A Prospective Surveillance Study of Candidaemia: Epidemiology, Risk Factors, Antifungal Treatment and Outcome in Hospitalized Patients

Amphotericin B in the Era of New Antifungals: Where Will It Stand?

Amphotericin B (AmB) has long stood as a cornerstone in the treatment of invasive fungal infections (IFIs), especially among immunocompromised patients. However, the landscape of antifungal therapy is evolving. New antifungal agents, boasting novel mechanisms of action and better safety profiles, are entering the scene, presenting alternatives to AmB's traditional dominance. This shift, prompted by an increase in the incidence of IFIs, the growing demographic of immunocompromised individuals, and changing patterns of fungal resistance, underscores the continuous need for effective treatments. Despite these challenges, AmB's broad efficacy and low resistance rates maintain its essential status in antifungal therapy. Innovations in AmB formulations, such as lipid complexes and liposomal delivery systems, have significantly mitigated its notorious nephrotoxicity and infusion-related reactions, thereby enhancing its clinical utility. Moreover, AmB's efficacy in treating severe and rare fungal infections and its pivotal role as prophylaxis in high-risk settings highlight its value and ongoing relevance. This review examines AmB's standing amidst the ever-changing antifungal landscape, focusing on its enduring significance in current clinical practice and exploring its potential future therapeutic adaptations.

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.

Outbreaks of Fungal Infections in Hospitals: Epidemiology, Detection, and Management

Nosocomial clusters of fungal infections, whilst uncommon, cannot be predicted and are associated with significant morbidity and mortality. Here, we review reports of nosocomial outbreaks of invasive fungal disease to glean insight into their epidemiology, risks for infection, methods employed in outbreak detection including genomic testing to confirm the outbreak, and approaches to clinical and infection control management. Both yeasts and filamentous fungi cause outbreaks, with each having general and specific risks. The early detection and confirmation of the outbreak are essential for diagnosis, treatment of affected patients, and termination of the outbreak. Environmental sampling, including the air in mould outbreaks, for the pathogen may be indicated. The genetic analysis of epidemiologically linked isolates is strongly recommended through a sufficiently discriminatory approach such as whole genome sequencing or a method that is acceptably discriminatory for that pathogen. An analysis of both linked isolates and epidemiologically unrelated strains is required to enable genetic similarity comparisons. The management of the outbreak encompasses input from a multi-disciplinary team with epidemiological investigation and infection control measures, including screening for additional cases, patient cohorting, and strict hygiene and cleaning procedures. Automated methods for fungal infection surveillance would greatly aid earlier outbreak detection and should be a focus of research.

Potential Strategies to Control the Risk of Antifungal Resistance in Humans: A Comprehensive Review

Fungal infections are becoming one of the main causes of morbidity and mortality in people with weakened immune systems. Mycoses are becoming more common, despite greater knowledge and better treatment methods, due to the regular emergence of resistance to the antifungal medications used in clinical settings. Antifungal therapy is the mainstay of patient management for acute and chronic mycoses. However, the limited availability of antifungal drug classes limits the range of available treatments. Additionally, several drawbacks to treating mycoses include unfavourable side effects, a limited activity spectrum, a paucity of targets, and fungal resistance, all of which continue to be significant issues in developing antifungal drugs. The emergence of antifungal drug resistance has eliminated accessible drug classes as treatment choices, which significantly compromises the clinical management of fungal illnesses. In some situations, the emergence of strains resistant to many antifungal medications is a major concern. Although new medications have been developed to address this issue, antifungal drug resistance has grown more pronounced, particularly in patients who need long-term care or are undergoing antifungal prophylaxis. Moreover, the mechanisms that cause resistance must be well understood, including modifications in drug target affinities and abundances, along with biofilms and efflux pumps that diminish intracellular drug levels, to find novel antifungal drugs and drug targets. In this review, different classes of antifungal agents, and their resistance mechanisms, have been discussed. The latter part of the review focuses on the strategies by which we can overcome this serious issue of antifungal resistance in humans.

An integrated transcriptomic and metabolomic approach to investigate the heterogeneous Candida albicans biofilm phenotype

Candida albicans is the most prevalent and notorious of the Candida species involved in bloodstream infections, which is characterised by its capacity to form robust biofilms. Biofilm formation is an important clinical entity shown to be highly variable among clinical isolates. There are various environmental and physiological factors, including nutrient availability which influence the phenotype of Candida species. However, mechanisms underpinning adaptive biofilm heterogeneity have not yet been fully explored. Within this study we have profiled previously characterised and phenotypically distinct C. albicans bloodstream isolates. We assessed the dynamic susceptibility of these differing populations to antifungal treatments using population analysis profiling in addition to assessing biofilm formation and morphological changes. High throughput methodologies of RNA-Seq and LC-MS were employed to map and integrate the transcriptional and metabolic reprogramming undertaken by heterogenous C. albicans isolates in response to biofilm and hyphal inducing serum. We found a significant relationship between biofilm heterogeneity and azole resistance (P < 0.05). In addition, we observed that in response to serum our low biofilm forming (LBF) C. albicans exhibited a significant increase in biofilm formation and hyphal elongation. The transcriptional reprogramming of LBF strains compared to high biofilm forming (HBF) was distinct, indicating a high level of plasticity and variation in stress responses by heterogenous strains. The metabolic responses, although variable between LBF and HBF, shared many of the same responses to serum. Notably, a high upregulation of the arachidonic acid cascade, part of the COX pathway, was observed and this pathway was found to induce biofilm formation in LBF 3-fold. C. albicans is a highly heterogenous bloodstream pathogen with clinical isolates varying in antifungal tolerance and biofilm formation. In addition to this, C. albicans is capable of highly complex and variable regulation of transcription and metabolic pathways and heterogeneity across isolates further increases the complexity of these pathways. Here we have shown with a dual and integrated approach, the importance of studying a diverse panel of C. albicans isolates, which has the potential to reveal distinct pathways that can harnessed for drug discovery.

Characteristics, risk factors, and outcomes of bloodstream Candida infections in the intensive care unit: a retrospective cohort study

OBJECTIVE

The main objective was to assess the clinical characteristics, associated factors, and outcomes of patients admitted to the ICU for candidemia. The secondary objective was to examine the relationship of candidemia with the length of stay and mortality.

METHODS

The analysis was a retrospective single-center cohort study addressing the effect of invasive candidemia on outcomes. This study was performed in a medical-surgical ICU located in a tertiary private hospital in São Paulo, Brazil. Data was collected through the review of the hospital database.

RESULTS

In total, 18,442 patients were included in our study, including 22 patients with candidemia. The median age was similar in patients with and without candidemia [67 (56-84) vs. 67 (51-80)]. Most patients were male, and the proportion of men was higher among patients with candidemia (77% vs. 55.3%). The rates of renal replacement therapy (40.9% vs. 3.3%), mechanical ventilation (63.6% vs. 29.6%), and parenteral nutrition (40.9% vs. 4.8%) were higher in patients with candidemia than in those without candidemia. The mortality rate (77.3% vs. 11.9%) and length of hospital stay [42 days (23.0-78.8) vs. 8 days (5.0-17.0)] were significantly higher in patients with candidemia.

CONCLUSIONS

Patients with candidemia are prone to longer hospital stay and mortality. In addition, we found associations of candidemia with the use of invasive mechanical ventilation, renal replacement therapy, and parenteral nutrition.

Epidemiology, management and outcome of candidaemia in patients with diabetes

BACKGROUND

Candidaemia is the commonest fungal bloodstream infection in hospitalised patients. Diabetes is one of the risk factors for mortality from candidaemia.

