Executive Summary: Clinical Practice Guideline for the Management of Candidiasis: 2016 Update by the Infectious Diseases Society of America

Congenital Cutaneous Candidiasis: Prompt Systemic Treatment Is Associated With Improved Outcomes in Neonates

Background

Congenital cutaneous candidiasis (CCC) is a challenging diagnosis due to various rash presentations. Inadequate early treatment is associated with high rates of dissemination and death. The effects of early diagnosis, dermatologic presentation, and antifungal treatment on outcomes are lacking.

Methods

CCC cases were reviewed from 2 academic neonatal intensive care units (NICUs) from 2004 to 2015. We defined CCC as a diffuse rash involving the body, extremities, face or scalp, and/or funisitis, presenting in the first week (≤7 days), with identification of Candida species from skin or mucous membrane cultures, and/or by culture or staining of the placenta or umbilical cord.

Results

CCC occurred in 0.1% of all NICU admissions (21 of 19 303) and 0.6% of infants <1000 grams birth weight. Median gestational age of CCC infants was 26 3/7 (range, 23 0/7-40 4/7) weeks. Skin findings were commonly present on the day of birth [median (range): 0 (0-6) days], appearing most frequently as a desquamating, maculopapular, papulopustular, and/or erythematous diffuse rash. When systemic antifungal therapy was started empirically at the time of rash presentation and continued for a median (interquartile range) of 14 (14-15) days, all patients survived and none developed dissemination. Delaying systemic treatment, exclusive use of nystatin, and treating for <10 days was associated with Candida bloodstream dissemination.

Conclusions

CCC is an invasive infection that presents as a diffuse rash in preterm and term infants. Prompt systemic antifungal treatment at the time of skin presentation for ≥14 days prevents dissemination and Candida-related mortality.

Transcription factor network efficiency in the regulation of Candida albicans biofilms: it is a small world

Complex biological processes are frequently regulated through networks comprised of multiple signaling pathways, transcription factors, and effector molecules. The identity of specific genes carrying out these functions is usually determined by single mutant genetic analysis. However, to understand how the individual genes/gene products function, it is necessary to determine how they interact with other components of the larger network; one approach to this is to use genetic interaction analysis. The human fungal pathogen Candida albicans regulates biofilm formation through an interconnected set of transcription factor hubs and is, therefore, an example of this type of complex network. Here, we describe experiments and analyses designed to understand how the C. albicans biofilm transcription factor hubs interact and to explore the role of network structure in its overall function. To do so, we analyzed published binding and genetic interaction data to characterize the topology of the network. The hubs are best characterized as a small world network that functions with high efficiency and low robustness (high fragility). Highly efficient networks rapidly transmit perturbations at given nodes to the rest of the network. Consistent with this model, we have found that relatively modest perturbations, such as reduction in the gene dosage of hub transcription factors by one-half, lead to significant alterations in target gene expression and biofilm fitness. C. albicans biofilm formation occurs under very specific environmental conditions and we propose that the fragile, small world structure of the genetic network is part of the mechanism that imposes this stringency.

Feasibility and applicability of antimicrobial stewardship in immunocompromised patients

PURPOSE OF REVIEW

Antimicrobial stewardship is the primary intervention in the battle against antimicrobial resistance, but clinicians do not always apply many key antimicrobial stewardship principles to patients with significant immune defects due to lack of data and fear of bad outcomes. We review evidence regarding the application of stewardship principles to immunocompromised patients, with a focus on solid organ and hematopoietic stem cell transplant recipients.

RECENT FINDINGS

Antimicrobial stewardship programs (ASPs), targeting immunocompromised patient populations such as oncology and transplant, are gaining traction. Emerging literature suggests that several stewardship interventions can be adapted to immunocompromised hosts and improve antimicrobial utilization, but data supporting improved outcomes is very limited.

SUMMARY

The application of antimicrobial stewardship principles to immunocompromised patients is feasible, necessary, and urgent. As antimicrobial stewardship programs gain momentum across a diverse range of healthcare settings more immunocompromised patients will fall under their purview. It is imperative that centers applying antimicrobial stewardship principles share their experience and establish collaborative research efforts to advance our knowledge base in applying antimicrobial stewardship initiatives to immunocompromised host populations, both in terms of programmatic success and patient outcomes.

What Could Be the Role of Antifungal Lock-Solutions? From Bench to Bedside

Candidemia related to the presence of a biofilm are often reported in patients with vascular catheters. Once they are mature, biofilms are persistent infectious reservoirs, and the yeasts dispersed from biofilms can cause infections. Sessile yeasts typically display increased levels of resistance to most antimicrobial agents and systemic treatments usually fail to eradicate previously formed fungal biofilms. In a curative strategy, antifungal lock therapy may help to sterilize catheters, with very high concentrations of antifungal agents, which are not compatible with systemic use. This strategy has been studied by several authors in in vitro and in vivo studies, and more rarely, in clinical settings for adult and paediatric patients. Our study aims to assess the efficacy of the antifungal solutions used for lock therapy and demonstrated by the different teams.

Management of bloodstream infections by infection specialists: an international ESCMID cross-sectional survey

Bloodstream infections (BSIs) are common, however international guidelines are available only for methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia and candidaemia. This international ESCMID cross-sectional survey, open from December 2016 to February 2017, explored the management of BSIs by infection specialists. All infection specialists (senior or trainees) giving at least weekly advice on positive blood cultures could participate. Their practices were evaluated using six clinical vignettes presenting uncomplicated BSI cases. A total of 616 professionals from 56 countries participated [333/616 (54%) infectious diseases specialists, 188/616 (31%) clinical microbiologists], of whom 76% (468/616) were members of an antimicrobial stewardship team. Large variations in practice were noted, in particular for the Escherichia coli, Enterococcus faecalis and Pseudomonas aeruginosa vignettes. Echocardiography was considered standard of care by 81% (373/459) of participants for MRSA, 78% (400/510) for methicillin-susceptible S. aureus and 60% (236/395) for Candida albicans. Antimicrobial combination therapy was recommended by 2% (8/360) of respondents for C. albicans, 11% (43/378) for E. coli, 27% (114/420) for MRSA and 39% (155/393) for E. faecalis. Intravenous-to-oral switch was considered in 68% (285/418) for MRSA, 79% (306/388) for E. faecalis, 72% (264/366) for P. aeruginosa and 75% (270/362) for C. albicans. In multivariable analysis, IDSA guideline-compliant practice was more frequent among participants belonging to an antimicrobial stewardship team (aOR = 1.7, P = 0.018 for the MRSA vignette; and aOR = 2.0, P = 0.008 for the candidaemia vignette). This survey showed large variations in practice among infection specialists. International guidelines on management of BSI are urgently needed.

