Candidemia in cancer patients: a prospective, multicenter surveillance study by the Invasive Fungal Infection Group (IFIG) of the European Organization for Research and Treatment of Cancer (EORTC)

Approaches to the Management of Invasive Fungal Infections in Hematologic Malignancy and Hematopoietic Cell Transplantation

Patients with hematologic malignancy and hematopoietic cell transplant (HCT) recipients are at increased risk for invasive fungal infection (IFI) as a result of immunosuppression or organ damage stemming from their underlying disease, its treatment, or both. Such IFIs can cause significant morbidity and mortality, and the diagnosis and treatment of infected patients frequently are clinically challenging. This article discusses the epidemiology and risk factors for IFI in patients with hematologic malignancy and HCT recipients. The pros and cons of available antifungal agents are discussed, and evolving treatment strategies and recent prophylaxis guidelines from various professional organizations are reviewed. Finally, recommendations are offered for antifungal prophylaxis according to risk group.

Candidemia in patients with diabetes mellitus: epidemiology and predictors of mortality

Candidemia is the fourth most frequent nosocomial bloodstream infection in the US. The clinical characteristics and outcome of candidemia in adult patients with diabetes mellitus (DM) have not been reported in the literature. The objective of the study was to determine the epidemiology and determinants of mortality in diabetic patients with candidemia. A retrospective cohort study among diabetic patients with candidemia was carried out at 2 medical centers. The primary outcome was death from any cause after the onset of candidemia until discharge from the hospital. A stepwise logistic regression analysis was performed to determine the predictors of mortality. From June 1995 to June 2003, 87 patients with both DM and candidemia were studied. Candida albicans was the most common (48/87, 55%) and Candida glabrata the second most common isolate of candidemia (18/87, 21%). Overall hospital mortality was 39% (34/87). Logistic regression analysis identified 3 independent determinants of death; Apache II score > or =23 (OR 8.3, 95% CI{2.7, 25.4}, p =0.0002), nosocomial candidemia (OR 10.2, 95% CI{1.1, 97.9}, p = 0.04), and mechanical ventilation (OR 3.6, 95% CI{1.1, 11.2}, p = 0.03). The study demonstrates the emergence of non-albicans species of Candida as major causes of candidemia among diabetic patients. The severity of illness reflected by Apache II was the most significant predictor of mortality among diabetic patients with candidemia.

The changing face of epidemiology of invasive fungal disease in Europe

Invasive fungal diseases (IFDs) are an increasingly common complication in critically ill patients in Europe and are frequently fatal. Because of changes in treatment strategies and the increased use of antifungal prophylaxis, the epidemiology of IFDs has changed substantially in recent years and infections due to Candida species are no longer the majority in many institutions. In contrast, the emergence of non-Candida IFDs such as aspergillosis, zygomycosis and fusariosis has increased. European surveys indicate that Candida albicans is responsible for more than half the cases of invasive candidaemia; however, the occurrence of non-albicans-related IFDs appears to be increasing. Rates of IFD-related mortality in Europe depend on the pathogen, geographical location and underlying patient characteristics, with rates ranging from 28 to 59% for Candida infections and from 38 to 80% for invasive aspergillosis. Early initiation of antifungal therapy is critical for improving outcomes; however, this is complicated by the difficulty in diagnosing IFDs rapidly and accurately. The introduction of new extended-spectrum azole antifungal agents (e.g. voriconazole, posaconazole) and echinocandins (e.g. micafungin, caspofungin, anidulafungin) has increased the number of therapeutic options for early therapy. Choice between agents should be based on a variety of factors, including spectrum of activity, adverse events, drug interactions, route of administration, clinical efficacy of individual agents and local epidemiology.

Efflux-mediated antifungal drug resistance

Fungi cause serious infections in the immunocompromised and debilitated, and the incidence of invasive mycoses has increased significantly over the last 3 decades. Slow diagnosis and the relatively few classes of antifungal drugs result in high attributable mortality for systemic fungal infections. Azole antifungals are commonly used for fungal infections, but azole resistance can be a problem for some patient groups. High-level, clinically significant azole resistance usually involves overexpression of plasma membrane efflux pumps belonging to the ATP-binding cassette (ABC) or the major facilitator superfamily class of transporters. The heterologous expression of efflux pumps in model systems, such Saccharomyces cerevisiae, has enabled the functional analysis of efflux pumps from a variety of fungi. Phylogenetic analysis of the ABC pleiotropic drug resistance family has provided a new view of the evolution of this important class of efflux pumps. There are several ways in which the clinical significance of efflux-mediated antifungal drug resistance can be mitigated. Alternative antifungal drugs, such as the echinocandins, that are not efflux pump substrates provide one option. Potential therapeutic approaches that could overcome azole resistance include targeting efflux pump transcriptional regulators and fungal stress response pathways, blockade of energy supply, and direct inhibition of efflux pumps.

