Epidemiology of candidaemia in Europe: results of 28-month European Confederation of Medical Mycology (ECMM) hospital-based surveillance study

Polymerase chain reaction melting profiles of Candida glabrata clinical isolates in solid organ transplant recipients in comparison to the other group of surgical patients

The aim of the retrospective study were to estimate the prevalence of Candida glabrata in liver and kidney transplant recipients compared to patients with short bowel syndrome receiving chronic total parenteral nutrition and relevance of the polymerase chain reaction melting profile (PCR MP) method for Candida glabrata strains differentiation. C. glabrata clinical strains isolated from patients were identified by using standard mycological procedures. The analysis of genetic relatedness of the isolated strains was conducted using the PCR MP method. The prevalence of C. glabrata comprised 29% of all episodes of fungal colonization and infection in solid organ transplant recipients, and 54% of those in hospitalized patients receiving long-term total parenteral nutrition. Among 78 isolates obtained from 55 solid organ transplant recipients and 2 organ donors, 44 different C. glabrata PCR MP fingerprints were observed. Forty-seven organ recipients and one organ donor carried unique C. glabrata strains. Among 37 isolates obtained from 31 patients receiving long-term TPN, 8 different PCR MP profiles of C. glabrata strains were observed. Two patients carried unique C. glabrata strains. Most of the C. glabrata colonization and infections in solid-organ transplant recipients were caused by endogenic strains. Most of the C. glabrata colonization and infections in hospitalized patients receiving long-term total parenteral nutrition could result by patient-to-patient transmission. The results showed that the PCR MP technique is a good discriminatory method for genotyping for C. glabrata strains.

Epidemiology, species distribution and outcome of nosocomial Candida spp. bloodstream infection in Shanghai

Background

Yeasts, mostly Candida, are important causes of bloodstream infections (BSI), responsible for significant mortality and morbidity among hospitalized patients. The epidemiology and species distribution vary from different regions. The goals of this study were to report the current epidemiology of Candida BSI in a Shanghai Teaching Hospital and estimate the impact of appropriate antifungal therapy on the outcome.

Methods

From January 2008 to December 2012, all consecutive patients who developed Candida BSI at Ruijin University Hospital were enrolled. Underlying diseases, clinical severity, species distribution, antifungal therapy and its impact on the outcome were analyzed.

Results

A total of 121 episodes of Candida BSI were identified, with an incidence of 0.32 episodes/1,000 admissions (0.21 in 2008 and 0.42 in 2012) The proportion of candidemia caused by non-albicans species (62.8%), including C. parapsilosis (19.8%), C. tropicalis (14.9%), C. glabrata (7.4%), C. guilliermondii (5.8%), C. sake (5.0%) was higher than that of candidemia caused by C. albicans (37.2%). The overall crude 28-day mortality was 28.1% and significantly reduced with appropriate empiric antifungal therapy administered within 5 days (P = 0.006). Advanced age (OR 1.04; P = 0.014), neutropenia < 500/mm³ (OR 17.44; P < 0.001) were independent risk factors for 28-day mortality, while appropriate empiric antifungal therapy (OR 0.369; P = 0.035) was protective against 28-day mortality.

Conclusion

The epidemiology of candidemia in Shanghai differed from that observed in Western countries. Appropriate empiric antifungal therapy influenced the short-term survival.

The peptide-binding cavity is essential for Als3-mediated adhesion of Candida albicans to human cells

The adhesive phenotype of Candida albicans contributes to its ability to colonize the host and cause disease. Als proteins are one of the most widely studied C. albicans virulence attributes; deletion of ALS3 produces the greatest reduction in adhesive function. Although adhesive activity is thought to reside within the N-terminal domain of Als proteins (NT-Als), the molecular mechanism of adhesion remains unclear. We designed mutations in NT-Als3 that test the contribution of the peptide-binding cavity (PBC) to C. albicans adhesion and assessed the adhesive properties of other NT-Als3 features in the absence of a functional PBC. Structural analysis of purified loss-of-PBC-function mutant proteins showed that the mutations did not alter the overall structure or surface properties of NT-Als3. The mutations were incorporated into full-length ALS3 and integrated into the ALS3 locus of a deletion mutant, under control of the native ALS3 promoter. The PBC mutant phenotype was evaluated in assays using monolayers of human pharyngeal epithelial and umbilical vein endothelial cells, and freshly collected human buccal epithelial cells in suspension. Loss of PBC function resulted in an adhesion phenotype that was indistinguishable from the Δals3/Δals3 strain. The adhesive contribution of the Als3 amyloid-forming-region (AFR) was also tested using these methods. C. albicans strains producing cell surface Als3 in which the amyloidogenic potential was destroyed showed little contribution of the AFR to adhesion, instead suggesting an aggregative function for the AFR. Collectively, these results demonstrate the essential and principal role of the PBC in Als3 adhesion.