Chronic disseminated candidiasis and acute leukemia: Impact on survival and hematopoietic stem cell transplantation agenda

OBJECTIVES

To study the management of chronic disseminated candidiasis (CDC) in patients presenting with acute leukemia.

PATIENTS AND METHODS

Single-center retrospective study of acute leukemia patients (2006-2015) to investigate three aspects of CDC: its impact on the time interval between diagnosis and hematopoietic stem cell transplantation, when required (non-parametric Wilcoxon-Mann-Whitney test); its impact on overall survival (Cox proportional hazard regression model); antifungal therapeutic strategies implemented.

RESULTS

A total of 639 patients presenting with acute leukemia were included; 144 were transplanted and 29 developed CDC. CDC did not significantly increase the time interval between diagnosis and transplantation, nor did it impact the overall survival of recipients. An improved overall survival was observed in non-transplanted acute leukemia patients presenting with CDC.

CONCLUSION

CDC should not postpone transplantation if antifungal treatment is optimized.

Evaluating predictors of invasive candidiasis in patients with and without candidemia on micafungin

Numerous risk factors have been linked to invasive candidiasis; however, they are nonspecific and often trigger empiric antifungal therapy in a large number of patients. Identification of more precise predictors could promote judicious use of empiric echinocandins. In this retrospective review, 127 patients with blood cultures positive for Candida spp. were compared to a randomly selected cohort of 134 patients on empiric micafungin for ≥3 days and with blood cultures negative for Candida spp. Factors associated with candidemia included total parenteral nutrition (TPN; 26.0% vs 15.7%, P = 0.040), multifocal Candida colonization (23.6% vs 3.0%, P < 0.001), and positive 1,3-β-d-glucan assay (95.0% vs 35.0%, P < 0.001). Patients without candidemia on empiric micafungin were more likely to receive antibiotic therapy in the previous 10 days (55.9% vs 79.9%, P < 0.001) and to be taking immunosuppressive medications (11.0% vs 30.6%, P < 0.001). Receipt of TPN (odds ratio [OR] = 2.07, 95% confidence interval [CI], 1.02-4.21), severe sepsis (OR = 2.20, 95% CI, 1.00-4.83), and multifocal Candida colonization (OR = 13.87, 95% CI, 4.43-43.37) were independently associated with candidemia in the multivariable logistic regression model. Therefore, the absence of these risk factors, especially in conjunction with a negative 1,3-β-d-glucan assay, may be used to recommend de-escalation of empiric micafungin therapy.

What has changed in the treatment of invasive candidiasis? A look at the past 10 years and ahead

The treatment of invasive candidiasis has changed greatly in the past decade and must continue to evolve if we are to improve outcomes in this serious infection. A review of recent history may provide insights for the future. The morbidity and mortality of invasive candidiasis remain difficult to measure despite an obvious clinical burden. Current treatment guidelines now recommend echinocandins as first-line empirical treatment, with fluconazole as an acceptable alternative for selected patients, reflecting the efficacy demonstrated by echinocandins and increasing resistance observed with fluconazole. The selection of antifungal therapy now must consider not only resistance but also the shift in predominance from Candida albicans to non-albicans species, notably Candida glabrata. The recent emergence of Candida auris has been met with great interest, although the longer-term implications of this phenomenon remain unclear. The broad goal of treatment continues to be administration of safe, efficacious antifungal therapy as soon as possible. Diagnostic methods beyond traditional blood culture present an opportunity to shorten the time to an accurate diagnosis, and earlier treatment initiation based on prophylactic and empirical or pre-emptive strategies seeks to ensure timely therapeutic intervention. In addition, there are novel agents in the antifungal pipeline. These developments, as well as ongoing studies of dosing, toxicity and resistance development, are important items on the current research agenda and may play a role in future changes to the treatment of invasive candidiasis.

Common Child and Adolescent Cutaneous Infestations and Fungal Infections

Cutaneous infections and infestations are common among children and adolescents. Ectoparasitic infestations affect individuals across the globe. Head lice, body lice, scabies, and infestations with bed bugs are seen in individuals who reside in both resource poor areas and in developed countries. Superficial cutaneous and mucosal candida infections occur throughout the life cycle. Dermatophyte infections of keratin-containing skin and skin structures result in tinea capitis (scalp), tinea corporis (body), tinea pedis (foot), and tinea unguium (nails). Less frequent endemic fungal infections such as blastomycosis, coccidiodomycosis, and histoplasmosis may present with skin findings. This article will describe the epidemiology and transmission of these conditions as well as their clinical manifestations. The approach to diagnosis will be addressed as well as primary prevention and current therapies.

Candida auris: a Review of the Literature

The emerging pathogen Candida auris has been associated with nosocomial outbreaks on five continents. Genetic analysis indicates the simultaneous emergence of separate clades of this organism in different geographical locations. Invasive infection and colonization have been detected predominantly in patients in high-dependency settings and have garnered attention due to variable antifungal resistance profiles and transmission within units instituting a range of infection prevention and control measures. Issues with the identification of C. auris using both phenotypic and molecular techniques have raised concerns about detecting the true scale of the problem. This review considers the literature available on C. auris and highlights the key unknowns, which will provide direction for further work in this field.

Antimycotic Activity of Conifer Green Needle Complex against Clinical Strains of Candida Species

Resistance of some Candida species to antimycotic agents is a public health threat, with new treatments a priority. Conifer Green Needle Complex (CGNC) is a pharmaceutical-grade complex substance from the green verdure of Pinus sylvestris and Picea abies. Characterization of the chemical composition of CGNC (gas chromatography/mass spectrometry/HPLC) showed resin acids (ca 20 %w/w), unsaponafiables, primarily terpenoid alcohols (ca 22% w/w), higher fatty acids (ca 10% w/w), bound acids (ca 11% w/w) and polyprenols (ca 2.5% w/w). Other significant components include phytosterols, carotenoids, chlorophyll derivatives, vitamin E acetate and vitamin K1. CGNC has high antioxidant activity. Preliminary results for antimycotic activity against clinical strains of Candida albicans, C. glabrata and C. krusei showed some Candida spp. were sensitive to CGNC, including fluconazole- and ketoconazole-resistant strains. Antimycotic activity of CGNC should be investigated in larger studies.

