Candida glabrata fungaemia in a tertiary centre in Taiwan: antifungal susceptibility and outcomes

A novel model for predicting deep-seated candidiasis due to Candida glabrata among cancer patients: A 6-year study in a cancer center of China

Followed by Candida albicans, Candida glabrata ranks as the second major species contributing to invasive candidiasis. Given the higher medical burden and lower susceptibility to azoles in C. glabrata infections, identifying these infections is critical. From 2016 to 2021, patients with deep-seated candidiasis due to C. glabrata and non-glabrata Candida met the criteria to be enrolled in the study. Clinical data were randomly divided into training and validation cohorts. A predictive model and nomogram were constructed using R software based on the stepwise algorithm and logistic regression. The performance of the model was assessed by the area under the receiver operating characteristic curve and decision curve analysis (DCA). A total of 197 patients were included in the study, 134 of them infected with non-glabrata Candida and 63 with C. glabrata. The predictive model for C. glabrata infection consisted of gastrointestinal cancer, co-infected with bacteria, diabetes mellitus, and kidney dysfunction. The specificity was 84.1% and the sensitivity was 61.5% in the validation cohort when the cutoff value was set to the same as the training cohort. Based on the model, treatment for patients with a high-risk threshold was better than 'treatment for all' in DCA, while opting low-risk patients out of treatment was also better than 'treatment for none' in opt-out DCA. The predictive model provides a rapid method for judging the probability of infections due to C. glabrata and will be of benefit to clinicians making decisions about therapy strategies.

Correlation Between Drug Resistance and Virulence of Candida Isolates from Patients with Candidiasis

Purpose

This article aims to provide a theoretical basis for new or adjuvant strategies to facilitate the early diagnosis and treatment of candidiasis and to determine if drug-resistant Candida would affect virulence.

Patients and Methods

Our strains were collected from patients diagnosed with candidiasis in our hospital. The strains were identified by MALDI-TOF system and ITS sequencing. Antifungal sensitivity testing in vitro was performed to evaluate susceptibility of these isolates to current widely used antifungal drugs. The Galleria mellonella larvae model infected by Candida spp. was used to compare the virulence of drug-resistant and susceptible Candida spp.

Results

A total of 206 Candida strains were collected from clinical specimens. Candida albicans was the most common species among them, and was predominantly isolated from male patients aged over 40 years in ICU environments suffering from pulmonary and/or cerebral conditions. The accuracy rate of MALDI TOF-MS identification was 92.72% when compared with ITS sequencing as the standard method. Most Candida species, except for C. tropicalis which showed high resistance to micafungin, showed high susceptibilities to voriconazole, itraconazole, amphotericin B and micafungin but were highly resistant to terbinafine. For each specific Candida species, the G. mellonella larvae model revealed that the virulence of drug-resistant Candida isolates did not markedly differ from that of the drug-susceptible isolates, however, the virulence was dose-dependent on inoculated fungal cells in this model.

Conclusion

The possibility of Candida infection should not be neglected in patients at critical care hospital settings and C. albicans is the most common causative agent. MALDI-TOF MS has the advantages of rapidity and high accuracy, and should be a preferred method for identification of Candida spp. in a clinical laboratory. Voriconazole, itraconazole, amphotericin B and micafungin can still be recommended as the first line antifungals to treat candidiasis.

Biofilm formation is a risk factor for mortality in patients with Candida albicans bloodstream infection-Scotland, 2012-2013

Bloodstream infections caused by Candida species remain a significant cause of morbidity and mortality in hospitalized patients. Biofilm formation by Candida species is an important virulence factor for disease pathogenesis. A prospective analysis of patients with Candida bloodstream infection (n = 217) in Scotland (2012–2013) was performed to assess the risk factors associated with patient mortality, in particular the impact of biofilm formation. Candida bloodstream isolates (n = 280) and clinical records for 157 patients were collected through 11 different health boards across Scotland. Biofilm formation by clinical isolates was assessed in vitro with standard biomass assays. The role of biofilm phenotype on treatment efficacy was also evaluated in vitro by treating preformed biofilms with fixed concentrations of different classes of antifungal. Available mortality data for 134 patients showed that the 30-day candidaemia case mortality rate was 41%, with predisposing factors including patient age and catheter removal. Multivariate Cox regression survival analysis for 42 patients showed a significantly higher mortality rate for Candida albicans infection than for Candida glabrata infection. Biofilm-forming ability was significantly associated with C. albicans mortality (34 patients). Finally, in vitro antifungal sensitivity testing showed that low biofilm formers and high biofilm formers were differentially affected by azoles and echinocandins, but not by polyenes. This study provides further evidence that the biofilm phenotype represents a significant clinical entity, and that isolates with this phenotype differentially respond to antifungal therapy in vitro. Collectively, these findings show that greater clinical understanding is required with respect to Candida biofilm infections, and the implications of isolate heterogeneity.

