Epidemiology, diagnosis and treatment of systemic Candida infection in surgical patients under intensive care

The atypical antipsychotic aripiprazole alters the outcome of disseminated Candida albicans infections

Invasive fungal infections impose an enormous clinical, social, and economic burden on humankind. One of the most common species responsible for invasive fungal infections is Candida albicans. More than 30% of patients with disseminated candidiasis fail therapy with existing antifungal drugs, including the widely used azole class. We previously identified a collection of 13 medications that antagonize the activity of the azoles on C. albicans. Although gain-of-function mutations responsible for antifungal resistance are often associated with reduced fitness and virulence, it is currently unknown how exposure to azole antagonistic drugs impacts C. albicans physiology, fitness, or virulence. In this study, we examined how exposure to seven azole antagonists affects C. albicans phenotype and capacity to cause disease. Most of the azole antagonists appear to have little impact on fungal growth, morphology, stress tolerance, or gene transcription. However, aripiprazole had a modest impact on C. albicans hyphal growth and increased cell wall chitin content. It also aggravated the disseminated C. albicans infections in mice. This effect was abrogated in immunosuppressed mice, indicating that it is at least in part dependent upon host immune responses. Collectively, these data provide proof of principle that unanticipated drug-fungus interactions have the potential to influence the incidence and outcomes of invasive fungal disease.

The atypical antipsychotic aripiprazole alters the outcome of disseminated Candida albicans infections

Invasive fungal infections (IFIs) impose an enormous clinical, social, and economic burden on humankind. For many IFIs, ≥ 30% of patients fail therapy with existing antifungal drugs, including the widely used azole class. We previously identified a collection of 13 approved medications that antagonize azole activity. While gain-of-function mutants resulting in antifungal resistance are often associated with reduced fitness and virulence, it is currently unknown how exposure to azole antagonistic drugs impact C. albicans physiology, fitness, or virulence. In this study, we examined how exposure to azole antagonists affected C. albicans phenotype and capacity to cause disease. We discovered that most of the azole antagonists had little impact on fungal growth, morphology, stress tolerance, or gene transcription. However, aripiprazole had a modest impact on C. albicans hyphal growth and increased cell wall chitin content. It also worsened the outcome of disseminated infections in mice at human equivalent concentrations. This effect was abrogated in immunosuppressed mice, indicating an additional impact of aripiprazole on host immunity. Collectively, these data provide proof-of-principle that unanticipated drug-fungus interactions have the potential to influence the incidence and outcomes of invasive fungal disease.

Risk of candidiasis associated with interleukin-17 inhibitors: Implications and management

The application of interleukin-17 (IL-17) inhibitors, including secukinumab, ixekizumab, brodalumab, and bimekizumab, are associated with elevated risk of candidiasis. These medications interfere with the IL-17 pathway, which is essential for maintaining mucosal barriers and coordinating the immune response against Candida species. The observational data and clinical trials demonstrate the increased incidence of candidiasis in individuals treated with IL-17 inhibitors. Brodalumab and bimekizumab pose a greater risk than secukinumab in eliciting candidiasis, whereas the data regarding ixekizumab are equivocal. Higher doses and prolonged treatment duration of IL-17 inhibitors increase the risk of candidiasis by compromising the immune response against Candida species. Prior to prescribing IL-17 inhibitors, healthcare professionals should comprehensively evaluate patients' medical histories and assess their risk factors. Patients should be educated on the signs and symptoms of candidiasis to facilitate early detection and intervention. Future research should focus on identifying the risk factors associated with candidiasis in patients receiving IL-17 inhibitors. Prospective studies and long-term surveillance are required to explore the impact of specific inhibitors on the incidence and severity of candidiasis and to evaluate the effectiveness of combination therapies, such as concurrent use of IL-17 inhibitors and prophylactic antifungal agents.

Characterization and susceptibility of non-albicans Candida isolated from various clinical specimens in Lebanese hospitals

Background

Invasive fungal infections have presented a challenge in treatment. In the past, it was known that the frontrunner in such infections is Candida albicans with little emphasis placed on non-albicans Candida species (NAC). Studies worldwide have shown a rise in fungal infections attributed to non-albicans Candida species. The aim of this study is to describe the epidemiology of NAC infections along with an overview of resistance in Lebanese hospitals.

Methods

This is a two-year observational multi-central descriptive study. Between September 2016 and May of 2018, a total of 1000 isolates were collected from 10 different hospitals distributed all over the country. For the culture, Sabouraud Dextrose Agar was used. Antifungal Susceptibility was evaluated by determining the Minimum Inhibitory Concentration (MIC) in broth (microdilution) of the different antifungal treatments.

Results

Out of the 1000 collected isolates, Candida glabrata, being the most isolated species (40.8%), followed by Candida tropicalis: 231(23.1%), Candida parapsilosis: 103(10.3%), and other NAC species at lower percentage. Most of these isolates (88.67%) were susceptible to posaconazole, 98.22% were susceptible to micafungin, and 10% were susceptible to caspofungin.

Conclusion

The change of etiology of fungal infections involving a significant increase in NAC cases is alarming due to the different antifungal susceptibility patterns and the lack of local guidelines to guide the treatment. In this context, proper identification of such organisms is of utmost importance. The data presented here can help in establishing guidelines for the treatment of candida infections to decrease morbidity and mortality. Future surveillance data are needed.

Efficacy and safety of echinocandin monotherapy and combination therapy for immunocompromised patients with systemic candidiasis: A systematic review and meta-analysis

BACKGROUND

Systemic candidiasis is caused by Candida invading the bloodstream. The efficacy and safety of echinocandins in monotherapy and combination therapy regimes have not been adequately compared in immunocompromised patients with Candidiasis, and thus this systematic review aims to do so.

METHODS

A protocol was prepared a priori. PubMed, Embase and Cochrane Library databases were searched systematically (from inception of each database to September 2022) to identify randomized controlled trials. Two reviewers performed screening, quality assessment of trials, and extracted data independently. Pairwise meta-analysis was performed using random-effects model to compare echinocandin monotherapy versus other antifungals. The primary outcomes of interest were treatment success and treatment-related adverse events.