METHODS

We compared the epidemiology, clinical characteristics and management of candidaemia in patients with and without diabetes.

RESULTS

Over a 10-year period, 200 episodes of Candida bloodstream infection were documented. Patients with diabetes were younger (58.7 vs 65.5 years), less likely to be suffering from cancer (21.8% vs 36%), and had significantly lower 30-day and 90-day crude mortality (17.2% vs 35.6% and 28.4% vs 48.6%, respectively). Candida glabrata was more common in patients with diabetes (39.3% vs 29.7%). Based on European Confederation of Medical Mycology (ECMM) quality indicators, the management of patients with and without diabetes was similar.

DISCUSSION

Our study highlights the importance of epidemiological data in relation to candidaemia in patients with diabetes and the growing threat of invasive C. glabrata infection in this subset of patients.

Population genetics and microevolution of clinical Candida glabrata reveals recombinant sequence types and hyper-variation within mitochondrial genomes, virulence genes, and drug targets

Candida glabrata is the second most common etiological cause of worldwide systemic candidiasis in adult patients. Genome analysis of 68 isolates from 8 hospitals across Scotland, together with 83 global isolates, revealed insights into the population genetics and evolution of C. glabrata. Clinical isolates of C. glabrata from across Scotland are highly genetically diverse, including at least 19 separate sequence types that have been recovered previously in globally diverse locations, and 1 newly discovered sequence type. Several sequence types had evidence for ancestral recombination, suggesting transmission between distinct geographical regions has coincided with genetic exchange arising in new clades. Three isolates were missing MATα1, potentially representing a second mating type. Signatures of positive selection were identified in every sequence type including enrichment for epithelial adhesins thought to facilitate fungal adhesin to human epithelial cells. In patent microevolution was identified from 7 sets of recurrent cases of candidiasis, revealing an enrichment for nonsynonymous and frameshift indels in cell surface proteins. Microevolution within patients also affected epithelial adhesins genes, and several genes involved in drug resistance including the ergosterol synthesis gene ERG4 and the echinocandin target FKS1/2, the latter coinciding with a marked drop in fluconazole minimum inhibitory concentration. In addition to nuclear genome diversity, the C. glabrata mitochondrial genome was particularly diverse, with reduced conserved sequence and conserved protein-encoding genes in all nonreference ST15 isolates. Together, this study highlights the genetic diversity within the C. glabrata population that may impact virulence and drug resistance, and 2 major mechanisms generating this diversity: microevolution and genetic exchange/recombination.

A recyclable and light-triggered nanofibrous membrane against the emerging fungal pathogen Candida auris

The emerging "super fungus" Candida auris has become an important threat to human health due to its pandrug resistance and high lethality. Therefore, the development of novel antimicrobial strategy is essential. Antimicrobial photodynamic therapy (aPDT) has excellent performance in clinical applications. However, the relevant study on antifungal activity and the mechanism involved against C. auris remains scarce. Herein, a recyclable and biodegradable polylactic acid-hypocrellin A (PLA-HA) nanofibrous membrane is newly developed. In vitro PLA-HA-aPDT could significantly reduce the survival rate of C. auris plankton and its biofilms, and the fungicidal effect of the membrane is still significant after four repeated uses. Simultaneously, PLA-HA exhibits good biocompatibility and low hemolysis. In vivo experiments show that PLA-HA-aPDT can promote C. auris-infected wound healing, reduce inflammatory response, and without obvious toxic side-effects. Further results reveal that PLA-HA-aPDT could increase endogenous reactive oxygen species (ROS) levels, leading to mitochondrial dysfunction, release of cytochrome C, activation of metacaspase, and nuclear fragmentation, thereby triggering apoptosis of C. auris. Compared with HA, PLA-HA shows stronger controllability and reusability, which can greatly improve the utilization efficiency of HA alone. Taken together, the efficacy, safety and antifungal activity make PLA-HA-aPDT a highly promising antifungal candidate for skin or mucous membrane C. auris infection.

It is urgent to develop new antifungal strategies to address the problem of Candida auris infection and drug resistance. Previous studies have revealed that antimicrobial photodynamic therapy (aPDT) based on natural products, such as hypocrellin A (HA), is a promising method in clinical applications. However, equivalent studies of aPDT on antifungal activity and its mechanism against C. auris remain scarce. Herein, we successfully prepared a recyclable, biodegradable, and light-driven antifungal PLA-HA nanofibrous membrane through the electrospinning technique. C. auris infection has been treated by aPDT in vitro and in vivo for the first time, especially HA-mediated aPDT. In vitro and in vivo experiments have provided sufficient lines of evidence that PLA-HA is a promising antifungal material for superficial C. auris infections due to its antifungal effect and excellent biocompatibility. Notably, there still remains a very high antifungal activity after utilizing PLA-HA four times. In addition, this study clarifies that the anti-C. auris mechanism of PLA-HA, namely, PLA-HA-mediated aPDT, is attributed to the formation of intracellular ROS, resulting in mitochondrial dysfunction and a decline in the mitochondrial transmembrane potential, releasing cytochrome C from mitochondria to the cytoplasm, promoting the activation of metacaspase, and inducing nuclear condensation and fragmentation of C. auris, thus triggering yeast cell apoptosis. This study lays a foundation for developing new antimicrobial nanofibrous dressings mediated by aPDT and provides an alternative strategy for the treatment of local fungal infectious diseases.

Trends of the Epidemiology of Candidemia in Switzerland: A 15-Year FUNGINOS Survey

Background

The increasing incidence of candidemia and emergence of drug-resistant Candida species are major concerns worldwide. Long-term surveillance studies are needed.

Methods

The Fungal Infection Network of Switzerland (FUNGINOS) conducted a 15-year (2004–2018), nationwide, epidemiological study of candidemia. Hospital-based incidence of candidemia, Candida species distribution, antifungal susceptibility, and consumption were stratified in 3 periods (2004–2008, 2009–2013, 2014–2018). Population-based incidence over the period 2009–2018 derived from the Swiss Antibiotic Resistance Surveillance System (ANRESIS).

Results

A total of 2273 Candida blood isolates were studied. Population and hospital-based annual incidence of candidemia increased from 2.96 to 4.20/100 000 inhabitants (P = .022) and 0.86 to 0.99/10 000 patient-days (P = .124), respectively. The proportion of Candida albicans decreased significantly from 60% to 53% (P = .0023), whereas Candida glabrata increased from 18% to 27% (P < .0001). Other non-albicans Candida species remained stable. Candida glabrata bloodstream infections occurred predominantly in the age group 18–40 and above 65 years. A higher proportional increase of C glabrata was recorded in wards (18% to 29%, P < .0001) versus intensive care units (19% to 24%, P = .22). According to Clinical and Laboratory Standards Institute, nonsusceptibility to fluconazole in C albicans was observed in 1% of isolates, and anidulafungin and micafungin nonsusceptibility was observed in 2% of C albicans and C glabrata. Fluconazole consumption, the most frequently used antifungal, remained stable, whereas use of mold-active triazoles and echinocandins increased significantly in the last decade (P < .0001).

Conclusions

Over the 15-year period, the incidence of candidemia increased. A species shift toward C glabrata was recently observed, concurring with increased consumption of mold-active triazoles.