Development of Candida-associated denture stomatitis: new insights

Despite therapeutic progress, opportunistic oral fungal infectious diseases have increased in prevalence, especially in denture wearers. The combination of entrapment of yeast cells in irregularities in denture-base and denture-relining materials, poor oral hygiene and several systemic factors is the most probable cause for the onset of this infectious disease. Hence colonization and growth on prostheses by Candida species are of clinical importance. The purpose of this review is to critically discuss several key factors controlling the adhesion of Candida species which are relevant to denture-associated stomatitis. Although there is some consensus on the role of surface properties, studies on several other factors, as the use of denture liners, salivary properties and yeast-bacterial interactions, have shown contradictory findings. A comprehensive fundamental understanding is hampered by conflicting findings due to the large variations in experimental protocols, while other factors have never been thoroughly studied. Surface free energy and surface roughness control the initial adherence, but temporal changes have not been reported. Neither have in vivo studies shown if the substratum type is critical in dictating biofilm accumulation during longer periods in the oral environment. The contribution of saliva is unclear due to factors like variations in its collection and handling. Initial findings have disclosed that also bacteria are crucial for the successful establishment of Candida in biofilms, but the clinical significance of this observation is yet to be confirmed. In conclusion, there is a need to standardize experimental procedures, to bridge the gap between laboratory and in vivo methodologies and findings and – in general – to thoroughly investigate the factors that modulate the initial attachment and subsequent colonization of denture-base materials and the oral mucosa of patients subjected to Candida infections. Information on how these factors can be controlled is required and this may help to prevent the disease. The societal impact of such information is significant given the magnitude of the candidosis problem worldwide.

Clinical practice guidelines for the management of candidiasis: 2009 update by the Infectious Diseases Society of America

Guidelines for the management of patients with invasive candidiasis and mucosal candidiasis were prepared by an Expert Panel of the Infectious Diseases Society of America. These updated guidelines replace the previous guidelines published in the 15 January 2004 issue of Clinical Infectious Diseases and are intended for use by health care providers who care for patients who either have or are at risk of these infections. Since 2004, several new antifungal agents have become available, and several new studies have been published relating to the treatment of candidemia, other forms of invasive candidiasis, and mucosal disease, including oropharyngeal and esophageal candidiasis. There are also recent prospective data on the prevention of invasive candidiasis in high-risk neonates and adults and on the empiric treatment of suspected invasive candidiasis in adults. This new information is incorporated into this revised document.

Epidemiology of invasive fungal infection

Invasive fungal infection is a growing cause of morbidity and mortality in immunosuppressed patients. Furthermore, the use of azole prophylaxis against Candida species has coincided with an increase in the incidence of invasive aspergillosis and infections by other filamentous fungi such as Mucorales. New risk factors and different timescales for onset have been identified. Knowledge of changes in the epidemiology of, and risk factors for, invasive fungal infection is particularly important when developing therapeutic strategies and effective prophylaxis to improve the prognosis of immunosuppressed patients.

Pharmacokinetics of oral posaconazole in neutropenic patients receiving chemotherapy for acute myelogenous leukemia or myelodysplastic syndrome

STUDY OBJECTIVE

To analyze the pharmacokinetics of posaconazole administered as prophylaxis for invasive fungal infection (IFI) in neutropenic patients receiving chemotherapy for acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS).

DESIGN

Pharmacokinetic subanalysis of a phase III, prospective, randomized, multicenter, evaluator-blinded trial comparing posaconazole with standard azoles (fluconazole and itraconazole).

PATIENTS

One hundred ninety-four patients with AML or MDS who received posaconazole oral suspension 200 mg 3 times/day with meals or a nutritional supplement for a minimum of 7 days to achieve steady state and for a maximum of 12 weeks.

INTERVENTION

For the first 20 patients, blood samples were collected before the first dose on day 8 and at 2, 4, 6, and 24 hours after that first dose; for all other patients, blood samples were collected at 1 and 3 hours after the first dose on day 8 and during the first episode of evaluation for a possible IFI.

MEASUREMENTS AND MAIN RESULTS

The effects of the following covariates on average (Cav) and maximum (Cmax) posaconazole plasma concentrations at steady state were explored: age, sex, and race-ethnicity; proven or probable IFI; baseline body weight and body surface area; and baseline (on or before day 7) increases in liver enzyme levels, mucositis, neutropenia, diarrhea, vomiting, or use of an H2-receptor antagonist or proton pump inhibitor. Diarrhea, proton pump inhibitor use, gamma-glutamyl transferase level of 2 or more times the upper limit of normal, and race-ethnicity reduced Cav. Although statistically significant, these results were not considered clinically significant and did not necessitate posaconazole dosage adjustments. Mean Cav and Cmax values did not appear different in the six patients with IFIs (three with proven IFIs, three with probable IFIs) compared with the entire sample of 194 patients; however, a definitive conclusion cannot be made due to the small sample size of patients with IFI. No factor found to affect posaconazole concentrations predominated in patients with IFIs.

CONCLUSION

Oral posaconazole 200 mg 3 times/day provided plasma concentrations adequate for preventing IFIs. No dosage adjustments are recommended based on any covariate tested.

