Contribution of serological tests and blood culture to the early diagnosis of systemic candidiasis

Early diagnosis of candidemia with explainable machine learning on automatically extracted laboratory and microbiological data: results of the AUTO-CAND project

BACKGROUND

Candidemia is associated with a heavy burden of morbidity and mortality in hospitalized patients. The availability of blood culture results could require up to 48-72 h after blood draw; thus, early treatment decisions are made in the absence of a definite diagnosis.

METHODS

In this retrospective study, we assessed the performance of different supervised machine learning algorithms for the early differential diagnosis of candidemia and bacteremia in adult patients on a large dataset automatically extracted within the AUTO-CAND project.

RESULTS

Overall, 12,483 episodes of candidemia (1275; 10%) or bacteremia (11,208; 90%) were included in the analysis. A random forest classifier achieved the best diagnostic performance for candidemia, with sensitivity 0.98 and specificity 0.65 on the training set (true skill statistic [TSS] = 0.63) and sensitivity 0.74 and specificity 0.57 on the test set (TSS = 0.31). Then, the random classifier was trained in the subgroup of patients with available serum β-D-glucan (BDG) and procalcitonin (PCT) values by exploiting the feature ranking learned in the entire dataset. Although no statistically significant differences were observed from the performance measures obtained by employing BDG and PCT alone, the performance measures of the classifier that included the features selected in the entire dataset, plus BDG and PCT, were the highest in most cases.

CONCLUSIONS

Random forest classifiers trained on large datasets of automatically extracted data have the potential to improve current diagnostic algorithms for candidemia. However, further development through implementation of automatically extracted clinical features may be necessary to achieve crucial improvements.

Separation and Washing of Candida Cells from White Blood Cells Using Viscoelastic Microfluidics

An early and accurate diagnosis of Candida albicans is critical for the rapid antifungal treatment of candidemia, a mortal bloodstream infection. This study demonstrates viscoelastic microfluidic techniques for continuous separation, concentration, and subsequent washing of Candida cells in the blood. The total sample preparation system contains two-step microfluidic devices: a closed-loop separation and concentration device and a co-flow cell-washing device. To determine the flow conditions of the closed-loop device, such as the flow rate factor, a mixture of 4 and 13 μm particles was used. Candida cells were successfully separated from the white blood cells (WBCs) and concentrated by 74.6-fold in the sample reservoir of the closed-loop system at 800 μL/min with a flow rate factor of 3.3. In addition, the collected Candida cells were washed with washing buffer (deionized water) in the microchannels with an aspect ratio of 2 at a total flow rate of 100 μL/min. Finally, Candida cells at extremely low concentrations (Ct > 35) became detectable after the removal of WBCs, the additional buffer solution in the closed-loop system (Ct = 30.3 ± 1.3), and further removal of blood lysate and washing (Ct = 23.3 ± 1.6).

Validation of an Automated System for the Extraction of a Wide Dataset for Clinical Studies Aimed at Improving the Early Diagnosis of Candidemia

There is increasing interest in assessing whether machine learning (ML) techniques could further improve the early diagnosis of candidemia among patients with a consistent clinical picture. The objective of the present study is to validate the accuracy of a system for the automated extraction from a hospital laboratory software of a large number of features from candidemia and/or bacteremia episodes as the first phase of the AUTO-CAND project. The manual validation was performed on a representative and randomly extracted subset of episodes of candidemia and/or bacteremia. The manual validation of the random extraction of 381 episodes of candidemia and/or bacteremia, with automated organization in structured features of laboratory and microbiological data resulted in ≥99% correct extractions (with confidence interval < ±1%) for all variables. The final automatically extracted dataset consisted of 1338 episodes of candidemia (8%), 14,112 episodes of bacteremia (90%), and 302 episodes of mixed candidemia/bacteremia (2%). The final dataset will serve to assess the performance of different ML models for the early diagnosis of candidemia in the second phase of the AUTO-CAND project.

Expression and Purification along with Evaluation of Serological Response and Diagnostic Potential of Recombinant Sap2 Protein from C. parapsilosis for Use in Systemic Candidiasis

Systemic candidiasis is the fourth most common bloodstream infection in ICU patients worldwide. Although C. albicans is a predominant species causing systemic candidiasis, infections caused by non-albicans Candida (NAC) species are increasingly becoming more prevalent globally along with the emergence of drug resistance. The diagnosis of systemic candidiasis is difficult due to the absence of significant clinical symptoms in patients. We investigated the diagnostic potential of recombinant secreted aspartyl proteinase 2 (rSap2) from C. parapsilosis for the detection of Candida infection. The rSap2 protein was successfully cloned, expressed and purified using Ni-NTA chromatography under denaturing conditions using an E. coli-based prokaryotic expression system, and refolded using a multi-step dialysis procedure. Structural analysis by CD and FTIR spectroscopy revealed the refolded protein to be in its near native conformation. Immunogenicity analysis demonstrated the rSap2 protein to be highly immunogenic as evident from significantly high titers of Sap2-specific antibodies in antigen immunized Balb/c mice, compared to sham-immunized controls. The diagnostic potential of rSap2 protein was evaluated using immunoblotting and ELISA assays using proven candidiasis patient serum and controls. Immunoblotting results indicate that reactivity to rSap2 was specific to candidiasis patient sera with no cross reactivity observed in healthy controls. Increased levels of anti-Sap2-specific Ig, IgG and IgM antibodies were observed in candidiasis patients compared to controls and was similar in sensitivity obtained when whole Candida was used as coating antigen. In summary, the rSap2 protein from C. parapsilosis has the potential to be used in the diagnosis of systemic candidiasis, providing a rapid, convenient, accurate and cost-effective strategy.

Dissection of the anti-Candida albicans mannan immune response using synthetic oligomannosides reveals unique properties of β-1,2 mannotriose protective epitopes

Candida albicans mannan consists of a large repertoire of oligomannosides with different types of mannose linkages and chain lengths, which act as individual epitopes with more or less overlapping antibody specificities. Although anti-C. albicans mannan antibody levels are monitored for diagnostic purposes nothing is known about the qualitative distribution of these antibodies in terms of epitope specificity. We addressed this question using a bank of previously synthesized biotin sulfone tagged oligomannosides (BSTOs) of α and β anomery complemented with a synthetic β-mannotriose described as a protective epitope. The reactivity of these BSTOs was analyzed with IgM isotype monoclonal antibodies (MAbs) of known specificity, polyclonal sera from patients colonized or infected with C. albicans, and mannose binding lectin (MBL). Surface plasmon resonance (SPR) and multiple analyte profiling (MAP) were used. Both methods confirmed the usual reactivity of MAbs against either α or β linkages, excepted for MAb B6.1 (protective epitope) reacting with β-Man whereas the corresponding BSTO reacted with anti-α-Man. These results were confirmed in western blots with native C. albicans antigens. Using patients' sera in MAP, a significant correlation was observed between the detection of anti-mannan antibodies recognizing β- and α-Man epitopes and detection of antibodies against β-linked mannotriose suggesting that this epitope also reacts with human polyclonal antibodies of both specificities. By contrast, the reactivity of human sera with other α- and β-linked BSTOs clearly differed according to their colonized or infected status. In these cases, the establishment of an α/β ratio was extremely discriminant. Finally SPR with MBL, an important lectin of innate immunity to C. albicans, classically known to interact with α-mannose, also interacted in an unexpected way with the protective epitope. These cumulative data suggest that structure/activity investigations of the finely tuned C. albicans anti-mannose immune response are worthwhile to increase our basic knowledge and for translation in medicine.