Lessons from an Educational Invasive Fungal Disease Conference on Hospital Antifungal Stewardship Practices across the UK and Ireland

Invasive fungal disease (IFD) is a growing health burden. High mortality rates, increasing numbers of at-risk hosts, and a limited availability of rapid diagnostics and therapeutic options mean that patients are increasingly exposed to unnecessary antifungals. High rates of prescriptions promote patient exposure to undue toxicity and drive the emergence of resistance. Antifungal stewardship (AFS) aims to guide antifungal usage and reduce unnecessary exposure and antifungal consumption whilst maintaining or improving outcomes. Here, we examine several AFS approaches from hospitals across the UK and Ireland to demonstrate the benefits of AFS practices and support the broader implementation of AFS as both a necessary and achievable strategy. Since the accuracy and turnaround times (TATs) of diagnostic tools can impact treatment decisions, several AFS strategies have included the development and implementation of diagnostic-driven care pathways. AFS informed treatment strategies can help stratify patients on a risk basis ensuring the right patients receive antifungals at the optimal time. Using a multidisciplinary approach is also key due to the complexity of managing and treating patients at risk of IFD. Through knowledge sharing, such as The Gilead Antifungal Information Network (GAIN), we hope to drive practices that improve patient management and support the preservation of antifungals for future use.

Risk Factors of Candida parapsilosis Catheter-Related Bloodstream Infection

Catheter-related bloodstream infection (CRBSI) is an important healthcare-associated infection caused by various nosocomial pathogens. Candida parapsilosis has emerged as a crucial causative agent for the CRBSI in the last two decades. Many factors have been associated with the development of CRBSI including, demography, pre-maturity, comorbidities (diabetes mellitus, hypertension, heart diseases, neuropathy, respiratory diseases, renal dysfunction, hematological and solid organ malignancies, and intestinal dysfunction), intensive care unit (ICU) admission, mechanical ventilation (MV), total parenteral nutrition (TPN), prior antibiotic and/or antifungal therapy, neutropenia, prior surgery, immunosuppressant, and type, site, number, and duration of catheters. This study aims to determine C. parapsilosis CRBSI risk factors. A retrospective study has been performed in an 853-bedded tertiary-care hospital in north-eastern Malaysia. All inpatients with C. parapsilosis positive blood cultures from January 2006 to December 2018 were included, and their medical records were reviewed using a standardized checklist. Out of 208 candidemia episodes, 177 had at least one catheter during admission, and 31 cases had not been catheterized and were excluded. Among the 177 cases, 30 CRBSI cases were compared to 147 non-CRBSI cases [81 bloodstream infections (BSIs), 66 catheter colonizers]. The significance of different risk factors was calculated using multivariate analysis. Multivariate analysis of potential risk factors shows that ICU admission was significantly associated with non-CRBSI as compared to CRBSI [OR, 0.242; 95% CI (0.080-0.734); p = 0.012], and TPN was significantly positively associated with CRBSI than non-CRBSI [OR, 3.079; 95%CI (1.125-8.429); p = 0.029], while other risk factors were not associated significantly. Patients admitted in ICU were less likely to develop C. parapsilosis CRBSI while patients receiving TPN were more likely to have C. parapsilosis CRBSI when compared to the non-CRBSI group.

The host transcriptional response to Candidemia is dominated by neutrophil activation and heme biosynthesis and supports novel diagnostic approaches

BACKGROUND

Candidemia is one of the most common nosocomial bloodstream infections in the United States, causing significant morbidity and mortality in hospitalized patients, but the breadth of the host response to Candida infections in human patients remains poorly defined.

METHODS

In order to better define the host response to Candida infection at the transcriptional level, we performed RNA sequencing on serial peripheral blood samples from 48 hospitalized patients with blood cultures positive for Candida species and compared them to patients with other acute viral, bacterial, and non-infectious illnesses. Regularized multinomial regression was utilized to develop pathogen class-specific gene expression classifiers.

RESULTS

Candidemia triggers a unique, robust, and conserved transcriptomic response in human hosts with 1641 genes differentially upregulated compared to healthy controls. Many of these genes corresponded to components of the immune response to fungal infection, heavily weighted toward neutrophil activation, heme biosynthesis, and T cell signaling. We developed pathogen class-specific classifiers from these unique signals capable of identifying and differentiating candidemia, viral, or bacterial infection across a variety of hosts with a high degree of accuracy (auROC 0.98 for candidemia, 0.99 for viral and bacterial infection). This classifier was validated on two separate human cohorts (auROC 0.88 for viral infection and 0.87 for bacterial infection in one cohort; auROC 0.97 in another cohort) and an in vitro model (auROC 0.94 for fungal infection, 0.96 for bacterial, and 0.90 for viral infection).

CONCLUSIONS

Transcriptional analysis of circulating leukocytes in patients with acute Candida infections defines novel aspects of the breadth of the human immune response during candidemia and suggests promising diagnostic approaches for simultaneously differentiating multiple types of clinical illnesses in at-risk, acutely ill patients.

Deciphering the epidemiology of invasive candidiasis in the intensive care unit: is it possible?

Invasive candidiasis (IC) has emerged in the last decades as an important cause of morbidity, mortality, and economic load in the intensive care unit (ICU). The epidemiology of IC is still a difficult and unsolved enigma for the literature. Accurate estimation of the true burden of IC is difficult due to variation in definitions and limitations inherent to available case-finding methodologies. Candidemia and intra-abdominal candidiasis (IAC) are the two predominant types of IC in ICU. During the last two decades, an increase in the incidence of candidemia has been constantly reported particularly in the expanding populations of elderly or immunosuppressed patents, with a parallel change in Candida species (spp.) distribution worldwide. Epidemiological shift in non-albicans spp. has reached worrisome trends. Recently, a novel, multidrug-resistant Candida spp., Candida auris, has globally emerged as a nosocomial pathogen causing a broad range of healthcare-associated invasive infections. Epidemiological profile of IAC remains imprecise. Though antifungal drugs are available for Candida infections, mortality rates continue to be high, estimated to be up to 50%. Increased use of fluconazole and echinocandins has been associated with the emergence of resistance to these drugs, which affects particularly C. albicans and C. glabrata. Crucial priorities for clinicians are to recognize the epidemiological trends of IC as well as the emergence of resistance to antifungal agents to improve diagnostic techniques and strategies, develop international surveillance networks and antifungal stewardship programmes for a better epidemiological control of IC.

Evaluation of 11 DNA Automated Extraction Protocols for the Detection of the 5 Mains Candida Species from Artificially Spiked Blood

The molecular detection of Candida plays an important role in the diagnosis of candidaemia, a major cause of morbidity and mortality. The sensitivity of this diagnosis is partly related to the efficiency of yeast DNA extraction. In this monocentric study, we investigated the suitability of 11 recent automated procedures for the extraction of low and high amounts of Candida DNA from spiked blood. The efficacy of the DNA extraction procedures to detect Candida spp. in blood samples ranged from 31.4% to 80.6%. The NucliSENS^TM easyMAG^TM procedure was the most efficient, for each species and each inoculum. It significantly outperformed the other procedures at the lower Candida inocula mimicking the clinical setting. This study highlighted a heterogeneity in DNA extraction efficacy between the five main Candida species (Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis and Candida krusei). Up to five automated procedures were appropriate for C. krusei DNA extraction, whereas only one method yielded an appropriate detection of low amount of C. tropicalis. In the era of the syndromic approach to bloodstream infection diagnosis, this evaluation of 11 automated DNA extraction methods for the PCR diagnosis of candidaemia, puts the choice of an appropriate method in routine diagnosis within the reach of laboratories.