A prospective randomized controlled trial comparing PCR-based and empirical treatment with liposomal amphotericin B in patients after allo-SCT

We compared the efficacy and safety of empirical plus PCR-based vs empirical liposomal amphotericin B treatment after Allo-SCT. Allo-SCT recipients were randomized to receive either PCR-based preemptive therapy (group A; n=198) or empirical antifungal therapy (group B; n=211) with liposomal amphotericin B. In group A, therapy was started after one positive PCR result or after 120 h of febrile neutropenia refractory to broad-spectrum antibacterial therapy. In group B, liposomal amphotericin B was started after 120 h of refractory febrile neutropenia. Demographic and clinical characteristics were well balanced. A total of 112 (57.1%) patients in group A and 76 (36.7%) patients in group B received antifungal therapy (P<0.0001). Twelve patients in group A and 16 patients in group B developed proven invasive fungal infection (IFI). Survival curves showed better survival until day 30 when close PCR monitoring was performed (mortality 1.5 vs 6.3%; P=0.015), but there was no difference at day 100. At day 100, no difference was observed in the incidence of IFI (primary end point) and survival between the two arms. Further studies are required to assess the benefit of using PCR in patients after SCT.

Antifungals in the ICU

PURPOSE OF REVIEW

Invasive fungal infections remain a serious complication for critically ill ICU patients. The aim of this article is to review recent efficacy data of newer antifungal agents for the treatment of invasive candidiasis. The influence that recent epidemiological trends, advances in diagnostic testing, and risk prediction methods exert on the optimization of antifungal therapy for critically ill ICU patients will also be reviewed.

RECENT FINDINGS

Recent clinical trials have documented the clinical efficacy of the echinocandins and the newer triazoles for the management of invasive candidiasis. Thus far, resistance to echinocandins remains rare. Changes in the epidemiology of Candida spp. causing invasive candidiasis, such as an increasing relative proportion of non-albicans Candida spp., have not been universally reported, although they have important implications for the use of fluconazole as first-line therapy for invasive candidiasis. Efforts to improve the timeliness and accuracy of laboratory diagnostic techniques and clinical prediction models to allow early and accurately targeted antifungal intervention strategies continue.

SUMMARY

Echinocandins, given their clinical efficacy, spectrum of activity, and favourable pharmacological properties, are likely to replace fluconazole as initial antifungal agents of choice among critically ill ICU patients. The optimization of patient outcomes will require more accurately targeted early antifungal intervention strategies based upon sensitive and specific biological and clinical markers of risk.

Bloodstream infections in haematology: risks and new challenges for prevention

Bloodstream infections are an important cause of morbidity and mortality in the haematology population, and may contribute to delayed administration of chemotherapy, increased length of hospitalisation, and increased healthcare expenditure. For gram-positive, gram-negative, anaerobic and fungal infections, specific risk factors are recognised. Unique host and environmental factors contributing to pathogenesis are acknowledged in this population. Trends in spectrum and antimicrobial susceptibility of pathogens are examined, and potential contributing factors are discussed. These include the widespread use of empiric antimicrobial therapy, increasingly intensive chemotherapeutic regimens, frequent use of central venous catheters, and local infection control practices. In addition, the risks and benefits of prophylaxis, and spectrum of endemic flora are identified as relevant factors within individual centres. Finally, challenges are presented regarding prevention, early detection, surveillance and prophylaxis. To reduce the rate and impact of bloodstream infections multifaceted and customised strategies are required within individual haematology units.

Recommendations for the treatment of established fungal infections

Evidence-based guidelines for the treatment of established fungal infections in the adult haematology/oncology setting were developed by a national consensus working group representing clinicians, pharmacists and microbiologists. These updated guidelines replace the previous guidelines published in the Internal Medicine Journal by Slavin et al. in 2004. The guidelines are pathogen-specific and cover the treatment of the most common fungal infections including candidiasis, aspergillosis, cryptococcosis, zygomycosis, fusariosis, scedosporiosis, and dermatophytosis. Recommendations are provided for management of refractory disease or salvage therapies, and special sites of infections such as the cerebral nervous system and the eye. Because of the widespread use newer broad-spectrum triazoles in prophylaxis and empiric therapy, these guidelines should be implemented in concert with the updated prophylaxis and empiric therapy guidelines published by this group.

