The Epidemiology and Susceptibility of Candidemia in Jerusalem, Israel

Candida glabrata (Nakaseomyces glabrata): A systematic review of clinical and microbiological data from 2011 to 2021 to inform the World Health Organization Fungal Priority Pathogens List

Recognising the growing global burden of fungal infections, the World Health Organization (WHO) established an advisory group consisting of experts in fungal diseases to develop a Fungal Priority Pathogen List. Pathogens were ranked based on their research and development needs and perceived public health importance using a series of global surveys and pathogen characteristics derived from systematic reviews. This systematic review evaluates the features and global impact of invasive disease caused by Candida glabrata (Nakaseomyces glabrata). PubMed and Web of Science were searched for studies reporting on mortality, morbidity (hospitalization and disability), drug resistance (including isolates from sterile and non-sterile sites, since these reflect the same organisms causing invasive infections), preventability, yearly incidence, diagnostics, treatability, and distribution/emergence in the last 10 years. Candida glabrata (N. glabrata) causes difficult-to-treat invasive infections, particularly in patients with underlying conditions such as immunodeficiency, diabetes, or those who have received broad-spectrum antibiotics or chemotherapy. Beyond standard infection prevention and control measures, no specific preventative measures have been described. We found that infection is associated with high mortality rates and that there is a lack of data on complications and sequelae. Resistance to azoles is common and well described in echinocandins-in both cases, the resistance rates are increasing. Candida glabrata remains mostly susceptible to amphotericin and flucytosine. However, the incidence of the disease is increasing, both at the population level and as a proportion of all invasive yeast infections, and the increases appear related to the use of antifungal agents.

Pichia kudriavzevii (Candida krusei): A systematic review to inform the World Health Organisation priority list of fungal pathogens

In response to the growing global threat of fungal infections, in 2020 the World Health Organisation (WHO) established an Expert Group to identify priority fungi and develop the first WHO fungal priority pathogen list (FPPL). The aim of this systematic review was to evaluate the features and global impact of invasive infections caused by Pichia kudriavzevii (formerly known as Candida krusei). PubMed and Web of Science were used to identify studies published between 1 January 2011 and 18 February 2021 reporting on the criteria of mortality, morbidity (defined as hospitalisation and length of stay), drug resistance, preventability, yearly incidence, and distribution/emergence. Overall, 33 studies were evaluated. Mortality rates of up to 67% in adults were reported. Despite the intrinsic resistance of P. kudriavzevii to fluconazole with decreased susceptibility to amphotericin B, resistance (or non-wild-type rate) to other azoles and echinocandins was low, ranging between 0 and 5%. Risk factors for developing P. kudriavzevii infections included low birth weight, prior use of antibiotics/antifungals, and an underlying diagnosis of gastrointestinal disease or cancer. The incidence of infections caused by P. kudriavzevii is generally low (∼5% of all Candida-like blood isolates) and stable over the 10-year timeframe, although additional surveillance data are needed. Strategies targeting the identified risk factors for developing P. kudriavzevii infections should be developed and tested for effectiveness and feasibility of implementation. Studies presenting data on epidemiology and susceptibility of P. kudriavzevii were scarce, especially in low- and middle-income countries (LMICs). Thus, global surveillance systems are required to monitor the incidence, susceptibility, and morbidity of P. kudriavzevii invasive infections to inform diagnosis and treatment. Timely species-level identification and susceptibility testing should be conducted to reduce the high mortality and limit the spread of P. kudriavzevii in healthcare facilities.

Antifungal susceptibility and virulence determinants profile of candida species isolated from patients with candidemia

Candida is the most prevalent fungal bloodstream infection (BSI) with a high mortality rate among hospitalized patients. Another concern facing physicians is rising global incidence of drug-resistant Candida. This study aimed to characterize the prevalence, antifungal susceptibility, biofilm formation, and virulence genes (HWP1, ALS1, SAP2) of different Candida spp. isolated from patients with candidemia. 52 isolates of Candida spp. were identified from blood cultures by chromogenic Candida agar and confirmed by the VITEK 2 system. Isolates were tested for antifungal susceptibility by disk diffusion and VITEK 2 system. Biofilm formation and investigated genes were detected by the Congo red method and conventional PCR, respectively. Candida spp. caused 2.3% of detected BSIs, of which 32.7% were caused by Candida albicans (C. albicans) and 67.3% by non-albicans Candida (NAC), with the predominance of C. tropicalis (25%), followed by C. parapsilosis (17.3%), and C. krusei (13.5%). The susceptibility rates to fluconazole, voriconazole, caspofungin, micafungin, amphotericin B, and flucytosine were 64.7%, 76.5%, 100.0%, 100%, 100.0%, and 100.0% in C. albicans, while 53.6%, 71.4%, 91.4%, 91.4%, 94.3%, and 94.3% in NAC, respectively. Biofilm production, HWP1, ALS1, and SAP2 were detected in 70.6%, 82.4%, 76.5%, and 52.9% of C. albicans and 74.3%, 85.7%, 80.0%, and 48.6% of NAC, respectively. There is remarkable shift to NAC BSIs and high azole resistance. Antifungal stewardship and analysis of risk factors associated with this shift are needed.

Treatment of vaginitis caused by non-albicans Candida species

INTRODUCTION

In the face of increased frequency of non-albicans Candida vulvovaginitis (VVC) reported worldwide, there is a paucity of effective oral and topical antifungal drugs available. Drug selection is further handicapped by an absence of data of clinical efficacy of available antifungal drugs for these infections.