Isavuconazole, micafungin, and 8 comparator antifungal agents' susceptibility profiles for common and uncommon opportunistic fungi collected in 2013: temporal analysis of antifungal drug resistance using CLSI species-specific clinical breakpoints and proposed epidemiological cutoff values

The in vitro activities of isavuconazole, micafungin, and 8 comparator antifungal agents were determined for 1613 clinical isolates of fungi (1320 isolates of Candida spp., 155 of Aspergillus spp., 103 of non-Candida yeasts, and 35 non-Aspergillus molds) collected during a global survey conducted in 2013. The vast majority of the isolates of the 21 different species of Candida, with the exception of Candida glabrata (MIC90, 2 μg/mL), Candida krusei (MIC90, 1 μg/mL), and Candida guilliermondii (MIC90, 8 μg/mL), were inhibited by ≤0.25 μg/mL of isavuconazole. C. glabrata and C. krusei were largely inhibited by ≤1 μg/mL of isavuconazole. Resistance to fluconazole was seen in 0.5% of Candida albicans isolates, 11.1% of C. glabrata isolates, 2.5% of Candida parapsilosis isolates, 4.5% of Candida tropicalis isolates, and 20.0% of C. guilliermondii isolates. Resistance to the echinocandins was restricted to C. glabrata (1.3-2.1%) and C. tropicalis (0.9-1.8%). All agents except for the echinocandins were active against 69 Cryptococcus neoformans isolates, and the triazoles, including isavuconazole, were active against the other yeasts. Both the mold active triazoles as well as the echinocandins were active against 155 Aspergillus spp. isolates belonging to 10 species/species complex. In general, there was low resistance levels to the available systemically active antifungal agents in a large, contemporary (2013), global collection of molecularly characterized yeasts and molds. Resistance to azoles and echinocandins was most prominent among isolates of C. glabrata, C. tropicalis, and C. guilliermondii.

Candida glabrata candidemia: An emerging threat in critically ill patients

Background:

Candidemia is an important nosocomial blood stream infection in critically ill patients. Although several studies have addressed candidemia, very few have reviewed the impact of Candida glabrata candidemia in Intensive Care Unit (ICU) patients.

Materials and Methods:

The medical records of ICU patients between 2006 and 2010 were reviewed retrospectively. The epidemiology, clinical features and mortality related risk factors among our adult ICU patients were seen.

Results:

Among 144 episodes of candidemia, C. glabrata (n = 26; 18.05%) was the third most common species isolated. The incidence of C. glabrata candidemia was 0.21/1000 ICU admissions. The most common risk factors were prior exposure to broad spectrum antibiotics (100%), central venous catheter (100%), mechanical ventilation (76.9%), diabetes mellitus (50%), age >65 years (46.15%). Urine (23%) was the most common source of C. glabrata candidemia. Overall in hospital 30 days mortality rate due to C. glabrata fungemia was 53.8%. Patients who were treated with fluconazole showed better outcome than patients treated with amphotericin B. Renal failure requiring hemodialysis was the significantly associated with mortality in our study.

Conclusion:

Candida glabrata was the 3^rd most common Candida causing candidemia in our ICUs with a incidence of 0.21/1000 ICU admissions. The outcome of ICU acquired C. glabrata candidemia was poor with 30 days mortality rate of 53.8%. Renal failure requiring hemodialysis was the only risk factor associated with mortality. Further studies are required to identify the other risk factors associated with mortality in C. glabrata candidemia.