Current and promising pharmacotherapeutic options for candidiasis

Introduction: Candida spp. are commensal yeasts capable of causing infections such as superficial, oral, vaginal, or systemic infections. Despite medical advances, the antifungal pharmacopeia remains limited and the development of alternative strategies is needed.Areas covered: We discuss available treatments for Candida spp. infections, highlighting advantages and limitations related to pharmacokinetics, cytotoxicity, and antimicrobial resistance. Moreover, we present new perspectives to improve the activity of the available antifungals, discussing their immunomodulatory potential and advances on drug delivery carriers. New therapeutic approaches are presented including recent synthesized antifungal compounds (Enchochleated-Amphotericin B, tetrazoles, rezafungin, enfumafungin, manogepix and arylamidine); drug repurposing using a diversity of antibacterial, antiviral and non-antimicrobial drugs; combination therapies with different compounds or photodynamic therapy; and innovations based on nano-particulate delivery systems.Expert opinion: With the lack of novel drugs, the available assets must be leveraged to their best advantage through modifications that enhance delivery, efficacy, and solubility. However, these efforts are met with continuous challenges presented by microbes in their infinite plight to resist and survive therapeutic drugs. The pharmacotherapeutic options in development need to focus on new antimicrobial targets. The success of each antimicrobial agent brings strategic insights to the next phased approach in treatingCandida spp. infections.

Risk factors for candidaemia: A prospective multi-centre case-control study

OBJECTIVES

Candidaemia carries a mortality of up to 40% and may be related to increasing complexity of medical care. Here, we determined risk factors for the development of candidaemia.

METHODS

We conducted a prospective, multi-centre, case-control study over 12 months. Cases were aged ≥18 years with at least one blood culture positive for Candida spp. Each case was matched with two controls, by age within 10 years, admission within 6 months, admitting unit, and admission duration at least as long as the time between admission and onset of candidaemia.

RESULTS

A total of 118 incident cases and 236 matched controls were compared. By multivariate analysis, risk factors for candidaemia included neutropenia, solid organ transplant, significant liver, respiratory or cardiovascular disease, recent gastrointestinal, biliary or urological surgery, central venous access device, intravenous drug use, urinary catheter and carbapenem receipt.

CONCLUSIONS

Risk factors for candidaemia derive from the infection source, carbapenem use, host immune function and organ-based co-morbidities. Preventive strategies should target iatrogenic disruption of mucocutaneous barriers and intravenous drug use.

Predicting Mortality in Critical Care Patients with Fungemia Using Structured and Unstructured Data

Fungemia is a life-threatening infection, but predictive models of in-patient mortality in this infection are few. In this study, we developed models predicting all-cause in-hospital mortality among 265 fungemic patients in the Medical Information Mart for Intensive Care (MIMIC-III) database using both structured and unstructured data. Structured data models included multivariable logistic regression, extreme gradient boosting, and stacked ensemble models. Unstructured data models were developed using Amazon Comprehend Medical and BioWordVec embeddings in logistic regression, convolutional neural networks (CNNs), and recurrent neural networks (RNNs). We evaluated models trained on all notes, notes from only the first three days of hospitalization, and models trained on only physician notes. The best-performing structured data model was a multivariable logistic regression model that achieved an accuracy of 0.74 and AUC of 0.76. Liver disease, acute renal failure, and intubation were some of the top features driving prediction in multiple models. CNNs using unstructured data achieved similar performance even when trained with notes from only the first three days of hospitalization. The best-performing unstructured data models used the Amazon Comprehend Medical document classifier and CNNs, achieving accuracy ranging from 0.99-1.00, and AUCs of 1.00. Therefore, unstructured data - particularly notes composed by physicians - offer added predictive value over models based on structured data alone.

Potential antibiofilm activity of farnesol-loaded poly(DL-lactide-co-glycolide) (PLGA) nanoparticles against Candida albicans

Candida species are ubiquitous fungal pathogens and are the most common causes of mucosal and invasive fungal infections in humans. Especially Candida albicans commonly resides as a commensal in the mucosal tissues of approximately half of the human population. When the balance of the normal flora is disrupted or the immune defenses are compromised, Candida species can become pathogenic, often causing recurrent disease in susceptible individuals.

The treatments available for Candida infection are commonly drug-based and can involve topical and systemic antifungal agents. However, the use of standard antifungal therapies can be limited because of toxicity, low efficacy rates, and drug resistance. Candida species ability to produce drug-resistant biofilm is an important factor in human infections, because microorganisms within biofilm benefit from various advantages over their planktonic counterparts including protection from antimicrobials and chemicals. These limitations emphasize the need to develop new and more effective antifungal agents. Natural products are attractive alternatives for this purpose due to their broad spectrum of biological activities. Farnesol is produced by many microorganisms and found in some essential oils. It has also a great attention as a quorum-sensing molecule and virulence factor. It has also antimicrobial potential due to its inhibitory effects on various bacteria and fungi. However, as it is a hydrophobic component, its solubility and biofilm inhibiting properties are limited.

To overcome these shortcomings, nanoparticle-based drug delivery systems have been successfully used. For this purpose, especially using biodegradable polymeric nanoparticles has gained increasing attention owing to their biocompatibility and minimal toxicity. Poly (DL-lactide-co-glycolide) (PLGA) is the most widely used polymer in this area. In this study, farnesol is loaded to PLGA nanoparticles (F-PLGA NPs) by emulsion evaporation method and characterized by DLS, TEM, and FT-IR analyses. Our TEM findings indicate that the sizes of F-PLGA NPs are approximately 140 nm. The effects of F-PLGA NPs on planktonic cells and biofilm formation of C. albicans were compared with effects of farnesol alone. Farnesol inhibits the growth at a range of 53% at a concentration of 2.5 μL compared to the control group. This rate is 45% for F-PLGA NPs at the same concentration. However, although farnesol amount in F-PLGA is approximately 22.5% of the total volume, the observed effect is significant. In TEM examinations, planktonic Candida cells treated with farnesol showed relatively regular ultrastructural morphology. Few membrane and wall damage and electron density in the cytoplasm were determined. In F-PLGA NP-treated cells, increased irregular cell morphology, membrane and wall damages, and large vacuoles are observed. Our SEM and XTT data suggest that F-PLGA NPs can reduce the biofilm formation at lower concentrations than farnesol alone 57%, and our results showed that F-PLGA NPs are effective and biocompatible alternatives for inhibiting growth and biofilm formation of C. albicans, but detailed studies are needed.

Microbiota-driven interleukin-17 production provides immune protection against invasive candidiasis

Background

The intestinal microbiota plays a crucial role in human health, which could affect host immunity and the susceptibility to infectious diseases. However, the role of intestinal microbiota in the immunopathology of invasive candidiasis remains unknown.

Methods

In this work, an antibiotic cocktail was used to eliminate the intestinal microbiota of conventional-housed (CNV) C57/BL6 mice, and then both antibiotic-treated (ABX) mice and CNV mice were intravenously infected with Candida albicans to investigate their differential responses to infection. Furthermore, fecal microbiota transplantation (FMT) was applied to ABX mice in order to assess its effects on host immunity against invasive candidiasis after restoring the intestinal microbiota, and 16S ribosomal RNA gene sequencing was conducted on fecal samples from both uninfected ABX and CNV group of mice to analyze their microbiomes.

Results

We found that ABX mice displayed significantly increased weight loss, mortality, and organ damage during invasive candidiasis when compared with CNV mice, which could be alleviated by FMT. In addition, the level of IL-17A in ABX mice was significantly lower than that in the CNV group during invasive candidiasis. Treatment with recombinant IL-17A could improve the survival of ABX mice during invasive candidiasis. Besides, the microbial diversity of ABX mice was significantly reduced, and the intestinal microbiota structure of ABX mice was significantly deviated from the CNV mice.