Pooled analysis of T2 Candida for rapid diagnosis of candidiasis

Background

The present meta-analysis examined the diagnostic accuracy of T2 Candida for candidiasis.

Methods

The literature databases, such as PubMed, Embase, DVIO, Cochrane library, Web of Science, and CNKI, were searched on T2 Candida detection.

Results

A total of 8 articles, comprising of 2717 research subjects, were included in the study. The pooled sensitivity and specificity were 0.91 (95% confidence interval (CI): 0.88–0.94) and 0.94 95% CI: 0.93–0.95), respectively. The pooled positive likelihood ratio and negative likelihood ratio was 10.16 (95% CI: 2.75–37.50) and 0.08 (95% CI: 0.02–0.35), respectively. The combined diagnostic odds ratio is 133.65 95% CI: 17.21–1037.73), and the AUC of SROC is 0.9702 [(SE = 0.0235), Q* = 0.9201(SE = 0.0381)].

Conclusions

The current evidence supported that T2 Candida has high accuracy and sensitivity and is of major clinical significance in the diagnosis of Candida infection.

Viscoelastic Separation and Concentration of Fungi from Blood for Highly Sensitive Molecular Diagnostics

Isolation and concentration of fungi in the blood improves sensitivity of the polymerase chain reaction (PCR) method to detect fungi in blood. This study demonstrates a sheathless, continuous separation and concentration method of candida cells using a viscoelastic fluid that enables rapid detection of rare candida cells by PCR analysis. To validate device performance using a viscoelastic fluid, flow characteristics of 2 μm particles were estimated at different flow rates. Additionally, a mixture of 2 μm and 13 μm particles was successfully separated based on size difference at 100 μl/min. Candida cells were successfully separated from the white blood cells (WBCs) with a separation efficiency of 99.1% and concentrated approximately 9.9-fold at the center outlet compared to the initial concentration (~2.5 × 10⁷ cells/ml). Sequential 1st and 2nd concentration processes were used to increase the final number of candida cells to ~2.3 × 10⁹ cells/ml, which was concentrated ~92-fold. Finally, despite the undetectable initial concentration of 10¹ CFU/ml, removal of WBCs and the additional buffer solution enabled the quantitative reverse transcription (RT)-PCR detection of candida cells after the 1st concentration (Ct = 31.43) and the 2nd concentration process (Ct = 29.30).

Biomarker-guided antifungal stewardship policies for patients with invasive candidiasis

Invasive fungal infections (IFIs) are among the life-threatening issues in patients with impaired immune system. High administration of antifungals in these patients imposes a heavy economic burden on the national health system. In addition, despite the usually expensive antifungal regimens, the mortality rate due to fungal infections is still high, resulting in the loss of hundreds of lives per year. Survival rate is an indicator of the success of national healthcare policies. Early diagnosis of IFI is critical because any delays may be fatal. The weakness of the old-fashioned culture-based diagnostic methods lies in their time-consuming laboratory procedures. To overcome this problem, several diagnostic approaches have been developed to facilitate the early diagnosis of invasive candidiasis as the most prevalent IFI. These methods are based on the detection of serologic and molecular footprints. However, nowadays, antibiotic resistance and proper and cost-effective use of antibiotics are given special attention in national healthcare policies. The instructions for controlling these indices have been collected under the name of antibiotic stewardship. The present review study was targeted toward providing insight into novel diagnostic biomarkers and antifungal stewardship programs. The simultaneous investigation of these two issues facilitates the achievement of a novel health policy for the treatment of systemic candidiasis in immunocompromised patients.

Serological biomarkers of candidemia: a retrospective evaluation of three assays

PURPOSE

Serologic testing allows for rapid detection of candidemia. More data are needed for the Virion\Serion ELISA antigen test (Ag), Hemkit Candida IHA antibody test (Ab), and Wako β-1,3-D-glucan assay (BDG).

METHODS

Tests were performed on serum samples from 120 cases of culture-confirmed candidemia and 44 Candida-negative controls. Sensitivities and specificities of individual tests as well as combinations were assessed.

RESULTS

The overall sensitivity of Ag, Ab, and Ag/Ab testing was 30, 40, and 54%, respectively, while in transplant patients it significantly dropped to 16, 26, and 40% (p = 0.02). For BDG testing it was 67%, both overall and in transplant patients. Especially Ag testing performed poorly among women ≤ 65 years with a significantly reduced sensitivity of 9% (p < 0.002). While the sensitivity of Ag/Ab testing was somewhat higher at 67% for C. albicans, it was significantly lower for non-albicans species at 42% (p = 0.006). The sensitivity of BDG testing for C. albicans and non-albicans species was not significantly different at 64 and 69%, respectively. Both Ag/Ab and BDG testing had a high specificity of 93%, for Ag testing it was 100%. Similar sensitivities were calculated for sera sampled on the day of and 4-6 days before sampling of positive blood cultures.

CONCLUSIONS

Serological markers are valuable tools for the early diagnosis of candidemia. Ab, Ag, and BDG testing are all characterized by high specificity. The Wako BDG test is significantly more sensitive compared to combined Candida-Ag/Ab testing, particularly in the setting of non-albicans species and specific host factors.

Diagnosis of invasive fungal diseases in haematology and oncology: 2018 update of the recommendations of the infectious diseases working party of the German society for hematology and medical oncology (AGIHO)

Invasive fungal diseases (IFD) are a primary cause of morbidity and mortality in patients with haematological malignancies. These infections are mostly life-threatening and an early diagnosis and initiation of appropriate antifungal therapy are essential for the clinical outcome. Most commonly, Aspergillus and Candida species are involved. However, other Non-Aspergillus moulds are increasingly identified in case of documented IFD. For definite diagnosis of IFD, a combination of diagnostic tools have to be applied, including conventional mycological culture and non-conventional microbiological tests such as antibody/antigen and molecular tests, as well as histopathology and radiology. Although varying widely in cancer patients, the risk of invasive fungal infection is highest in those with allogeneic stem cell transplantation and those with acute leukaemia and markedly lower in patients with solid cancer. Since the last edition of Diagnosis of Invasive Fungal Diseases recommendations of the German Society for Hematology and Oncology in 2012, integrated care pathways have been proposed for the management and therapy of IFDs with either a diagnostic driven strategy as opposed to a clinical or empirical driven strategy. This update discusses the impact of this additional evidence and effective revisions.