Antifungal resistance does not necessarily affect Candida glabrata fitness

Although there has been an overall good coverage of Candida glabrata infections by the echinocandins, emergence of antifungal resistance during therapy has been reported. We investigated, by using an invertebrate host model, the fitness of sequential C. glabrata isolates with different echinocandins susceptibility patterns. The studied strains were isolated from a case of recurrent fungemia with a fatal outcome due to C. glabrata that developed cross-resistance to echinocandins during caspofungin therapy. The sequential strains isolated post-therapy showed a S663P mutation in the Fks2p hot spot 1. In vivo study in the invertebrate host Galleria mellonella did not suggest a fitness cost related to the acquired antifungal resistance, the three isolates displayed a similar rate of killing (P  =  0.54). We observed a clear correlation between emergence of antifungal resistance and persistence of the causal agent, probably aided by the unchanged fitness and unresponsiveness in vivo to the adopted therapy.

Changing epidemiology of candidemia in a medical center in middle Taiwan

BACKGROUND

Candidemia remains a major cause of morbidity and mortality in the health care setting, and the epidemiology of Candida infection is changing.

METHODS

Clinical and laboratory data from patients with candidemia were collected retrospectively at a tertiary medical center in Taiwan from July 1, 2009 to June 30, 2012 (a 36-month period). Demographics, clinical characteristics, and drug susceptibility of the invading Candida species of patients at the onset of candidemia were analyzed and compared with previous study from January 1, 2001 to June 30, 2003 (a 30-month period).

RESULTS

A total of 209 episodes of candidemia in 205 patients were identified in this study period. When compared with the previous study period, more patients were admitted for medical conditions at percentages ranging from 49.5% to 69.8%; the incidence rate of health care-associated candidemia increased from 0.76 to 1.14 per 1000 discharges; the proportion of Candida albicans in patients with candidemia decreased from 64.8% to 43.6% whereas the proportion of Candida glabrata increased greatly from 1.1% to 21.6% and the proportions of Candida tropicalis and Candida parapsilosis were slightly elevated (19.8-22.0% and 2.2-7.3%, respectively). All of the C. albicans isolates remained susceptible to fluconazole, whereas 66.7% of C. glabrata isolates were dose-dependent susceptible, and 4.4% of C. glabrata isolates and 11.6% C. tropicalis isolates were resistant. There was one C. glabrata and one Candida guilliermondii resistant to echinocandin. The predictors for 30-day mortality included the high Acute Physiology and Chronic Health Evaluation II (APACHE II) score, use of parenteral nutrition, underlying malignancy, liver cirrhosis, and neutropenia whereas candidemia by C. parapsilosis or C. glabrata is a favorable predictor when compared with C. albicans.

CONCLUSION

The distribution of Candida species in candidemia was changed. Although C. albicans remained the major species, the isolation of non-C. albicans spp., especially C. glabrata, increased. Patients with candidemia still had high mortalities due to severity of illness and underlying conditions.

Assessment of the types of catheter infectivity caused by Candida species and their biofilm formation. First study in an intensive care unit in Algeria

Nosocomial candidiasis remains a potential risk in intensive care units (ICUs), wherein Candida albicans is most responsible for its occurrence. Equally, non-C. albicans species, especially C. glabrata, are also involved. These infections are frequently associated with biofilms that contaminate medical devices, such as catheters. These biofilms constitute a significant clinical problem, and cause therapeutic failures, because they can escape the immune response and considerably decrease sensitivity to antifungal therapy. The diagnosis of catheter-related candidiasis is difficult; however, the differentiation between an infection of the catheter (or other medical implant) and a simple contamination is essential to start an antifungal treatment. Among the methods used for this type of study is the Brun-Buisson method, but this method only examines the infectivity of catheters caused by bacteria. For this reason, we wanted to adapt this method to the yeast cells of Candida spp. To assess the various types of infectivity of catheters (contamination, colonization, or infection) and their corresponding rates, as well as the responsible yeast species, we conducted our study, between February 2011 and January 2012, in the ICU at the University Hospital Center of Sidi Bel Abbes, Algeria; during this study, we took photographic images of the tongue of one patient and of that patient’s implanted orobronchial catheter. In addition, catheters contaminated by C. albicans biofilms were observed by scanning electron microscopy.