Conclusions

Our data revealed that intestinal microbiota plays a protective role in invasive candidiasis by enhancing IL-17A production in our model system.

The Pharmaceutical Ability of Pistacia lentiscus L. Leaves Essential Oil Against Periodontal Bacteria and Candida sp. and Its Anti-Inflammatory Potential

BACKGROUND

Given the increasing request for natural pharmacological molecules, this study assessed the antimicrobial capacity of Pistacia lentiscus L. essential oil (PLL-EO) obtained from the leaves of wild plants growing in North Sardinia (Italy) toward a wide range of periodontal bacteria and Candida, including laboratory and clinical isolates sp., together with its anti-inflammatory activity and safety.

METHODS

PLL-EO was screened by gas chromatography/mass spectrometry. The minimal inhibitory concentration (MIC) was determined. The anti-inflammatory activity was measured by cyclooxygenase (COX-1/2) and lipoxygenase (LOX) inhibition, while the antioxidant capacity was determined electro-chemically and by the MTT assay. The WST-1 assay was used to ascertain cytotoxicity toward four lines of oral cells.

RESULTS

According to the concentrations of terpens, PLL-EO is a pharmacologically-active phytocomplex. MICs against periodontal bacteria ranged between 3.13 and 12.5 µg/ml, while against Candida sp. they were between 6.25 and 12.5 µg/mL. Oxidation by COX-1/2 and LOX was inhibited by 80% and 20% µg/mL of the oil, respectively. Antioxidant activity seemed negligible, and no cytotoxicity arose.

CONCLUSIONS

PLL-EO exhibits a broad-spectrum activity against periodontal bacteria and Candida, with an interesting dual inhibitory capacity toward COX-2 and LOX inflammatory enzymes, and without side effects against oral cells.

Expression of ERG11 and efflux pump genes CDR1, CDR2 and SNQ2 in voriconazole susceptible and resistant Candida glabrata strains

Candida glabrata causes difficult to treat invasive candidiasis due to its antifungal resistance, mainly to azoles. The aim of the present work was to study the role of the genes ERG11, CDR1, CDR2, and SNQ2 on the resistance to voriconazole (VRC) in a set of C. glabrata strains with known in vitro and in vivo susceptibility to this drug. Eighteen clinical isolates of C. glabrata were exposed in vitro to VRC, and the expression of the cited genes was quantified by real time quantitative polymerase chain reaction (q-PCR). In addition, the ERG11 gene was amplified and sequenced to detect possible mutations. Ten synonymous mutations were found in 15 strains, two of them being reported for the first time; however, no amino acid changes were detected. ERG11 and CDR1 were the most expressed genes in all the strains tested, while the expression of CDR2 and SNQ2 was modest. Our results show that gene expression does not directly correlate with the VRC MIC. In addition, the expression profiles of ERG11 and efflux pump genes did not change consistently after exposure to VRC. Although individual analysis did not result in a clear correlation between MIC and gene expression, we did observe an increase in ERG11 and CDR1 expression in resistant strains. It is of interest that considering both in vitro and in vivo results, the slight increase in such gene expression correlates with the observed resistance to VRC.

Rapid species identification of Candida directly from blood culture broths by Sepsityper-MALDI-TOF mass spectrometry: impact on antifungal therapy

Rapid identification of Candida species facilitates pathogen-directed therapy with either fluconazole or an echinocandin.

METHOD

We applied Sepsityper matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI-TOF-MS) technology on positive blood culture broths for rapid species identification.

RESULTS

Of the 74 patients with candidaemia, 25 had the species identified on the day of the positive blood culture directly from the broth (rapid identification group) while the remaining 49 had the species identified from culture (conventional identification group). Three (13.6%) out of 22 treated patients in the rapid identification group received echinocandin compared to 20/45 (44.4%) in the conventional identification group. The appropriateness of therapy was 90.9% in the rapid identification group and 62.2% in the conventional identification group (p = 0.01). Cost savings were more than £10,000 in the first three days of treatment.

CONCLUSION

Sepsityper-MALDI-TOF-MS is a useful tool in supporting antifungal stewardship programmes.

Probiotic Yeasts Inhibit Virulence of Non-albicans Candida Species

Systemic infections of Candida species pose a significant threat to public health. Toxicity associated with current therapies and emergence of resistant strains present major therapeutic challenges. Here, we report exploitation of the probiotic properties of two novel, food-derived yeasts, Saccharomyces cerevisiae (strain KTP) and Issatchenkia occidentalis (strain ApC), as an alternative approach to combat widespread opportunistic fungal infections. Both yeasts inhibit virulence traits such as adhesion, filamentation, and biofilm formation of several non-albicans Candida species, including Candida tropicalis, Candida krusei, Candida glabrata, and Candida parapsilosis as well as the recently identified multidrug-resistant species Candida auris They inhibit adhesion to abiotic surfaces as well as cultured colon epithelial cells. Furthermore, probiotic treatment blocks the formation of biofilms of individual non-albicans Candida strains as well as mixed-culture biofilms of each non-albicans Candida strain in combination with Candida albicans The probiotic yeasts attenuated non-albicans Candida infections in a live animal. In vivo studies using Caenorhabditis elegans suggest that exposure to probiotic yeasts protects nematodes from infection with non-albicans Candida strains compared to worms that were not exposed to the probiotic yeasts. Furthermore, application of probiotic yeasts postinfection with non-albicans Candida alleviated pathogenic colonization of the nematode gut. The probiotic properties of these novel yeasts are better than or comparable to those of the commercially available probiotic yeast Saccharomyces boulardii, which was used as a reference strain throughout this study. These results indicate that yeasts derived from food sources could serve as an effective alternative to antifungal therapy against emerging pathogenic Candida species.IMPORTANCE Non-albicans Candida-associated infections have emerged as a major risk factor in the hospitalized and immunecompromised patients. Besides, antifungal-associated complications occur more frequently with these non-albicans Candida species than with C. albicans Therefore, as an alternative approach to combat these widespread non-albicans Candida-associated infections, here we showed the probiotic effect of two yeasts, Saccharomyces cerevisiae (strain KTP) and Issatchenkia occidentalis (ApC), in preventing adhesion and biofilm formation of five non-albicans Candida strains, Candida tropicalis, Candida krusei, Candida glabrata, Candida parapsilosis, and Candida auris The result would influence the current trend of the conversion of conventional antimicrobial therapy into beneficial probiotic microbe-associated antimicrobial treatment.

Genetic diversity of Candida albicans isolates recovered from hospital environments and patients with severe acquired brain injuries

Although the epidemiology of pathogenic Candida species causing invasive human diseases is changing, Candida albicans still remains the most common cause of bloodstream infections worldwide. The propensity of this pathogen to cause infections is undoubtedly the result of its unique genetic plasticity that allow it to adapt and respond quickly to a myriad of changing conditions both in the host and in the environment. For this reason, we decided to investigate the genetic diversity of this important fungal pathogen in a particular category of patients with severe neurological deficits including the hospital environments where they are hospitalized. Genetic diversity of 21 C. albicans isolates recovered from blood, hands of healthcare workers and hospital environments was evaluated by using multilocus sequence typing (MLST) which revealed a high genetic heterogeneity with a set of 18 diploid sequence types (DSTs) recovered among 21 isolates investigated. Interestingly, 13 of these 18 MLST genotypes were completely new and added to the C. albicans MLST central database. Six eBURST clonal complexes (CC-1, CC-2, CC-6, CC-9, CC-27 and CC-42) and three singletons contained all DSTs found in this study. Among all the new DSTs identified, DST3388 was the most intriguing as this genotype was recovered from a typical C. albicans isolate clustering within the MLST-Clade 13, the most divergent evolutionary lineage within C. albicans population containing only isolates with unusual phenotypes originally known as Candida africana. In conclusion, the results of this study expand our understanding of the molecular epidemiology and global population structure of C. albicans suggesting that further studies on different categories of patients and hospital environments are needed to better understand how the population of this species adapts and evolves in heterogeneous hosts and changing environments.