[Candidemia in a Brazilian tertiary care hospital: incidence, frequency of different species, risk factors and antifungal susceptibility]

Results from a cross-sectional observational study on candidemia conducted at Hospital de Clínicas, Federal University of Paraná, are presented. From January 2001 to December 2004, one hundred candidemia cases were evaluated. The incidence was 1.27 episodes per 1,000 hospitalizations and Candida was the eighth most frequently isolated agent from bloodstream infections. The patients ages ranged from five days to 89 years, with a mean of 32 years. Sixty percent of the cases occurred in adults (66% > 50 years old) and 40% in children (52% < one year old). Fifty-nine percent had been admitted to medical wards and 41% to the intensive care unit. Candida albicans was the most (59%) frequent species followed by Candida tropicalis (15%) and Candida parapsilosis (9%). The most (97%) prevalent coexisting conditions were the use of antibacterial drugs, central venous catheter (77%), H2 blockers (57%), total parenteral nutrition (49%) and admission to the intensive care unit (41%). Out of the 51 isolates tested, three of Candida glabrata presented dose-dependent susceptibility to fluconazole and resistance to itraconazole. One sample of Candida krusei presented dose-dependent susceptibility to fluconazole and one of Candida pelliculosa presented dose-dependent susceptibility to itraconazole. Among the study population, 68% received antifungal therapy, but the mortality was 56%.

The relationship between antifungal usage and antifungal susceptibility in clinical isolates of Candida: a multicenter Korean study

There have been very few multicenter studies of the relationship between the use of antifungals and resistance to them. We investigated the antifungal susceptibility of 1,301 clinical isolates of Candida collected from nine Korean hospitals during a 3-month period in 2006 to explore the existence of this type of relationship. Antifungal usage in the preceding year, defined as the daily dose per 1,000 patient days (DDD/1,000 PD), was calculated for each hospital. Resistance to fluconazole, itraconazole, and amphotericin B was detected in 2, 9, and 0.2% of the isolates, respectively. The MIC(50)/MIC(90) values were 0.03/0.125 mg/L for voriconazole, 0.06/0.25 mg/l for caspofungin, and 0.03/0.125 mg/l for micafungin. The total usage of systemic antifungals varied considerably among the nine hospitals, ranging from 6.1 to 96.2 DDD/1,000 PD. No relationship was found between the use of fluconazole (MIC> or =64 mg/l) or itraconazole (MIC> or =1 mg/l) and resistance in the Candida species (P>0.05). However, significant correlations were found between the percentage of Candida isolates that were non-susceptible to fluconazole (MIC> or =16 mg/l) and fluconazole usage (r=0.733, P=0.025) or total antifungal usage (r=0.767, P=0.016).

Candidemia in nonneutropenic critically ill patients: risk factors for non-albicans Candida spp

OBJECTIVE

The objective of this study was to determine the clinical features associated with candidemia caused by non-albicans Candida spp. and with potentially fluconazole-resistant Candida spp. (C. glabrata and C. krusei) among candidemic intensive care unit patients.

DESIGN

The authors conducted a nationwide prospective cohort study.

SETTING

The study was conducted in Australian intensive care units.

PATIENTS

All patients with intensive care unit-acquired candidemia over a 3-yr period were included in the study.

MEASUREMENTS

Clinical risk factors occurring up to 30 days before candidemia, Candida spp. associated with candidemia, and outcomes were determined. Risk factors associated with either non-albicans Candida spp. or with potentially fluconazole-resistant Candida spp. (C. glabrata or C. krusei) were assessed using multivariate logistic regression.

MAIN RESULTS

Among 179 episodes of intensive care unit-acquired candidemia, C. albicans accounted for 62%, C. glabrata 18%, C. krusei 4%, and other Candida spp. 16%. Independently significant variables associated with non-albicans Candida bloodstream infection included recent prior gastrointestinal surgery (adjusted odds ratio, 2.87; 95% confidence interval, 1.68-4.91) and recent prior systemic antifungal exposure (4.6; 1.36-15.53). Those associated with potentially fluconazole-resistant candidemia included recent prior gastrointestinal surgery (3.31; 1.79-6.11) and recent prior fluconazole exposure (5.47; 1.23-24.32). No significant differences in outcomes were demonstrated for non-albicans or potentially fluconazole-resistant candidemia.

CONCLUSIONS

Among candidemic intensive care unit patients, prior gastrointestinal surgery and systemic antifungal exposure were significantly associated with both a non-albicans Candida spp. and a potentially fluconazole-resistant Candida spp.

Trend reversal in the frequency of mycoses in hematological neoplasias: autopsy results from 1976 to 2005

INTRODUCTION

Fungal infections of internal organs are a major complication for patients with hematological neoplasias. For more than 20 years, the frequency of such mycoses has been increasing with the aggressiveness of tumor treatment.

METHODS

Autopsy findings over a 30-year period (1976 to 2005) from a single institution (Institute of Pathology, University of Essen) were retrospectively classified according to basic disease, frequency of mycoses, kind of mycoses, organs involved, hematopoietic transplantation, and cause of death.

RESULTS

340 of 1591 autopsied patients with hematological neoplasias (21.4%) revealed an invasive mycosis. The proportion increased from about 10% before 1980 to some 30% in the 1990s but fell to 21% by 2005. The frequency of mycoses decreased significantly both for transplanted patients (from 47.5% to 30.3%) and for non-transplanted patients (from 29.8% to 16.4%). The rate of deaths due to mycosis also decreased. The relative frequency of candidal mycoses went down, while aspergilloses predominated. The organ most frequently involved was the lung.