Current status of antifungal resistance and its impact on clinical practice

Mortality linked to invasive fungal diseases remains very high despite the availability of novel antifungals and new therapeutic strategies. Candida albicans and Aspergillus fumigatus account for most invasive mycosis produced by yeast or moulds, respectively. Other Candida non-albicans are increasingly being reported and newly emerging, as well as cryptic, filamentous fungi often cause disseminated infections in immunocompromised hosts. Management of invasive fungal infections is becoming a challenge as emerging fungal pathogens generally show poor response to many antifungals. The ability of reference antifungal susceptibility testing methods to detect emerging resistance patterns, together with the molecular characterization of antifungal resistance mechanisms, are providing useful information to optimize the effectiveness of antifungal therapy. The current status of antifungal resistance epidemiology with special emphasis on the molecular resistant mechanisms that have been described in the main pathogenic fungal species are reviewed.

The Prospective Antifungal Therapy Alliance(®) registry: A two-centre Canadian experience

BACKGROUND

The Prospective Antifungal Therapy Alliance(®) registry is a prospective surveillance study that collected data on the diagnosis, management and outcomes of invasive fungal infections (IFIs) from 25 centres in North America from 2004 to 2008.

OBJECTIVE

To evaluate surveillance data on IFIs obtained from study centres located in Canada.

METHODS

Patients with proven or probable IFIs at two Canadian medical centres were enrolled in the registry. Information regarding patient demographics, fungal species, infection sites, diagnosis techniques, therapy and survival were analyzed.

RESULTS

A total of 347 patients from Canada with documented IFIs were enrolled in the Prospective Antifungal Therapy Alliance registry. Infections occurred most commonly in general medicine (71.8%), nontransplant surgery (32.6%) and patients with hematological malignancies (21.0%). There were 287 proven IFIs, including 248 Candida infections. Forty-six patients had invasive aspergillosis (IA); all of these were probable infections. Most cases of invasive candidiasis were confirmed using blood culture (90.5%), while IA was most frequently diagnosed using computed tomography scan (82.6%) and serological methods (82.6%). Fluconazole was the most common therapy used for Candida infections, followed by the echinocandins. Voriconazole therapy was most commonly prescribed for IA.

CONCLUSIONS

The present study demonstrated that general medicine, surgery and hematological malignancy patients in Canada are susceptible to developing IFIs. In contrast to the United States, Candida albicans remains responsible for most IFIs in these Canadian centres. Surrogate serum markers are commonly being used for the diagnosis of IA, while therapy for both IFIs has shifted to broader-spectrum azoles and echinocandins.

Historical trends in the epidemiology of candidaemia: analysis of an 11-year period in a tertiary care hospital in Brazil

Candida species are an important cause of bloodstream infections (BSI). To evaluate the epidemiological, clinical and microbiological aspects of two cohorts {1994-1999 [period 1 (P1) ]; 2000-2004 [period 2 (P2) ]} of candidaemic patients, we performed a retrospective analysis from a laboratory-based survey. A total of 388 candidaemias were identified, with an incidence of 0.20/1,000 patient-days and a significant increase in P2 vs. P1 (0.25 vs. 0.15, p = 0.04). Cancer and prior antibiotic use were frequent and Candida albicans was the most prevalent species found (42.4%). Resistance to fluconazole was found in 2.47% of the strains. No differences were observed in the species distribution of Candida during the study periods. In the P2 cohort, there were higher prevalence of elderly individuals, cardiac, pulmonary and liver diseases, renal failure, central venous catheters and antibiotic therapy. In P1, there were higher prevalence of neurological diseases and chemotherapy. The crude mortality was 55.4%. In conclusion, our incidence rates remained high. Furthermore, the distribution pattern of Candida species and the fluconazole resistance profile remained unchanged. Moreover, we found a clear trend of higher prevalence of candidaemia among the elderly and among patients with comorbidities. Finally, it is necessary to discuss strategies for the prevention and control of Candida BSI in Brazil.

Association of clinical and demographic factors in invasive candidiasis caused by fluconazole-resistant Candida species: a study in 15 hospitals, Medellín, Colombia 2010-2011

Candida is the most important agent of fungal infections. Several risk factors have been described associated with invasive infection by fluconazole-resistant Candida spp. A prospective cross-sectional study with case-control analysis was conducted. Case group patients with fluconazole-resistant Candida isolate were included; control group were patients with fluconazole-susceptible Candida spp. A multivariate logistic regression model was performed. Three hundred isolates of Candida spp. were analyzed. Most frequent species were Candida albicans/Candida dubliniensis (48.3%) and Candida tropicalis (22.3%). Posaconazole susceptibility was 93.7%; voriconazole, 84%; and fluconazole, 78.7%. Susceptibility to anidulafungin and caspofungin was 92.7% and 92.3%, respectively. Neutropenia (adjusted odds ratio [aOR] 6.5, 95% confidence interval [CI] 1.0-43.1), antifungal exposure (aOR 5.1, 95% CI 2.3-11.2), and antituberculosis therapy (aOR 7.7, 95% CI 1.4-43.2) were associated to fluconazole resistance. Susceptibility results are useful to guide the selection of empiric antifungal treatment and the design of local therapeutic guidelines. Previous antifungal exposure suggests possible resistance to fluconazole, pointing towards the selection of a different class of antifungal agents.