Recent Insights into the Paradoxical Effect of Echinocandins

Echinocandin antifungals represent one of the most important drug classes for the treatment of invasive fungal infections. The mode of action of the echinocandins relies on inhibition of the β-1,3-glucan synthase, an enzyme essentially required for the synthesis of the major fungal cell wall carbohydrate β-1,3-glucan. Depending on the species, echinocandins may exert fungicidal or fungistatic activity. Apparently independent of this differential activity, a surprising in vitro phenomenon called the “paradoxical effect” can be observed. The paradoxical effect is characterized by the ability of certain fungal isolates to reconstitute growth in the presence of higher echinocandin concentrations, while being fully susceptible at lower concentrations. The nature of the paradoxical effect is not fully understood and has been the focus of multiple studies in the last two decades. Here we concisely review the current literature and propose an updated model for the paradoxical effect, taking into account recent advances in the field.

Meta-analysis of the safety of voriconazole in definitive, empirical, and prophylactic therapies for invasive fungal infections

BACKGROUND

Voriconazole has been used in the treatment and prophylaxis of invasive fungal infections (IFIs) while its wide use was limited by some frequent adverse events, especially neurotoxicity, hepatotoxicity and even renal disruption. The aim of this study was to comprehensively compare voriconazole-induced toxicity, including tolerability, neurotoxicity, visual toxicity, hepatotoxicity and nephrotoxicity with the composite of other antifungals commonly used in clinic.

METHODS

Bibliography databases were searched to select randomized controlled trials providing information about the incidence of toxicity referred above. A total of 4122 patients from 16 studies were included in the meta-analysis.

RESULTS

Analysis of individual types of toxicity showed that there was a significant difference between voriconazole and the composite of other antifungal agents. The primary outcome, the tolerability of voriconazole was slightly inferior (OR = 1.71, 95% CI = 1.21-2.40, P = 0.002) and it is noteworthy that the probabilities of neurotoxicity and visual toxicity were around twice higher and six-fold for voriconazole compared with the counterpart (OR = 1.99, 95% CI = 1.05-3.75, P = 0.03 and OR = 6.50, 95% CI = 2.93-14.41, P < 0.00001, respectively). Hepatotoxicity was more common in voriconazole group (OR = 1.60, 95% CI = 1.17-2.19, P = 0.003) whereas its pooled risk of nephrotoxicity was about half of the composite of other five antifungal agents (OR = 0.46, 95% CI = 0.26-0.84, P = 0.01).

CONCLUSION

Our analysis has revealed differences in multiple types of toxicity induced by VRC versus other antifungals and quantified the corresponding pooled risks, which could provide an alternative for patients with a certain antifungal intolerance and help the clinician to select the optimal intervention.

Profile of GenMark's ePlex® blood culture identification fungal pathogen panel

INTRODUCTION

Fungemia presents high morbi-mortality and thus rapid microbiological diagnosis may contribute to appropriate patient management. In the last decade, kits based on molecular technologies have become available and health care institutes are increasingly facing critical investment choices. Although all these tools aim to achieve rapid fungal detection and species identification, they display different inherent characteristics. Areas covered: Considering technologies allowing detection and identification of fungal species in a sepsis context, the market proposes either tests on positive blood culture or tests on patient's whole blood. In this review, the authors describe and compare the ePlex® Blood Culture Identification Fungal Pathogen (BCID-FP) test, a fully automated one-step single-use cartridge assay that has been designed to detect identify frequent or rare but emerging, fungal species, from positive blood culture. A comparison with the competing kits is provided. Expert commentaries: The ePlex BCID-FP test provides a diversified and rather relevant panel. Its easy-to-use cartridges allow flexible use around the clock. Nevertheless, prospective clinical studies assessing the time-to-result benefit on antifungal stewardship and on hospital length of stay are not available yet. New tools aim to benefit clinicians and patients, but they should be accompanied by supervision of result interpretation and adaptation of antifungal stewardship.

Rapid Detection and Differentiation of Clinically Relevant Candida Species Simultaneously from Blood Culture by Use of a Novel Signal Amplification Approach

Fungal bloodstream infections are a significant problem in the United States, with an attributable mortality rate of up to 40%. An early diagnosis to direct appropriate therapy has been shown to be critical to reduce mortality rates. Conventional phenotypic methods for fungal detection take several days, which is often too late to impact outcomes. Herein, we describe a cost-effective multiplex assay platform for the rapid detection and differentiation of major clinically relevant Candida species directly from blood culture. This approach utilizes a novel biotin-labeled polymer-mediated signal amplification process combined with targeting rRNA to exploit phylogenetic differences for sensitive and unambiguous species identification; this assay detects seven pathogenic Candida species (C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei, C. lusitaniae, and C. guilliermondii) simultaneously with very high specificity to the species level in less than 80 min with the limits of detection at 1 × 10³ to 10 × 10³ CFU/ml or as few as 50 CFU per assay. The performance of the described assay was verified with 67 clinical samples (including mixed multiple-species infections as well), with an overall 100% agreement with matrix-assisted laser desorption ionization (MALDI) mass spectrometry-based reference results. By providing a species identity rapidly, the clinician is aided with information that may direct appropriate therapy sooner and more accurately than current approaches, including PCR-based tests.

Overtreatment of Asymptomatic Candiduria among Hospitalized Patients: a Multi-institutional Study

Candiduria is common in hospitalized patients, and asymptomatic candiduria contributes to antifungal overuse. The guidelines for management of asymptomatic candiduria do not recommend antifungal use, but rather the elimination of predisposing factors. It is unknown whether these recommendations are being followed. The primary objective of this study was to characterize candiduria management among hospitalized patients. This was a retrospective cohort study of a random sample of 305 hospitalized patients with candiduria at four U.S. medical centers from January 2010 to December 2013. Patients were classified as asymptomatic or symptomatic based on established criteria, and data were collected by chart review. Infectious Diseases Society of America (IDSA) treatment guideline adherence and its association with clinical outcomes, including candiduria recurrence (short- and long-term) and 30-day readmission, were assessed. Eighty percent of patients were classified as having asymptomatic candiduria. Overall, 143 (47%) patients were not managed according to recommended guidelines, including 105/243 (43%) in the asymptomatic candiduria group and 38/62 (61%) in the symptomatic group (P = 0.01). Discordance among asymptomatic patients was driven by overtreatment with an antifungal (98/105 [93%]). Thirty-three percent of patients with asymptomatic candiduria not managed according to the guidelines were treated for over 7 days, and 5% received over 14 days of therapy. Fluconazole was the most commonly used empirical antifungal among asymptomatic candiduria patients (96%), followed by micafungin (4%). Asymptomatic candiduria patients not managed according to the guidelines had a trend toward higher 30-day readmission (35% versus 26%, P = 0.27). Inappropriate management of candiduria among hospitalized patients was high, leading to overtreatment with antifungal therapy.