A Retrospective Assessment of Four Antigen Assays for the Detection of Invasive Candidiasis Among High-Risk Hospitalized Patients

Because of their high mortality rates and non-specific symptoms, invasive Candida infections pose a huge diagnostic and therapeutic challenge. In this study, we evaluated the three mannan antigen assays Platelia, Platelia Plus and Serion, and the (1-3)-β-D-glucan assay Fungitell in a group of high-risk (hematological and surgical) patients. Test results of 305 patients hospitalized at the Vienna General Hospital and the University Hospital of Innsbruck were retrospectively analyzed. We assessed the test accuracy by means of descriptive statistics. Nine (2.95%) patients were affected by invasive candidiasis (IC), and 25 (8.2%) patients had a probable/possible infection. The majority of patients (271; 88.9%) showed no signs of infection. The Platelia and Serion mannan assays had a low sensitivity (65% and 52%, respectively), but high specificity (98% for both tests). The newer version of the Platelia assay, the Platelia Plus, had a higher sensitivity (85%) but a lower specificity (89%). The sensitivity of the Fungitell assay was high (100%), while its specificity was low (58%). The positive predictive values were 0.48 for the Platelia and 0.41 for the Serion assay, 0.26 for the Platelia Plus and 0.09 for the Fungitell assay. Our limited, retrospective study suggests the efficacy of mannan assays as screening (Platelia Plus) and confirmatory (Serion) tests, while the Fungitell assay can be used to exclude invasive Candida infections.

Laboratory Diagnostics for Fungal Infections: A Review of Current and Future Diagnostic Assays

This article reviews the current diagnostic approaches, both serologic and molecular, for the detection of fungi associated with pulmonary disease. Classic serologic techniques, including immunodiffusion and complement fixation, both of which remain a cornerstone for fungal diagnostic testing, are reviewed and their performance characteristics presented. More recent advances in this field, including novel lateral-flow assays for fungal antigen detection, are also described. Molecular techniques for fungal identification both from culture and directly from patient specimens, including nucleic acid probes, mass spectrometry-based methods, nucleic acid amplification testing, and traditional and broad-range sequencing, are discussed and their performance evaluated.

High Interleukin-12 Levels May Prevent an Increase in the Amount of Fungi in the Gastrointestinal Tract during the First Years of Diabetes Mellitus Type 1

The objective of the research was to investigate serum levels of interleukin-12 (IL12) in relation to percentage of yeast-like fungi colonies residing in the gastrointestinal tract in children and adolescents with type 1 diabetes mellitus (T1DM). The study involved 83 children and adolescents, including 53 T1DM patients and 30 healthy control subjects. In the studied population biochemical tests were performed and yeast-like fungi were identified in the faeces. Moreover, IL12 absorbance was measured and measurements of Candida albicans IgG and IgM antibodies were performed with microplate reader ChroMate 4300 (Awareness Technology, Inc., USA) at wavelength λ = 450 nm. In the group of T1DM children and adolescents with disease duration ≤ 2 years, high levels of IL12 were found with lower percentage of yeast-like fungal colonies versus T1DM patients with disease duration > 2 years and ≤5 years, as well as versus T1DM patients with disease duration > 5 years. Additionally, serum levels of IL12 were found to be decreasing by 18.1 pg/ml with each year of diabetes duration. IL12 serum levels were also found to be decreasing by 52.9 pg/ml with each 1% increase in HbA1c. We suggest that high IL12 levels can inhibit infection with yeast-like fungi colonizing the gastrointestinal tract in children and adolescents with T1DM. Further studies are needed to confirm the antifungal activity of IL12.

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

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Diagnosis of Invasive Fungal Diseases in Hematological Malignancies: A Critical Review of Evidence and Turkish Expert Opinion (TEO-2)

One of the most problematic issues in hematological malignancies is the diagnosis of invasive fungal diseases. Especially, the difficulty of mycological diagnosis and the necessity of immediate intervention in molds have led to the adoption of “surrogate markers” that do not verify but rather strongly suggest fungal infection. The markers commonly used are galactomannan (GM), beta-glucan, and imaging methods. Although there are numerous studies on these diagnostic approaches, none of these markers serve as a support for the clinician, as is the case in human immunodeficiency virus (HIV) or cytomegalovirus (CMV) infections. This paper has been prepared to explain the diagnostic tests. As molecular tests have not been standardized and are not used routinely in the clinics, they will not be mentioned here.

Serological response and diagnostic value of recombinant candida cell wall protein enolase, phosphoglycerate kinase, and β-glucosidase

There are no specific signs and symtoms for invasive candidiasis (IC), which makes its diagnosis a challenge. Efforts have been made for decades to establish serological assays for rapid diagnosis of IC, but none of them have found widespread clinical use. Using a systemic candiasis murine model, serological response to recombinant proteins of enolase (rEno1), phosphoglycerate kinase (rPgk1), and β-glucosidase (rBgl2) were evaluated and rEno1 was found to possess the strongest immunoreactivity, followed by rPgk1 and rBgl2. Likewise, IgG antibody titers to rEno1, rPgk1, and rBgl2 in the positive sera of proven IC patients were determined by ELISA. Results show anti-rEno1 antibody possesses the highest titer, followed by rPgk1 and rBgl2. Antibodies against rEno1, rPgk1, and rBgl2 were detected by ELISA tests in a group of 52 proven IC patients or 50 healthy subjects, The sensitivity, specificity, positive and negative predictive values were 88.5, 90.0, 90.2, and 88.2% for anti-rEno1 detection, 86.5, 92.0, 91.8, and 86.8% for anti-rPgk1 detection, and 80.8, 90.0, 89.4, and 81.8% for anti-rBgl2 detection, respectively. The data clearly demonstrate that the recombinant proteins of Eno1, Pgk1, and Bgl2 are promising candidates for IC serodiagnosis. There's great possibility that the recombinant Eno1 will be more applicable in serodiagnosis and vaccine research on account of its strong serological response.

Application of Culture-Independent Rapid Diagnostic Tests in the Management of Invasive Candidiasis and Cryptococcosis

The diagnosis of invasive candidiasis (IC) and cryptococcosis is often complicated by slow and insensitive culture-based methods. Such delay results in poor outcomes due to the lack of timely therapeutic interventions. Advances in serological, biochemical, molecular and proteomic approaches have made a favorable impact on this process, improving the timeliness and accuracy of diagnosis with resultant improvements in outcome. This paper will serve as an overview of recent developments in the diagnostic approaches to infections due to these important yeast-fungi.