Epidemiology and risk factors for invasive candidiasis

The number of immunosuppressive patients has increased significantly in recent years. These patients are at risk for opportunistic infections, especially fungal infections. Candidiasis is one of the most frequent fungal infections determined in these immunosuppressive patients and its epidemiology has changed over the last two decades. Recently, new antifungal agents and new therapy strategies such as antifungal prophylaxis, secondary prophylaxis, and preemptive therapy have come into use. These changes resulted in the alteration of Candida species causing invasive infections. The incidence of Candida albicans was decreased in many countries, especially among patients with immunosuppressive disorders, while the incidence of species other than C. albicans was increased. In this review, incidence, risk factors, and species distribution of invasive candidiasis are discussed.

Antifungal susceptibility and distribution of Candida spp. isolates from the University Hospital in the municipality of Dourados, State of Mato Grosso do Sul, Brazil

INTRODUCTION

Hospital infections caused by Candida spp. are a leading cause of morbidity and mortality in hospitalized patients, particularly those that are critically ill or immunocompromised. In this study, the distribution of Candida species in isolates from the University Hospital of the Federal University at Grande Dourados and their in vitro susceptibility to antifungal drugs were analyzed.

METHODS

Yeasts were phenotypically identified using classical methodologies. Antifungal susceptibility tests to amphotericin B and fluconazole were performed using the broth microdilution technique.

RESULTS

A total of 50 Candida isolates were obtained from hospitalized patients during the study period. We analyzed yeast isolates from urine (n=31; 62%), blood (n=12; 24%), and tracheal secretions (n=7; 14%). The following Candida species were identified: C. tropicalis (n=21; 42%), C. albicans (n=18; 36%), C. glabrata (n=10; 20%), and C. krusei (n=1; 2%). Antifungal susceptibility tests demonstrated that C. albicans was susceptible to both antifungal agents. However, 31.2% of the non-C. albicans Candida isolates displayed dose-dependent susceptibility to fluconazole, and 3.1% were resistant to amphotericin B.

CONCLUSIONS

In contrast to previous reports, our results indicated that C. tropicalis was the most commonly isolated yeast species among the hospital patients. The predominance of non-C. albicans Candida infections confirms the importance of species-level identification for implementing appropriate antifungal therapies.

Invasive fungal infections in the ICU: how to approach, how to treat

Invasive fungal infections are a growing problem in critically ill patients and are associated with increased morbidity and mortality. Most of them are due to Candida species, especially Candida albicans. Invasive candidiasis includes candidaemia, disseminated candidiasis with deep organ involvement and chronic disseminated candidiasis. During the last decades rare pathogenic fungi, such as Aspergillus species, Zygomycetes, Fusarium species and Scedosporium have also emerged. Timely diagnosis and proper treatment are of paramount importance for a favorable outcome. Besides blood cultures, several laboratory tests have been developed in the hope of facilitating an earlier detection of infection. The antifungal armamentarium has also been expanded allowing a treatment choice tailored to individual patients' needs. The physician can choose among the old class of polyenes, the older and newer azoles and the echinocandins. Factors related to patient's clinical situation and present co-morbidities, local epidemiology data and purpose of treatment (prophylactic, pre-emptive, empiric or definitive) should be taken into account for the appropriate choice of antifungal agent.

Clinical and economic burden of invasive fungal diseases in Europe: focus on pre-emptive and empirical treatment of Aspergillus and Candida species

Invasive fungal diseases (IFDs) have been widely studied in recent years, largely because of the increasing population at risk. Aspergillus and Candida species remain the most common causes of IFDs, but other fungi are emerging. The early and accurate diagnosis of IFD is critical to outcome and the optimisation of treatment. Rapid diagnostic methods and new antifungal therapies have advanced disease management in recent years. Strategies for the prevention and treatment of IFDs include prophylaxis, and empirical and pre-emptive therapy. Here, we review the available primary literature on the clinical and economic burden of IFDs in Europe from 2000 to early 2011, with a focus on the value and outcomes of different approaches.

Characterization of biofilm formation and the role of BCR1 in clinical isolates of Candida parapsilosis

In Candida parapsilosis, biofilm formation is considered to be a major virulence factor. Previously, we determined the ability of 33 clinical isolates causing bloodstream infection to form biofilms and identified three distinct groups of biofilm-forming strains (negative, low, and high). Here, we establish two different biofilm structures among strains forming large amounts of biofilm in which strains with complex spider-like structures formed robust biofilms on different surface materials with increased resistance to fluconazole. Surprisingly, the transcription factor Bcr1, required for biofilm formation in Candida albicans and C. parapsilosis, has an essential role only in strains with low capacity for biofilm formation. Although BCR1 leads to the formation of more and longer pseudohyphae, it was not required for initial adhesion and formation of mature biofilms in strains with a high level of biofilm formation. Furthermore, an additional phenotype affected by BCR1 was the switch in colony morphology from rough to crepe, but only in strains forming high levels of biofilm. All bcr1Δ/Δ mutants showed increased proteolytic activity and increased susceptibility to the antimicrobial peptides protamine and RP-1 compared to corresponding wild-type and complemented strains. Taken together, our results demonstrate that biofilm formation in clinical isolates of C. parapsilosis is both dependent and independent of BCR1, but even in strains which showed a BCR1-independent biofilm phenotype, BCR1 has alternative physiological functions.

Fungal infections associated with long-term mechanical circulatory support-diagnosis and management

Left ventricular assist devices (LVADs) are increasingly used as a treatment option for advanced heart failure. Fungal infections present a serious concern given the high association with major adverse events including death in this group of patients. The objective of this review is to summarize the incidence, risk factors, method for diagnosis, complication rate, and outcomes in patients with VADs who develop fungal infections.