RESULTS

547 records (PubMed=310, EMBASE=210 and Cochrane Library=27) were reviewed. Following our screening criteria, six trials involving 177 patients were included. Risk of bias of four included studies had some concerns due to lack of a pre-specified analysis plan. Meta-analysis shows that echinocandin monotherapy does not have significantly higher rates of "treatment success" compared to other classes of antifungals (RR 1.12, 95%CI 0.80-1.56). However, echinocandins appeared to be significantly safer than other forms of antifungal therapy (RR 0.79, 95%CI 0.73-0.86).

CONCLUSION

Our findings have shown that echinocandin monotherapy (micafungin, caspofungin) given intravenously are just as effective as other antifungals (amphotericin B, itraconazole) in the treatment of systemic candidiasis in immunocompromised patients. There appears to be similar benefits when using echinocandins compared to amphotericin B which has also been used as a broad-spectrum antifungal, while avoiding the severe adverse effects that amphotericin B causes, such as nephrotoxicity.

Identification of Inhibitors of Fungal Fatty Acid Biosynthesis

Fungal fatty acid (FA) synthase and desaturase enzymes are essential for the growth and virulence of human fungal pathogens. These enzymes are structurally distinct from their mammalian counterparts, making them attractive targets for antifungal development. However, there has been little progress in identifying chemotypes that target fungal FA biosynthesis. To accomplish this, we applied a whole-cell-based method known as Target Abundance-based FItness Screening using Candida albicans. Strains with varying levels of FA synthase or desaturase expression were grown in competition to screen a custom small-molecule library. Hit compounds were defined as preferentially inhibiting the growth of the low target-expressing strains. Dose-response experiments confirmed that 16 hits (11 with an acyl hydrazide core) differentially inhibited the growth of strains with an altered desaturase expression, indicating a specific chemical-target interaction. Exogenous unsaturated FAs restored C. albicans growth in the presence of inhibitory concentrations of the most potent acyl hydrazides, further supporting the primary mechanism being inhibition of FA desaturase. A systematic analysis of the structure-activity relationship confirmed the acyl hydrazide core as essential for inhibitory activity. This collection demonstrated broad-spectrum activity against Candida auris and mucormycetes and retained the activity against azole-resistant candida isolates. Finally, a preliminary analysis of toxicity to mammalian cells identified potential lead compounds with desirable selectivities. Collectively, these results establish a scaffold that targets fungal FA biosynthesis with a potential for development into novel therapeutics.

One stone, three birds: one AIEgen with three colors for fast differentiation of three pathogens

Visually identifying pathogens favors rapid diagnosis at the point-of-care testing level. Here, we developed a microenvironment-sensitive aggregation-induced emission luminogen (AIEgen), namely IQ-Cm, for achieving fast discrimination of Gram-negative bacteria, Gram-positive bacteria and fungi by the naked-eye. With a twisted donor-acceptor and multi-rotor structure, IQ-Cm shows twisted intramolecular charge transfer (TICT) and AIE properties with sensitive fluorescence color response to the microenvironment of pathogens. Driven by the intrinsic structural differences of pathogens, IQ-Cm with a cationic isoquinolinium moiety and a membrane-active coumarin unit as the targeting and interacting groups selectively locates in different sites of three pathogens and gives three naked-eye discernible emission colors. Gram-negative bacteria are weak pink, Gram-positive bacteria are orange-red and fungi are bright yellow. Therefore, based on their distinctive fluorescence response, IQ-Cm can directly discriminate the three pathogens at the cell level under a fluorescence microscope. Furthermore, we demonstrated the feasibility of IQ-Cm as a visual probe for fast diagnosis of urinary tract infections, timely monitoring of hospital-acquired infection processes and fast detection of molds in the food field. This simple visualization strategy based on one single AIEgen provides a promising platform for rapid pathogen detection and point-of-care diagnosis.

A Paradigm Shift in the Development of Anti-Candida Drugs

BACKGROUND

The considerable increase in the incidence of Candida infection in recent times has prompted the use of numerous antifungal agents, which has resulted in the development of resistance towards various antifungal agents. With rising Candida infections, the need for design and development of novel antifungal agents is in great demand. However, new therapeutic approaches are very essential in preventing the mortality rate and improving the patient outcome in those suffering from Candida infections.

OBJECTIVE

The present review objective is to describe the burden, types of Candidiasis, mechanism of action of antifungal agents and its resistance and the current novel approaches used to combat candidiasis.

METHODS

We have collected and analyzed 135 different peer-reviewed literature studies pertinent to candidiasis. In this review, we have compiled the major findings from these studies.

RESULTS AND CONCLUSION

The review describes the concerns related to candidiasis, its current treatment strategy, resistance mechanisms and imminent ways to tackle the problem. The review explored that natural plant extracts and essential oils could act as sources of newer therapeutic agents, however, the focus was on novel strategies, such as combinational therapy, new antibodies, utilization of photodynamic therapy and adaptive transfer primed immune cells with emphasis on the development of effective vaccination.

A Systematic Screen Reveals a Diverse Collection of Medications That Induce Antifungal Resistance in Candida Species

The increasing incidence of and high mortality rates associated with invasive fungal infections (IFIs) impose an enormous clinical, social, and economic burden on humankind. In addition to microbiological resistance to existing antifungal drugs, the large number of unexplained treatment failures is a serious concern. Due to the extremely limited therapeutic options available, it is critical to identify and understand the various causes of treatment failure if patient outcomes are to improve. In this study, we examined one potential source of treatment failure: antagonistic drug interactions. Using a simple screen, we systematically identified currently approved medications that undermine the antifungal activity of three major antifungal drugs-fluconazole, caspofungin, and amphotericin B-on four prevalent human fungal pathogens-Candida albicans, Candida glabrata, Candida parapsilosis, and Candida tropicalis This revealed that a diverse collection of structurally distinct drugs exhibit antagonistic interactions with fluconazole. Several antagonistic agents selected for follow-up studies induce azole resistance through a mechanism that depends on Tac1p/Pdr1p zinc-cluster transcription factors, which activate the expression of drug efflux pumps belonging to the ABC-type transporter family. Few antagonistic interactions were identified with caspofungin or amphotericin B, possibly reflecting their cell surface mode of action that should not be affected by drug efflux mechanisms. Given that patients at greatest risk of IFIs usually receive a multitude of drugs to treat various underlying conditions, these studies suggest that chemically inducible azole resistance may be much more common and important than previously realized.