IgG1 anti-cell wall and IgG2 anti-phosphopeptidomannan antibodies in the diagnosis of invasive candidiasis and heavy Candida colonization

We conducted a retrospective study to evaluate the usefulness of immunoglobulin G (IgG) subclasses against Candida cell wall fragments (CW) and phosphopeptidomannan (PPM) for the diagnosis of invasive candidiasis (IC). We analyzed 54 patients with IC (n = 19), Candida heavy colonization (HC; n = 16), and controls (no IC or HC, n = 19).In nonneutropenic patients (n = 47), the sensitivity and specificity values of IgG1 anti-CW and IgG2 anti-PPM in IC were 88%, 59%, and 88%, 94%, respectively. The areas under the receiver operating characteristic curves were 0.69 (0.51-0.88) and 0.901 (0.78-1.02), respectively. IgG1 mean values (arbitrary units) and 95% confidence interval were 46 (20-71), 42 (-0.38 to 84) and 20 (8.3-32) in IC, HC, and in controls, respectively, and discriminated IC but not HC from controls (P = .032, and P = .77, respectively). IgG2 mean values were 26 (9.2-42), 19 (4.4-33), and 3.2 (0.28-6.6) in IC, HC, and in controls, respectively, and discriminated both IC and HC from controls (P < .0001 and P = .035, respectively) but did not separate IC from HC (P = .2). IgG2 showed positivity as early as one day after the IC diagnosis. Antibodies were detected in only two out of a total of seven neutropenic patients.For both IC and HC patients, the diagnostic performance of IgG2 anti-PPM was better than the one of IgG1 anti-CW. In nonneutropenic patients, IgG2 anti-PPM accurately identified not only IC patients but also HC patients at high risk for IC. This marker may help clinicians in the initiation of early preemptive therapy.

Invasive candidiasis serological diagnosis in solid organ transplant recipients

Solid organ transplant recipients are at high risk of fungal infections, because of ongoing immunosuppressive treatment. There are three post organ transplant phases: early, intermediate, and late, all of them at risk of Candida infections. Since conventional tests are insufficient, specific secondary diagnostic tests are still being explored. Serological tests are currently the most common choice. The present study was to determine the usefulness of mannan antigen and anti-mannan antibody detection in diagnosing invasive candidiasis in liver or kidney transplant recipients. The levels of mannan and anti-mannan antibodies were assessed with Platelia Candida Ag Plus, and Platelia Candida Ab Plus (Biorad, Marne-la-Coquette, France) commercial tests, according to manufacturer's guidelines. Sixty six serum samples were obtained from 25 patients (9 liver transplant recipients, 7 kidney transplant recipients, and 9 patients prepared for a kidney transplant), 29 serum samples from 15 patients tested positive for mannan antigen. Serum samples were obtained from 14 patients tested positive for anti- mannan antibodies. Fungal antigen detection in blood serum in patients under immunosuppression, especially with neutropenia, suggests that antifungal treatment should be administered. Serological tests, especially mannan and anti-mannan ones, are very useful for confirmation or exclusion of invasive candidiasis in high-risk patients.

A research agenda on the management of intra-abdominal candidiasis: results from a consensus of multinational experts

INTRODUCTION

intra-abdominal candidiasis (IAC) may include Candida involvement of peritoneum or intra-abdominal abscess and is burdened by high morbidity and mortality rates in surgical patients. Unfortunately, international guidelines do not specifically address this particular clinical setting due to heterogeneity of definitions and scant direct evidence. In order to cover this unmet clinical need, the Italian Society of Intensive Care and the International Society of Chemotherapy endorsed a project aimed at producing practice recommendations for the management of immune-competent adult patients with IAC.

METHODS

A multidisciplinary expert panel of 22 members (surgeons, infectious disease and intensive care physicians) was convened and assisted by a methodologist between April 2012 and May 2013. Evidence supporting each statement was graded according to the European Society of Clinical Microbiology and Infection Diseases (ESCMID) grading system.

RESULTS

Only a few of the numerous recommendations can be summarized in the Abstract. Direct microscopy examination for yeast detection from purulent and necrotic intra-abdominal specimens during surgery or by percutaneous aspiration is recommended in all patients with nonappendicular abdominal infections including secondary and tertiary peritonitis. Samples obtained from drainage tubes are not valuable except for evaluation of colonization. Prophylactic usage of fluconazole should be adopted in patients with recent abdominal surgery and recurrent gastrointestinal perforation or anastomotic leakage. Empirical antifungal treatment with echinocandins or lipid formulations of amphotericin B should be strongly considered in critically ill patients or those with previous exposure to azoles and suspected intra-abdominal infection with at least one specific risk factor for Candida infection. In patients with nonspecific risk factors, a positive mannan/antimannan or (1→3)-β-D-glucan (BDG) or polymerase chain reaction (PCR) test result should be present to start empirical therapy. Fluconazole can be adopted for the empirical and targeted therapy of non-critically ill patients without previous exposure to azoles unless they are known to be colonized with a Candida strain with reduced susceptibility to azoles. Treatment can be simplified by stepping down to an azole (fluconazole or voriconazole) after at least 5-7 days of treatment with echinocandins or lipid formulations of amphotericin B, if the species is susceptible and the patient has clinically improved.

CONCLUSIONS

Specific recommendations were elaborated on IAC management based on the best direct and indirect evidence and on the expertise of a multinational panel.

Evaluation of human body fluids for the diagnosis of fungal infections

Invasive fungal infections are a major cause of morbidity and mortality in immunocompromised patients. Because the etiologic agents of these infections are abundant in nature, their isolation from biopsy material or sterile body fluids is needed to document infection. This review evaluates and discusses different human body fluids used to diagnose fungal infections.

Diagnostic value of immunoglobulin G antibodies against Candida enolase and fructose-bisphosphate aldolase for candidemia

Background

The yeast Candida is one of the most frequent pathogens isolated from bloodstream infections and is associated with significant morbidity and mortality. Problems with clinical and microbiological diagnosis of invasive candidiasis (IC) have prompted the development of non-culture-based laboratory methods. Previous reports suggest that serological detection of antibodies might be useful for diagnosing systemic candidiasis.

Methods

Diagnosis of IC using antibodies against recombinant Candida albicans enolase (Eno) and fructose-bisphosphate aldolase (Fba1) was evaluated. Using recombinant Eno and Fba1 as coating antigens, enzyme-linked immunosorbent assays (ELISAs) were used to analyze sera from patients with candidemia (n = 101), Candida colonization (n = 50), bacteremia (n = 84), invasive aspergillosis (n = 40); and from healthy controls (n = 200).