Fluconazole Susceptibility ofCandidaspp. Isolates Collected Over Nine Years in a Teaching Hospital of Ancona, Italy

The in vitro activity of fluconazole was investigated against 476 yeast isolates collected during a 9-year period (1997-2005) from patients hospitalised in a teaching hospital of Ancona. They included 373 isolates of Candida albicans, 53 of Candida glabrata and 50 of Candida parapsilosis. Minimum inhibitory concentrations (MICs) determined in accordance with the Clinical Laboratory Standards Institute methodology showed that 96% of the isolates were susceptible (MIC < or =8.0 microg/ml). The uncommon, resistant isolates (MIC > or =64 microg/ml) were randomly distributed over time. Our data show that resistance to fluconazole in this geographical area is a rare event and suggest that this triazole can still represent first-line therapy in our institution.

Epidemiology of candidaemia and invasive candidiasis. A changing face

Invasive candidiasis is a leading cause of mortality. Candidaemia is the most common clinical presentation of invasive candidiasis but more that 30% of these infections do not yield positive blood cultures. Candida albicans remains the predominant aetiology, accounting for 50% of all cases. However, there has been an epidemiological shift in the last decades. Some species of Candida different to C. albicans have emerged as an important cause of severe candidaemia as they can exhibit resistance to fluconazole and other antifungal agents. Moreover, there is a different distribution of non C. albicans Candida species in relationship to patients' and hospital characteristics. Thus, Candida parapsilosis has been associated to candidaemia in neonates and young adults. This species usually has an exogenously origin and contaminates medical devices, causing central venous catheter-associated candidaemias. Candida glabrata, Candida tropicalis and Candida krusei are isolated in blood cultures from older patients (>65 years) with important risk factors, such as major abdominal surgery, solid tumours and haematologic malignancies, transplants, and/or prolonged treatment with corticoids. Moreover, important geographical differences in the distribution of the Candida species different to C. albicans causing invasive candidiasis have been reported: C. parapsilosis predominates in Australia, Latin America and Mediterranean countries of Africa, Asia and Europe. In contrast, C. glabrata has an important aetiological role in USA and Central and Northern Europe. Finally, an important and worrying issue is that mortality due to invasive candidiasis remains unacceptably high. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).

[Contribution of the chromogenic medium CHROMagar(®)Candida in mycological diagnosis of yeasts]

The incidence of invasive candidiasis has increased dramatically over the last decades due to a larger number of patients at risk. The diagnosis remains difficult as the clinical presentation is not specific and the biological diagnosis usually takes several days to become positive. We propose in this work through a prospective study to evaluate the contribution of a chromogenic medium CHROMagar(®) (Becton-Dickinson) in the mycological diagnosis of Candida. We selected 680 samples from patients hospitalized in the intensive care unit for epidemiological surveillance over a period of 11 weeks. We treated samples by culture on Sabouraud and on CHROMagar(®). The species identification was performed by chlamydosporulation test and carbohydrate assimilation tests. We found that the CHROMagar(®)Candida evaluated in our work was a valuable tool in the primary culture in differentiating the most frequently isolated yeast species and in better detection of mixed cultures.

Surgical pathology and the diagnosis of invasive visceral yeast infection: two case reports and literature review

Invasive mycoses are life-threatening opportunistic infections that have recently emerged as a cause of morbidity and mortality following general and gastrointestinal surgery.Candida species are the main fungal strains of gut flora. Gastrointestinal tract surgery might lead to mucosal disruption and cause Candida spp. to disseminate in the bloodstream.Here we report and discuss the peculiar clinical and morphological presentation of two cases of gastrointestinal Candida albicans lesions in patients who underwent abdominal surgery.Although in the majority of cases reported in the literature, diagnosis was made on the basis of microbiological criteria, we suggest that morphological features of fungi in histological sections of appropriate surgical specimens could help to detect the degree of yeast colonization and identify patients at risk of developing severe abdominal Candida infection.Better prevention and early antifungal treatments are highlighted, and relevant scientific literature is reviewed.

Treatment of invasive fungal infections in cancer patients-updated recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

The Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO) here presents its updated recommendations for the treatment of documented fungal infections. Invasive fungal infections are a main cause of morbidity and mortality in cancer patients undergoing intensive chemotherapy regimens. In recent years, new antifungal agents have been licensed, and agents already approved have been studied in new indications. The choice of the most appropriate antifungal treatment depends on the fungal species suspected or identified, the patient's risk factors (e.g., length and depth of neutropenia), and the expected side effects. This guideline reviews the clinical studies that served as a basis for the following recommendations. All recommendations including the levels of evidence are summarized in tables to give the reader rapid access to the information.