AREAS COVERED

In this review, attention is directed at the cause of drug shortage as well as increased frequency of non-albicans Candida (NAC) vulvovaginitis. There is widespread recognition of reduced in vitro azole drug susceptibility in NAC species. Moreover, antifungal susceptibility tests have not been standardized or validated for NAC isolates, hence clinicians rely on an element of empiricism especially given the absence of randomized controlled comparative studies targeting NAC species. Clinical spectrum of NAC species isolates is highly variable with ongoing difficulty in determining a causal role in symptomatic patients.

EXPERT OPINION

We have entered the era of demand for Candida species-specific therapy and although consensus treatment guidelines are emerging, new antifungal agents that target these multiple-azole resistant or relatively resistant vaginal NAC species are urgently needed.

Unresolved issues in the diagnosis of catheter related candidemia: A position paper

The incidence and recent trends of candidemia and the contribution of the COVID-19 pandemic to its evolution are not well documented. The catheter is a major focus of Candida spp. infections, but the methods used to confirm the origin of candidemia are still based on the data generated for bacterial infection. The presence of Candida spp. on the tip of a removed catheter is the gold standard for confirmation but it is not always possible to remove it. Conservative methods, without catheter removal, have not been specifically studied for microorganisms whose times of growth are different from those of bacteria and therefore these results are not applicable to candidemia. The different Candida species do not have a particular tropism for catheter colonization and fungal biomarkers have not yet been able to contribute to the determination of the origin of candidemia. Techniques such Candida T2 Magnetic Resonance (T2MR) has not yet been applied for this purpose. Finally, there is not yet a consensus of how to proceed when Candida spp. is isolated from an extracted catheter and blood cultures obtained from simultaneous peripheral veins are negative. In this lack of firm data, a group of experts has formulated a series of questions trying to answer them based on the literature, indicating the current deficiencies and offering their own opinion. All authors agree with the conclusions of the manuscript and offer it as a position and discussion paper.

Population genomic analyses reveal high diversity, recombination and nosocomial transmission among Candida glabrata (Nakaseomyces glabrata) isolates causing invasive infections

Candida glabrata is a commensal yeast of the gastrointestinal tract and skin of humans. However, it causes opportunistic infections in immunocompromised patients, and is the second most common Candida pathogen causing bloodstream infections. Although there are many studies on the epidemiology of C. glabrata infections, the fine- and large-scale geographical nature of C. glabrata remain incompletely understood. Here we investigated both the fine- and large-scale population structure of C. glabrata through genome sequencing of 80 clinical isolates obtained from six tertiary hospitals in Qatar and by comparing with global collections. Our fine-scale analyses revealed high genetic diversity within the Qatari population of C. glabrata and identified signatures of recombination, inbreeding and clonal expansion within and between hospitals, including evidence for nosocomial transmission among coronavirus disease 2019 (COVID-19) patients. In addition to signatures of recombination at the population level, both MATa and MATα alleles were detected in most hospitals, indicating the potential for sexual reproduction in clinical environments. Comparisons with global samples showed that the Qatari C. glabrata population was very similar to those from other parts of the world, consistent with the significant role of recent anthropogenic activities in shaping its population structure. Genome-wide association studies identified both known and novel genomic variants associated with reduced susceptibilities to fluconazole, 5-flucytosine and echinocandins. Together, our genomic analyses revealed the diversity, transmission patterns and antifungal drug resistance mechanisms of C. glabrata in Qatar as well as the relationships between Qatari isolates and those from other parts of the world.

A 14-Year Cohort of Candidemia in the Pediatric Population in a Tertiary Center in Jerusalem: Clinical Characteristics, Antifungal Susceptibility, and Risk Factors for Mortality

Candida spp. can cause bloodstream infection and is associated with significant mortality. The proportion of fluconazole-resistant Candida non-albicans has increased over the years, and empirical fluconazole maybe inappropriate. In this retrospective study, we analyzed clinical characteristics, antifungal resistance patterns, and mortality in children with candidemia treated at a tertiary medical center in Jerusalem between 2009 and 2022. A total of 122 children developed 127 candidemia episodes with 132 Candida isolates. Half the episodes occurred in immunocompromised children. Septic shock was present in 27 (21.3%). Candida non-albicans was responsible for 71/132 (56.5%) episodes; 16/132 (12.1%) of isolates were fluconazole-resistant. The rate of Candida non-albicans was significantly higher in fluconazole-resistant episodes (90 vs. 50.5%, p = 0.02). Prolonged severe neutropenia and previous fluconazole exposure were more frequent in fluconazole-resistant episodes. Thirty-day mortality was 25 (19.7%). Greater mortality, as shown by multivariate analysis, was associated with candidemia contracted in the pediatric intensive care unit (PICU), previous use of azoles or carbapenems, and in the presence of shock. In conclusion, mortality rates in our study were higher than those previously reported. In suspected infection associated with factors which we found to increase the probability of mortality-PICU admission, shock, and earlier azole or carbapenems exposure-empirical antifungals should be considered.

Epidemiology, Clinical Characteristics and Risk Factors for Severity of Chronic Disseminated Candidiasis in Jerusalem, Israel

Chronic disseminated candidiasis (CDC) occurs mostly in patients with acute hematologic malignancy and its clinical manifestations derive from immune reconstitution following neutrophil recovery. The aim of this study was to describe epidemiological and clinical characteristics of CDC and define risk factors for disease severity. Demographic and clinical data were collected from medical files of patients with CDC hospitalized in two tertiary medical centers in Jerusalem between 2005 and 2020. Associations between different variables and disease severity were evaluated, as well as characterization of Candida species. The study included 35 patients. CDC incidence slightly increased during study years and the average number of involved organs and disease duration was 3 ± 1.26 and 178 ± 123 days, respectively. Candida grew in blood in less than third of cases and the most common isolated pathogen was Candida tropicalis (50%). Histopathological or microbiological workup in patients who underwent an organ biopsy demonstrated Candida in about half of the patients. Nine months after starting antifungals, 43% of the patients still didn't have resolution of organ lesions in imaging modalities. Factors associated with protracted and extensive disease were prolonged fever prior to CDC and absence of candidemia. A C- Reactive Protein (CRP) cutoff level of 7.18 mg/dL was found to predict extensive disease. In conclusion, CDC incidence is increasing and the number of involved organs is higher than previously described. Clinical factors such as fever duration prior to CDC and absence of candidemia can predict severe course of disease and assist in treatment decisions and follow-up planning.