Pre-clinical Imaging of Invasive Candidiasis Using ImmunoPET/MR

The human commensal yeast Candida is the fourth most common cause of hospital-acquired bloodstream infections, with Candida albicans accounting for the majority of the >400,000 life-threatening infections annually. Diagnosis of invasive candidiasis (IC), a disease encompassing candidemia (blood-borne yeast infection) and deep-seated organ infections, is a major challenge since clinical manifestations of the disease are indistinguishable from viral, bacterial and other fungal diseases, and diagnostic tests for biomarkers in the bloodstream such as PCR, ELISA, and pan-fungal β-D-glucan lack either standardization, sensitivity, or specificity. Blood culture remains the gold standard for diagnosis, but test sensitivity is poor and turn-around time slow. Furthermore, cultures can only be obtained when the yeast resides in the bloodstream, with samples recovered from hematogenous infections often yielding negative results. Consequently, there is a pressing need for a diagnostic test that allows the identification of metastatic foci in deep-seated Candida infections, without the need for invasive biopsy. Here, we report the development of a highly specific mouse IgG3 monoclonal antibody (MC3) that binds to a putative β-1,2-mannan epitope present in high molecular weight mannoproteins and phospholipomannans on the surface of yeast and hyphal morphotypes of C. albicans, and its use as a [⁶⁴Cu]NODAGA-labeled tracer for whole-body pre-clinical imaging of deep-seated C. albicans infections using antibody-guided positron emission tomography and magnetic resonance imaging (immunoPET/MRI). When used in a mouse intravenous (i.v.) challenge model that faithfully mimics disseminated C. albicans infections in humans, the [⁶⁴Cu]NODAGA-MC3 tracer accurately detects infections of the kidney, the principal site of blood-borne candidiasis in this model. Using a strain of the emerging human pathogen Candida auris that reacts with MC3 in vitro, but which is non-infective in i.v. challenged mice, we demonstrate the accuracy of the tracer in diagnosing invasive infections in vivo. This pre-clinical study demonstrates the principle of using antibody-guided molecular imaging for detection of deep organ infections in IC, without the need for invasive tissue biopsy.

Novel Cell-Killing Mechanisms of Hydroxyurea and the Implication toward Combination Therapy for the Treatment of Fungal Infections

We have previously reported that an erg11 mutation affecting ergosterol synthesis and a hem13 mutation in the heme synthesis pathway significantly sensitize the fission yeast Schizosaccharomyces pombe to hydroxyurea (HU) (1, 2). Here we show that treatment with inhibitors of Erg11 and heme biosynthesis phenocopies the two mutations in sensitizing wild-type cells to HU. Importantly, HU synergistically interacts with the heme biosynthesis inhibitor sampangine and several Erg11 inhibitors, the antifungal azoles, in causing cell lethality. Since the synergistic drug interactions are also observed in the phylogenetically divergent Saccharomyces cerevisiae and the opportunistic fungal pathogen Candida albicans, the synergism is likely conserved in eukaryotes. Interestingly, our genetic data for S. pombe has also led to the discovery of a robust synergism between sampangine and the azoles in C. albicans Thus, combinations of HU, sampangine, and the azoles can be further studied as a new method for the treatment of fungal infections.

Acute Rhinosinusitis in Immunosuppressed Children: Diagnostic and Therapeutic Management

BACKGROUND

Immunosuppressive therapy places pediatric patients at risk of developing life-threatening sinonasal infections. Diagnosis and treatment are challenging owing to nonspecific signs and symptoms. The aim of this study was to present our department's experience with the surgical management of acute rhinosinusitis in immunosuppressed children.

METHODS

The records of all children with a hematologic or oncologic disease who underwent endoscopic sinus surgery (ESS) for acute rhinosinusitis from January 2005 to May 2014 were reviewed. Data were retrospectively collected on demographics, clinical and imaging characteristics, microbiology, pathology, treatment and outcome.

RESULTS

Thirty-four-immunosuppressed children underwent ESS for acute rhinosinusitis. Most patients had a fungal infection. Nineteen patients died at the end of follow-up; 10 deaths were infection-related. Facial swelling was the only symptom that correlated with death of infection. Relapse of the underlying disease, bone marrow transplantation, and long duration of neutropenia correlated with infection-related mortality. Fungal infection, and specifically Aspergillus, correlated with death from infection.

CONCLUSIONS

ESS is a safe and efficient procedure for diagnosing and treating immunosuppressed pediatric patients with acute rhinosinusitis. Early detection and aggressive medical and surgical treatment, with control of underlying risk factors, are crucial to improve outcome.

Neutrophil Integrins and Matrix Ligands and NET Release

Neutrophils are motile and responsive to tissue injury and infection. As neutrophils emigrate from the bloodstream and migrate toward a site of affliction, they encounter the tissue extracellular matrix (ECM) and thereby engage integrins. Our laboratory studies the neutrophilic response to the fungal pathogen Candida albicans either in the filamentous state of the microbe or to the purified pathogen-associated molecular pattern, β-glucan. We have gained an appreciation for the role of integrins in regulating the neutrophil anti-Candida response and how the presence or absence of ECM can drive experimental outcome. The β2 integrin CR3 (complement receptor 3; αMβ2; Mac-1; CD11b/CD18) plays an important role in fungal recognition by its ability to bind β-glucan at a unique lectin-like domain. The presence of ECM differentially regulates essential neutrophil anti-fungal functions, including chemotaxis, respiratory burst, homotypic aggregation, and the release of neutrophil extracellular traps (NETs). We have shown that NET release to C. albicans hyphae or immobilized β-glucan occurs rapidly and without the requirement for respiratory burst on ECM. This is in contrast to the more frequently reported mechanisms of NETosis to other pathogens without the context of ECM, which occur after a prolonged lag period and require respiratory burst. As expected for an ECM-dependent phenotype, NETosis and other neutrophil functions are dependent on specific integrins. The focus of this review is the role of ECM ligation by neutrophil integrins as it pertains to host defense functions with an emphasis on lessons we have learned studying the anti-Candida response of human neutrophils.