DISCUSSION

The autopsy results signal a trend reversal in the leading complication of the treatment of hematological neoplasias and lend support to the assumption that antimycotic strategies are having a positive effect.

Geographic distribution and antifungal susceptibility of the newly described species Candida orthopsilosis and Candida metapsilosis in comparison to the closely related species Candida parapsilosis

Candida orthopsilosis and Candida metapsilosis are recently described species, having previously been grouped with the more prevalent species Candida parapsilosis. Current literature contains very little data pertaining to the distributions and antifungal susceptibilities of these Candida species. We determined the species and antifungal susceptibilities of 1,929 invasive clinical isolates from the ARTEMIS antifungal surveillance program collected between 2001 and 2006 and identified as C. parapsilosis using Vitek and conventional methods. Of the 1,929 isolates of presumed C. parapsilosis tested, 117 (6.1%) were identified as C. orthopsilosis and 34 (1.8%) as C. metapsilosis. The percentage of presumed C. parapsilosis isolates found to be C. orthopsilosis varied greatly by region, with the highest percentage (10.9%) from South America and the lowest (0.7%) from Africa. The MIC distributions of the C. orthopsilosis and C. metapsilosis isolates were statistically significantly lower than those of C. parapsilosis for all drugs except fluconazole, for which they were significantly higher (P < 0.001 for all). No C. orthopsilosis or C. metapsilosis isolates were fluconazole resistant, and all were susceptible to caspofungin, anidulafungin, and micafungin.

Human epithelial cells establish direct antifungal defense through TLR4-mediated signaling

Mammalian TLRs are central mediators of the innate immune system that instruct cells of the innate and adaptive response to clear microbial infections. Here, we demonstrate that human epithelial TLR4 directly protected the oral mucosa from fungal infection via a process mediated by polymorphonuclear leukocytes (PMNs). In an in vitro epithelial model of oral candidiasis, the fungal pathogen Candida albicans induced a chemoattractive and proinflammatory cytokine response but failed to directly modulate the expression of genes encoding TLRs. However, the addition of PMNs to the C. albicans-infected model strongly upregulated cytoplasmic and cell-surface epithelial TLR4 expression, which correlated directly with protection against fungal invasion and cell injury. C. albicans invasion and cell injury was restored by the addition of TLR4-specific neutralizing antibodies and knockdown of TLR4 using RNA interference, even in the presence of PMNs, demonstrating the direct role of epithelial TLR4 in the protective process. Furthermore, treatment with neutralizing antibodies specific for TNF-alpha resulted in strongly reduced TLR4 expression accompanied by augmented epithelial cell damage and fungal invasion. To our knowledge, this is the first description of such a PMN-dependent, TLR4-mediated protective mechanism at epithelial surfaces, which may provide significant insights into how microbial infections are managed and controlled in the oral mucosa.

In vitro and in vivo antifungal activities of T-2307, a novel arylamidine

The in vitro and in vivo antifungal activities of T-2307, a novel arylamidine, were evaluated and compared with those of fluconazole, voriconazole, micafungin, and amphotericin B. T-2307 exhibited broad-spectrum activity against clinically significant pathogens, including Candida species (MIC range, 0.00025 to 0.0078 microg/ml), Cryptococcus neoformans (MIC range, 0.0039 to 0.0625 microg/ml), and Aspergillus species (MIC range, 0.0156 to 4 microg/ml). Furthermore, T-2307 exhibited potent activity against fluconazole-resistant and fluconazole-susceptible-dose-dependent Candida albicans strains as well as against azole-susceptible strains. T-2307 exhibited fungicidal activity against some Candida and Aspergillus species and against Cryptococcus neoformans. In mouse models of disseminated candidiasis, cryptococcosis, and aspergillosis, the 50% effective doses of T-2307 were 0.00755, 0.117, and 0.391 mg.kg(-1).dose(-1), respectively. This agent was considerably more active than micafungin and amphotericin B against candidiasis and than amphotericin B against cryptococcosis, and its activity was comparable to the activities of micafungin and amphotericin B against aspergillosis. The results of preclinical in vitro and in vivo evaluations performed thus far indicate that T-2307 could represent a potent injectable agent for the treatment of candidiasis, cryptococcosis, and aspergillosis.

Will resistance in fungi emerge on a scale similar to that seen in bacteria?

Growing numbers of patients receive azoles as prophylaxis or treatment for invasive fungal infections, begging the question of whether emergence of resistance will occur, as has been seen with bacteria. This review examines resistance pathways shared by bacteria and fungi, including alteration and overproduction of drug targets, changes in biosynthetic pathways, and enhanced drug efflux, and assesses whether such commonalities predict increased resistance to azoles. Important differences exist between the two kingdoms, including little, if any, horizontal transfer of extrachromosomal material across fungal species and a longer fungal generation time, thereby slowing vertical transfer of mutant traits. Further, no enzymatic modulation or inactivation of azoles has been reported in fungi. The newer broad-spectrum azoles posaconazole and voriconazole are active against the vast majority of yeasts and moulds and are likely to prevent the emergence of inherently resistant strains. Therefore, the likelihood for an explosion of fungal resistance is relatively low.