Study of Candidemia and its Antifungal Susceptibility Profile at the University Hospital of Montevideo, Uruguay

Systemic candidiasis are high mortality infections caused by yeasts of the genus Candida, affecting patients with numerous risk factors. Nowadays, candidemia produced by "non-albicans" species has increased considerably. Timely diagnosis and subsequent treatment substantially improve patients' survival. Our objectives are to study the frequency, distribution, and antifungal susceptibility profiles of candidemia isolates in our hospital. We conducted a descriptive, cross-sectional study. Positive blood cultures were recorded from January 2018 to December 2021. Positive Candida genus blood cultures were selected, classified, and analyzed on their susceptibility profile for amphotericin B, fluconazole and caspofungin using AST-YS08® card for VITEK 2 Compact® to determine minimum inhibitory concentration (MIC) and CLSI M60 2020 2nd Edition to determine breakpoints. 3862 positive blood cultures were obtained, 113 (2.93%) presented growth of Candida spp., corresponding to 58 patients. 55.2% came from the Hospitalization Ward and Emergency Services and 44.8% from the Intensive Care Unit. The species were distributed as follows: Nakaseomyces glabratus (Candida glabrata) (32.74%), Candida albicans (27.43%), Candida parapsilosis (23.01%), Candida tropicalis (7.08%) and others (9.73%). Most species were found to be susceptible to most antifungals, except for C. parapsilosis, presenting 4 isolates with resistance to fluconazole and N. glabratus (C. glabrata), whose clinical susceptibility data remains insufficient to provide accurate breakpoints. The percentage of recorded positive blood cultures of Candida spp. was 2.93%, these results were consistent with those reported at a regional level. A predominance of "non-albicans" species was observed. It is essential to know the prevalence, epidemiology, and susceptibility profiles of candidemia in our country, as well as being updated on its subsequent changes, maintaining epidemiological surveillance. This allows professionals to map out early and effective therapeutic strategies, staying alert of possible multi-resistant strains.

The role of fruits as reservoirs for resistant and virulent strains of opportunistic yeasts

Strains of the Candida parapsilosis and Meyerozyma guilliermondii species complexes isolated from the internal tissues of 26 fruit species from 21 countries were evaluated for their susceptibility to conventional antifungal compounds (fluconazole, voriconazole, amphotericin B) and hydrolytic activity. A total of 144 strains were studied. Resistance to at least one of the antifungal compounds tested was found in 26.4% of the endophytic strains examined. Most of the strains were insensitive to fluconazole. Multiresistance was detected only in two strains of C. parapsilosis sensu stricto from tropical apples. Phospholipase production and proteolytic and hemolytic activities were significantly higher in endophytes from tropical fruits. Resistant and virulent strains of opportunistic yeasts can thus spread worldwide via purchased fruit, which can harm people with a weakened immune status and children whose immune systems are not yet fully developed.

Incidence of Invasive Infections Among Hemato-Oncology Patients with Significant Burden of Candida in Stool

Candidemia is a serious infection associated with increased mortality. It is unclear whether a high concentration of Candida in stool in patients with hematologic malignancies is associated with a higher risk for developing candidemia. In this observational historical study in patients hospitalized in hemato-oncology departments, we describe the association between gastrointestinal Candida colonization and the risk for candidemia and other severe outcomes. Data from 166 patients with heavy burden of Candida in stool were collected and compared to a control group of 309 patients with minimal or no Candida in stool, from 2005 to 2020. Severe immunosuppression and recent use of antibiotics were more common in heavily colonized patients. Outcomes of heavily colonized patients were worse as compared to the control group with statistical significance in 1-year mortality (53% vs. 37.5%, p = 0.001) and borderline statistical significance in candidemia rate (12.6% vs. 7.1%, p = 0.07). Risk factors for 1-year mortality were significant colonization of Candida in stool, older age and recent use of antibiotics. In conclusion, significant stool burden of Candida among hospitalized hemato-oncology patients may pose a risk for 1-year mortality and increased candidemia rate.

Epidemiology, antifungal susceptibility, risk factors, and mortality of persistent candidemia in adult patients in China: a 6-year multicenter retrospective study

BACKGROUND

Data on persistent candidemia (PC), a recognized complication of candidemia, are lacking in China. This study aimed to investigate the clinical characteristics and risk factors for the mortality of PC among adults in China.

METHODS

This 6-year retrospective study analyzed the prevalence, species distribution, antifungal susceptibility, risk factors, and patient mortality of PC among adults in three regional tertiary teaching hospitals in China from 2016 to 2021. We collected electronic laboratory records data of PC and non-PC patients and used the Student test or Mann-Whitney U test for a retrospective study. Logistic regression was used to identify risk factors associated with persistent candidemia.