Antimicrobial potential of two traditional herbometallic drugs against certain pathogenic microbial species

Background

Mineral based preparations are widely used for centuries as antimicrobial agents. However, the efficacy and the mode of action of mineral based preparations are uncertain due to the insufficient antimicrobial studies. Arogyawardhana Vati (AV) and Manikya Rasa (MR) are such two Rasashastra herbo-minerallic drugs commonly in India and other countries in South Asia. Despite of their well known traditional use of skin diseases, reported antimicrobial and mineralogical studies are limited. Therefore, in this study antimicrobial activities of the drugs and their organic, inorganic fractions were evaluated against Pseudomonas aeruginosa, Escherischia coli, Staphylococcus aureus, Methecilline Resistance Staphylococcus aureus - MRSA and Candida albicans.

Methods

Antimicrobial activity of the drugs, their inorganic residues and organic extracts were determined using four assay techniques viz agar well diffusion, modified well diffusion, Miles and Misra viable cell counting and broth turbidity measurements. Mineralogical constituents of the drugs were determined using X-ray diffraction, while total cation constituents and water soluble cation constituents were determined using inductively coupled plasma-mass spectrometer and the atomic absorption spectrophotometer respectively. Thermogravimetric analysis was used to determine the weight percentages of organic and inorganic fraction of the drugs. Particle sizes of the drugs were determined using the particle size analyzer.

Results

AV and MR drugs showed antibacterial activity against both gram positive and gram negative bacterial species when analyzed separately. Inorganic residues of the drugs and organic extracts showed activity at least against two or more bacterial species tested. All tested components were inactive against C. albicans. Common mineral constituents of drugs are cinnabar, biotite and Fe-rich phases. Drugs were rich in essential elements such as Na, K, Ca, Mg and Fe and toxic elements such as Zn, Cu and As. However, the water soluble concentrations of the toxic elements were below the detection limits. Both drugs have significantly higher percentages of organic constituents and volatile minerals and particle sizes of drugs are in the nanometer range.

Conclusions

AV and MR Rasashastra preparations could provide alternatives to synthetic antibiotics against human bacterial infections. Improved solubility and reduced particle sizes are influential physicochemical properties used to enhance the antimicrobial efficacy of the drugs. Therefore, traditional knowledge on the use of antimicrobial mineral sources could provide a novel path for the producing of effective antimicrobial drugs. However, further chemical and toxicological studies are urgently needed for a greater understanding of their toxicity to humans.

Antifungal Susceptibility Patterns of Candida Species Recovered from Endotracheal Tube in an Intensive Care Unit

Aims. Biofilms formed by Candida species which associated with drastically enhanced resistance against most antimicrobial agents. The aim of this study was to identify and determine the antifungal susceptibility pattern of Candida species isolated from endotracheal tubes from ICU patients. Methods. One hundred forty ICU patients with tracheal tubes who were intubated and mechanically ventilated were surveyed for endotracheal tube biofilms. Samples were processed for quantitative microbial culture. Yeast isolates were identified to the species level based on morphological characteristics and their identity was confirmed by PCR-RFLP. Antifungal susceptibility testing was determined according to CLSI document (M27-A3). Results. Ninety-five strains of Candida were obtained from endotracheal tubes of which C. albicans (n = 34; 35.7%) was the most frequently isolated species followed by other species which included C. glabrata (n = 24; 25.2%), C. parapsilosis (n = 16; 16.8%), C. tropicalis (n = 12; 12.6%), and C. krusei (n = 9; 9.4%). The resulting MIC90 for all Candida species were in increasing order as follows: caspofungin (0.5 μg/mL); amphotericin B (2 μg/mL); voriconazole (8.8 μg/mL); itraconazole (16 μg/mL); and fluconazole (64 μg/mL). Conclusion. Candida species recovered from endotracheal tube are the most susceptible to caspofungin.

ICU-acquired candidemia within selective digestive decontamination studies: a meta-analysis

PURPOSE

To estimate the direct and indirect (contextual) effects of the factorized constituents of selective digestive decontamination and selective oropharyngeal decontamination (SDD/SOD), being topical antibiotic (TA) and protocolized antifungal prophylaxis (PAFP), on ICU-acquired candidemia.

METHODS

A broad range of ICU candidemia incidence studies were sourced to serve as points of reference. The candidemia incidence was extracted from component (control and intervention) groups decanted from studies of various designs (concurrent or non-concurrent) and whether investigating SDD/SOD versus non-TA methods of ICU infection prevention. The candidemia incidences were summarized in regression models using generalized estimating equation (GEE) methods. Groups derived from observational studies (no prevention method under study) provided an overarching external benchmark candidemia incidence for calibration.

RESULTS

Within studies investigating SDD/SOD, the mean (and 95% confidence interval) candidemia incidence among concurrent component groups (40 control; 2.4%; 1.7-3.2% and 43 intervention groups; 2.4%; 1.6-3.1%), but not non-concurrent control groups (11 groups; 1.6%; 0.1-2.7%), is higher than that of the benchmark candidemia incidence derived from 54 observational groups (1.5%; 1.2-1.9%). The TA constituent within SDD/SOD has significant direct and indirect (contextual) effects in GEE models even after adjusting for the publication year and the group-wide presence of either candidemia risk factors or PAFP use.

CONCLUSION

The TA constituent of SDD/SOD is associated with a contextual effect on candidemia incidence which is similar in magnitude to that of the conventional candidemia risk factors and against which PAFP partially attenuates. This increase is inapparent within individual SDD/SOD studies examined in isolation.