[Spectrum and risk factors of invasive fungal infection]

In recent years, invasive fungal infection has become a growing problem in immunosuppressed patients. Simultaneously, changes in medical practice, such as the use of anti-Candida prophylaxis with azoles, has led to a shift in the epidemiology of these infections from Candida spp. to Aspergillus and other filamentous molds. Moreover, new risk factors for invasive fungal infection have been identified and the time of onset is different from that seen a decade ago. Recognition of these trends in patients receiving novel immunosuppressive regimens has important implications for the clinical management of fungal infection in this population.

Changing pattern of candidaemia 2001–2006 and use of antifungal therapy at the University Hospital of Vienna, Austria

A retrospective survey of candidaemia between 2001 and 2006 was performed at the University Hospital of Vienna, a 2200-bed centre with large organ transplantation and haematology-oncology units. The incidence rate of Candida spp. in blood cultures increased from 0.27 cases/1000 admissions in 2001 to 0.77 cases/1000 admissions in 2006 (p <0.005). The incidence of candidaemia caused by Candida albicans and by non-albicans Candida spp. both increased during this period; although there was a trend towards an increased incidence (37%) of non-albicans Candida spp., particularly Candida glabrata, in surgical wards, C. albicans remained the predominant pathogen (63%). In the haematology-oncology unit, C. albicans remained the leading pathogen (23/29 isolates, 79%), followed by Candida tropicalis and C. glabrata (2/29, 7% each), Candida sake and Candida lusitaniae (1/29, 3% each). The overall survival rate was 43.8%, ranging from 32.8% in 2004 to 63.6% in 2002. In total, 108 (33.2%) patients died within 4 weeks of the first isolation of Candida spp. from blood; 58 (54%) of these patients died within the first 7 days, and a further 34 patients died within the next 3 months. Fluconazole was used extensively (24 701.5 defined daily doses), followed by amphotericin B (8981.4 defined daily doses), during 2005. The consumption of antifungal agents increased continuously (p <0.05) because of increased use of voriconazole and caspofungin. Although the numbers of susceptible patients remained unchanged, the net increase in the number of cases of candidaemia warrants a re-evaluation of the risk-factors and the use of improved diagnostic procedures for invasive fungal infections.

In vitro activity of fluconazole, voriconazole and caspofungin against clinical yeast isolates

Predicting the clinical outcome of a systemic mycosis is often a difficult task, especially when microbiological resistance is one of the factors contributing to therapeutic failure. Some of these factors are host-related--e.g. immune state, site and severity of infection, poor compliance to therapy--while others are associated with the drug's characteristics--e.g. dosage, type of compound (fungistatic/fungicidal), pharmacokinetic properties and drug-drug interactions. In the last few years, clinicians have been confronted with the problem of selecting the most appropriate antifungal therapy for systemic infections and have highlighted the need for a reliable method to assay the in vitro susceptibility of yeasts and molds to different antifungal agents, which would allow them to institute a tailored therapy. Using the CLSI micromethod--the reference method for clinically relevant yeast testing--we assayed 70 clinical yeast isolates ( Candida spp., collected from patients with systemic mycosis) for susceptibility against fluconazole, voriconazole and caspofungin. Data obtained from our in vitro susceptibility assays revealed good activity of azoles against the majority of Candida spp. In particular, 88.6% of the assayed isolates were susceptible to fluconazole, with minimum inhibitory concentrations (MICs) ranging from =0.125 microg/mL to 8 microg/mL; 97.1% of the isolates were susceptible to voriconazole, with MICs ranging from 0.008 microg/mL to 1 microg/mL; regarding caspofungin 72.9% of the isolates had MICs ranging from 0.25 microg/mL to 1 microg/mL.

Rapid identification of Candida species in oral rinse solutions by PCR

AIMS

To determine the sensitivity and specificity of a multiplex PCR assay for the contemporary identification of major species involved in oral candidiasis, without extraction and purification of DNA from the samples under investigation; and evaluation of this method in comparison with routine phenotypic culture identification.

METHODS

78 oral rinse solutions were collected. The concentrated oral rinse technique was used for a quantitative and qualitative study. Research and identification of Candida spp, with routine phenotypic culture identification (germ-tube test in serum at 37 degrees C for 3 hours and sugar assimilation strip analysis), were performed. Each sample was analysed with multiplex PCR directly on oral rinse solution. Samples giving discrepant results between routine phenotypic and PCR identification methods were resubcultured on CHROMagar Candida plates. The fungus-specific primers ITS1, ITS2, CA3, and CA4 were used. For the identification of other species (C kefyr, C famata and C dubliniensis), ITS1F, ITS1K, and ITS2D primers were designed.

RESULTS

Multiplex PCR correctly identified all samples, including those with single species, or with mixed species, negative samples and positive samples which appeared to be negative from routine phenotypic methods.