Treatment of invasive candidiasis in the elderly: a review

Fungi are major causes of infections among immunocompromised or hospitalized patients with serious underlying diseases and comorbidities. Candida species remain the most important cause of opportunistic infections worldwide, affecting predominantly patients over 65 years old, while they are considered to be the fourth most common cause of nosocomial bloodstream infections. The rapidly growing elderly population has specific physiological characteristics, which makes it susceptible to colonization and subsequent infection due to Candida species. Comorbidities and multidrug use should be taken into account any time the therapeutic regimen is under consideration. Different classes of antifungal drugs are available for the treatment of invasive fungal infections but echinocandins, apart from their activity against resistant strains (Candida glabrata and Candida krusei), seem to be safe, with limited adverse events and minimal drug-drug interactions in comparison to the other regimens. Therefore, these agents are strongly recommended when dealing with elderly patients suffering from an invasive form of Candida infection.

Pharmacokinetics of amphotericin B lipid complex in critically ill patients undergoing continuous venovenous haemodiafiltration

The objective of this study was to examine the effect of continuous venovenous haemodiafiltration (CVVHDF) on the pharmacokinetics of amphotericin B (AmB) in critically ill patients following administration of amphotericin B lipid complex (ABLC). Plasma and ultrafiltrate (UF) samples were collected from patients administered ABLC and either receiving or not receiving CVVHDF. Pharmacokinetic (PK) analysis was performed on eight profiles from patients receiving CVVHDF and six profiles from patients not receiving CVVHDF. For patients receiving CVVHDF, the following median PK data were calculated: area under the concentration-time curve (AUC) = 13.9 h·μg/mL, volume of distribution at steady state (V(ss)) = 1476L and drug clearance (CL) = 27.4 L/h; for patients not receiving CVVHDF, the corresponding median PK data were 11.5 h μg/mL, 2048 L and 43.7 L/h, respectively. The median half-lives calculated during the dosage interval (t(1/2int)) were 30.9 h and 32.5 h on and off CVVHDF, respectively, and the total range of t(1/2int) values was 15.6-180.4 h. Observed median peak concentrations on Day 1 were 0.563 μg/mL and 0.468 μg/mL in patients on and off CVVHDF, respectively. From AmB present in the UF, clearance via CVVHDF contributed<1% of total plasma clearance. The AmB concentration-time profiles for patients administered ABLC on and off CVVHDF were compared and no statistically significant differences in AUC, CL, t(1/2int) and V(ss) were observed. In conclusion, CVVHDF had no clinically significant effect on the pharmacokinetics of AmB following administration of ABLC.

A prospective, cohort, multicentre study of candidaemia in hospitalized adult patients with haematological malignancies

Invasive candidiasis is a life-threatening infection in patients with haematological malignancies. The objective of our study was to determine the incidence, microbiological characteristics and clinical outcome of candidaemia among hospitalized adult patients with haematological malignancies. This is a population-based, prospective, multicentre study of patients ≥ 18 years admitted to haematology and/or haematopoietic stem cell transplantation units of nine tertiary care Greek hospitals from January 2009 through to February 2012. Within this cohort, we conducted a nested case-control study to determine the risk factors for candidaemia. Stepwise logistic regression was used to identify independent predictors of 28-day mortality. Candidaemia was detected in 40 of 27,864 patients with haematological malignancies vs. 967 of 1,158,018 non-haematology patients for an incidence of 1.4 cases/1000 admissions vs. 0.83/1000 respectively (p <0.001). Candidaemia was caused predominantly (35/40, 87.5%) by non-Candida albicans species, particularly Candida parapsilosis (20/40, 50%). In vitro resistance to at least one antifungal agent was observed in 27% of Candida isolates. Twenty-one patients (53%) developed breakthrough candidaemia while receiving antifungal agents. Central venous catheters, hypogammaglobulinaemia and a high APACHE II score were independent risk factors for the development of candidaemia. Crude mortality at day 28 was greater in those with candidaemia than in control cases (18/40 (45%) vs. 9/80 (11%); p <0.0001). In conclusion, despite antifungal prophylaxis, candidaemia is a relatively frequent infection associated with high mortality caused by non-C. albicans spp., especially C. parapsilosis. Central venous catheters and hypogammaglobulinaemia are independent risk factors for candidaemia that provide potential targets for improving the outcome.

Surveillance study of species distribution, antifungal susceptibility and mortality of nosocomial candidemia in a tertiary care hospital in China

Background

Bloodstream infections due to Candida species cause significant morbidity and mortality, and the epidemiology of Candida infection is changing. Surveillance for candidemia is necessary to detect trends in species distribution and antifungal resistance.

Methods

The medical and electronic records of all patients who had candidemia at the authors’ hospital from 2009 to 2011 were reviewed for demographic data and clinical information, including the infecting Candida species, resistance to antifungals and survival, and the presence of risk factors associated with candidemia.

Results

A total of 133 distinct episodes of candidemia were identified over the study period. The annual incidence of candidemia ranged between 0.71 and 0.85 cases/1000 hospital discharges. The most frequent Candida species were C. tropicalis (28.6%), followed by C. albicans (23.3%) and C. parapsilosis (19.5%). The rates of susceptibility to antifungal agents were as followed: voriconazole (97.8%), itraconazole (69.5%), fluconazole (46.1%), ketoconazole (38.9%). Out of 131 evaluable patients, 34 (26.0%) died within 30 days from the onset of candidemia. C. tropicalis candidemia was associated with the highest mortality rate (44.7%). Regarding the crude mortality in the different units, patients in Hemato-Oncology ward had the highest mortality rate (66.7%), followed by patients in cardiovascular wards and ICU (57.1% and 25.6%, respectively). Predictors of 30-day mortality were identified by uni- and multivariate analyses. Complicated abdominal surgery, presence of central venous catheter (CVC), neutropenia, candidemia due to C. tropicalis and poor treatment with fluconazole were significantly associated with the 30-day mortality. Presence of CVC (odds ratio[OR] = 4.177; 95% confidence interval [CI] = 1.698 to 10.278; P = 0.002) was the only independent predictor for mortality in the multivariate analysis.