RESULTS

The definition of PC was fulfilled by 36 patients (13.7%, 36/263). The mean age of the patients was 59.9 years (60 years for patients with PC; 59.8 years for those with non-PC; P > 0.05) and 131 (60.1%) were men [16 with PC (44.4%), 115 with non-PC (63.2%), P < 0.05]. The mean annual incidence was 0.15/1000 admissions (including PC 0.03/1000 admissions vs. non-PC 0.12/1000 admissions, P < 0.05). Candida parapsilosis (14/36, 38.9%) and Candida albicans (81/182, 44.5%) were the predominant pathogens in patients with PC and non-PC, respectively. Most isolates were susceptible to flucytosine (99.0%) and amphotericin B (99.5%), and the activity of antifungal agents against Candida species was not statistically significantly different between patients with PC and non-PC (P > 0.05). The 30-day mortality rate was 20.2% (16.7% with PC vs. 20.9% with non-PC, P > 0.05). Multivariable regression analysis showed that use of broad-spectrum antibiotics (odds ratio (OR), 5.925; 95% confidence interval (CI), 1.886-18.616, P = 0.002), fluconazole (OR, 3.389; 95% CI, 1.302-8.820, P = 0.012) and C. parapsilosis infection (OR, 6.143; 95% CI, 2.093-18.031, P = 0.001) were independent predictors of PC, sex (male) (OR, 0.199; 95% CI, 0.077-0.518, P = 0.001) was the protective factor for PC. Respiratory dysfunction (OR, 5.763; 95% CI, 1.592-20.864, P = 0.008) and length of hospital stay(OR, 0.925; 95% CI, 0.880-0.973, P = 0.002) were independent predictors of 30-day mortality in patients with non-PC. C. tropicalis bloodstream infection (OR, 12.642; 95% CI, 1.059-150.951; P = 0.045) was an independent predictor of 30-day mortality in patients with PC.

CONCLUSIONS

The epidemiological data of patients with PC and non-PC were different in the distribution of Candida species, the mean annual incidence and independent predictors of 30-day mortality. Flucytosine and amphotericin B could be used as first-choice drugs in the presence of PC infections.

Risk Factors and Characteristics of Candidemia After Cardiac Surgery in Pediatric Patients in Central Israel

BACKGROUND

Candidemia is a serious complication in pediatric patients with congenital heart defects (CHD) after cardiac surgery. Information about the epidemiology, clinical characteristics and risk factors for candidemia in this vulnerable population remains limited.

METHODS

This retrospective case-control study was conducted in 2 pediatric intensive care units between 2004 and 2019. All patients <18 years old who developed candidemia following cardiac surgery were included. Each case was matched with 2 control patients based on age and date of surgery. Multivariable logistic regression analysis was conducted to determine the risk factors for postoperative candidemia.

RESULTS

Thirty-five candidemia cases were identified and matched to 70 control cases. The incidence of candidemia was 6.3 episodes per 1000 admissions. The median age for candidemia cases was 4 months. The attributable mortality was 28.5%. The predominant (54%) pathogens isolated were non- albicans Candida species, of which C. parapsilosis isolates demonstrated high resistance to fluconazole (70%). Independent risk factors associated with candidemia included cumulative antibiotic exposure for ≥4 days [OR: -4.3; 95% confidence interval (CI): 1.3-14.6; P = 0.02], the need for total parenteral nutrition or peritoneal dialysis (OR: -6.1; 95% CI: 2-18.8; P = 0.001), male sex (OR: 6.2; 95% CI: 1.9-20.3; P = 0.002) and delayed sternal closure≥2 days (OR: -3.2; 95% CI: 1-11.2; P = 0.05).

CONCLUSIONS

Postoperative candidemia in children with CHD is an uncommon but severe complication. Our study revealed an unexpectedly high frequency of fluconazole-resistant C. parapsilosis as the main cause of non- albicans candidemia. In addition to confirming previously recognized risk factors, our results reveal new potential risk factors such as delayed sternal closure and male sex.

Epidemiologic features, clinical characteristics, and predictors of mortality in patients with candidemia in Alameda County, California; a 2017–2020 retrospective analysis

Background

Bloodstream infections caused by Candida species are responsible for significant morbidity and mortality worldwide, with an ever-changing epidemiology. We conducted this study to assess trends in the epidemiologic features, risk factors and Candida species distribution in candidemia patients in Alameda County, California.

Methods

We analyzed data collected from patients in Alameda County, California between 2017 and 2020 as part of the California Emerging Infections Program (CEIP). This is a laboratory-based, active surveillance program for candidemia. In our study, we included incident cases only.

Results

During the 4-year period from January 1st, 2017, to December 31st, 2020, 392 incident cases of candidemia were identified. The mean crude annual cumulative incidence was 5.9 cases per 100,000 inhabitants (range 5.0–6.5 cases per 100,000 population). Candida glabrata was the most common Candida species and was present as the only Candida species in 149 cases (38.0%), followed by Candida albicans, 130 (33.2%). Mixed Candida species were present in 13 patients (3.3%). Most of the cases of candidemia occurred in individuals with one or more underlying conditions. Multivariate regression models showed that age ≥ 65 years (RR 1.66, CI 1.28–2.14), prior administration of systemic antibiotic therapy, (RR 1.84, CI 1.06–3.17), cirrhosis of the liver, (RR 2.01, CI 1.51–2.68), and prior admission to the ICU (RR1.82, CI 1.36–2.43) were significant predictors of mortality.

Conclusions

Non-albicans Candida species currently account for the majority of candidemia cases in Alameda County.

Systematic Characterization of Epidemiology, Antifungal Susceptibility, Risk Factors and Outcomes of Candidaemia: A Six-Year Chinese Study

Background

Candida bloodstream infection (BSI), the fourth most common nosocomial BSI, is an urgent global health challenge with the tremendous growth in antifungal resistance rate and mortality rate.

Purpose

To establish the epidemiology, species distribution, risk factors, and 30-day mortality of candidaemia among 115 patients in this 6-year surveillance study.

Materials and Methods

We retrospectively analyzed the clinical characteristics, epidemiology, antifungal susceptibility patterns, and risk factors for morbidity and mortality of 115 candidaemia cases diagnosed in one tertiary care hospital from January 2016 through December 2021.