Clinical and therapeutic aspects of candidemia: a five year single centre study

Background

Candida is an important cause of bloodstream infections (BSI) in nosocomial settings causing significant mortality and morbidity. This study was performed to evaluate contemporary epidemiology, species distribution, antifungal susceptibility and outcome of candida BSI in an Italian hospital.

Methods

All consecutive patients who developed candidemia at Santa Maria della Misericordia University Hospital (Italy) between January 2009 and June 2014 were enrolled in the study.

Results

A total of 204 episodes of candidemia were identified during the study period with an incidence of 0.79 episodes/1000 admissions. C. albicans was isolated in 60.3% of cases, followed by C. parapsilosis (16.7%), C. glabrata (11.8%) and C. tropicalis (6.4%). Of all Candida BSI, 124 (60.8 %) occurred in patients admitted to IMW, 31/204 (15.2 %) in ICUs, 33/204 (16.2%) in surgical units and 16/204 (7.8%) in Hematology/Oncology wards. Overall, 47% of patients died within 30 days from the onset of candidemia. C. parapsilosis and C. glabrata candidemia were associated with the lowest mortality rate (36%), while patients with C. tropicalis BSI had the highest mortality rate (58.3%). Lower mortality rates were detected in patients receiving therapy within 48 hours from the time of execution of the blood cultures (57,1% vs 38,9%, P <0.05). At multivariate analysis, steroids treatment (OR= 0.27, p=0.005) and CVC removal (OR=3.77, p=0.014) were independently associated with lower and higher survival probability, respectively. Candidemia in patients with peripherally inserted central catheters (PICC) showed to be associated with higher mortality in comparison with central venous catheters (CVC, Short catheters and Portacath) and no CVC use. For each point increase of APACHE III score, survival probability decreased of 2%. Caspofungin (OR=3.45, p=0.015) and Amphothericin B lipid formulation (OR=15.26, p=0.033) were independently associated with higher survival probability compared with no treatment.

Development and validation of a clinical prediction rule for candidemia in hospitalized patients with severe sepsis and septic shock

OBJECTIVE

To develop and internally validate a prediction rule for the presence of candidemia in patients with severe sepsis and septic shock (candidemia rule) that will fill the gap left by previous rules. To compare the accuracy of the available Candida prediction models.

DESIGN

Retrospective cohort study.

SETTING

Barnes-Jewish Hospital, St. Louis, Missouri.

PATIENTS/SUBJECTS

Two thousand five hundred ninety-seven consecutive patients with a positive blood culture and severe sepsis or septic shock.

INTERVENTIONS

Logistic regression and a bootstrap resampling procedure were employed for model development and internal validation.

MEASUREMENTS AND MAIN RESULTS

Two hundred sixty-six (10.2%) had blood cultures positive for Candida spp. Mortality was significantly higher in patients with candidemia than in patients with bacteremia (47.0% versus 28.4%; P<.001). Administration of total parenteral nutrition, prior antibiotic exposure, transfer from an outside hospital or admission from a nursing home, mechanical ventilation and presence of a central vein catheter were independent predictors of candidemia while the lung as a source for infection was protective. The prediction rule had an area under the receiver operating characteristic curve of 0.798 (95% CI 0.77-0.82). Internal validation using bootstrapping technique with 1000 repetitions produced a similar area under the receiver operating characteristic curve of 0.797 (bias, -0.037; root mean square error 0.039). Our prediction rule outperformed previous rules with a better calibration slope of 0.96 and Brier score of 0.08.

CONCLUSIONS

We developed and internally validated a prediction rule for candidemia in hospitalized patients with severe sepsis and septic shock that outperformed previous prediction rules. Our study suggests that locally derived prediction models may be superior by accounting for local case mix and risk factor distribution.

DNA protection, antioxidant, antibacterial and enzyme inhibition activities of heartwood and sapwood extracts from juniper and olive woods

In this study, DNA protective, antioxidant, antibacterial and enzyme inhibiting properties of methanol extracts obtained from juniper and olive heartwood and sapwood were determined.

Novel mechanisms of surfactants against Candida albicans growth and morphogenesis

Candida albicans is a common opportunistic fungal pathogen, causing not only superficial mucosal infections but also life-threatening systemic candidiasis in immune-compromised individuals. Surfactants are a kind of amphiphilic compounds implemented in a wide range of applications. Although their antimicrobial activity has been characterized, their effect on C. albicans physiology remains to be elucidated. In this study, we investigated the inhibitory effect of two representative surfactants, cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS), on C. albicans growth and morphogenesis. Both surfactants exhibited inhibitory effect on C. albicans growth. This effect was not attributed to plasma membrane (PM) damage, but was associated with mitochondrial dysfunction. Excitingly, the surfactants, especially CTAB, showed strong inhibitory effect on hyphal development (IC50=0.183 ppm for CTAB and 6.312 ppm for SDS) and biofilms (0.888 ppm for CTAB and 76.092 ppm for SDS). Actin staining and Hwp1-GFP localization further revealed that this inhibition is related to abnormal organization of actin skeleton and subsequent defect in polarized transport of hyphae-related factors. This study sheds a novel light on the antimicrobial mechanisms of surfactants, and suggests these agents as potential drugs against C. albicans hyphae-related infections in clinical practice.

Novel strategies to fight Candida species infection

In recent years, there has been a significant increase in the incidence of human fungal infections. The increase in cases of infection caused by Candida species, and the consequent excessive use of antimicrobials, has favored the emergence of resistance to conventional antifungal agents over the past decades. Consequently, Candida infections morbidity and mortality are also increasing. Therefore, new approaches are needed to improve the outcome of patients suffering from Candida infections, because it seems unlikely that the established standard treatments will drastically lower the morbidity of mucocutaneous Candida infections and the high mortality associated with invasive candidiasis. This review aims to present the last advances in the traditional antifungal therapy, and present an overview of novel strategies that are being explored for the treatment of Candida infections, with a special focus on combined antifungal agents, antifungal therapies with alternative compounds (plant extracts and essential oils), adjuvant immunotherapy, photodynamic therapy and laser therapy.