Clinical characteristics of candidaemia in adults with haematological malignancy, and antimicrobial susceptibilities of the isolates at a medical centre in Taiwan, 2001-2010

During the period 2001-2010, a total of 154 episodes of candidaemia were noted in 111 of 2574 patients with haematological malignancies at the National Taiwan University Hospital (Taipei, Taiwan). Patients with acute lymphoblastic leukaemia had a significantly higher rate of candidaemia than patients with other haematological malignancies (odds ratio=2.69; P<0.001). Candida tropicalis was the most common Candida species (n=51; 46%), followed by Candida albicans (n=35; 32%), Candida parapsilosis (n=13; 12%), Candida glabrata (n=8; 7%) and Candida krusei (n=4; 4%). Persistent candidaemia was initially identified in 21 patients (18.9%) and was frequently associated with central venous catheter-related infection (52% vs. 24%; P=0.017). Multivariate analysis revealed that shock (P<0.001), allogeneic transplantation (P=0.033) and elderly age (≥60 years) (P=0.041) were independent prognostic factors of 30-day overall survival in patients with haematological malignancy and candidaemia. Minimum inhibitory concentrations (MICs) of a total of 103 non-duplicate blood isolates of Candida spp., including 82 isolates from 82 patients without persistent candidaemia and 21 isolates causing first episodes among 21 patients with persistent candidaemia, to nine antifungal agents were determined using the broth microdilution method. Among the 103 Candida isolates, 53 (51.5%), 94 (91.3%) and 102 (99.0%) were susceptible to itraconazole, fluconazole and voriconazole, respectively. All Candida isolates were susceptible to caspofungin, and 2 (15%) of the 13 C. parapsilosis isolates were not susceptible to micafungin or anidulafungin. The MIC(90) (MIC for 90% of the organisms) of posaconazole was 0.03 mg/L for C. albicans, 0.5 mg/L for C. tropicalis, 0.12 mg/L for C. parapsilosis and 2 mg/L for C. glabrata.

Failure of echinocandin therapy in the treatment of Candida glabrata chorioretinitis

Echinocandins are commonly used as initial empiric therapy in cases of moderate to severe invasive candidiasis. The authors demonstrate that caution should be exercised in applying this approach in certain clinical situations. A case of Candida glabrata fungemia and associated chorioretinitis that was clinically resistant to therapy with micafungin but appeared to resolve with amphotericin B is presented. The authors then briefly review current issues regarding the diagnosis and treatment of C glabrata chorioretinitis.

Clinical and economic outcomes of decreased fluconazole susceptibility in patients with Candida glabrata bloodstream infections

BACKGROUND

The impact of reduced fluconazole susceptibility on clinical and economic outcomes in patients with Candida glabrata bloodstream infections (BSI) is unknown.

METHODS

A retrospective cohort study was conducted to evaluate 30-day inpatient mortality and postculture hospital charges in patients with C glabrata BSI with decreased fluconazole susceptibility (minimum inhibitory concentration [MIC] ≥ 16 μg/mL) versus fluconazole-susceptible C glabrata BSI (MIC ≤ 8 μg/mL). These analyses were adjusted for demographics, comorbidities, and time at risk. Secondary analyses limited the C glabrata group with decreased fluconazole susceptibility to MIC ≥ 64 μg/mL.

RESULTS

There were 45 (31%) deaths among 144 enrolled patients: 19 deaths (25%) among 76 patients with C glabrata BSI with decreased fluconazole susceptibility and 26 deaths (38%) among 68 patients with fluconazole-susceptible C glabrata BSI. Decreased fluconazole susceptibility was not independently associated with increased 30-day inpatient mortality (adjusted odds ratio, .60; 95% confidence interval (CI): .26-1.35; P = 0.22) or hospital charges (multiplicative change in hospital charges, .93; 95% CI: .60-1.43; P = 0.73). Older age was associated with increased mortality and increased time at risk was associated with increased hospital charges.

CONCLUSION

Crude mortality rates remain high in patients with C glabrata BSI. However, decreased fluconazole susceptibility was not associated with increased mortality or hospital charges.