Results

Of the 115 candidaemia cases, the most prevalent species were Candida tropicalis (33.0%), followed by Candida albicans (27.8%), Candida parapsilosis complex (19.1%), and others. The overall incidence was 0.21 cases/1000 admissions. The overall crude resistance rate of Candida spp. against azoles was 20.0% (23/115), while Candida tropicalis showed a significant increase in the resistance rate to azoles (from 1/6, 16.7% in 2017 to 6/10, 60.0% in 2021). Multivariate analyses demonstrated that hematological malignancy and neutropenia were significantly associated with Candida tropicalis BSI than Candida non-tropicalis BSI. Candida albicans BSI had a significantly higher rate of previous surgery than Candida non-albicans BSI. Candida parapsilosis BSI had a significantly higher rate of receiving total parenteral nutrition (TPN). The overall 30-day mortality rate was 27.0% (31/115). The presence of high age-adjusted Charlson comorbidity index (aCCI), neutropenia, and septic shock were factors independently associated with increased 30-day mortality.

Conclusion

Candida tropicalis are emerging as the predominant isolate in candidaemia. Of note, the unexpectedly increased resistance rate to azoles in Candida tropicalis BSI was observed. The aCCI scores, neutropenia, and septic shock were independently associated with 30-day mortality. Prompt, adequate antifungal treatment among high-risk patients may lead to a reduction in mortality.

Prevalence and species distribution of Candida bloodstream infection in children and adults in two teaching university hospitals in Egypt: first report of Candida kefyr

BACKGROUND

Candidemia is a pervasive problem associated with significant morbidity and mortality in health care settings. This study aimed to determine the changing distribution of Candida species and the emergence of uncommon species.

METHODS

This was a cross-sectional study performed in two Cairo University hospitals between 2019 and 2020. All Candida species isolates recovered from blood cultures of adults and pediatrics patients admitted to the hospitals were included. Candida isolates were identified by chromogenic Candida agar and Vitek2 YST identification card. Candida kefyr was confirmed by chip array.

RESULTS

Candida species were responsible for 1.6% of bloodstream infections in adults and 10.8% in pediatric patients. C. albicans was the most prevalent species representing 27.8% in adults and 48.3% in pediatrics. Non-albicans species (NAC) represented the most isolated Candida species among adults and pediatrics (72.2% and 51.6%, respectively) with the predominance of C. tropicalis (27.8% and 22.5%, respectively) followed by C. parapsilosis (16.7% and 10.8%, respectively). The uncommon Candida, which is Candida species other than C. albicans, C. parapsilosis, C. tropicalis, C. glabrata, and C. krusei, represents 16.6% and 14% of all candidemia in adults and pediatrics, respectively. Only one of each of C. lusitaniae, C. utilis, and C. kefyr were detected in adults. C. lusitaniae was the most frequently recovered uncommon Candida among pediatrics resulting in 6.4% of candidemia followed by C. famata (4.3%), C. utilis (2.2%), and C. kefyr (1.1%).

CONCLUSIONS

C. albicans is still the primary species isolated from pediatrics and adults with candidemia despite the considerable shift to the non-albicans species. C. tropicalis and C. parapsilosis are the most prevalent NAC. The increased prevalence of uncommon Candida species is alarming and necessitates a prompt stewardship program.

Prevalence and Antifungal Susceptibility of Clinically Relevant Candida Species, Identification of Candida auris and Kodamaea ohmeri in Bangladesh

Candida species are major fungal pathogens in humans. The aim of this study was to determine the prevalence of individual Candida species and their susceptibility to antifungal drugs among clinical isolates in a tertiary care hospital in Bangladesh. During a 10-month period in 2021, high vaginal swabs (HVSs), blood, and aural swabs were collected from 360 patients. From these specimens, Candida spp. was isolated from cultures on Sabouraud dextrose agar media, and phenotypic and genetic analyses were performed. A total of 109 isolates were recovered, and C. albicans accounted for 37%, being derived mostly from HVSs. Among non-albicans Candida (NAC), C. parapsilosis was the most frequent, followed by C. ciferrii, C. tropicalis, and C. glabrata. Three isolates from blood and two isolates from aural discharge were genetically identified as C. auris and Kodamaea ohmeri, respectively. NAC isolates were more resistant to fluconazole (overall rate, 29%) than C. albicans (10%). Candida isolates from blood showed 95% susceptibility to voriconazole and less susceptibility to fluconazole (67%). Two or three amino acid substitutions were detected in the ERG11 of two fluconazole-resistant C. albicans isolates. The present study is the first to reveal the prevalence of Candida species and their antifungal susceptibility in Bangladesh.

Effects of β-lapachone and β-nor-lapachone on multidrug efflux transporters and biofilms of Candida glabrata

Infections caused particularly by Candida glabrata are hard to treat due to the development of antifungal resistance that occurs mainly through the production of efflux pumps and biofilm. Thus, a promising strategy to overcome infections caused by C. glabrata could be to use a substance able to inhibit efflux pumps and eradicate biofilms. Lapachones are natural naphthoquinones that possess a variety of pharmacological properties. Previous studies show that these substances inhibit the growth, virulence factors and efflux pumps of C. albicans. The aim of the present study was to evaluate whether lapachones are able to inhibit efflux pumps related to antifungal resistance in C. glabrata and either prevent biofilm formation or affect mature biofilms. Assays were performed with Saccharomyces cerevisiae strains that overexpress C. glabrata transporters (CgCdr1p and CgCdr2p). One C. glabrata clinical isolate that overexpresses CgCdr1p was also used. Both β-lapachone and β-nor-lapachone affected the growth of S. cerevisiae and C. glabrata when combined to fluconazole, and this action was inhibited by ascorbic acid. Both lapachones stimulated ROS production, inhibited efflux activity, adhesion, biofilm formation and the metabolism of mature biofilms of C. glabrata. Data obtained on the present study point to the potential use of β-lapachone and β-nor-lapachone as antibiofilm agents and adjuvants on the antifungal therapy related to resistant infections caused by C. glabrata.