Primary antifungal prophylaxis: decrease of invasive fungal disease incidence and reduction of risk factors in haematological patients in a 5-year retrospective study

BACKGROUND

Invasive fungal disease (IFD) is a major cause of morbidity and mortality in patients with haematological malignancies.

AIM

To evaluate the efficacy and rationality of primary antifungal prophylaxis (PAP) in a 5-year real-life setting and choose an appropriate PAP strategy.

METHODS

Clinical data of patients were retrospectively reviewed and IFD was diagnosed using the revised diagnostic criteria. The efficacy of PAP and the risk factors for IFD, especially the rationality of PAP, were evaluated.

RESULTS

Of the 1340 patients enrolled, 749 patients received PAP (55.9%), and IFD occurred in 157 patients: 51 (6.8%) in the PAP group and 106 (17.9%) in the non-PAP group (P = 0.000). The IFD-related mortality was 10.1 and 29.7% in the PAP group and non-PAP group (P = 0.000) respectively. PAP was an independent protective factor for IFD (odds ratio = 0.183, 95% confidence interval: 0.122-0.274, P = 0.000) and could reduce the effect of risk factors, such as allogeneic haemopoietic stem cell transplantation, prolonged neutropenia and corticosteroid. The IFD incidence was not significantly different among different PAP regimens and PAP start time subgroups, and it was lowest (4.2%) when PAP started after a short period of neutropenia (1-10 days).

CONCLUSION

PAP is necessary and efficient to prevent IFD in haematological patients, and the real-life PAP strategy is reasonable. Different drugs can be chosen, and it is better to start PAP as soon as neutropenia begins.

Impact of inappropriate antifungal therapy according to current susceptibility breakpoints on Candida bloodstream infection mortality, a retrospective analysis

BACKGROUND

The mortality of Candida Bloodstream Infection (CBSI) remains high. Antifungal susceptibility breakpoints were recently updated for Candida species, the impact remains unknown. In this study we evaluated the impact of inappropriate antifungal treatment according to recent breakpoints on 30-day mortality of CBSI.

METHODS

From June 2008 to July 2014, data on CBSI episodes from two tertiary-care centers, treated > 72 h were analyzed. Antifungal therapy and 30-day mortality were registered. Inappropriate antifungal treatment according to current Clinical & Laboratory Standards Institute (CLSI) breakpoints was adjusted with 30-day mortality-related co-variates.

RESULTS

One hundred forty-nine episodes of CBSI were analyzed. The most frequent species were: C. albicans (40%), C. tropicalis (23%) and C. glabrata complex (20%). According to the 2012 CLSI, 10.7% received inappropriate treatment. The 30-day mortality was 38%; severe sepsis [Odds ratio (OR) 3.4; 95% CI 1.3-8.4], cirrhosis (OR 36; 95% CI 12.2-605), early central venous catheter removal (OR 0.23; 95% CI 0.08-0.66) and previous antifungal therapy (OR 0.15; 95%CI 0.03-0.62), were associated with 30-day mortality by multivariate analysis. Inappropriate antifungal treatment was not (OR 0.19; 95% CI 0.03-1.2).

CONCLUSIONS

Appropriate antifungal therapy according to CLSI 2012 did not have an impact on mortality. Mortality of CBSI remains high due to disease severity and comorbidities; early antifungal therapy and catheter removal may reduce it.

Modulating host immune responses to fight invasive fungal infections

Modulation of host immunity in invasive fungal infection is an appealing but as yet mostly elusive treatment strategy. Animal studies in invasive candidiasis and aspergillosis have demonstrated beneficial effects of colony stimulating factors, interferon-gamma and monoclonal antibodies. More recent studies transfusing leukocytes pre-loaded with lipophilic anti-fungal drugs, or modulated T-cells, along with novel vaccination strategies show great promise. The translation of immune therapies into clinical studies has been limited to date but this is changing and the results of new Candida vaccine trials are eagerly awaited. Immune modulation in HIV-associated mycoses remains complicated by the risk of immune reconstitution inflammatory syndrome and although exogenous interferon-gamma therapy may be beneficial in cryptococcal meningitis, early initiation of anti-retroviral therapy leads to increased mortality. Further study is required to better target protective immune responses.

Antifungal Drugs in Newborns and Children

Invasive fungal infections are a significant cause of morbidity and mortality in infants and children. Early diagnosis is critical, and treatment with the appropriate drug and dose should be initiated promptly. Although an increasing number of studies have examined dosing of antifungals in this population, pediatric safety and efficacy data are lacking.

Particularities of the management and the treatment in a rare sepsis with Candida tropicalis of a Collodion baby: Case report

RATIONALE

Collodion baby is a rare autosomal recessive disorder. It can be the first expression of some forms of ichthyosis.

PATIENT CONCERNS

The authors present the case of a newborn diagnosed with severe Collodion baby syndrome who required prolonged hospitalization in the intensive care unit because of infectious complications like the fungal sepsis and other bacterial superinfections.

DIAGNOSES

The case has many diagnostic and therapeutic particularities and management difficulties. Skin culture, dermatological and genetic exam were required.

INTERVENTIONS

The treatment required multidisciplinary involvement: neonatologist, pediatrician, geneticist, dermatologist, psychologist, ophthalmologist, audiologist.

OUTCOMES

The evolution during hospitalization was slowly favorable, but later, after a few months, it developed some complications.

LESSONS

In our case, skin injuries, total parenteral nutrition, aggressive and prolonged antibiotic therapy, intravenous devices, high hospitalization duration were risk factors for colonization and sepsis with fungi, especially in the neonatal period, sometimes with severe evolution and prognosis.

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.

Cost Effectiveness of Candida Polymerase Chain Reaction Detection and Empirical Antifungal Treatment among Patients with Suspected Fungal Peritonitis in the Intensive Care Unit

BACKGROUND

Mortality from intra-abdominal candidiasis in intensive care units (ICUs) is high. It takes many days for peritoneal-fluid fungal culture to become positive, and the recommended empirical antifungal therapy involves excessive costs. Polymerase chain reaction (PCR) should produce results more rapidly than fungal culture.