Recent trends in molecular diagnostics of yeast infections: from PCR to NGS

The incidence of opportunistic yeast infections in humans has been increasing over recent years. These infections are difficult to treat and diagnose, in part due to the large number and broad diversity of species that can underlie the infection. In addition, resistance to one or several antifungal drugs in infecting strains is increasingly being reported, severely limiting therapeutic options and showcasing the need for rapid detection of the infecting agent and its drug susceptibility profile. Current methods for species and resistance identification lack satisfactory sensitivity and specificity, and often require prior culturing of the infecting agent, which delays diagnosis. Recently developed high-throughput technologies such as next generation sequencing or proteomics are opening completely new avenues for more sensitive, accurate and fast diagnosis of yeast pathogens. These approaches are the focus of intensive research, but translation into the clinics requires overcoming important challenges. In this review, we provide an overview of existing and recently emerged approaches that can be used in the identification of yeast pathogens and their drug resistance profiles. Throughout the text we highlight the advantages and disadvantages of each methodology and discuss the most promising developments in their path from bench to bedside.

Candidaemia and a risk predictive model for overall mortality: a prospective multicentre study

Background

Candidaemia is associated with high mortality. Variables associated with mortality have been published previously, but not developed into a risk predictive model for mortality. We sought to describe the current epidemiology of candidaemia in Australia, analyse predictors of 30-day all-cause mortality, and develop and validate a mortality risk predictive model.

Methods

Adults with candidaemia were studied prospectively over 12 months at eight institutions. Clinical and laboratory variables at time of blood culture-positivity were subject to multivariate analysis for association with 30-day all-cause mortality. A predictive score for mortality was examined by area under receiver operator characteristic curves and a historical data set was used for validation.

Results

The median age of 133 patients with candidaemia was 62 years; 76 (57%) were male and 57 (43%) were female. Co-morbidities included underlying haematologic malignancy (n = 20; 15%), and solid organ malignancy in (n = 25; 19%); 55 (41%) were in an intensive care unit (ICU). Non-albicans Candida spp. accounted for 61% of cases (81/133). All-cause 30-day mortality was 31%. A gastrointestinal or unknown source was associated with higher overall mortality than an intravascular or urologic source (p < 0.01). A risk predictive score based on age > 65 years, ICU admission, chronic organ dysfunction, preceding surgery within 30 days, haematological malignancy, source of candidaemia and antibiotic therapy for ≥10 days stratified patients into < 20% or ≥ 20% predicted mortality. The model retained accuracy when validated against a historical dataset (n = 741).

Conclusions

Mortality in patients with candidaemia remains high. A simple mortality risk predictive score stratifying patients with candidaemia into < 20% and ≥ 20% 30-day mortality is presented. This model uses information available at time of candidaemia diagnosis is easy to incorporate into decision support systems. Further validation of this model is warranted.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4065-5) contains supplementary material, which is available to authorized users.

Diagnostic Performance of T2Candida Among ICU Patients With Risk Factors for Invasive Candidiasis

Background

Invasive candidiasis (IC) comprises candidemia and deep-seated candidiasis. Blood culture (BC) is the gold standard test, but sensitivity is low. T2Candida is a new diagnostic test. We investigated the performance of T2Candida, BC, and Candida mannan antigen (MAg) for detection of IC in a high-risk intensive care unit (ICU) population.

Methods

One-hundred twenty-six ICU patients at high risk of IC with sepsis despite 3 days of broad-spectrum antibiotics were included. Paired BC, T2Candida, and MAg were obtained twice weekly (334 sets). Patients were classified into proven, likely, possible, or unlikely IC based on patient record review.

Results

At enrollment, 92 (77%) patients were receiving antifungal therapy (mainly fluconazole 66%). Fifteen (11.9%) patients were positive by BC (n = 4), T2Candida (n = 11), or MAg (n = 10). The T2Candida species distribution at inclusion (Candida albicans/Candida tropicalis: 8/11 [72.3%] and Candida glabrata/Candida krusei: 3/11 [27.3%]) was supported by the identification of BC or colonizing isolates in 10/11 cases. Patients were classified with proven (11), likely (6), possible (11), and unlikely (98) IC. Defining IC as proven/proven&likely/proven&likely&possible, respectively, the sensitivity was as follows: T2Candida (55%/59%/39%), BC (45%/29%/ 8%), and MAg (36%/41%/32%). The negative predictive value was similar across the tests for proven vs others and proven/likely vs others (94%–96% and 90%–95%, respectively). For test combinations including T2Candida, the sensitivity increased to 64%–65%, without hampering the positive predictive value.

Conclusions

In conclusion, although the diagnostic performance was modest for all the tests, the combination of T2Candida and BC seemed to have the best diagnostic performance, and thus implementation of T2Candida may improve the diagnosis of IC.

Antifungal susceptibility of yeast bloodstream isolates collected during a 10-year period in Austria

BACKGROUND

Candida-associated infections put a significant burden on western healthcare systems. Development of (multi-)resistant fungi can become untreatable and threaten especially vulnerable target groups, such as the immunocompromised.

OBJECTIVES

We assessed antifungal susceptibility and explored possible influence factors of clinical Candida isolates collected from Austrian hospitals between 2007 and 2016.

METHODS

Thousand three hundred and sixty clinical Candida spp. isolated from blood cultures were subjected to antifungal susceptibility testing (AFST) in a liquid-handling aided continuous microdilution assay. We tested against fluconazole, voriconazole, posaconazole, itraconazole, isavuconazole, anidulafungin, caspofungin and micafungin according to EUCAST with additional recording of growth curves. We performed rigid quality control on each assay via growth curve assessment and included two standard reference strains. Minimal inhibitory concentrations (MIC) were quantified according to EUCAST guideline E.DEF 7.3.1, and susceptibility was evaluated using EUCAST clinical breakpoints.

RESULTS

The isolate collection consisted of Candida albicans (59%), C. glabrata (19%), C. parapsilosis (9%), C. tropicalis (5%) and C. krusei (3%) and few other Candida species and fungi (5%). During the observed time period, species abundance and antifungal resistance rates remained constant. Multi-resistance was rare and we found no single isolate which was resistant to both azoles and echinocandins. Within the antifungal resistance profile of our strain collection, we observed clusters along species boundaries.

CONCLUSIONS

Over the last decade, the distribution of Candida species and its level of antifungal resistance remained constant in Austria. Our data compare well with other European countries. Principal component analysis of the susceptibility profile of this collection revealed species-specific clusters and substantial intra-species variation, especially for C. glabrata.

Treatment of candidemia in a nationwide setting: increased survival with primary echinocandin treatment

Background

In accordance with international guidelines, primary antifungal treatment (AFT) of candidemia with echinocandins has been nationally recommended in Denmark since 2009. Our nationwide cohort study describes the management of candidemia treatment focusing on the impact of prophylactic AFT on species distribution, the rate of adherence to the recommended national guidelines for AFT, and the effect of AFT on patient outcomes.