Invasive fungal infections in critically ill COVID-19 patients in a large tertiary university hospital in Israel

An increasing number of studies have tried to determine the incidence of invasive fungal infections (IFIs) in COVID-19 patients. Challenges in the diagnosis of pulmonary aspergillosis in these patients have led to new definitions of COVID-19-associated pulmonary aspergillosis (CAPA). The aim of this study was to determine the incidence and outcomes of and risk factors for IFIs in critically-ill COVID-19 patients, using the new definitions, in a tertiary center in Israel.

Methods

A case-controlled study (from 1 September 2020 to 31 March 2021) in which data from COVID-19 critically-ill patients with a diagnosis of IFI were collected and compared to a control group without IFI.

Results

The incidence of IFI amongst 311 COVID-19 critically-ill patients was 6.1%. 3.5% had CAPA and 3.5% had candidemia. In-hospital mortality was higher amongst patients with IFI compared to those without IFI (89.4% vs 60%, p < 0.03). The most significant predictors of IFI were cardiovascular co-morbidity and carbapenem use.

Conclusions

The low incidence of CAPA in our group of COVID-19 critically-ill patients was consistent with recent reports, underscoring the importance of differentiating between true infection and colonization. Awareness and timely diagnosis of IFIs in COVID-19 critically-ill patients are imperative considering the associated high mortality.

Identification of differentially expressed genes and signaling pathways with Candida infection by bioinformatics analysis

BACKGROUND

Opportunistic Candida species causes severe infections when the human immune system is weakened, leading to high mortality.

METHODS

In our study, bioinformatics analysis was used to study the high-throughput sequencing data of samples infected with four kinds of Candida species. And the hub genes were obtained by statistical analysis.

RESULTS

A total of 547, 422, 415 and 405 differentially expressed genes (DEGs) of Candida albicans, Candida glabrata, Candida parapsilosis and Candida tropicalis groups were obtained, respectively. A total of 216 DEGs were obtained after taking intersections of DEGs from the four groups. A protein-protein interaction (PPI) network was established using these 216 genes. The top 10 hub genes (FOSB, EGR1, JUNB, ATF3, EGR2, NR4A1, NR4A2, DUSP1, BTG2, and EGR3) were acquired through calculation by the cytoHubba plug-in in Cytoscape software. Validated by the sequencing data of peripheral blood, JUNB, ATF3 and EGR2 genes were  significant statistical significance.

CONCLUSIONS

In conclusion, our study demonstrated the potential pathogenic genes in Candida species and their underlying mechanisms by bioinformatic analysis methods. Further, after statistical validation, JUNB, ATF3 and EGR2 genes were attained, which may be used as potential biomarkers with Candida species infection.

Lower beta-1,3-D-glucan testing cut-offs increase sensitivity for non-albicans Candida species blood stream infections

PURPOSE

Fungal biomarkers support early diagnosis of invasive fungal infections. In this study, we evaluated the impact of a recent update to the manufacturer-recommended cut-off for beta-1,3-D-glucan (BDG) testing (Fujifilm Wako BDG assay) on sensitivity and specificity for the detection of candidemia. Additionally, we compared the performance with tests for Candida antigen (Ag by Serion ELISA antigen Candida, Virion\Serion) and anti-mannan antibodies (Ab by Hemkit Candida IHA, Ravo Diagnostika).

METHODS

Sera of 82 patients with candidemia, which were sampled with a maximum distance of ±14 days from the date of sampling of the corresponding positive blood cultures, were retrospectively analyzed for BDG, Ag, and Ab. Results of BDG testing were compared with results from sera of 129 patients with candidemia from a different hospital.

RESULTS

Sensitivity of BDG testing (47%) was higher than for Ag (17%) or Ab (20%). By combining Ag and Ab testing, sensitivity was raised to 32%. Lowering the cut-off of BDG from 11 pg/ml to the newly recommended cut-off of 7 pg/ml resulted in a significant increase in sensitivity (47% vs. 58%, p=0.01 and 63 % vs. 71% p<0.01). At both centers, the increase was significant in NAC but not in C. albicans candidemia. No significant effects on specificity where observed.

CONCLUSION

BDG-testing outperformed Ag and Ab testing and its combination. Lowering the BDG cut-off had no significant impact on specificity. The increase in sensitivity can be mainly attributed to a gain in sensitivity for non-albicans Candida species blood stream infections.

Changing Trends of Candida Species and Antifungal Susceptibility Profile of Candida Bloodstream Isolates: A 5-Year Retrospective Survey

Background: Candida species have emerged as one of the most common causes of bloodstream infections (BSIs). There are limited data on the distribution of Candida spp. and susceptibility by year. Objectives: In this study, we analyzed changes in the distribution of Candida spp. and their antifungal susceptibility profiles from blood cultures. Methods: Records from January 2016 to December 2020 were obtained from the microbiology laboratory in Istanbul. Antifungal susceptibility tests were performed using the VITEK 2 compact system and evaluated according to EUCAST breakpoints. A total of 241 unique candidemia episodes were included in this study. Results: Candida albicans was the predominant pathogen (n = 95, 39.42%), followed by C. parapsilosis (n = 82, 34.02%), C. glabrata (n = 18, 7.47%), C. tropicalis (n = 17, 7.05%), C. krusei (n = 15, 6.22%), and other Candida spp. (n = 14, 5.79%). There was no statistically significant difference in the percentage of episodes of Candida spp. After data analysis, a tendency to shift from C. albicans to C. parapsilosis was observed in the period analyzed in this study. Candida albicans was the most common species in intensive care units (ICUs), hematology and hemopoietic stem cell transplantation units, and surgical clinics, with C. parapsilosis predominant in medical clinics. In general, micafungin susceptibility was the highest, and fluconazole was the lowest. There was reduced sensitivity to fluconazole and voriconazole for C. albicans and C. parapsilosis over 5 years. Conclusions: Detecting changes in the distribution of Candida spp. and antifungal susceptibility over time will lead to the selection of appropriate empirical therapy and monitor phenomena of antifungal resistance. Empirical treatment with antifungal agents is associated with high costs, toxicities, and risk of antifungal resistance. Therefore, it is mandatory to determine and monitor Candida spp. and antifungal susceptibility testing to select appropriate antifungal agents.