CONCLUSION

This multiplex PCR assay provides a rapid alternative to the conventional culture based technique for the identification and speciation of the most frequently isolated Candida species. The absence of an extraction method made identification of 10 species possible in a few hours.

Evaluation of Vitek 2 for identification of yeasts in the clinical laboratory

The Vitek 2 system was compared with conventional assimilation, fermentation and morphological methods for its ability to identify yeast isolates from among 151 clinical specimens and 16 known type culture or quality control strains. An unequivocal identification was obtained for 155 (92.8%) isolates, with low discrimination for nine (5.4%) and false identification for three (1.8%) isolates. All isolates of Candida albicans, Candida glabrata and Candida krusei were identified correctly. It was concluded that the Vitek 2 system offers an excellent alternative for the identification of yeasts in a clinical laboratory.

Polymicrobial bloodstream infections involving Candida species: analysis of patients and review of the literature

Candida species are the 4th most common cause of nosocomial bloodstream infections in North America. It is not widely appreciated, however, that many of these infections are polymicrobial, that is, that bacteria and occasionally more than 1 species of Candida are present in the same blood culture bottle. Analysis of 2 groups of candidemic patients and a review of the literature were performed. Review of 141 candidemic patients from 8 Veterans Affairs hospitals and 231 patients from a tertiary care hospital with transplant services was performed. Of the 372 patients with candidemia, 100 (27%) had polymicrobial blood cultures: 88 patients (24%) had synchronous bacteremia and 12 patients (3%) had more than 1 species of Candida. One hundred bacteria were isolated from these patients, 69 were Gram positive, and 31 were Gram negative. Candidemia was shown to occur in a setting of polymicrobial bacteremia extending over days, whereas Staphylococcus aureus and coagulase-negative Staphylococcus were less frequently associated with polymicrobial bloodstream infections. Review of more than 8000 reported episodes of candidemia revealed high rates of polymicrobial infection occurring with candidemia. Of blood cultures isolating Candida, 23% were polymicrobial and 4% had more than 1 species of Candida. Thus, almost 1 in 4 patients with candidemia will have a polymicrobial bloodstream infection. As detection of bloodborne infections evolves toward nonculture methodologies, documentation of the frequency of polymicrobial bloodstream infections involving Candida is important. This finding may have treatment implications for clinicians.

Comparative evaluation of (1, 3)-beta-D-glucan, mannan and anti-mannan antibodies, and Candida species-specific snPCR in patients with candidemia

BACKGROUND

Candidemia is a major infectious complication of seriously immunocompromised patients. In the absence of specific signs and symptoms, there is a need to evolve an appropriate diagnostic approach. A number of methods based on the detection of Candida mannan, nucleic acid and (1,3)-beta- D- glucan (BDG) have been used with varying specificities and sensitivities. In this retrospective study, attention has been focused to evaluate the usefulness of two or more disease markers in the diagnosis of candidemia.

METHODS

Diagnostic usefulness of Platelia Candida Ag for the detection of mannan, Platelia Candida Ab for the detection of anti-mannan antibodies, Fungitell for the detection of BDG, and of a semi-nested PCR (snPCR) for the detection Candida species-specific DNA have been retrospectively evaluated using 32 sera from 27 patients with culture-proven candidemia, 51 sera from 39 patients with clinically suspected candidemia, sera of 10 women with C. albicans vaginitis, and sera of 16 healthy controls.

RESULTS

Using cut-off values recommended by the manufacturers, the sensitivity of the assays for candidemia patients were as follows: Candida snPCR 88%, BDG 47%, mannan 41%, anti-mannan antibodies 47%, respectively. snPCR detected 5 patients who had candidemia due to more than one Candida species. The sensitivities of the combined tests were as follows: Candida mannan and anti-mannan antibodies 75%, and Candida mannan and BDG 56%. Addition of snPCR data improved the sensitivity further to 88%, thus adding 10 sera that were negative by BDG and/or mannan. In clinically suspected, blood culture negative patients; the positivities of the tests were as follows: Candida DNA was positive in 53%, BDG in 29%, mannan in 16%, and anti-mannan antibodies in 29%. The combined detection of mannan and BDG, and mannan, BDG and Candida DNA enhanced the positivity to 36% and 54%, respectively. None of the sera from Candida vaginitis patients and healthy subjects were positive for Candida DNA and mannan.

CONCLUSION

The observations made in this study reinforce the diagnostic value of snPCR in the sensitive and specific diagnosis of candidemia and detection of more than one Candida species in a given patient. Additionally, in the absence of a positive blood culture, snPCR detected Candida DNA in sera of more than half of the clinically suspected patients. While detection of BDG, mannan and anti-mannan antibodies singly or in combination could help enhancing sensitivity and eliminating false positive tests, a more extensive evaluation of these assays in sequentially collected serum samples is required to assess their value in the early diagnosis of candidemia.