[iNKT cells participate in the exacerbation of systemic candidal infection]

Candida species are one major causal microorganism of hospital acquired bloodstream infections associated with high mortality. Phagocytes like neutrophils in innate immunity and CD4 T cells in acquired immunity have a major role in host defense immune response. It has been recently found that a type of innate-like lymphocyte called NKT cells respond against various organisms but its role in candidal infection remained unknown. Thus, we analyzed the role of NKT cells in the immune response against systemic candidiasis using mice deficient of NKT cells. In vivo studies revealed that invariant NKT cells play a limited role for controlling systemic candidal infection. On the other hand, studies looking at the role of glycolipid-activated NKT cells during candidal infection revealed that candida-infected mice injected with glycolipid had shorter survival period and greater number of fungal colonies in the kidney accompanied with reduced number of neutrophils in the blood and bone marrow. Surprisingly, glycolipid-mediated exacerbation of candidal infection was absent in IFNγ deficient mice. Co-infection of candida with intestinal commensals caused exacerbated infection in which IFNγ played a critical role in impairing fungal elimination. These results suggest that the excessive IFNγ released from candida and bacterial co-infection is a critical factor in worsening candidal infection.

Bloodstream infections in patients with hematological malignancies: which is more fatal - cancer or resistant pathogens?

Background

The primary objective of this study was to report the incidence of bloodstream infections (BSIs) and clinically or microbiologically proven bacterial or fungal BSIs during neutropenic episodes in patients with hematological malignancies.

Methods

In this retrospective observational study, all patients in the hematology department older than 14 years who developed febrile neutropenia during chemotherapy for hematological cancers were evaluated. Patients were included if they had experienced at least one neutropenic episode between November 2010 and November 2012 due to chemotherapy in the hematology ward.

Results

During 282 febrile episodes in 126 patients, 66 (23%) episodes of bacteremia and 24 (8%) episodes of fungemia were recorded in 48 (38%) and 18 (14%) patients, respectively. Gram-negative bacteria caused 74% (n=49) of all bacteremic episodes. Carbapenem-resistant Gram-negative bacteria (n=6) caused 12% and 9% of Gram-negative bacteremia episodes and all bacteremia episodes, respectively. Carbapenem-resistant Gram-negative bacteria included Acinetobacter baumannii (n=4), Pseudomonas aeruginosa (n=1), and Serratia marcescens (n=1). Culture-proven invasive fungal infection occurred in 24 episodes in 18 cases during the study period, with 15 episodes in ten cases occurring in the first study year and nine episodes in eight cases in the second study year. In 13 of 18 cases (72%) with bloodstream yeast infections, previous azole exposure was recorded. Candida parapsilosis, C. glabrata, and C. albicans isolates were resistant to voriconazole and fluconazole.

Conclusion

BSIs that occur during febrile neutropenic episodes in hematology patients due to Gram-negative bacteria should be treated initially with non-carbapenem-based antipseudomonal therapy taking into consideration antimicrobial stewardship. Non-azole antifungal drugs, including caspofungin and liposomal amphotericin B, should be preferred as empirical antifungal therapy in the events of possible or probable invasive fungal infections with an absence of pulmonary findings due to increase azole resistance.

Candida colonization index and subsequent infection in critically ill surgical patients: 20 years later

Introduction

For decades, clinicians dealing with immunocompromised and critically ill patients have perceived a link between Candida colonization and subsequent infection. However, the pathophysiological progression from colonization to infection was clearly established only through the formal description of the colonization index (CI) in critically ill patients. Unfortunately, the literature reflects intense confusion about the pathophysiology of invasive candidiasis and specific associated risk factors.

Methods

We review the contribution of the CI in the field of Candida infection and its development in the 20 years following its original description in 1994. The development of the CI enabled an improved understanding of the pathogenesis of invasive candidiasis and the use of targeted empirical antifungal therapy in subgroups of patients at increased risk for infection.

Results

The recognition of specific characteristics among underlying conditions, such as neutropenia, solid organ transplantation, and surgical and nonsurgical critical illness, has enabled the description of distinct epidemiological patterns in the development of invasive candidiasis.

Conclusions

Despite its limited bedside practicality and before confirmation of potentially more accurate predictors, such as specific biomarkers, the CI remains an important way to characterize the dynamics of colonization, which increases early in patients who develop invasive candidiasis.

Invasive candidiasis in intensive care unit; consensus statement from an Iranian panel of experts, July 2013

Invasive candidiasis (IC) is associated with high mortality in intensive care unit (ICU) patients. Timely diagnosis of this potentially fatal condition remains a challenge; on the other hand, the criteria for initiating empirical antifungal therapy in critically ill patients are not well defined in different patient population and ICU settings. Alongside the international guidelines, reaching regional and local consensus on diagnosis and management of IC in ICU setting is essential. This report summarizes our present status of IC management in ICU, considered by a group of Iranian experts in the fields of intensive care and infectious diseases. A round table of 17 experts was held to review the available data and discuss the optimal treatment strategies for IC in critical care setting. Comparative published data on the management of IC were analytically reviewed and the commonly asked questions about the management of IC in ICU were isolated. These questions were interactively discussed by the panel and audience responses were taken to consolidate point-to-point agreement with the panel arriving at consensus in many instances. The responses indicated that patients’ risk stratification, clinical discretion, fungal diagnostic techniques and the empirical therapy for IC are likely to save more patients. Treatment options were recommended to be based on the disease severity, prior azole exposure, and the presence of suspected azole-resistant Candida species. This report was reviewed, edited and discussed by all participants to include further evidence-based insights. The panel expects such endorsed recommendations to be soon formulated for implementation across the country.

Micafungin: the US perspective

Invasive fungal infections cause considerable morbidity and mortality in nosocomial settings and amongst immunocompromised hosts. Invasive candidiasis and aspergillosis remain the most common invasive fungal infections, with Candida spp. constituting the fourth most common bloodstream infection in the USA. Currently available antifungal therapies include the polyene, antimetabolite, allylamine, azole and echinocandin drug classes. Micafungin, approved in March 2005 by the Food and Drug Administration for use in the USA, has shown safety and efficacy for the treatment of candidiasis and aspergillosis in clinical trials in Japan, Europe and South Africa. Micafungin holds promise as a first-line treatment option for candidiasis, as well as prophylaxis against invasive fungal infections during periods of neutropenia in high-risk patients.

