrations. We identified iron responsive genes and clarified the potential effect of temperature on iron homeostasis. Our exploration of the datasets was facilitated by the inference of functional networks of co-expressed genes, which can be accessed through a web interface. Relying on stringent selection and independently of existing knowledge, we characterized a list of 214 genes as key elements of C. glabrata iron homeostasis and interesting candidates for medical applications.

Cytokine adsorption as a promising option for septic shock and multiple organ failure due to Candida infection and decompensated type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) represents one of the most common chronic diseases in childhood. It is associated with high morbidity and mortality rates due to metabolic dysregulation, immunosuppressive effects, and a predisposition to fungal infections. Candidiasis is a severe infection and its prevalence has increased throughout the last decades. We report the case of a 19-year-old female patient admitted to our intensive care unit with T1DM and Candida infection associated with severe metabolic acidosis. In the absence of response to high dose catecholamine cardiovascular therapy and the presence of severe metabolic acidosis, a CytoSorb cartridge was implemented into the extracorporeal dialysis circuit resulting in a stabilization of hemodynamics accompanied by a tremendous decrease in vasopressor requirements, control of the hyperinflammatory response, as well as a resolution of metabolic acidosis and regeneration of renal function. Treatment with CytoSorb was safe and feasible without technical problems. Notably, this is the first case description reporting on the effects of CytoSorb in a patient with Candida infection as part of T1DM.

Microbiological Laboratory Testing in the Diagnosis of Fungal Infections in Pulmonary and Critical Care Practice. An Official American Thoracic Society Clinical Practice Guideline

Background: Fungal infections are of increasing incidence and importance in immunocompromised and immunocompetent patients. Timely diagnosis relies on appropriate use of laboratory testing in susceptible patients.Methods: The relevant literature related to diagnosis of invasive pulmonary aspergillosis, invasive candidiasis, and the common endemic mycoses was systematically reviewed. Meta-analysis was performed when appropriate. Recommendations were developed using the Grading of Recommendations Assessment, Development, and Evaluation approach.Results: This guideline includes specific recommendations on the use of galactomannan testing in serum and BAL and for the diagnosis of invasive pulmonary aspergillosis, the role of PCR in the diagnosis of invasive pulmonary aspergillosis, the role of β-d-glucan assays in the diagnosis of invasive candidiasis, and the application of serology and antigen testing in the diagnosis of the endemic mycoses.Conclusions: Rapid, accurate diagnosis of fungal infections relies on appropriate application of laboratory testing, including antigen testing, serological testing, and PCR-based assays.

A high-throughput and rapid method for accurate identification of emerging multidrug-resistant Candida auris

Candida auris is an emerging multidrug-resistant yeast associated with invasive infection in healthcare settings. Recently, C auris cases in the United States have been detected in 11 states with the majority of cases in New York, New Jersey and Illinois. Rapid and accurate identification of C auris is critical for patient care and the implementation of public health measures to control the spread of infection. Our aim was to develop and validate a rapid DNA extraction method using the Roche MagNA Pure 96 instrument and a TaqMan real-time PCR assay for reliable, high-throughput identification of C auris. We evaluated 247 patient dermal swab samples previously analysed by culture/MALDI-TOF. The diagnostic sensitivity and specificity were 93.6% and 97.2%, respectively. The assay was highly reproducible with a detection limit of 1 C auris CFU/10 μL. A receiver operating characteristic curve analysis of the real-time PCR data showed an area of 0.982 under the curve, with a CT cut-off value of ≤37.0. The turnaround time from DNA extraction to real-time PCR results was approximately 200 samples/day. In conclusion, we successfully validated a rapid and high-throughput method for accurate and reproducible identification of C auris with a significantly reduced turnaround time compared to culture/MALDI-TOF based methods.