Candidemia in immunocompromised and immunocompetent critically ill patients: a prospective comparative study

The purpose of this study was to compare the risk factors, clinical manifestations, and outcome of candidemia in immunocompromised (IC) and nonimmunocompromised (NIC) critically ill patients. Data were collected prospectively over a 2-year period (02/2000–01/2002) from patients in a 25-bed, medical–surgical intensive care unit (ICU). Eligible for participation in this study were patients who developed candidemia during their ICU stay. Patients under antifungal therapy and with a confirmed systemic fungal infection prior to the diagnosis of candidemia were excluded. Cultures of blood, urine, and stool were performed for all patients in the study, and all patients underwent endoscopy/biopsy of the esophagus for detection of Candida. Smears and/or scrapings of oropharyngeal and esophageal lesions were examined for hyphae and/or pseudohyphae and were also cultured for yeasts. During the study period, 1,627 patients were hospitalized in the ICU, 57% for primary medical reasons and 43% for surgical reasons. After application of the study’s inclusion and exclusion criteria, 24 patients with candidemia (9 IC and 15 NIC) were analyzed. Total parenteral nutrition was more common in IC than in NIC patients (9/9 [100%] vs 8/15 [53%], p = 0.02). Oropharyngeal candidiasis was detected in 5 of 9 (55.5%) IC patients and in 1 of 15 (6.5%) NIC patients (p = 0.015). Esophageal candidiasis was also more common in IC than in NIC patients (4/9 [44%] vs 0/15 [0%], p = 0.012). Among the 9 IC patients, all except 2 died, resulting in a crude mortality of 78%; among the 15 NIC patients, 9 died, resulting in a crude mortality of 60% (p > 0.05). Autopsy was performed in two IC and in six NIC patients, with disseminated candidiasis found in one IC patient. Oropharyngeal and esophageal candidiasis are frequent in IC patients with candidemia. In contrast, this coexistence is rare in NIC critically ill patients with Candida bloodstream infections. A high mortality was noted in both IC and NIC critically ill patients with candidemia.

Mixed Fungemia: Incidence, Risk Factors, and Mortality in a General Hospital

BACKGROUND

Fungemia has been historically considered to be a disease caused by a single Candida species; the detection of >1 species of yeast in circulating blood was distinctly uncommon using traditional microbiological procedures. We describe episodes of mixed fungemia (MF), detected between 1985 and 2006, in a large teaching hospital.

METHODS

The study was divided into 2 periods that were separated by the introduction, in January 2005, of the CHROmagar Candida medium (CHROMagar) for the routine subculturing of blood cultures in which yeast has been identified. Overall, we documented 747 cases of fungemia. During the first period (1985-1994), we identified 217 episodes of fungemia and no single episode of MF; during the second period (1995-2006), 15 episodes of MF were detected among 530 episodes of fungemia (2.8%). Candida albicans was isolated in 13 patients, non-albicans species of Candida in 16 patients, and Saccharomyces cerevisiae in 1 patient. Each episode of MF was compared with 2 control episodes of monomicrobial fungemia.

RESULTS

Patients with MF had more frequently experienced organ transplantation (13% vs. 0%) and surgery (60% vs. 27%), had less frequently received parenteral nutrition (40% vs. 70%) or had intravenous lines (80% vs. 100%), and had a lower incidence of shock (6% vs. 37%) and a lower mortality (20% vs. 53%).

CONCLUSIONS

Despite the introduction of chromogenic agar, MF is still an uncommon disease and has a less severe outcome than does monomicrobial candidemia.

Fungemia at a tertiary care hospital: incidence, therapy, and distribution and antifungal susceptibility of causative species

The aim of this study was to review fungal bloodstream infections at a large tertiary care hospital to evaluate the incidence of fungemia and the distribution of causative species during the period 2001-2005. Another aim was to assess the extent of antifungal resistance. A review of all episodes of fungemia at the University Hospitals of Leuven (Belgium) was conducted between January 2001 and December 2005. For the first yeast isolate collected from each non-mould fungemic episode during a 1-year period (June 2004-June 2005), susceptibility to seven antifungal agents was determined using Sensititre YeastOne plates (Trek Diagnostic Systems, East Grinstead, UK), and the antifungal therapy was reviewed. The annual incidence of fungemia ranged between 1.30 and 1.68 episodes per 10,000 patient-days (on a total of 2,680,932 patient-days), with a decreasing trend observed over the 5-year study period. The most common species were Candida albicans (59%), Candida glabrata (22%), Candida parapsilosis (10%), and Candida tropicalis (4%). Overall, fluconazole resistance was rare (1.6%) and was detected only in C. glabrata and C. krusei. Voriconazole and caspofungin inhibited 100% of the isolates at a concentration of <or=1 microg/ml. Fluconazole was used to treat 75% of fungemic patients. Caspofungin was the second most commonly used antifungal agent (used to treat 11.7% of patients). The incidence of fungemia was higher than usually reported in other European countries. The low proportion of resistance supports the use of fluconazole as the treatment of first choice for candidemia in patients not previously exposed to this drug.