OBJECTIVES

To perform a cost-effectiveness analysis of the combination of several diagnostic and therapeutic strategies to manage Candida peritonitis in non-neutropenic adult patients in ICUs.

METHODS

We constructed a decision tree model to evaluate the cost effectiveness. Cost and effectiveness were taken into account in a 1-year time horizon and from the French National Health Insurance perspective. Six strategies were compared: fluconazole or echinocandin as an empirical therapy, plus diagnosis by fungal culture or detection by PCR of all Candida species, or use of PCR to detect most fluconazole-resistant Candida species (i.e., Candida krusei and Candida glabrata).

RESULTS

The use of fluconazole empirical treatment and PCR to detect all Candida species is more cost effective than using fluconazole empirical treatment without PCR (incremental cost-effectiveness ratio of €40,055/quality-adjusted life-year). Empirical treatment with echinocandin plus PCR to detect C. krusei and C. glabrata is the most effective strategy, but has an incremental cost-effectiveness ratio of €93,776/quality-adjusted life-year. If the cost of echinocandin decreases, then strategies involving PCR plus empirical echinocandin become more cost-effective.

CONCLUSIONS

Detection by PCR of all Candida species and of most fluconazole-resistant Candida species could improve the cost-effectiveness of fluconazole and echinocandin given to non-neutropenic patients with suspected peritoneal candidiasis in ICUs.

The Gastrointestinal Tract Is a Major Source of Echinocandin Drug Resistance in a Murine Model of Candida glabrata Colonization and Systemic Dissemination

Candida species are a part of the human microbiome and can cause systemic infection upon immune suppression. Candida glabrata infections are increasing and have greater rates of antifungal resistance than other species. Here, we present a C. glabrata gastrointestinal (GI) colonization model to explore whether colonized yeast exposed to caspofungin, an echinocandin antifungal, develop characteristic resistance mutations and, upon immunosuppression, breakthrough causing systemic infection. Daily therapeutic dosing (5 mg/kg of body weight) of caspofungin resulted in no reduction in fecal burdens, organ breakthrough rates similar to control groups, and resistance rates (0 to 10%) similar to those reported clinically. Treatment with 20 mg/kg caspofungin initially reduced burdens, but a rebound following 5 to 9 days of treatment was accompanied by high levels of resistance (FKS1/FKS2 mutants). Although breakthrough rates decreased in this group, the same FKS mutants were recovered from organs. In an attempt to negate drug tolerance that is critical for resistance development, we cotreated mice with daily caspofungin and the chitin synthase inhibitor nikkomycin Z. The largest reduction (3 log) in GI burdens was obtained within 3 to 5 days of 20 mg/kg caspofungin plus nikkomycin treatment. Yet, echinocandin resistance, characterized by a novel Fks1-L630R substitution, was identified following 5 to 7 days of treatment. Therapeutic caspofungin plus nikkomycin treatment left GI burdens unchanged but significantly reduced organ breakthrough rates (20%; P < 0.05). Single-dose pharmacokinetics demonstrated low levels of drug penetration into the GI lumen posttreatment with caspofungin. Overall, we show that C. glabrata echinocandin resistance can arise within the GI tract and that resistant mutants can readily disseminate upon immunosuppression.

Fungal Pneumonia in Patients with Hematologic Malignancies and Hematopoietic Cell Transplantation

Invasive fungal infections, which occur primarily as a consequence of prolonged neutropenia and immunosuppression, are a life-threatening complication seen among patients with hematologic malignancies. The routine use of triazole antifungal prophylaxis, enhanced diagnostics, and newer antifungal agents have led to improvements in the care of fungal pneumonias, but invasive fungal infections remain a major cause of morbidity and mortality. This article covers risk factors for major fungal infections, diagnostic approaches, and treatment options for specific fungal pathogens, including Aspergillus and Mucorales species, and discusses current approved strategies for prevention of common and uncommon fungal pneumonias.

Pharmacoeconomic evaluation of micafungin versus caspofungin as definitive therapy for candidaemia and invasive candidiasis (IC) in Turkey

Micafungin was shown to be as efficacious as caspofungin in treating patients with candidaemia and invasive candidiasis (IC). However, it remains unknown if micafungin or caspofungin is a cost-effective definitive therapy for candidaemia and IC in Turkey. The present study aimed to determine the economic impact of using micafungin versus caspofungin for treatment of candidaemia and IC in the Turkish setting. A decision analytic model was constructed and was populated with data (i.e. transition probabilities, duration of initial antifungal treatment, reasons for treatment failure, percentage of patients who stepped down to oral fluconazole, and duration on oral fluconazole) obtained from a published randomised clinical trial. Cost inputs were derived from the latest Turkish resources while data that were not readily available in the literature were estimated by expert panels. One-way sensitivity analyses, threshold analyses, scenario analyses and probabilistic sensitivity analyses were conducted. Caspofungin (€2693) incurred a lower total cost than micafungin (€4422), with a net cost saving of €1729 per treated patient. Drug acquisition cost was the main cost driver for both study arms. The model outcome was robust over wide variations (of ±100.0% from the base case value) for all input parameters except for micafungin drug cost and the duration of initial treatment with micafungin. Caspofungin appears to be a cost-saving option in treating candidaemia and IC from the Turkish hospital perspective.

Comparative study of Candida spp. isolates: Identification and echinocandin susceptibility in isolates obtained from blood cultures in 15 hospitals in Medellín, Colombia

OBJECTIVES

Invasive candidiasis has a high impact on morbidity and mortality in hospitalised patients. Accurate and timely methods for identification of Candida spp. and determination of echinocandin susceptibility have become a priority for clinical microbiology laboratories.

METHODS

This study was performed to compare matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS) identification with sequencing of the D1/D2 region of the rRNA gene complex 28 subunit in 147 Candida spp. isolates obtained from patients with candidaemia. Antimicrobial susceptibility testing was performed by broth microdilution (BMD) and Etest. Sequencing of the FKS1 and FKS2 genes was performed.