Invasive candidiasis: update on current pharmacotherapy options and future perspectives

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

The persistence of multifocal colonisation by a single ABC genotype of Candida albicans may predict the transition from commensalism to infection

Candida albicans is a common member of the human microbiota and may cause invasive disease in susceptible populations. Several risk factors have been proposed for candidaemia acquisition. Previous Candida multifocal colonisation among hospitalised patients may be crucial for the successful establishment of candidaemia. Nevertheless, it is still not clear whether the persistence or replacement of a single clone of C. albicans in multiple anatomical sites of the organism may represent an additional risk for candidaemia acquisition. Therefore, we prospectively evaluated the dynamics of the colonising strains of C. albicans for two groups of seven critically ill patients: group I included patients colonised by C. albicans in multiple sites who did not develop candidaemia and group II included patients who were colonised and who developed candidaemia. ABC and microsatellite genotyping of 51 strains of C. albicans revealed that patients who did not develop candidaemia were multiply colonised by at least two ABC genotypes of C. albicans, whereas candidaemic patients had highly related microsatellites and the same ABC genotype in colonising and bloodstream isolates that were probably present in different body sites before the onset of candidaemia.

Intensive care unit-related fluconazole use in Spain and Germany: patient characteristics and outcomes of a prospective multicenter longitudinal observational study

BACKGROUND

Candida spp. are a frequent cause of nosocomial bloodstream infections worldwide.

OBJECTIVE

To evaluate the use patterns and outcomes associated with intravenous (IV) fluconazole therapy in intensive care units in Spain and Germany.

PATIENTS AND METHODS

The research reported here was a prospective multicenter longitudinal observational study in adult intensive care unit patients receiving IV fluconazole. Demographic, microbiologic, therapy success, length of hospital stay, adverse event, and all-cause mortality data were collected at 14 sites in Spain and five in Germany, from February 2004 to November 2005.

RESULTS

Patients (n = 303) received prophylaxis (n = 29), empiric therapy (n = 140), preemptive therapy (n = 85), or definitive therapy (n = 49). A total of 298 patients (98.4%) were treated with IV fluconazole as first-line therapy. The treating physicians judged therapy successful in 66% of prophylactic, 55% of empiric, 45% of preemptive, and 43% of definitive group patients. In the subgroup of 152 patients with proven and specified Candida infection only, 32% suffered from Candida specified as potentially resistant to IV fluconazole. The overall mortality rate was 42%.

CONCLUSION

Our study informs treatment decision makers that approximately 32% of the patients with microbiological results available suffered from Candida specified as potentially resistant to IV fluconazole, highlighting the importance of appropriate therapy.

European expert opinion on the management of invasive candidiasis in adults

This report discusses the present status of antifungal therapy and treatment options for candidaemia, considered by experts in the field in Europe. A conference of 26 experts from 13 European countries was held to discuss strategies for the treatment and prevention of invasive candidiasis, with the aim of providing a review on optimal management strategies. Published and unpublished comparative trials on antifungal therapy were analysed and discussed. Commonly asked questions about the management of candidaemia were selected, and possible responses to these questions were discussed. Panellists were then asked to respond to each question by using a touchpad answering system. After the initial conference, the viewpoint document has been reviewed and edited to include new insights and developments since the initial meeting. For many situations, consensus on treatment could not be reached, and the responses indicate that treatment is likely to be modified on a patient-to-patient basis, depending on factors such as degree of illness, prior exposure to azole antifungals, and the presence of potentially antifungal drug-resistant Candida species.

Diagnosis of invasive candidiasis in the ICU

Invasive candidiasis ranges from 5 to 10 cases per 1,000 ICU admissions and represents 5% to 10% of all ICU-acquired infections, with an overall mortality comparable to that of severe sepsis/septic shock. A large majority of them are due to Candida albicans, but the proportion of strains with decreased sensitivity or resistance to fluconazole is increasingly reported. A high proportion of ICU patients become colonized, but only 5% to 30% of them develop an invasive infection. Progressive colonization and major abdominal surgery are common risk factors, but invasive candidiasis is difficult to predict and early diagnosis remains a major challenge. Indeed, blood cultures are positive in a minority of cases and often late in the course of infection. New nonculture-based laboratory techniques may contribute to early diagnosis and management of invasive candidiasis. Both serologic (mannan, antimannan, and betaglucan) and molecular (Candida-specific PCR in blood and serum) have been applied as serial screening procedures in high-risk patients. However, although reasonably sensitive and specific, these techniques are largely investigational and their clinical usefulness remains to be established. Identification of patients susceptible to benefit from empirical antifungal treatment remains challenging, but it is mandatory to avoid antifungal overuse in critically ill patients. Growing evidence suggests that monitoring the dynamic of Candida colonization in surgical patients and prediction rules based on combined risk factors may be used to identify ICU patients at high risk of invasive candidiasis susceptible to benefit from prophylaxis or preemptive antifungal treatment.

Candida bloodstream infections in intensive care units: analysis of the extended prevalence of infection in intensive care unit study

OBJECTIVES

To provide a global, up-to-date picture of the prevalence, treatment, and outcomes of Candida bloodstream infections in intensive care unit patients and compare Candida with bacterial bloodstream infection.

DESIGN

A retrospective analysis of the Extended Prevalence of Infection in the ICU Study (EPIC II). Demographic, physiological, infection-related and therapeutic data were collected. Patients were grouped as having Candida, Gram-positive, Gram-negative, and combined Candida/bacterial bloodstream infection. Outcome data were assessed at intensive care unit and hospital discharge.

SETTING

EPIC II included 1265 intensive care units in 76 countries.