Materials and methods

Incident candidemia cases from a 2-year period, 2010-2011, were included. Information on AFT was retrospectively collected from patient charts. Vital status was obtained from the Danish Civil Registration System. HRs of mortality were reported with 95% CIs using Cox regression.

Results

A total of 841 candidemia patients was identified. Prior to candidemia diagnosis, 19.3% of patients received AFT (162/841). The risk of non-albicans candidemia increased after prior AFT (59.3% vs 45.5% among nontreated). Echinocandins as primary AFT were given for 44.2% (302/683) of patients. Primary treatment with echinocandins resulted in adequate treatment in a higher proportion of patients (97.7% vs 72.1%) and was associated with lower 0- to 14-day mortality compared with azole treatment (adj. HR 0.76, 95% CI: 0.55-1.06). Significantly lower 0- to 14-day mortality was observed for patients with Candida glabrata and Candida krusei with echinocandin treatment compared with azole treatment (adj. HR 0.50, 95% CI: 0.28-0.89), but not for patients with Candida albicans or Candida tropicalis.

Conclusion

The association shown between prior AFT and non-albicans species underlines the importance of treatment history when selecting treatment for candidemia. Compliance with national recommendations was low, but similar to previously reported international rates. Primary treatment of candidemia with echinocandins compared with azoles yielded both a higher proportion of adequately treated patients and improved mortality rates. This real-life setting supports guidelines recommendation, and further focus on compliance with these seems warranted.

High incidence of candidaemia in a nationwide cohort: Underlying diseases, risk factors and mortality

BACKGROUND

Denmark has a high incidence rate of candidaemia. A Nordic study suggested a higher Danish prevalence of haematological malignancies as an underlying reason. This nationwide study ascertained clinical characteristics of Danish candidaemia patients and investigated potential factors contributing to the high incidence and mortality.

METHODS

Microbiological and clinical data for candidaemia patients in 2010-2011 were retrieved. 30-day mortality was estimated by hazard ratios (HR) with 95% confidence intervals (CI, Cox regression).

RESULTS

Data were available for 912/973 candidaemia episodes (93.7%). Intensive care unit (ICU) held the largest share of patients (43.2%). Prevalent host factors were multi-morbidity (≥2 underlying diseases, 74.2%) and gastrointestinal disease (52.5%). Haematological disease was infrequent (7.8%). Risk factors included antibiotic exposure (90.5%), CVC (71.9%) and Candida colonisation (66.7%). 30-day mortality was 43.4%, and 53.6% in ICU. Mortality was lower for patients with recent abdominal surgery (HR 0.70, 95% CI: 0.54-0.92).

CONCLUSION

A substantial prevalence of multi-morbidity and a high 30-day mortality was found. We hypothesise, that an increasing population of severely ill patients with prolonged supportive treatment and microbiological testing may in part explain the high candidaemia incidence in Denmark. Nationwide studies are warranted to clarify this issue.

Molecular Analysis of Resistance and Detection of Non-Wild-Type Strains Using Etest Epidemiological Cutoff Values for Amphotericin B and Echinocandins for Bloodstream Candida Infections from a Tertiary Hospital in Qatar

A total of 301 Candida bloodstream isolates collected from 289 patients over 5 years at a tertiary hospital in Qatar were evaluated. Out of all Candida infections, 53% were diagnosed in patients admitted to the intensive care units. Steady increases in non-albicans Candida species were reported from 2009 to 2014 (30.2% for Candida albicans versus 69.8% for the other Candida species). Etest antifungal susceptibility testing was performed on all recovered clinical isolates to determine echinocandin (micafungin and anidulafungin) and amphotericin B susceptibilities and assess non-wild-type (non-WT) strains (strains for which MICs were above the epidemiological cutoff values). DNA sequence analysis was performed on all isolates to assess the presence of FKS mutations, which confer echinocandin resistance in Candida species. A total of 3.9% of isolates (12/301) among strains of C. albicans and C. orthopsilosis contained FKS hot spot mutations, including heterozygous mutations in FKS1 For C. tropicalis, the Etest appeared to overestimate strains non-WT for micafungin, anidulafungin, and amphotericin B, as 14%, 11%, and 35% of strains, respectively, had values above the epidemiological cutoff value. However, no FKS mutations were identified in this species. For all other species, micafungin best reported the echinocandin non-WT strains relative to the FKS genotype, as anidulafungin tended to overestimate non-wild-type strains. Besides C. tropicalis, few strains were classified as non-WT for amphotericin B.

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

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

The continuous changes in the aetiology and epidemiology of invasive candidiasis: from familiar Candida albicans to multiresistant Candida auris

Recent changes in the aetiology and epidemiology of invasive candidiasis have serious implications for current and future diagnosis, treatment and prognosis. The aim of the current review was to discuss the epidemiology of invasive candidiasis, the distribution of Candida species in different regions of the world, the medical concerns of the changing aetiology and the emergence of antifungal resistance. Overall burden of invasive candidiasis remains high, especially in vulnerable persons, such as the elderly, immunosuppressed or debilitated patients. Moreover, there is a progressive shift in the aetiology of invasive candidiasis from Candida albicans to other species of Candida, probably related to the increased use of azole drugs with a clear trend towards increased antifungal resistance. Finally, the emergence and rise of multiresistant species, such as Candida auris or Candida glabrata, is a major threat making necessary invasive candidiasis worldwide surveillances. These changes have serious implications for the diagnosis, treatment and prognosis of invasive candidiasis. Updated knowledge of the current local epidemiology of invasive candidiasis is critical for the clinical management.

Do we need to adopt antifungal stewardship programmes?

Background

Although antimicrobial stewardship programmes are one of the highest priorities in healthcare systems and many articles have been published, few refer to the implementation of antifungal stewardship and highlight specific points on which efforts should be focused.

Objective

To assess the percentage of patients with confirmed candidaemia in whom de-escalation was conducted, and the economic impact of step-down or step-up antifungal therapy. Additionally, we attempted to estimate the potential increase in drug minimum inhibitory concentrations or to detect resistant strains of Candida species.

Methods

We selected, retrospectively, patients who had received systemic antifungal therapy between 2011 and 2016 for documented candidaemia. Statistical analysis and diagrams were used to assess the results.

Results

Of 157 patients with confirmed candidaemia, 58 received azoles, 74 echinocandinsand 18 liposomal amphotericin B for empirical therapy. 51 patients were eligible to step-down to fluconazole but only 23 patients did so. Furthermore, in nine patients unjustified step-up from fluconazole to echinocandins or liposomal amphotericin B was carried out. The additional cost incurred bythe healthcare system due to high prices of echinocandins and liposomal amphotericin B in comparison with fluconazole was€211 837. Interestingly, it was found that one strain of C. albicans and two strains of C. glabrata were resistant to echinocandins.

Conclusion

The presence of a multidisciplinary team, including an infection control specialist and a clinical pharmacist, would limit the prescription of advanced antifungal agents as empirical therapy. Moreover, this team would control the de-escalation process-where applicable-leading to a reduction in costs and, probably, a decrease in the emergence of resistant Candida species. These facts contribute to the broader discussion on the adoption of antifungal stewardship programmes.