RESULTS

The most common species isolated were Candida albicans (40.8%), followed by Candida parapsilosis (23.1%) and Candida tropicalis (17.0%). Overall agreement between the results of identification by MALDI-TOF/MS and molecular identification was 99.3%. Anidulafungin and caspofungin susceptibility by the BMD method was 98.0% and 88.4%, respectively. Susceptibility to anidulafungin and caspofungin by Etest was 93.9% and 98.6%, respectively. Categorical agreement between Etest and BMD was 91.8% for anidulafungin and 89.8% for caspofungin, with lower agreements in C. parapsilosis for anidulafungin (76.5%) and C. glabrata for caspofungin (40.0%). No mutations related to resistance were found in the FKS genes, although 54 isolates presented synonymous polymorphisms in the hotspots sequenced.

CONCLUSIONS

MALDI-TOF/MS is a good alternative for routine identification of Candida spp. isolates. DNA sequencing of the FKS genes suggested that the isolates analysed were susceptible to echinocandins; alternatively, unknown resistance mechanisms or limitations related to antifungal susceptibility tests may explain the resistance found in a few isolates.

Pharmacokinetic Properties of Micafungin in Critically Ill Patients Diagnosed with Invasive Candidiasis

The estimated attributable mortality rate for invasive candidiasis (IC) in the intensive care unit (ICU) setting varies from 30 to 40%. Physiological changes in critically ill patients may affect the distribution and elimination of micafungin, and therefore, dosing adjustments might be mandatory. The objective of this study was to determine the pharmacokinetic parameters of micafungin in critically ill patients and assess the probability of target attainment. Micafungin plasma concentrations were measured to estimate the pharmacokinetic properties of micafungin. MIC values for Candida isolates were determined to assess the probability of target attainment for patients. Data from 19 patients with suspected or proven invasive candidiasis were available for analysis. The median area under the concentration-time curve from 0 to 24 h at steady state (AUC_0-24) was 89.6 mg · h/liter (interquartile range [IQR], 75.4 to 113.6 mg · h/liter); this was significantly lower than the median micafungin AUC_0-24 values of 152.0 mg · h/liter (IQR, 136.0 to 162.0 mg · h/liter) and 134.0 mg · h/liter (IQR, 118.0 to 148.6 mg · h/liter) in healthy volunteers (P = <0.0001 and P = <0.001, respectively). All Candida isolates were susceptible to micafungin, with a median MIC of 0.016 mg/liter (IQR, 0.012 to 0.023 mg/liter). The median AUC_0-24/MIC ratio was 5,684 (IQR, 4,325 to 7,578), and 3 of the 17 evaluable patients (17.6%) diagnosed with proven invasive candidiasis did not meet the AUC/MIC ratio target of 5,000. Micafungin exposure was lower in critically ill patients than in healthy volunteers. The variability in micafungin exposure in this ICU population could be explained by the patients' body weight. Our findings suggest that healthier patients (sequential organ failure assessment [SOFA] score of <10) weighing more than 100 kg and receiving 100 mg micafungin daily are at risk for inappropriate micafungin exposure and potentially inadequate antifungal treatment. (This study has been registered at ClinicalTrials.gov under identifier NCT01716988.).

Choosing Optimal Antifungal Agents To Prevent Fungal Infections in Nonneutropenic Critically Ill Patients: Trial Sequential Analysis, Network Meta-analysis, and Pharmacoeconomic Analysis

The use of antifungal interventions in critically ill patients prior to invasive fungal infection (IFI) being microbiologically confirmed and the preferred drug are still controversial. A systematic literature search was performed to identify randomized controlled trials (RCTs) that compared untargeted antifungal treatments applied to nonneutropenic critically ill patients. The primary outcomes were all-cause mortality and proven IFI rates. A random-effects model was used with trial sequential analyses (TSA), a network meta-analysis (NMA) was conducted to obtain indirect evidence, and a cost-effectiveness analysis using a decision-analytic model was completed from the patient perspective over a lifetime horizon. In total, 19 RCTs involving 2,556 patients (7 interventions) were included. Untargeted antifungal treatment did not significantly decrease the incidence of all-cause mortality (odds ratio [OR] = 0.89, 95% confidence interval [95%CI] = 0.70 to 1.14), but it did reduce the incidence of proven IFI (OR = 0.45, 95%CI = 0.29 to 0.71) relative to placebo/no intervention. The TSA showed that there was sufficient evidence supporting these findings. In the NMA, the only significant difference found for both primary outcomes was between fluconazole and placebo/no intervention in preventing proven IFI (OR = 0.35, 95%CI = 0.19 to 0.65). Based on drug and hospital costs in China, the incremental cost-effectiveness ratios per life-year saved for fluconazole, caspofungin, and micafungin relative to placebo/no intervention corresponded to US$889, US$9,994, and US$10,351, respectively. Untargeted antifungal treatment significantly reduced proven IFI rates in nonneutropenic critically ill patients but with no mortality benefits relative to placebo/no intervention. Among the well-tolerated antifungals, fluconazole remains the only one that is effective for IFI prevention and significantly cheaper than echinocandins.

Microbiologic and clinical characteristics of biofilm-forming Candida parapsilosis isolates associated with fungaemia and their impact on mortality

OBJECTIVES

Biofilm formation (BF) by fungal isolates may dramatically complicate infection. We determined the ability of Candida parapsilosis isolates from single fungaemia episodes to form biofilms and we analysed biofilm subgroups for antifungal susceptibility and pathogenic potential. We then correlated BF with clinical characteristics and outcomes of the episodes.

METHODS

BF was measured using the crystal violet biomass assay. Antifungal susceptibility of preformed biofilms was assessed, and virulence was studied using the Galleria mellonella model. A retrospective analysis of patients' clinical records was performed.

RESULTS

Of 190 patient-unique isolates, 84, 38 and 68 were identified as having high BF (HBF), moderate BF (MBF) or low BF (LBF), respectively. Among 30 randomly selected isolates, nine (eight HBF and one MBF), six (all HBF) and one (HBF) isolates had elevated sessile minimum inhibitory concentrations to fluconazole, anidulafungin or amphotericin B; all HBF and MBF isolates had elevated voriconazole sessile minimum inhibitory concentrations. G. mellonella killing rates of HBF isolates were significantly greater than MBF (or LBF) isolates (50% vs. 20%, 2 days from infection). By comparing HBF/MBF (106 patients) and LBF (84 patients) groups, we found that HBF/MBF patients had more central venous catheter-related fungaemias (62/106 (58.5%) vs. 29/84 (34.5%), p 0.001) and were more likely to die at 30 days from fungaemia onset (61/106 (57.5%) vs. 28/84 (33.3%), p 0.01). In the HBF/MBF group, azole antifungal therapy and central venous catheter removal were significantly associated with a higher and lower 30-day mortality rate, respectively.