PATIENTS

Patients in participating intensive care units on study day.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Of the 14,414 patients in EPIC II, 99 patients had Candida bloodstream infections for a prevalence of 6.9 per 1000 patients. Sixty-one patients had candidemia alone and 38 patients had combined bloodstream infections. Candida albicans (n = 70) was the predominant species. Primary therapy included monotherapy with fluconazole (n = 39), caspofungin (n = 16), and a polyene-based product (n = 12). Combination therapy was infrequently used (n = 10). Compared with patients with Gram-positive (n = 420) and Gram-negative (n = 264) bloodstream infections, patients with candidemia were more likely to have solid tumors (p < .05) and appeared to have been in an intensive care unit longer (14 days [range, 5-25 days], 8 days [range, 3-20 days], and 10 days [range, 2-23 days], respectively), but this difference was not statistically significant. Severity of illness and organ dysfunction scores were similar between groups. Patients with Candida bloodstream infections, compared with patients with Gram-positive and Gram-negative bloodstream infections, had the greatest crude intensive care unit mortality rates (42.6%, 25.3%, and 29.1%, respectively) and longer intensive care unit lengths of stay (median [interquartile range]) (33 days [18-44], 20 days [9-43], and 21 days [8-46], respectively); however, these differences were not statistically significant.

CONCLUSION

Candidemia remains a significant problem in intensive care units patients. In the EPIC II population, Candida albicans was the most common organism and fluconazole remained the predominant antifungal agent used. Candida bloodstream infections are associated with high intensive care unit and hospital mortality rates and resource use.

Design and use of Candida scores at the intensive care unit

Invasive Candida infections are recognised as a cause of increased morbidity and mortality in intensive care patients, particularly those with recent extensive gastroabdominal surgery. Due to the difficulties of diagnosis, several authors have analysed risk factors suggestive of invasive candidiasis to identify patients at highest risk. Such patients may be potential candidates for preemptive antifungal therapy before becoming seriously ill. The extent of body site colonisation due to Candida species was recognised to be related with consequent invasive disease. The quantification of the colonisation was expressed as the Candida colonisation index. Based on the evaluation of independent risk factors predictive of invasive Candida infections, clinically relevant scores were evaluated in the last decade. Particularly, the Candida score that combines the clinical risk factors preceding surgery, total parenteral nutrition and severe sepsis with Candida multi-site colonisation can be considered a useful bedside scoring system to discern patients with mere Candida colonisation from patients with the risk of invasive candidiasis in non-neutropaenic critically ill patient population.

[What should and should not be covered in intraabdominal infection]

Despite improvements in our knowledge of the physiopathology of severe infection, diagnostic methods, antibiotic therapy, postoperative care and surgical techniques, a substantial number of patients with intraabdominal infection (IAI) will develop advanced stages of septic insult requiring admission to the intensive care unit. The success of treatment of IAI is multifactorial and the best antibiotic protocol may be insufficient unless adequate control of the focus of infection has been achieved. The present article discusses the appropriacy of empirical antibiotic therapy and the main pathogens associated with treatment failure. We also analyze the patients at risk of infection with microorganisms requiring broad-spectrum antimicrobial coverage. However, excessive antibiotic treatment, in terms of either spectrum or duration, could jeopardize future patients in an environment already threatened by the scarcity of research and development into new molecules required for the emergence of pathogens resistant to current antibiotics.

Posaconazole as part of the antifungal armamentarium in the intensive care unit--case reports from a surgical ICU

The authors describe two cases of successful and safe posaconazole use in patients of a surgical intensive care unit of a university hospital.

Economic considerations of antifungal prophylaxis in patients undergoing surgical procedures

Fungi are a frequent cause of nosocomial infections, with an incidence that has increased significantly in recent years, especially among critically ill patients who require intensive care unit (ICU) admission. Among ICU patients, postsurgical patients have a higher risk of Candida infections in the bloodstream. In consideration of the high incidence of fungal infections in these patients, their strong impact on mortality rate, and of the difficulties in Candida diagnosis, some experts suggest the use of antifungal prophylaxis in critically ill surgical patients. A clinical benefit from this strategy has been demonstrated, but the economic impact of the use of antifungal prophylaxis in surgical patients has not been systematically evaluated, and its cost-benefit ratio has not been defined. Whereas the costs associated with treating fungal infections are very high, the cost of antifungal drugs varies from affordable (ie, the older azoles) to expensive (ie, echinocandins, polyenes, and the newer azoles). Adverse drug-related effects and the possibly increased incidence of fluconazole resistance and of isolates other than Candida albicans must also be taken into account. From the published studies of antifungal prophylaxis in surgical patients, a likely economic benefit of this strategy could be inferred, but its usefulness and cost-benefits should be evaluated in light of local data, because the available evidence does not permit general recommendations.

Candidemia after cardiac surgery in the intensive care unit: an observational study

Candidemia is a well-recognized complication of hospital stay, especially in critically ill patients. There is not a general consensus that predictors for candidemia in cardiosurgical intensive care unit (cICU) are different from a general ICU and it has been reported that cardiopulmonary bypass time is a specific risk factor in the cICU. We performed a prospective study to evaluate the main predictors for candidemia in patients admitted to the cICU. Included patients were adults admitted between July 2005 and December 2007 with an ICU-length of stay (ICU-LOS) ≥48 hours after cardiac surgery. Exclusion criteria were solid organ or bone marrow transplants, previous diagnosis of candidemia or other invasive infections and ICU stay before surgery. A multiple regression analysis was performed to identify the risk factors. Among 1955 patients admitted to the cICU, 345 were enrolled. Only 26 patients (1.3%) had candidemia after an ICU-LOS of 20 days (inter-quartile range, IQR 8-49 days). Total parenteral nutrition [odds ratio (OR)=9.56; confidence interval (CI)=1.741-52.534], severe sepsis (OR=4.20; CI=1.292-13.667), simplified acute physiology score II (OR=1.16; CI=1.052-1.278) and ICU-LOS >20 days (OR=6.38; CI=1.971-20.660) were independent predictors of candidemia. Patients undergoing cardiac surgery developed candidemia late after cICU admission and the independent predictors were similar to the general ICU.