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

Background:

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

Objective:

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

Materials and Methods:

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

Results:

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

Conclusion:

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

Antifungal Resistance in Clinical Isolates of Candida glabrata in Ibero-America

In different regions worldwide, there exists an intra-and inter-regional variability in the rates of resistance to antifungal agents in Candida glabrata, highlighting the importance of understanding the epidemiology and antifungal susceptibility profiles of C. glabrata in each region. However, in some regions, such as Ibero-America, limited data are available in this context. Therefore, in the present study, a systematic review was conducted to determine the antifungal resistance in C. glabrata in Ibero-America over the last five years. A literature search for articles published between January 2015 and December 2020 was conducted without language restrictions, using the PubMed, Embase, Cochrane Library, and LILACS databases. The search terms that were used were "Candida glabrata" AND "antifungal resistance" AND "Country", and 22 publications were retrieved from different countries. The use of azoles (fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole, ketoconazole, and miconazole) varied between 4.0% and 100%, and that of echinocandins (micafungin, caspofungin, and anidulafungin) between 1.1% and 10.0%. The limited information on this subject in the region of Ibero-America emphasizes the need to identify the pathogens at the species level and perform antifungal susceptibility tests that may lead to the appropriate use of these drugs and the optimal doses in order to avoid the development of antifungal resistance or multi-resistance.

Candida glabrata Antifungal Resistance and Virulence Factors, a Perfect Pathogenic Combination

In recent years, a progressive increase in the incidence of invasive fungal infections (IFIs) caused by Candida glabrata has been observed. The objective of this literature review was to study the epidemiology, drug resistance, and virulence factors associated with the C. glabrata complex. For this purpose, a systematic review (January 2001-February 2021) was conducted on the PubMed, Scielo, and Cochrane search engines with the following terms: "C. glabrata complex (C. glabrata sensu stricto, C. nivariensis, C. bracarensis)" associated with "pathogenicity" or "epidemiology" or "antibiotics resistance" or "virulence factors" with language restrictions of English and Spanish. One hundred and ninety-nine articles were found during the search. Various mechanisms of drug resistance to azoles, polyenes, and echinocandins were found for the C. glabrata complex, depending on the geographical region. Among the mechanisms found are the overexpression of drug transporters, gene mutations that alter thermotolerance, the generation of hypervirulence due to increased adhesion factors, and modifications in vital enzymes that produce cell wall proteins that prevent the activity of drugs designed for its inhibition. In addition, it was observed that the C. glabrata complex has virulence factors such as the production of proteases, phospholipases, and hemolysins, and the formation of biofilms that allows the complex to evade the host immune response and generate fungal resistance. Because of this, the C. glabrata complex possesses a perfect pathogenetic combination for the invasion of the immunocompromised host.

Direct Fluconazole Disk Susceptibility Testing for Candida glabrata-Positive Blood Cultures

Direct susceptibility testing from blood cultures has been reported to reduce the time interval between a positive blood culture to preliminary reporting of susceptibility and can underpin timely appropriate treatment of candidemia. The aim of this study was to evaluate direct susceptibility testing of Candida glabrata to fluconazole using disk diffusion compared to the Sensititre YeastOne broth microdilution-based method. We tested 83 isolates recovered from 93 spiked and prospective blood culture bottles. Comparison of the two methods showed excellent agreement, with no very major errors and only two major errors (2.4%). The accuracy of the fluconazole disk method was 97.6% (95% confidence interval [CI], 91.6 to 99.7), with a sensitivity of 100% (95% CI, 82.3 to 100) and a specificity of 96.9% (95% CI, 89.2 to 99.6). Direct antifungal disk susceptibility testing from blood cultures is a rapid and easy-to-perform method to determine fluconazole susceptibility of C. glabrata isolates and can be used safely to reduce susceptibility report time and improve clinical decision making regarding appropriate treatment.

No Impact of Fluconazole to Echinocandins Replacement as First-Line Therapy on the Epidemiology of Yeast Fungemia (Hospital-Driven Active Surveillance, 2004-2017, Paris, France)

Replacement of fluconazole by echinocandins as the first-line therapy for yeast-related fungemia could have an impact on both the mortality rate and the epidemiology of yeast species responsible for candidemia. We analyzed the individual clinical and microbiological data collected through the active surveillance program on yeast fungemia (YEASTS program, 2004-2016, Paris area, France) within 14 University Hospitals. The cohort included 3,092 patients [male:female ratio: 1.56; median age 61.0 years (IQR: 23.8)]. The mean mortality rate within 30 days was 38.5% (1,103/2,868) and significantly higher in intensive care units (690/1,358, 50.8%) than outside (413/1,510, 27.4%, p < 0.0001) without significant change over time. The yeast species distribution [Candida albicans (n = 1,614, 48.0%), Candida glabrata (n = 607, 18.1%), Candida parapsilosis (n = 390, 11.6%), Candida tropicalis (n = 299, 8.9%), Candida krusei (n = 96, 2.9%), rare species (n = 357, 10.6%)], minimal inhibitory concentration distribution, and the distribution between the patient populations (hematological malignancies, solid tumors, without malignancy) did not change either while the proportion of patients ≥60-years increased from 48.7% (91/187) in 2004 to 56.8% (133/234) in 2017 (p = 0.0002). Fluconazole as first-line therapy dramatically decreased (64.4% in 2004 to 27.7% in 2017, p < 0.0001) with a corresponding increase in echinocandins (11.6% in 2004 to 57.8% in 2017, p < 0.0001). Survival rates did not differ according to the first antifungal therapy. The progressive replacement of fluconazole by echinocandins as the first-line antifungal therapy was not associated with change in global mortality, regardless of species involved and antifungal susceptibility profiles. Other factors remain to be uncovered to improve the prognosis of yeast fungemia.