Conclusion

This report provides baseline data for future epidemiological and susceptibility studies and for the mortality rates associated with candidemia in our hospital. The knowledge of the local epidemiological trends in Candida species isolated in blood cultures is important to guide therapeutic choices.

The synthetic amphipathic peptidomimetic LTX109 is a potent fungicide that disturbs plasma membrane integrity in a sphingolipid dependent manner

The peptidomimetic LTX109 (arginine-tertbutyl tryptophan-arginine-phenylethan) was previously shown to have antibacterial properties. Here, we investigated the activity of this novel antimicrobial peptidomimetic on the yeast Saccharomyces cerevisiae. We found that LTX109 was an efficient fungicide that killed all viable cells in an exponentially growing population as well as a large proportion of cells in biofilm formed on an abiotic surface. LTX109 had similar killing kinetics to the membrane-permeabilizing fungicide amphotericin B, which led us to investigate the ability of LTX109 to disrupt plasma membrane integrity. S. cerevisiae cells exposed to a high concentration of LTX109 showed rapid release of potassium and amino acids, suggesting that LTX109 acted by destabilizing the plasma membrane. This was supported by the finding that cells were permeable to the fluorescent nucleic acid stain SYTOX Green after a few minutes of LTX109 treatment. We screened a haploid S. cerevisiae gene deletion library for mutants resistant to LTX109 to uncover potential molecular targets. Eight genes conferred LTX109 resistance when deleted and six were involved in the sphingolipid biosynthetic pathway (SUR1, SUR2, SKN1, IPT1, FEN1 and ORM2). The involvement of all of these genes in the biosynthetic pathway for the fungal-specific lipids mannosylinositol phosphorylceramide (MIPC) and mannosyl di-(inositol phosphoryl) ceramide (M(IP)2C) suggested that these lipids were essential for LTX109 sensitivity. Our observations are consistent with a model in which LTX109 kills S. cerevisiae by nonspecific destabilization of the plasma membrane through direct or indirect interaction with the sphingolipids.

Efficacy of micafungin in invasive candidiasis caused by common Candida species with special emphasis on non-albicans Candida species

The incidence of invasive candidiasis caused by non-albicans Candida (NAC) spp. is increasing. The aim of this analysis was to evaluate the efficacy of micafungin, caspofungin and liposomal amphotericin B in patients with invasive candidiasis and candidaemia caused by different Candida spp. This post hoc analysis used data obtained from two randomised phase III trials was conducted to evaluate the efficacy and safety of micafungin vs. caspofungin and micafungin vs. liposomal amphotericin B. Treatment success, clinical response, mycological response and mortality were evaluated in patients infected with C. albicans and NAC spp. Treatment success rates in patients with either C. albicans or NAC infections were similar. Outcomes were similar for micafungin, caspofungin and liposomal amphotericin B. Candida albicans was the most prevalent pathogen recovered (41.0%), followed by C. tropicalis (17.9%), C. parapsilosis (14.4%), C. glabrata (10.4%), multiple Candida spp. (7.3%) and C. krusei (3.2%). Age, primary diagnosis (i.e. candidaemia or invasive candidiasis), previous corticosteroid therapy and Acute Physiology and Chronic Health Evaluation II score were identified as potential predictors of treatment success and mortality. Micafungin, caspofungin and liposomal amphotericin B exhibit favourable treatment response rates that are comparable for patients infected with different Candida spp.

Visual analysis of DNA microarray data for accurate molecular identification of non-albicans Candida isolates from patients with candidemia episodes

The performance of a visual slide-based DNA microarray for the identification of non-albicans Candida spp. was evaluated. Among 167 isolates that had previously been identified by Vitek 2, the agreement between DNA microarray and sequencing results was 97.6%. This DNA microarray platform showed excellent performance.

[Towards an early diagnosis of invasive candidiasis in the critically ill patient]

The management of invasive fungal infections in critically ill patients, from diagnosis to selection of the therapeutic protocol, is often a challenge. Early diagnosis and treatment are associated with a better prognosis, but apart from cases with positive cultures from blood or fluid/tissue biopsy, diagnosis is neither sensitive nor specific, and there is a need for specific markers in these diseases. Serodiagnostic assays such as mannan antigen, mannan antibodies, Candida albicans germ-tube antibodies or (1→3)-β-D-glucan detection, and molecular techniques for the detection of fungal-specific DNA have been developed with promising results in critical care settings. One of the main features in diagnosis is the evaluation of risk factors for infection, which will identify patients in need of preemptive or empirical treatment. Clinical scores were built from those risk factors. The combination of prediction rules and non-culture microbiological tools could be currently be the key to improving the diagnosis and prognosis of invasive fungal infections in critically ill patients.