CONCLUSIONS

C. parapsilosis BF influences the clinical outcome in patients with fungaemia.

Epidemiological data and antifungal susceptibility in invasive fungal infections - a Romanian infectious diseases tertiary hospital’s experience. Preliminary report

Introduction: Invasive fungal infections have stood as an important research subject for the past 20 years, being considered as a crucial effect of advancing healthcare services. Low identification rates of invasive fungal infections in blood cultures and low sensibility of biomarkers determine empiric treatments which lead to a change in epidemiological data and antifungal susceptibility. The aim: The epidemiological evaluation of invasive fungal infections and the assessment of antifungal resistance related to this condition. Methods and material: An “antifungal stewardship” retrospective study was developed between January 2010 and April 2016. An epidemiological analysis was performed on 79 cases with proven invasive fungal infections in bloodstream, catheter, and cerebrospinal fluid. We considered: age, gender, HIV status, place of residence, and first option in medical practice of antifungal treatment. The laboratory analysis was performed by the Microbiology Laboratory at “Prof. Dr. Matei Bals” National Institute for Infectious Diseases, Bucharest. Minimum inhibitory concentrations (MIC’s) of 15 isolates were identified using colorimetric micro broth dilution panel YEASTONE ®YO10 and compared with susceptibilities obtained by VITEK2®C system. Candida parapsilosis ATCC 22019 was used as reference. Results: The incidence of invasive fungal infections was 3.7 on 1000 hospitalized patients. The age of the study population ranged between 12 and 83 years, and most were male (59%). The majority of subjects were from an urban area (84%), and 27% of them were HIV positive. The results obtained in VITEK2C® were similar with those from YEASTONE® YO10 for fluconazole, voriconazole, amphotericin B (100%), without any minor, major or very major errors. The fluconazole was the first option of treatment, followed by voriconazole, caspofungin, anidulafungin. In 37% of cases the first treatment option was replaced with a secondary antifungal therapy accordingly with antifungal breakpoints obtained by Vitek ®. Conclusions: No rates of resistance to fluconazole, amphotericin B, voriconazole were obtained. Fluconazole was the major first line antifungal therapy. Conclusions: No rates of resistance to fluconazole, amphotericin B, voriconazole were obtained. Fluconazole was the major first line antifungal therapy.

Sepsis in alcohol-related liver disease

Alcohol-related liver disease (ALD) remains the most important cause of death due to alcohol. Infections, particularly bacterial infections, are one of the most frequent and severe complications of advanced ALDs, such as alcoholic cirrhosis and severe alcoholic hepatitis (sAH). The specific mechanisms responsible for this altered host defence are yet to be deciphered. The aim of the present study is to review the current knowledge of infectious complications in ALD and its pathophysiological mechanisms, distinguishing the role of alcohol consumption and the contribution of different forms of ALD. To date, corticosteroids are the only treatment with proven efficacy in sAH, but their impact on the occurrence of infections remains controversial. The combination of an altered host defence and corticosteroid treatment in sAH has been suggested as a cause of opportunistic fungal and viral infections. A high level of suspicion with systematic screening and prompt, adequate treatment are warranted to improve outcomes in these patients. Prophylactic or preemptive strategies in this high-risk population might be a preferable option, because of the high short-term mortality rate despite adequate therapies. However, these strategies should be assessed in well-designed trials before clinical implementation.

Antifungal Prevention of Systemic Candidiasis in Immunocompetent ICU Adults: Systematic Review and Meta-Analysis of Clinical Trials

OBJECTIVES

The aim of this study was to identify the impact of antifungal prevention in critically ill immunocompetent adult patients on mortality and subsequent infection.

DATA SOURCES

A systematic review and meta-analysis of randomized controlled trials comparing any antifungal use versus placebo to prevent candidiasis in ICU patients were performed.

STUDY SELECTION

Searches were performed on PubMed, Embase, Scopus, main conference proceedings, and ClinicalTrials.gov, as well as reference lists.

DATA EXTRACTION

The primary outcomes were mortality and invasive candidiasis. The secondary outcome was the rate of Candida albicans and nonalbicans strains after treatment. A random effect model was used, and sensitivity analysis was performed for both outcomes. Results are expressed as risk ratios and their 95% CIs.

DATA SYNTHESIS

Nineteen trials (10 with fluconazole, four with ketoconazole, one with itraconazole, three with micafungin, and one with caspofungin) including 2,792 patients were identified. No individual trial showed a decreased mortality rate. Combined analysis showed that preventive antifungal did not decrease mortality (risk ratio, 0.88; 95% CI, 0.74-1.04; p = 0.14) but significantly decreased secondary fungal infections by 50% (risk ratio, 0.49; 95% CI, 0.35-0.68; p = 0.0001). No shift across nonalbicans strains was observed during treatment (risk ratio, 0.62; 95% CI, 0.19-1.97; p = 0.42). However, publication biases preclude any definite conclusions for prevention of infection.

CONCLUSIONS

Antifungal prevention of systemic candidiasis in immunocompetent critically ill adults did not reduce mortality and may have decreased secondary fungal infection rates. However, significant publication bias was present.

Management of candidemia in patients with Clostridium difficile infection

INTRODUCTION

Patients with C. difficile infection (CDI) experience intestinal microflora changes that can promote the overgrowth and subsequent translocation of gut resident pathogens into the blood. Consistently, CDI due to PCR-ribotype 027 strain, severe or relapsing CDI, and treatment with high-dosage vancomycin are independent risk factors for candidemia.

AREAS COVERED

We review the role played by the gut microbiota during CDI and its treatment, as well as the clinical profile of CDI patients who are at risk of developing candidemia. Also, we discuss the management of these patients by focusing on pre-emptive strategies aimed at reducing the risk of candidemia, and on innovative anti-C. difficile therapies that may mitigate CDI-related effects such as the altered gut microbiota composition and prolonged intestinal mucosa damage. Expert commentary: A closer clinical and diagnostic monitoring of patients with CDI should help to limit the CDI-associated long-term consequences, including Candida infections, which worsen the outcome of hospitalized patients.