Cluster analysis to define distinct clinical phenotypes among septic patients with bloodstream infections

Prior attempts at identifying outcome determinants associated with bloodstream infection have employed a priori determined classification schemes based on readily identifiable microbiology, infection site, and patient characteristics. We hypothesized that even amongst this heterogeneous population, clinically relevant groupings can be described that transcend old a priori classifications.We applied cluster analysis to variables from three domains: patient characteristics, acuity of illness/clinical presentation and infection characteristics. We validated our clusters based on both content validity and predictive validity.Among 3715 patients with bloodstream infections from Barnes-Jewish Hospital (2008-2015), the most stable cluster arrangement occurred with the formation of 4 clusters. This clustering arrangement resulted in an approximately uniform distribution of the population: Cluster One "Surgical Outside Hospital Transfers" (21.5%), Cluster Two "Functional Immunocompromised Patients" (27.9%), Cluster Three "Women with Skin and Urinary Tract Infection" (28.7%) and Cluster Four "Acutely Sick Pneumonia" (21.8%). Staphylococcus aureus distributed primarily to Clusters Three (40%) and Four (25%), while nonfermenting Gram-negative bacteria grouped mainly in Clusters Two and Four (31% and 30%). More than half of the pneumonia cases occurred in Cluster Four. Clusters One and Two contained 33% and 31% respectively of the individuals receiving inappropriate antibiotic administration. Mortality was greatest for Cluster Four (33.8%, 27.4%, 19.2%, 44.6%; P < .001), while Cluster One patients were most likely to be discharged to a nursing home.Our results support the potential for machine learning methods to identify homogenous groupings in infectious diseases that transcend old a priori classifications. These methods may allow new clinical phenotypes to be identified potentially improving the severity staging and development of new treatments for complex infectious diseases.

Can intravenous antifungal therapy be safely used in the outpatient parenteral antimicrobial therapy (OPAT) setting?

Outpatient parenteral antimicrobial therapy (OPAT) is an established treatment option for patients with a variety of infections who require a period of intravenous therapy, are clinically stable, and do not require continuous monitoring. Many patients with fungal infections require prolonged therapy due to resistance or intolerance to oral antifungal agents. Despite the widespread use of OPAT by infection specialists, antifungal agents appear infrequently used in this setting. We suggest that with appropriate patient selection, patients with fungal infections could successfully be treated on OPAT.

Clinical characteristics and predictors of mortality in patients with candidemia: a six-year retrospective study

Although candidemia has been reported globally, little is known about the differences in candidemia episodes between ICU and surgical wards or the correlation between serum biomarkers and mortality from candidemia. A retrospective study of hospitalized patients with candidemia was conducted in southwest China. A total of 198 non-duplicate candidemia episodes were identified between January 2011 and December 2016. Candida albicans was the leading species causing candidemia (34.9%), and 78.8% of these isolates were susceptible to fluconazole. More than half of candidemic patients were hospitalized in surgical wards, but the incidence of these surgical patients was much lower than that of ICU patients. Compared with surgical patients, patients admitted to ICU were more frequently subjected to extensive invasive procedures, severe clinical presentations, and heavy exposure to antibiotics. In addition, the mortality in ICU was significantly higher than that in surgical wards. Multivariable analysis revealed that ascites, catheter-related candidemia, ICU admission, septic shock, and concomitant bacterial infection were independent factors associated with mortality. Moreover, we observed that high PCT and BDG levels as well as low PLT counts were also associated with mortality from candidemia. Better understanding of the specific predictors in different wards could facilitate the identification of high-risk candidates to receive early antifungal therapy, thus improving the outcomes of critically ill patients with candidemia.

Synthesis, activity, and docking studies of eugenol-based glucosides as new agents against Candida sp

Seventeen new synthetic derivatives of eugenol (6, 8-15 and 8'-15') were planned following literature reports on antifungal activities of nitroeugenol and eugenol glucoside. The anti-Candida activity of these compounds was investigated by in vitro assay, and the cytotoxicity evaluation was performed with the most active compounds. The peracetylated glucosides presented better biological results than their hydroxylated analogues. The glucoside 11, a 4-nitrobenzamide, showed the best potency (MIC₅₀ range 11.0-151.84 μm), the wider spectrum of action, and overall the best selectivity indexes, especially against C. tropicalis (~30) and C. krusei (~15). To investigate its possible mechanism of action, glucoside 11 was subjected to molecular docking studies with Candida sp. enzymes involved in ergosterol biosynthesis. Results have shown that the peracetyl glucosyl moiety and the 4-nitrobenzamide group in 11 are effectively involved in its high affinity with the active site of squalene epoxidase.