[Recommendations for the management of candidemia in adults in Latin America. Grupo Proyecto Épico]

Candidemia is one of the most frequent opportunistic mycoses worldwide. Limited epidemiological studies in Latin America indicate that incidence rates are higher in this region than in the Northern Hemisphere. Diagnosis is often made late in the infection, affecting the initiation of antifungal therapy. A more scientific approach, based on specific parameters, for diagnosis and management of candidemia in Latin America is warranted. 'Recommendations for the diagnosis and management of candidemia' are a series of manuscripts that have been developed by members of the Latin America Invasive Mycosis Network. They aim to provide a set of best-evidence recommendations for the diagnosis and management of candidemia. This publication, 'Recommendations for the management of candidemia in adults in Latin America', was written to provide guidance to healthcare professionals on the management of adults who have, or who are at risk of, candidemia. Computerized searches of existing literature were performed by PubMed. The data were extensively reviewed and analyzed by members of the group. The group also met on two occasions to pose questions, discuss conflicting views, and deliberate on a series of management recommendations. 'Recommendations for the management of candidemia in adults in Latin America' includes prophylaxis, empirical therapy, therapy for proven candidemia, patient work-up following diagnosis of candidemia, duration of candidemia treatment, and central venous catheter management in patients with candidemia. This manuscript is the second of this series that deals with diagnosis and treatment of invasive candidiasis. Other publications in this series include: 'Recommendations for the diagnosis of candidemia in Latin America', 'Recommendations for the management of candidemia in children in Latin America', and 'Recommendations for the management of candidemia in neonates in Latin America'.

Invasive candidiasis: update on current pharmacotherapy options and future perspectives

INTRODUCTION

Invasive candidiasis (IC), mainly candidemia, is a leading cause of morbidity and mortality among immunocompromised patients and those admitted to intensive care units. Despite the recognition of risk factors and advances in disease prevention, Candida-related hospitalizations and mortality continue to rise. For treatment, four classes of older and newer antifungal agents are currently available. Adjunctive immunotherapies and a monoclonal antibody against heat shock protein 90 (efungumab) are promising novel therapeutic approaches.

AREAS COVERED

In this article, approaches and therapeutic agents for candidemia and other forms of IC are reviewed.

EXPERT OPINION

The thorough understanding of the available antifungal agents in combination with the increasing knowledge of the mechanisms that underlie the pathogenesis of Candida infections and the development of newer approaches such as efungumab and immunotherapy with adjunctive cytokines may improve the prognosis of patients with life-threatening invasive Candida infections.

Population-based survey of filamentous fungi and antifungal resistance in Spain (FILPOP Study)

A population-based survey was conducted to investigate the epidemiology of and antifungal resistance in Spanish clinical strains of filamentous fungi isolated from deep tissue samples, blood cultures, and respiratory samples. The study was conducted in two different periods (October 2010 and May 2011) to analyze seasonal variations. A total of 325 strains were isolated in 29 different hospitals. The average prevalence was 0.016/1,000 inhabitants [corrected]. Strains were identified by sequencing of DNA targets and susceptibility testing by the European Committee for Antimicrobial Susceptibility Testing reference procedure. The most frequently isolated genus was Aspergillus, accounting for 86.3% of the isolates, followed by Scedosporium at 4.7%; the order Mucorales at 2.5%; Penicillium at 2.2%, and Fusarium at 1.2%. The most frequent species was Aspergillus fumigatus (48.5%), followed by A. flavus (8.4%), A. terreus (8.1%), A. tubingensis (6.8%), and A. niger (6.5%). Cryptic/sibling Aspergillus species accounted for 12% of the cases. Resistance to amphotericin B was found in 10.8% of the isolates tested, while extended-spectrum triazole resistance ranged from 10 to 12.7%, depending on the azole tested. Antifungal resistance was more common among emerging species such as those of Scedosporium and Mucorales and also among cryptic species of Aspergillus, with 40% of these isolates showing resistance to all of the antifungal compounds tested. Cryptic Aspergillus species seem to be underestimated, and their correct classification could be clinically relevant. The performance of antifungal susceptibility testing of the strains implicated in deep infections and multicentric studies is recommended to evaluate the incidence of these cryptic species in other geographic areas.

Occurrence, presentation and treatment of candidemia

Candida is one of the most common causes of nosocomial bloodstream infections. Candidemia is not confined to hematological patients, intensive care units or abdominal surgery wards, but it is remarkably frequent in the internal medicine setting. High mortality associated with candidemia can be reduced by prompt, appropriate antifungal therapy. The epidemiology of species has been shifting toward non-albicans strains. Significant improvements in nonculture-based diagnostic methods, such as serological markers, have been made in recent years, and novel diagnostic techniques should be further studied to enable early pre-emptive therapy. Treatment guidelines indicate that echinocandins are at present the best choice for patients who are severely ill or possibly infected with fluconazole-resistant strains.

Epidemiology of candidemia in Latin America: a laboratory-based survey

Background

The epidemiology of candidemia varies depending on the geographic region. Little is known about the epidemiology of candidemia in Latin America.

Methods

We conducted a 24-month laboratory-based survey of candidemia in 20 centers of seven Latin American countries. Incidence rates were calculated and the epidemiology of candidemia was characterized.