Change in species distribution and antifungal susceptibility of candidemias in an intensive care unit of a university hospital (10-year experience)

Candidemia is a nosocomial infection mostly found in critically ill patients. Our objectives were to evaluate the change in distribution and resistance profile of Candida spp. isolated from candidemic patients in our intensive care unit over two 5-year periods spanning 15 years and to evaluate the risk factors. Records from the microbiology laboratory were obtained, from January 2004 to December 2008 and from January 2013 to December 2017, retrospectively. Antifungal susceptibility was performed by E-test and evaluated according to EUCAST breakpoints. A total of 210 candidemia cases occurred; 238 Candida spp. were isolated in 197 patients (58.8% male; mean age, 59.2 ± 19.6 years). The most predominant risk factor was central venous catheter use. Species distribution rates were 32%, 28%, 17%, and 11% for C. albicans (n = 76), C. parapsilosis (n = 67), C. glabrata (n = 40), and C. tropicalis (n = 27), respectively. Resistance rate to anidulafungin was high in C. parapsilosis over both periods and increased to 73% in the second period. Fluconazole showed a remarkable decrease for susceptibility in C. parapsilosis (94 to 49%). The prevalence of MDR C. parapsilosis (6%/33%) and C. glabrata (0%/44%) increased in the second period. We observed a predominance of non-albicans Candida spp., with C. parapsilosis being the most frequent and C. glabrata infections presenting with the highest mortality. High level of echinocandin resistance in C. parapsilosis and increasing prevalences of MDR C. parapsilosis and C. glabrata seem emerging challenges in our institution.

A seven-year surveillance study of the epidemiology, antifungal susceptibility, risk factors and mortality of candidaemia among paediatric and adult inpatients in a tertiary teaching hospital in China

Background

There are no current national estimates of the candidaemia burden in China, and epidemiological candidaemia data from the underdeveloped region of China are lacking.

Methods

A 7-year retrospective study was carried out to analyse the prevalence, species distribution, antifungal susceptibility, risk factors and inpatient mortality of candidaemia among paediatric and adult patients in a regional tertiary teaching hospital in China.

Results

During the seven-year study period, a total of 201 inpatients with candidaemia were identified. The median age of the patients was 65 years (range, 1 day to 92 years), and 114 of the patients (56.7%) were male. The mean annual incidence of candidaemia was 0.26 cases per 1000 admissions (0.42 cases per 1000 paediatric admissions vs 0.24 cases per 1000 adult admissions, P < 0.05). Candida albicans was the most common fungal species (81/201, 40.3%) in all patients, Candida glabrata was the most common fungal species (18/35, 51.4%) in paediatric patients. Most isolates were susceptible to flucytosine (99.0%) and amphotericin B (99.0%), and the activity of antifungal agents against Candida species was no significant difference in satisfaction between paediatric and adult patients (P > 0.05). The all-cause mortality rate was 20.4% (paediatric patients: 11.4% vs adult patients:22.3%, P > 0.05). Fewer univariate predictors of poor outcomes were identified for paediatric patients than for adult patients (4 vs 11 predictors). Respiratory dysfunction and septic shock were independent predictors of 30-day mortality for all patients.

Conclusions

The epidemiological data of candidaemia in paediatric and adult patients are only different in the distributions of Candida species and the mean annual incidence of candidaemia. Flucytosine and amphotericin B can be used as first-choice agents when no antifungal susceptibility test results are available.

Antifungal Activity and Mode of Action of Miltefosine Against Clinical Isolates of Candida krusei

Candida krusei attracts attention from medical professionals mainly for its intrinsic resistance to fluconazole and the limited number of drugs available to treat C. krusei vulvovaginal candidiasis. Miltefosine was demonstrated to have good antifungal activity both in vitro and in vivo. Here, we determined the susceptibility profiles of 57 clinical C. krusei isolates from vulvovaginal candidiasis patients and assessed the antifungal activity of miltefosine against C. krusei. All isolates were susceptible to voriconazole and itraconazole, whereas 1.8% of the isolates were of non-wild-type phenotype to amphotericin B. In contrast, miltefosine showed low MICs against all C. krusei isolates with fungicidal activity. The checkerboard assay showed that the synergistic effect of miltefosine in combination with amphotericin B was observed in 25% of the tested planktonic C. krusei isolates and 18.8% of the tested preformed biofilms, whereas miltefosine in combination with fluconazole showed indifferent interaction for all tested planktonic isolates. The presence of sorbitol in the broth microdilution assay did not influence the MIC values of miltefosine against C. krusei, but the presence of ergosterol increased the MIC values. Visible changes in cell content in cells treated with miltefosine were observed. We found that cells treated with miltefosine showed decreased cell viability and chromatin condensation under PI staining, which indicates that miltefosine may induce apoptosis-like cell death in C. krusei. In conclusion, we found miltefosine has a good activity against C. krusei isolates and exerts its fungicidal effect by binding to ergosterol in the cell membrane and inducing apoptosis.