Results

The results demonstrated that ELISA detection of anti-Eno and anti-Fba1 IgG distinguished IC from other pathogenic infections in patients and healthy individuals. The sensitivity, specificity, and positive and negative predictive values were 72.3%, 94.7%, 78.5% and 93% for anti-Eno, and 87.1%, 92.8%, 76.5% and 96.4% for anti-Fba1 antibodies, respectively. Combining these two tests improved sensitivity up to 90.1% and negative predictive value up to 97.1%, with specificity and positive predictive values of 90.6% and 72.2%. The tests were specific to the Candida genus and antibody titers were higher for candidemia patients than for controls. Positive antibody tests were obtained before blood culture results for 42.2% of patients for anti-Eno and 51.1% for anti-Fba1.

Conclusion

These data suggest that tests that detect IgG antibodies against Candida enolase and fructose-bisphosphate aldolase, especially when used in combination, could be a powerful tool for diagnosing IC.

Surviving sepsis campaign: international guidelines for management of severe sepsis and septic shock: 2012

OBJECTIVE

To provide an update to the "Surviving Sepsis Campaign Guidelines for Management of Severe Sepsis and Septic Shock," last published in 2008.

DESIGN

A consensus committee of 68 international experts representing 30 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict of interest policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independent of any industry funding. A stand-alone meeting was held for all subgroup heads, co- and vice-chairs, and selected individuals. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.

METHODS

The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence from high (A) to very low (D) and to determine the strength of recommendations as strong (1) or weak (2). The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasized. Some recommendations were ungraded (UG). Recommendations were classified into three groups: 1) those directly targeting severe sepsis; 2) those targeting general care of the critically ill patient and considered high priority in severe sepsis; and 3) pediatric considerations.

RESULTS

Key recommendations and suggestions, listed by category, include: early quantitative resuscitation of the septic patient during the first 6 hrs after recognition (1C); blood cultures before antibiotic therapy (1C); imaging studies performed promptly to confirm a potential source of infection (UG); administration of broad-spectrum antimicrobials therapy within 1 hr of recognition of septic shock (1B) and severe sepsis without septic shock (1C) as the goal of therapy; reassessment of antimicrobial therapy daily for de-escalation, when appropriate (1B); infection source control with attention to the balance of risks and benefits of the chosen method within 12 hrs of diagnosis (1C); initial fluid resuscitation with crystalloid (1B) and consideration of the addition of albumin in patients who continue to require substantial amounts of crystalloid to maintain adequate mean arterial pressure (2C) and the avoidance of hetastarch formulations (1C); initial fluid challenge in patients with sepsis-induced tissue hypoperfusion and suspicion of hypovolemia to achieve a minimum of 30 mL/kg of crystalloids (more rapid administration and greater amounts of fluid may be needed in some patients) (1C); fluid challenge technique continued as long as hemodynamic improvement, as based on either dynamic or static variables (UG); norepinephrine as the first-choice vasopressor to maintain mean arterial pressure ≥ 65 mm Hg (1B); epinephrine when an additional agent is needed to maintain adequate blood pressure (2B); vasopressin (0.03 U/min) can be added to norepinephrine to either raise mean arterial pressure to target or to decrease norepinephrine dose but should not be used as the initial vasopressor (UG); dopamine is not recommended except in highly selected circumstances (2C); dobutamine infusion administered or added to vasopressor in the presence of a) myocardial dysfunction as suggested by elevated cardiac filling pressures and low cardiac output, or b) ongoing signs of hypoperfusion despite achieving adequate intravascular volume and adequate mean arterial pressure (1C); avoiding use of intravenous hydrocortisone in adult septic shock patients if adequate fluid resuscitation and vasopressor therapy are able to restore hemodynamic stability (2C); hemoglobin target of 7-9 g/dL in the absence of tissue hypoperfusion, ischemic coronary artery disease, or acute hemorrhage (1B); low tidal volume (1A) and limitation of inspiratory plateau pressure (1B) for acute respiratory distress syndrome (ARDS); application of at least a minimal amount of positive end-expiratory pressure (PEEP) in ARDS (1B); higher rather than lower level of PEEP for patients with sepsis-induced moderate or severe ARDS (2C); recruitment maneuvers in sepsis patients with severe refractory hypoxemia due to ARDS (2C); prone positioning in sepsis-induced ARDS patients with a PaO2/FIO2 ratio of ≤ 100 mm Hg in facilities that have experience with such practices (2C); head-of-bed elevation in mechanically ventilated patients unless contraindicated (1B); a conservative fluid strategy for patients with established ARDS who do not have evidence of tissue hypoperfusion (1C); protocols for weaning and sedation (1A); minimizing use of either intermittent bolus sedation or continuous infusion sedation targeting specific titration endpoints (1B); avoidance of neuromuscular blockers if possible in the septic patient without ARDS (1C); a short course of neuromuscular blocker (no longer than 48 hrs) for patients with early ARDS and a Pao2/Fio2 < 150 mm Hg (2C); a protocolized approach to blood glucose management commencing insulin dosing when two consecutive blood glucose levels are > 180 mg/dL, targeting an upper blood glucose ≤ 180 mg/dL (1A); equivalency of continuous veno-venous hemofiltration or intermittent hemodialysis (2B); prophylaxis for deep vein thrombosis (1B); use of stress ulcer prophylaxis to prevent upper gastrointestinal bleeding in patients with bleeding risk factors (1B); oral or enteral (if necessary) feedings, as tolerated, rather than either complete fasting or provision of only intravenous glucose within the first 48 hrs after a diagnosis of severe sepsis/septic shock (2C); and addressing goals of care, including treatment plans and end-of-life planning (as appropriate) (1B), as early as feasible, but within 72 hrs of intensive care unit admission (2C). Recommendations specific to pediatric severe sepsis include: therapy with face mask oxygen, high flow nasal cannula oxygen, or nasopharyngeal continuous PEEP in the presence of respiratory distress and hypoxemia (2C), use of physical examination therapeutic endpoints such as capillary refill (2C); for septic shock associated with hypovolemia, the use of crystalloids or albumin to deliver a bolus of 20 mL/kg of crystalloids (or albumin equivalent) over 5 to 10 mins (2C); more common use of inotropes and vasodilators for low cardiac output septic shock associated with elevated systemic vascular resistance (2C); and use of hydrocortisone only in children with suspected or proven "absolute"' adrenal insufficiency (2C).

CONCLUSIONS

Strong agreement existed among a large cohort of international experts regarding many level 1 recommendations for the best care of patients with severe sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for this important group of critically ill patients.

Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock, 2012

OBJECTIVE

To provide an update to the "Surviving Sepsis Campaign Guidelines for Management of Severe Sepsis and Septic Shock," last published in 2008.

DESIGN

A consensus committee of 68 international experts representing 30 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict of interest policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independent of any industry funding. A stand-alone meeting was held for all subgroup heads, co- and vice-chairs, and selected individuals. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.

METHODS

The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence from high (A) to very low (D) and to determine the strength of recommendations as strong (1) or weak (2). The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasized. Recommendations were classified into three groups: (1) those directly targeting severe sepsis; (2) those targeting general care of the critically ill patient and considered high priority in severe sepsis; and (3) pediatric considerations.

RESULTS

Key recommendations and suggestions, listed by category, include: early quantitative resuscitation of the septic patient during the first 6 h after recognition (1C); blood cultures before antibiotic therapy (1C); imaging studies performed promptly to confirm a potential source of infection (UG); administration of broad-spectrum antimicrobials therapy within 1 h of the recognition of septic shock (1B) and severe sepsis without septic shock (1C) as the goal of therapy; reassessment of antimicrobial therapy daily for de-escalation, when appropriate (1B); infection source control with attention to the balance of risks and benefits of the chosen method within 12 h of diagnosis (1C); initial fluid resuscitation with crystalloid (1B) and consideration of the addition of albumin in patients who continue to require substantial amounts of crystalloid to maintain adequate mean arterial pressure (2C) and the avoidance of hetastarch formulations (1B); initial fluid challenge in patients with sepsis-induced tissue hypoperfusion and suspicion of hypovolemia to achieve a minimum of 30 mL/kg of crystalloids (more rapid administration and greater amounts of fluid may be needed in some patients (1C); fluid challenge technique continued as long as hemodynamic improvement is based on either dynamic or static variables (UG); norepinephrine as the first-choice vasopressor to maintain mean arterial pressure ≥65 mmHg (1B); epinephrine when an additional agent is needed to maintain adequate blood pressure (2B); vasopressin (0.03 U/min) can be added to norepinephrine to either raise mean arterial pressure to target or to decrease norepinephrine dose but should not be used as the initial vasopressor (UG); dopamine is not recommended except in highly selected circumstances (2C); dobutamine infusion administered or added to vasopressor in the presence of (a) myocardial dysfunction as suggested by elevated cardiac filling pressures and low cardiac output, or (b) ongoing signs of hypoperfusion despite achieving adequate intravascular volume and adequate mean arterial pressure (1C); avoiding use of intravenous hydrocortisone in adult septic shock patients if adequate fluid resuscitation and vasopressor therapy are able to restore hemodynamic stability (2C); hemoglobin target of 7-9 g/dL in the absence of tissue hypoperfusion, ischemic coronary artery disease, or acute hemorrhage (1B); low tidal volume (1A) and limitation of inspiratory plateau pressure (1B) for acute respiratory distress syndrome (ARDS); application of at least a minimal amount of positive end-expiratory pressure (PEEP) in ARDS (1B); higher rather than lower level of PEEP for patients with sepsis-induced moderate or severe ARDS (2C); recruitment maneuvers in sepsis patients with severe refractory hypoxemia due to ARDS (2C); prone positioning in sepsis-induced ARDS patients with a PaO (2)/FiO (2) ratio of ≤100 mm Hg in facilities that have experience with such practices (2C); head-of-bed elevation in mechanically ventilated patients unless contraindicated (1B); a conservative fluid strategy for patients with established ARDS who do not have evidence of tissue hypoperfusion (1C); protocols for weaning and sedation (1A); minimizing use of either intermittent bolus sedation or continuous infusion sedation targeting specific titration endpoints (1B); avoidance of neuromuscular blockers if possible in the septic patient without ARDS (1C); a short course of neuromuscular blocker (no longer than 48 h) for patients with early ARDS and a PaO (2)/FI O (2) <150 mm Hg (2C); a protocolized approach to blood glucose management commencing insulin dosing when two consecutive blood glucose levels are >180 mg/dL, targeting an upper blood glucose ≤180 mg/dL (1A); equivalency of continuous veno-venous hemofiltration or intermittent hemodialysis (2B); prophylaxis for deep vein thrombosis (1B); use of stress ulcer prophylaxis to prevent upper gastrointestinal bleeding in patients with bleeding risk factors (1B); oral or enteral (if necessary) feedings, as tolerated, rather than either complete fasting or provision of only intravenous glucose within the first 48 h after a diagnosis of severe sepsis/septic shock (2C); and addressing goals of care, including treatment plans and end-of-life planning (as appropriate) (1B), as early as feasible, but within 72 h of intensive care unit admission (2C). Recommendations specific to pediatric severe sepsis include: therapy with face mask oxygen, high flow nasal cannula oxygen, or nasopharyngeal continuous PEEP in the presence of respiratory distress and hypoxemia (2C), use of physical examination therapeutic endpoints such as capillary refill (2C); for septic shock associated with hypovolemia, the use of crystalloids or albumin to deliver a bolus of 20 mL/kg of crystalloids (or albumin equivalent) over 5-10 min (2C); more common use of inotropes and vasodilators for low cardiac output septic shock associated with elevated systemic vascular resistance (2C); and use of hydrocortisone only in children with suspected or proven "absolute"' adrenal insufficiency (2C).

CONCLUSIONS

Strong agreement existed among a large cohort of international experts regarding many level 1 recommendations for the best care of patients with severe sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for this important group of critically ill patients.

Overview of invasive fungal infections

The incidence of invasive fungal infections (IFIs) has seen a marked increase in the last two decades. This is especially evident among transplant recipients, patients suffering from AIDS, in addition to those in receipt of immunosuppressive therapy. Worryingly, this increased incidence includes infections caused by opportunistic fungi and emerging fungal infections which are resistant to or certainly less susceptible than others to standard antifungal agents. As a direct response to this phenomenon, there has been a resolute effort over the past several decades to improve early and accurate diagnosis and provide reliable screening protocols thereby promoting the administration of appropriate antifungal therapy for fungal infections. Early diagnosis and treatment with antifungal therapy are vital if a patient is to survive an IFI. Substantial advancements have been made with regard to both the diagnosis and subsequent treatment of an IFI. In parallel, stark changes in the epidemiological profile of these IFIs have similarly occurred, often in direct response the type of antifungal agent being administered. The effects of an IFI can be far reaching, ranging from increased morbidity and mortality to increased length hospital stays and economic burden.