Multilocus Sequence Typing Reveals a New Cluster of Closely Related Candida tropicalis Genotypes in Italian Patients With Neurological Disorders

Candida tropicalis is a pathogenic yeast that has emerged as an important cause of candidemia especially in elderly patients with hematological malignancies. Infections caused by this species are mainly reported from Latin America and Asian-Pacific countries although recent epidemiological data revealed that C. tropicalis accounts for 6-16.4% of the Candida bloodstream infections (BSIs) in Italy by representing a relevant issue especially for patients receiving long-term hospital care. The aim of this study was to describe the genetic diversity of C. tropicalis isolates contaminating the hands of healthcare workers (HCWs) and hospital environments and/or associated with BSIs occurring in patients with different neurological disorders and without hematological disease. A total of 28 C. tropicalis isolates were genotyped using multilocus sequence typing analysis of six housekeeping (ICL1, MDR1, SAPT2, SAPT4, XYR1, and ZWF1) genes and data revealed the presence of only eight diploid sequence types (DSTs) of which 6 (75%) were completely new. Four eBURST clonal complexes (CC2, CC10, CC11, and CC33) contained all DSTs found in this study and the CC33 resulted in an exclusive, well-defined, clonal cluster from Italy. In conclusion, C. tropicalis could represent an important cause of BSIs in long-term hospitalized patients with no underlying hematological disease. The findings of this study also suggest a potential horizontal transmission of a specific C. tropicalis clone through hands of HCWs and expand our understanding of the molecular epidemiology of this pathogen whose population structure is still far from being fully elucidated as its complexity increases as different categories of patients and geographic areas are examined.

MicroRNA Regulation of Host Immune Responses following Fungal Exposure

Fungal bioaerosols are ubiquitous in the environment and human exposure can result in a variety of health effects ranging from systemic, subcutaneous, and cutaneous infections to respiratory morbidity including allergy, asthma, and hypersensitivity pneumonitis. Recent research has focused on the role of microRNAs (miRNAs) following fungal exposure and is overlooked, yet important, group of regulators capable of influencing fungal immune responses through a variety of cellular mechanisms. These small non-coding ribose nucleic acids function to regulate gene expression at the post-transcriptional level and have been shown to participate in multiple disease pathways including cancer, heart disease, apoptosis, as well as immune responses to microbial hazards and occupational allergens. Recent animal model studies have characterized miRNAs following the exposure to inflammatory stimuli. Studies focused on microbial exposure, including bacterial infections, as well as exposure to different allergens have shown miRNAs, such as miR-21, miR-146, miR-132, miR-155, and the let-7 family members, to be involved in immune and inflammatory responses. Interestingly, the few studies have assessed that the miRNA profiles following fungal exposure have identified the same critical miRNAs that have been characterized in other inflammatory-mediated and allergy-induced experimental models. Review of available in vitro, animal and human studies of exposures to Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, Paracoccidioides brasiliensis, and Stachybotrys chartarum identified several miRNAs that were shared between responses to these species including miR-125 a/b (macrophage polarization/activation), miR-132 [toll-like receptor (TLR)2-mediated signaling], miR-146a (TLR mediated signaling, alternative macrophage activation), and miR-29a/b (natural killer cell function, C-leptin signaling, inhibition of Th1 immune response). Although these datasets provide preliminary insight into the role of miRNAs in fungal exposed models, interpretation of miRNA datasets can be challenging for researchers. To assist in navigating this rapidly evolving field, the aim of this review is to describe miRNAs in the framework of host recognition mechanisms and provide initial insight into the regulatory pathways in response to fungal exposure.