Diabetes, malignancy and age as predictors of Candida glabrata bloodstream infection: A re-evaluation of the risk factors

OBJECTIVE

Echinocandins and azoles are widely used in the treatment of candidaemia. Guidelines of the Infectious Diseases Society of America recommend commencing treatment with an echinocandin in candidaemic patients with risk factors for Candida glabrata i.e. patients who are elderly, or who have diabetes or malignancy, or those with recent prescription of azoles. We attempted to validate whether age, diabetes and malignancy are associated with C. glabrata candidaemia.

PATIENTS, MATERIALS AND METHODS

Information in relation to demographics, patient associated risk factors, and laboratory parameters were collected from the casenotes and the laboratory information system. We then analysed the distribution of the risk factors (age, diabetes, and malignancy) in candidaemic patients with C. glabrata and patients with species other than C. glabrata (excluding Candida krusei).

RESULTS

Over a 42-month period (April 2011-September 2017), 124 patients had candidaemia. We analysed data for 119 patients of whom 33 (27.7%) had C. glabrata and the remaining 86 (72.2%) were infected with other species. Sixty-five patients were elderly (age≥65), 40 had some form of malignancy, 34 had diabetes, and 4 patients were prescribed azoles in the 30 days prior to candidaemia (many patients had multiple risk factors). Comparing patients with C. glabrata to patients infected with other species, we found no association with diabetes (39.3% vs. 24.4%, P=0.1), malignancy (36.3 vs. 32.5%, P=0.69), and age (54.5% vs. 54.6%, P=0.99).

CONCLUSIONS

Diabetes, malignancy and age are not reliable predictors of candidaemia due to C. glabrata.

Biofilm-Forming Capability of Highly Virulent, Multidrug-Resistant Candida auris

The emerging multidrug-resistant yeast pathogen Candida auris has attracted considerable attention as a source of healthcare–associated infections. We report that this highly virulent yeast has the capacity to form antifungal resistant biofilms sensitive to the disinfectant chlorhexidine in vitro.

Gaining Insights from Candida Biofilm Heterogeneity: One Size Does Not Fit All

Despite their clinical significance and substantial human health burden, fungal infections remain relatively under-appreciated. The widespread overuse of antibiotics and the increasing requirement for indwelling medical devices provides an opportunistic potential for the overgrowth and colonization of pathogenic Candida species on both biological and inert substrates. Indeed, it is now widely recognized that biofilms are a highly important part of their virulence repertoire. Candida albicans is regarded as the primary fungal biofilm forming species, yet there is also increasing interest and growing body of evidence for non-Candida albicans species (NCAS) biofilms, and interkingdom biofilm interactions. C. albicans biofilms are heterogeneous structures by definition, existing as three-dimensional populations of yeast, pseudo-hyphae, and hyphae, embedded within a self-produced extracellular matrix. Classical molecular approaches, driven by extensive studies of laboratory strains and mutants, have enhanced our knowledge and understanding of how these complex communities develop, thrive, and cause host-mediated damage. Yet our clinical observations tell a different story, with differential patient responses potentially due to inherent biological heterogeneity from specific clinical isolates associated with their infections. This review explores some of the recent advances made in an attempt to explore the importance of working with clinical isolates, and what this has taught us.

Up-regulation of chemokine CXCL13 in systemic candidiasis

Candida albicans is the leading cause of healthcare associated bloodstream infections. Chemokine CXCL13 is well-known involved in inflammation, but its role in candidemia has not been assessed. Our study firstly demonstrated that serum CXCL13 levels were significantly elevated in candidemic patients compared with bacteremic patients and control subjects by ELISA, and CXCL13 concentrations were positively and significantly correlated with clinical Sequential Organ Failure Assessment (SOFA) scores and several laboratory parameters in patients. Moreover, ROC curve analysis showed the diagnostic efficiency of CXCL13 was superior to CRP and PCT. To further study the role of CXCL13, a mouse model was established. Importantly, the data showed the dramatically elevated levels of CXCL13 in mice serum and infected kidney, were significantly correlated with renal fungal burden and pathology scores. In conclusion, our results indicated that CXCL13 had strong potential as a novel biomarker of diagnosis and prognosis for candidemia.

ICU-acquired candidaemia in France: Epidemiology and temporal trends, 2004-2013 - A study from the REA-RAISIN network

OBJECTIVE

Candidaemia is a life-threatening infectious disease, associated with septic shock, multiple organ failure, and a high mortality rate. In France, reported data on the incidence of ICU-acquired candidaemia and the causative Candida species are scarce. The objective of this study was to determine temporal trends in epidemiology and risk factors of intensive care unit-acquired candidaemia (ICU-Cand) and ICU mortality among a very large population of ICU patients.

METHOD

Demographics, patient risk factors, invasive device exposure and nosocomial infection in ICU patient were collected from 2004 to 2013 in a national network of 213 ICUs: REA-RAISIN. Incidence and risk factors for candidaemia and ICU mortality were assessed.

RESULTS

Out of 246,459 ICU patients, 851 developed an ICU-cand, representing 0.3 per 1000 patients-days. The incidence rose sharply over time. Candida albicans was the main species. The overall and ICU mortality was 52.4% in ICU-cand patients. The main risk factors of ICU-cand were length of stay, severity of illness and antimicrobial therapy at ICU admission, immune status and use of invasive procedure. ICU-cand was an independent risk factor of mortality (OR: 1.53; 95%CI [1.40-1.70]); in a sub-group analysis, independent effects on mortality were observed with C. albicans (OR: 1.45 [1.23-1.71]), Candida tropicalis (OR: 2.11 [1.31-3.39]) and "other" Candida species (OR: 1.64 [1.09-2.45]).

CONCLUSION

ICU candidaemia ranked sixth among bloodstream infections, and its average annual incidence was 0.3 per 1000 patients days. Despite of new therapy and international recommendation, the incidence rose sharply during the study period, and ICU mortality remained high.

Candida albicans Mycofilms Support Staphylococcus aureus Colonization and Enhances Miconazole Resistance in Dual-Species Interactions

Polymicrobial inter-kingdom biofilm infections represent a clinical management conundrum. The presence of co-isolation of bacteria and fungi complicates the ability to routinely administer single antimicrobial regimens, and synergy between the microorganisms influences infection severity. We therefore investigated the nosocomial pathogens Staphylococcus aureus and Candida albicans with respect to antimicrobial intervention. We characterized the interaction using biofilm assays and evaluated the effect of miconazole treatment using in vitro and in vivo assays. Finally, we assessed the impact of biofilm extracellular matrix (ECM) on these interactions. Data indicated that the C. albicans mycofilms supported adhesion and colonization by S. aureus through close interactions with hyphal elements, significantly increasing S. aureus biofilm formation throughout biofilm maturation. Miconazole sensitivity was shown to be reduced in both mono- and dual-species biofilms compared to planktonic cells. Within a three-dimensional biofilm model sensitivity was also hindered. Galleria mellonella survival analysis showed both enhanced pathogenicity of the dual-species infection, which was concomitantly desensitized to miconazole treatment. Analysis of the ECM revealed the importance of extracellular DNA, which supported the adhesion of S. aureus and the development of the dual-species biofilm structures. Collectively, these data highlight the clinical importance of dual-species inter-kingdom biofilm infections, though also provides translational opportunities to manage them more effectively.

The application of phenotypic microarray analysis to anti-fungal drug development

Candida albicans metabolic activity in the presence and absence of acetylcholine was measured using phenotypic microarray analysis. Acetylcholine inhibited C. albicans biofilm formation by slowing metabolism independent of biofilm forming capabilities. Phenotypic microarray analysis can therefore be used for screening compound libraries for novel anti-fungal drugs and measuring antifungal resistance.