Diagnosis and therapy of Candida infections: joint recommendations of the German Speaking Mycological Society and the Paul-Ehrlich-Society for Chemotherapy

Invasive Candida infections are important causes of morbidity and mortality in immunocompromised and hospitalised patients. This article provides the joint recommendations of the German-speaking Mycological Society (Deutschsprachige Mykologische Gesellschaft, DMyKG) and the Paul-Ehrlich-Society for Chemotherapy (PEG) for diagnosis and treatment of invasive and superficial Candida infections. The recommendations are based on published results of clinical trials, case-series and expert opinion using the evidence criteria set forth by the Infectious Diseases Society of America (IDSA). Key recommendations are summarised here: The cornerstone of diagnosis remains the detection of the organism by culture with identification of the isolate at the species level; in vitro susceptibility testing is mandatory for invasive isolates. Options for initial therapy of candidaemia and other invasive Candida infections in non-granulocytopenic patients include fluconazole or one of the three approved echinocandin compounds; liposomal amphotericin B and voriconazole are secondary alternatives because of their less favourable pharmacological properties. In granulocytopenic patients, an echinocandin or liposomal amphotericin B is recommended as initial therapy based on the fungicidal mode of action. Indwelling central venous catheters serve as a main source of infection independent of the pathogenesis of candidaemia in the individual patients and should be removed whenever feasible. Pre-existing immunosuppressive treatment, particularly by glucocorticosteroids, ought to be discontinued, if feasible, or reduced. The duration of treatment for uncomplicated candidaemia is 14 days following the first negative blood culture and resolution of all associated symptoms and findings. Ophthalmoscopy is recommended prior to the discontinuation of antifungal chemotherapy to rule out endophthalmitis or chorioretinitis. Beyond these key recommendations, this article provides detailed recommendations for specific disease entities, for antifungal treatment in paediatric patients as well as a comprehensive discussion of epidemiology, clinical presentation and emerging diagnostic options of invasive and superficial Candida infections.

Diagnosis of invasive fungal infections in hematology and oncology--guidelines from the Infectious Diseases Working Party in Haematology and Oncology of the German Society for Haematology and Oncology (AGIHO)

Invasive fungal infections (IFIs) are a primary cause of morbidity and mortality in patients with hematological malignancies. Establishing a definite diagnosis of IFI in immunocompromised patients is particularly challenging and time consuming, but delayed initiation of antifungal treatment increases mortality. The limited overall outcome has led to the strategy of initiating either 'empirical' or 'preemptive' antifungal therapy before the final diagnosis. However, diagnostic procedures have been vastly improved in recent years. Particularly noteworthy is the introduction of newer imaging techniques and non-culture methods, including antigen-based assays, metabolite detection and molecular detection of fungal DNA from body fluid samples. Though varying widely in cancer patients, the risk of IFI is highest in those with allogeneic stem cell transplantation and those with acute leukemia. The AGIHO presents recommendations for the diagnosis of IFIs with risk-adapted screening concepts for febrile episodes in patients with haemato-oncological disorders.

Clinical factors associated with a Candida albicans Germ Tube Antibody positive test in Intensive Care Unit patients

BACKGROUND

Poor outcomes of invasive candidiasis (IC) are associated with the difficulty in establishing the microbiological diagnosis at an early stage. New scores and laboratory tests have been developed in order to make an early therapeutic intervention in an attempt to reduce the high mortality associated with invasive fungal infections. Candida albicans IFA IgG has been recently commercialized for germ tube antibody detection (CAGTA). This test provides a rapid and simple diagnosis of IC (84.4% sensitivity and 94.7% specificity). The aim of this study is to identify the patients who could be benefited by the use of CAGTA test in critical care setting.

METHODS

A prospective, cohort, observational multicentre study was carried out in six medical/surgical Intensive care units (ICU) of tertiary-care Spanish hospitals. Candida albicans Germ Tube Antibody test was performed twice a week if predetermined risk factors were present, and serologically demonstrated candidiasis was considered if the testing serum dilution was ≥ 1:160 in at least one sample and no other microbiological evidence of invasive candidiasis was found.

RESULTS

Fifty-three critically ill non-neutropenic patients (37.7% post surgery) were included. Twenty-two patients (41.5%) had CAGTA-positive results, none of them with positive blood culture for Candida. Neither corrected colonization index nor antifungal treatment had influence on CAGTA results. This finding could corroborate that the CAGTA may be an important biomarker to distinguish between colonization and infection in these patients. The presence of acute renal failure at the beginning of the study was more frequent in CAGTA-negative patients. Previous surgery was statistically more frequent in CAGTA-positive patients.

CONCLUSIONS

This study identified previous surgery as the principal clinical factor associated with CAGTA-positive results and emphasises the utility of this promising technique, which was not influenced by high Candida colonization or antifungal treatment. Our results suggest that detection of CAGTA may be important for the diagnosis of invasive candidiasis in surgical patients admitted in ICU.

The use of mannan antigen and anti-mannan antibodies in the diagnosis of invasive candidiasis: recommendations from the Third European Conference on Infections in Leukemia

Introduction

Timely diagnosis of invasive candidiasis (IC) remains difficult as the clinical presentation is not specific and blood cultures lack sensitivity and need a long incubation time. Thus, non-culture-based methods for diagnosing IC have been developed. Mannan antigen (Mn) and anti-mannan antibodies (A-Mn) are present in patients with IC. On behalf of the Third European Conference on Infections in Leukemia, the performance of these tests was analysed and reviewed.

Methods

The literature was searched for studies using the commercially available sandwich enzyme-linked immunosorbent assays (Platelia™, Bio-Rad Laboratories, Marnes-la-Coquette, France) for detecting Mn and A-Mn in serum. The target condition of this review was IC defined according to 2008 European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria. Sensitivity, specificity and diagnostic odds ratios (DOR) were calculated for Mn, A-Mn and combined Mn/A-Mn testing.

Results

Overall, 14 studies that comprised 453 patients and 767 controls were reviewed. The patient populations included in the studies were mainly haematological and cancer cases in seven studies and mainly intensive care unit and surgery cases in the other seven studies. All studies but one were retrospective in design. Mn sensitivity was 58% (95% confidence interval [CI], 53-62); specificity, 93% (95% CI, 91-94) and DOR, 18 (95% CI 12-28). A-Mn sensitivity was 59% (95% CI, 54-65); specificity, 83% (95% CI, 79-97) and DOR, 12 (95% CI 7-21). Combined Mn/A-Mn sensitivity was 83% (95% CI, 79-87); specificity, 86% (95% CI, 82-90) and DOR, 58 (95% CI 27-122). Significant heterogeneity of the studies was detected. The sensitivity of both Mn and A-Mn varied for different Candida species, and it was the highest for C. albicans, followed by C. glabrata and C. tropicalis. In 73% of 45 patients with candidemia, at least one of the serological tests was positive before the culture results, with mean time advantage being 6 days for Mn and 7 days for A-Mn. In 21 patients with hepatosplenic IC, 18 (86%) had Mn or A-Mn positive test results at a median of 16 days before radiological detection of liver or spleen lesions.