Results

Among 672 episodes of candidemia, 297 (44.2%) occurred in children (23.7% younger than 1 year), 36.2% in adults between 19 and 60 years old and 19.6% in elderly patients. The overall incidence was 1.18 cases per 1,000 admissions, and varied across countries, with the highest incidence in Colombia and the lowest in Chile. Candida albicans (37.6%), C. parapsilosis (26.5%) and C. tropicalis (17.6%) were the leading agents, with great variability in species distribution in the different countries. Most isolates were highly susceptible to fluconazole, voriconazole, amphotericin B and anidulafungin. Fluconazole was the most frequent agent used as primary treatment (65.8%), and the overall 30-day survival was 59.3%.

Conclusions

This first large epidemiologic study of candidemia in Latin America showed a high incidence of candidemia, high percentage of children, typical species distribution, with C. albicans, C. parapsilosis and C. tropicalis accounting for the majority of episodes, and low resistance rates.

Nationwide study of candidemia, antifungal use, and antifungal drug resistance in Iceland, 2000 to 2011

Candidemia is often a life-threatening infection, with highly variable incidence among countries. We conducted a nationwide study of candidemia in Iceland from 2000 to 2011, in order to determine recent trends in incidence rates, fungal species distribution, antifungal susceptibility patterns, and concurrent antifungal consumption. A total of 208 infection episodes in 199 patients were identified. The average incidence during the 12 years was 5.7 cases/100,000 population/year, which was significantly higher than that from 1990 to 1999 (4.3/100,000/year; P = 0.02). A significant reduction in the use of blood cultures was noted in the last 3 years of the study, coinciding with the economic crisis in the country (P < 0.001). Age-specific incidence rates were highest among patients at the extremes of age, 20.7/100,000 for <1 year of age and 18.1/100,000 for >60 years, and varied by gender. Age-specific incidence among males >80 years old was 28.6/100,000/year, and it was 8.3/100,000/year for females in this age group (P = 0.028). The 30-day survival rate among adult patients remained unchanged compared to that from 1990 to 1999 (70.4% versus 69.5%, P = 0.97). Candida albicans was the predominant species (56%), followed by C. glabrata (16%) and C. tropicalis (13%). The species distribution remained stable compared to that from previous decades. Fluconazole use increased 2.4-fold from 2000 to 2011, with no increase in resistance. In summary, the incidence of candidemia in Iceland has continued to increase but may have reached a steady state, and no increase in antifungal drug resistance has been noted. Decreased use of blood cultures toward the end of the study may have influenced detection rates.

Oral nystatin prophylaxis in surgical/trauma ICU patients: a randomised clinical trial

Introduction

Candida prophylaxis in ICU is still a matter of debate. Oral chemoprophylaxis has been advocated to reduce the incidence of Candida colonisation and infection.

Methods

We performed a randomised trial studying a single drug (nystatin) versus control in surgical/trauma ICU patients. Multiple-site testing for fungi was performed in each patient on ICU admission (T0) and subsequently every 3 days (T3, T6, T9, and so forth). The primary evaluation criterion was the time course of the corrected colonisation index.

Results

Ninety-nine patients were enrolled. At admission, 69 patients exhibited Candida colonisation: the most frequently colonised body sites were the stomach and the pharynx. The most frequent isolated species was Candida albicans. The corrected colonisation index was similar in the two groups at T0 (P = 0.36), while a significant statistical difference was observed between the treatment and control groups at T6 (median 0.14 and 0.33, respectively; P = 0.0016), at T9 (median 0.00 and 0.28, respectively; P = 0.0001), at T12 (median 0.00 and 0.41, respectively; P = 0.0008), and at T15 (median 0.00 and 0.42, respectively; P <0.0003). The same results were obtained in the subgroup of patients already colonised at ICU admission.

Conclusion

This trial shows that nystatin prophylaxis significantly reduces fungal colonisation in surgical/trauma ICU patients, even if already colonised.

Trial registration

ClinicalTrials.gov: NCT01495039

Prevalence of biofilm formation in clinical isolates of Candida species causing bloodstream infection

Candida species are the fourth most common cause of nosocomial invasive infections. Biofilm formation is recognised as one virulence factor of Candida species. A total of 243 Candida albicans, 81 C. glabrata, 33 C. parapsilosis, 14 C. dubliniensis, 8 C. tropicalis, 8 C. lusitaniae, 5 C. krusei and 1 C. pelliculosa isolates causing bloodstream infections were evaluated for biofilm formation. The biofilm formed on silicone elastomer preincubated with human serum was quantified by estimation of the metabolic activity through XTT assay and visualised by light and scanning electron microscopy. Forty per cent of the C. albicans isolates formed biofilm compared to 88.7% of the non-albicans Candida isolates (P < 0.0001). Among non-albicans Candida spp., biofilm formation was most commonly observed in C. tropicalis and C. lusitaniae (100%), followed by C. glabrata (95%), C. dubliniensis (85.7%) and C. parapsilosis (66.7%). A quantitative correlation was observed between the amount of biofilm observed microscopically, and that determined by metabolic activity measurements. The biofilms of all Candida species were composed of basal yeast cells with the exception of C. parapsilosis which produced biofilms consisting of pseudohyphae and aggregated yeast cells. These results suggest that biofilm formation as a virulence factor might have a higher significance for non-albicans Candida species than for C. albicans.