Bilateral Candida endophthalmitis accompanying Candida lusitaniae bloodstream infection: A case report

Candida lusitaniae is an uncommon cause of candidiasis in humans. Ocular manifestations of C. lusitaniae infection have not been reported. C. lusitaniae is either intrinsically resistant to amphotericin B or can acquire such resistance. We describe a case of bilateral endophthalmitis due to C. lusitaniae bloodstream infection in a liver transplant patient with rectal cancer. The patient suffered fungemia and endophthalmitis and was treated with liposomal amphotericin B. The isolate was identified as C. lusitaniae by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, the system based on biochemical tests, and sequencing of the internal transcribed spacer region. The minimal inhibitory concentrations were 0.06 μg/mL for amphotericin B and 2.0 μg/mL for fluconazole. Repeat blood cultures were negative and the endophthalmitis improved following treatment with liposomal amphotericin B. However, the treatment was changed to fluconazole due to nephrotoxicity. No recurrence occurred after completion of treatment.

Characterization of carboxylate nanoparticle adhesion with the fungal pathogen Candida albicans

Candida albicans is the lead fungal pathogen of nosocomial bloodstream infections worldwide and has mortality rates of 43%. Nanoparticles have been identified as a means to improve medical outcomes for Candida infections, enabling sample concentration, serving as contrast agents for in vivo imaging, and delivering therapeutics. However, little is known about how nanoparticles interact with the fungal cell wall. In this report we used laser scanning confocal microscopy to examine the interaction of fluorescent polystyrene nanoparticles of specific surface chemistry and diameter with C. albicans and mutant strains deficient in various C. albicans surface proteins. Carboxylate-functionalized nanoparticles adsorbed mainly to the hyphae of wild-type C. albicans. The dissociative binding constant of the nanoparticles was ∼150, ∼30 and ∼2.5 pM for 40, 100 nm and 200 nm diameter particles, respectively. A significant reduction in particle binding was observed with a Δals3 strain compared to wild-type strains, identifying the Als3 adhesin as the main mediator of this nanoparticle adhesion. In the absence of Als3, nanoparticles bound to germ tubes and yeast cells in a pattern resembling the localization of Als1, indicating Als1 also plays a role. Nanoparticle surface charge was shown to influence binding - positively charged amine-functionalized nanoparticles failed to bind to the hyphal cell wall. Binding of carboxylate-functionalized nanoparticles was observed in the presence of serum, though interactions were reduced. These observations show that Als3 and Als1 are important targets for nanoparticle-mediated diagnostics and therapeutics, and provide direction for optimal diameter and surface characteristics of nanoparticles that bind to the fungal cell wall.

Is routine ophthalmoscopy really necessary in candidemic patients?

The purpose of this study was to determine among patients with candidemia the real rate of ophthalmoscopy and the impact of performing ocular assessment on the outcome of the disease. We performed a post hoc analysis of a prospective, multicenter, population-based candidemia surveillance program implemented in Spain during 2010–2011 (CANDIPOP). Ophthalmoscopy was performed in only 168 of the 365 patients with candidemia (46%). Ocular lesions related to candidemia were found in only 13/168 patients (7.7%), of whom 1 reported ocular symptoms (incidence of symptomatic disease in the whole population, 0.27% [1/365]). Ophthalmological findings led to a change in antifungal therapy in only 5.9% of cases (10/168), and performance of the test was not related to a better outcome. Ocular candidiasis was not associated with a worse outcome and progressed favorably in all but 1 evaluable patient, who did not experience vision loss. The low frequency of ophthalmoscopy and ocular involvement and the asymptomatic nature of ocular candidiasis, with a favorable outcome in almost all cases, lead us to reconsider the need for systematic ophthalmoscopy in all candidemic patients.

Mechanisms involved in the triggering of neutrophil extracellular traps (NETs) by Candida glabrata during planktonic and biofilm growth

Candida spp. adhere to medical devices, such as catheters, forming drug-tolerant biofilms that resist killing by the immune system. Little is known about how C. glabrata, an emerging pathogen, resists attack by phagocytes. Here we show that upon encounter with planktonic (non-biofilm) C. glabrata, human neutrophils initially phagocytose the yeast and subsequently release neutrophil extracellular traps (NETs), complexes of DNA, histones, and proteins capable of inhibiting fungal growth and dissemination. When exposed to C. glabrata biofilms, neutrophils also release NETs, but significantly fewer than in response to planktonic cells. Impaired killing of biofilm parallels the decrease in NET production. Compared to biofilm, neutrophils generate higher levels of reactive oxygen species (ROS) when presented with planktonic organisms, and pharmacologic inhibition of NADPH-oxidase partially impairs NET production. In contrast, inhibition of phagocytosis nearly completely blocks NET release to both biofilm and planktonic organisms. Imaging of the host response to C. glabrata in a rat vascular model of infection supports a role for NET release in vivo. Taken together, these findings show that C. glabrata triggers NET release. The diminished NET response to C. glabrata biofilms likely contributes to the resilience of these structured communities to host defenses.

In vitro activity of micafungin against biofilms of Candida albicans, Candida glabrata, and Candida parapsilosis at different stages of maturation

Candida spp. is able to form a biofilm, which is considered resistant to the majority of antifungals used in medicine. The aim of this study was to evaluate the in vitro activity of micafungin against Candida spp. biofilms at different stages of their maturation (2, 6, and 24 h). We assessed the inhibitory effect of micafungin against 78 clinical isolates of Candida spp., growing as planktonic or sessile cells, by widely recommended broth microdilution method. The in vitro effect on sessile cells viability was evaluated by colorimetric reduction assay. All examined strains were susceptible or intermediate to micafungin when growing as planktonic cells. At the early stages of biofilm maturation, from 11 (39.3%) to 20 (100%), tested strains, depending on the species, exhibited sessile minimal inhibitory concentrations (SMICs) of micafungin at ≤ 2 mg/L. For 24-h-old Candida spp. biofilms, from 3 (10.7%) to 20 (100%) of the tested strains displayed SMICs of micafungin at ≤ 2 mg/L. Our findings confirm that micafungin exhibits high potential anti-Candida-biofilm activity. However, this effect does not comprise all Candida species and strains. All strains were susceptible or intermediate to micafungin when growing as planktonic cells, but for biofilms, micafungin displays species- and strain-specific activity. Paradoxical growth of C. albicans and C. parapsilosis was observed. Antifungal susceptibility testing of Candida spp. biofilms would be the best solution, but to date, no reference method is available. The strongest antibiofilm activity of micafungin is observed at early stages of biofilm formation. Possibly, micafungin could be considered as an effective agent for prevention of biofilm-associated candidiasis, especially catheter-related candidaemia.