Conclusions

Mn and A-Mn are useful for diagnosis of IC. The performance of combined Mn/A-Mn testing is superior to either Mn or A-Mn testing.

[Management of candidemia and invasive candidiasis]

Candida species is the fourth most common cause of bloodstream infection and is the leading cause of invasive fungal infection among hospitalized patients. Acute disseminated candidiasis remains a life-threatening disease that now occurs mainly in intensive care units hospitalized patients. Delay in treatment of Candida bloodstream infections could be minimized by the development of more rapid and sensitive diagnostic techniques for the identification of Candida bloodstream infections. Current guidelines for the management of invasive candidiasis recommend fluconazole or an echinocandin as the primary therapeutic option. The optimal choice of the antifungal agent should depend on local epidemiology, prior antifungal therapy and patient's characteristics.

Early treatment of candidemia in adults: a review

Invasive candidiasis is associated with high mortality, particularly in adults. Retrospective studies show that shorter times to treatment are correlated with a lower risk of death. A number of factors can be used to predict which patients would benefit from antifungal prophylaxis or early (pre-emptive or empirical) therapy. Detection of the fungal cell wall component (1→3)-β-D-glucan (BDG) shows promise as an early biomarker of invasive fungal infection and may be useful in identifying patients who would benefit from early antifungal treatment. To date, no consistent early treatment strategy has evolved. Proof-of-concept studies are needed to assess the role of pre-emptive and empirical therapy in ICU patients and the relevance of BDG as an early marker of infection.

Early mannan detection in bronchoalveolar lavage fluid with preemptive treatment reduces the incidence of invasive Candida infections in preterm infants

BACKGROUND

Candida colonization is an important predictor for development of invasive fungal infection (IFI). We investigated whether early detection of Candida mannan (Mn) in bronchoalveolar lavage fluid (BALF) reduces IFI among preterm infants.

METHODS

We conducted an observational study of infants with gestational age of < or =28 weeks, where a group undergoing Candida surveillance cultures (pre-Mn detection group) was compared with a group defined after the initiation of routine use of Candida Mn detection in BALF (Mn detection group). Antifungal treatment was started based on positive microbiologic (surveillance culture or Mn-antigen assay) results.

RESULTS

No significant differences were detected when the groups were compared for several predictors of IFI. IFI was observed for 12 (23%) of 51 infants in the pre-Mn detection group, and for 0 (0%) of 29 infants in the Mn detection group (P = 0.003). Surveillance cultures in the pre-Mn detection group became positive at 15.0 +/- 7.2 days after birth, whereas the mean age at time of positive Mn antigen results in the Mn detection group was 4.3 +/- 3.1 days (P < 0.0001). Among 16 infants positive for surveillance cultures, 12 (75%) developed IFI (P < 0.0001).

CONCLUSIONS

This study suggests that Candida Mn detection in BALF may be useful for earlier identification and preemptive therapy targeting preterm infants at high risk of IFI.

No interference of the 1,3-β-D-glucan containing nutritional supplement ImunixX with the 1,3-β-D-glucan serum test

The detection of 1,3-β-D-glucan serum levels may permit establishing the diagnosis of invasive fungal infections more early. We tested in six healthy volunteers whether the intake of a 1,3-β-D-glucan-containing nutritional supplement leads to false-positive 1,3-β-D-glucan levels. All levels were negative, even in two different dosing regimens.

Serum concentration of interleukin 10, anti-mannan Candida antibodies and the fungal colonization of the gastrointestinal tract in patients with ulcerative colitis

PURPOSE

There is evidence for the immunomodulation disorders in the response to intestinal flora in inflammatory bowel disease, however, the role of yeasts in the aetiopathogenesis of ulcerative colitis has not been fully clarified. The aim of this study was to assess the serum concentration of interleukin 10 (IL-10), serum levels of anti-mannan Candida antibodies and fungal colonization of the lower part of the gastrointestinal tract in accordance with the clinical course of ulcerative colitis.

MATERIAL/METHODS

In 42 consecutive patients with ulcerative colitis serum concentration of IL-10 and anti-mannan Candida antibodies serum levels were measured with ELISA and the quantitative and qualitative fungal cultures of stool samples were performed.

RESULTS

In 20 patients IL-10 serum concentration was below the test sensitivity and in 11 patients it ranged between 0.78 and 9.43 (mean 3.38 +/- 2.8) pg/mL. Anti-mannan Candida antibodies were detected in 8 subjects (19.04%). Stool cultures revealed significant fungal colonization in 3 (8.33%) patients with the predominance of Candida albicans. In comparison with mild/moderate UC, IL-10 serum concentration was not higher in patients with severe course of the disease.

CONCLUSIONS

The results of our study show that IL-10 serum concentration correlates neither with the disease activity nor with the levels of anti-mannan Candida antibodies and the fungal colonization of the gastrointestinal tract in ulcerative colitis. It seems that IL-10 serum concentration cannot be a universal marker for the assessment of ulcerative colitis activity. Moreover, anti-mannan Candida antibodies and significant fungal colonization are present in the minority of patients with ulcerative colitis suggesting that yeasts have minor, if any, influence on the clinical course of the disease.

Clinical aspects of invasive candidiasis in critically ill patients

Invasive candidiasis has emerged as an important cause of morbidity and mortality in intensive care unit patients. This short review focuses on many aspects of Candida infection in critically ill patients including epidemiology, impact on mortality, problems related to diagnosis, strategies to identify patients at risk of developing fungal infections, role of prophylaxis and pre-emptive strategies, empiric treatment and the role of different classes of antifungal drugs. New antifungal agents, specifically new azoles and echinocandins are discussed.

Current status and future perspectives on molecular and serological methods in diagnostic mycology

Invasive fungal infections are an important cause of infectious morbidity. Nonculture-based methods are increasingly used for rapid, accurate diagnosis to improve patient outcomes. New and existing DNA amplification platforms have high sensitivity and specificity for direct detection and identification of fungi in clinical specimens. Since laboratories are increasingly reliant on DNA sequencing for fungal identification, measures to improve sequence interpretation should support validation of reference isolates and quality control in public gene repositories. Novel technologies (e.g., isothermal and PNA FISH methods), platforms enabling high-throughput analyses (e.g., DNA microarrays and Luminex® xMAP™) and/or commercial PCR assays warrant further evaluation for routine diagnostic use. Notwithstanding the advantages of molecular tests, serological assays remain clinically useful for patient management. The serum Aspergillus galactomannan test has been incorporated into diagnostic algorithms of invasive aspergillosis. Both the galactomannan and the serum β-D-glucan test have value for diagnosing infection and monitoring therapeutic response.