Epidemiology and management of candidaemia - a retrospective, multicentre study in five hospitals in the UK

Candida parapsilosis Virulence and Antifungal Resistance Mechanisms: A Comprehensive Review of Key Determinants

Candida parapsilosis is the second most common Candida species isolated in Asia, Southern Europe, and Latin America and is often involved in invasive infections that seriously impact human health. This pathogen is part of the psilosis complex, which also includes Candida orthopsilosis and Candida metapsilosis. C. parapsilosis infections are particularly prevalent among neonates with low birth weights, individuals who are immunocompromised, and patients who require prolonged use of a central venous catheter or other indwelling devices, whose surfaces C. parapsilosis exhibits an enhanced capacity to adhere to and form biofilms. Despite this well-acknowledged prevalence, the biology of C. parapsilosis has not been as extensively explored as that of Candida albicans. In this paper, we describe the molecular mechanistic pathways of virulence in C. parapsilosis and show how they differ from those of C. albicans. We also describe the mode of action of antifungal drugs used for the treatment of Candida infections, namely, polyenes, echinocandins, and azoles, as well as the resistance mechanisms developed by C. parapsilosis to overcome them. Finally, we stress the importance of the ongoing search for species-specific features that may aid the development of effective control strategies and thus reduce the burden on patients and healthcare costs.

Continuing Shifts in Epidemiology and Antifungal Susceptibility Highlight the Need for Improved Disease Management of Invasive Candidiasis

Invasive candidiasis (IC) is a systemic life-threatening infection of immunocompromised humans, but remains a relatively neglected disease among public health authorities. Ongoing assessments of disease epidemiology are needed to identify and map trends of importance that may necessitate improvements in disease management and patient care. Well-established incidence increases, largely due to expanding populations of patients with pre-disposing risk factors, has led to increased clinical use and pressures on antifungal drugs. This has been exacerbated by a lack of fast, accurate diagnostics that have led treatment guidelines to often recommend preventative strategies in the absence of proven infection, resulting in unnecessary antifungal use in many instances. The consequences of this are multifactorial, but a contribution to emerging drug resistance is of primary concern, with high levels of antifungal use heavily implicated in global shifts to more resistant Candida strains. Preserving and expanding the utility and number of antifungals should therefore be of the highest priority. This may be achievable through the development and use of biomarker tests, bringing about a new era in improved antifungal stewardship, as well as novel antifungals that offer favorable profiles by targeting Candida pathogenesis mechanisms over cell viability.

Attributable mortality of candidemia at a German tertiary hospital from 1997 to 2001 before the introduction of echinocandins

OBJECTIVES

The relevance of candidemia has increased over the last decades due to higher incidence rates in an ageing society. Studies on amphotericin B and fluconazole have shown high attributable mortality rates of 38% and 49% in the United States. Incidence rates and locational factors might have an impact on the mortality rates at the University Hospital of Cologne (UHC), Germany.

METHODS

We performed a matched case-control study including 57 patients with candidemia, hospitalised at the UHC between 1 July 1997 and 30 June 2001. Controls were matched by age, sex, admission date, treatment on intensive care unit (ICU), number of days at risk, underlying diseases, surgical procedures and the Charlson Comorbidity Index.

RESULTS

The incidence of candidemia was 3.5 per 10 000 admissions. For cases and controls, we observed in-hospital-mortality rates of 33.3% and 11.8%, and a 30-day mortality of 23.5% and 7.8% respectively. The attributable mortality rate to candidemia was 21.5%, and at 30 days, it was 15.7%. Underlying conditions were more frequent in cases than in controls, especially central venous catheter (80% vs 33%, P < .001), chronic cardiovascular disease (39.2% vs 25.5%, P = .138), treatment on ICU (31.4% vs 13.7%, P = .033) and chronic liver disease (21.6% vs 0%, P < .001).

CONCLUSIONS

The attributable mortality of candidemia at the UHC between 1997 and 2001 was lower compared to studies performed in the United States with a similar design. Contributing factors might be lower incidence rates and less comorbidities in our study.

Echinocandins versus Amphotericin B Against Candida tropicalis Fungemia in Adult Hematological Patients with Neutropenia: A Multicenter Retrospective Cohort Study

Background

Candida tropicalis is the most common non-albicans Candida species identified in immunocompromised patients, which often appears with high mortality. However, data on the outcomes of treatment for Candida tropicalis fungemia in patients with neutropenia remain limited.

Methods

In the present study, 90 neutropenic adult patients with proven Candida tropicalis fungemia, who received initial antifungal therapy, were retrospectively analyzed.

Results

These results revealed that the overall 8-day and 30-day mortality among patients in the entire data set were 22.2% and 33.3%, respectively. However, there was no significant difference between the survival and death group, in terms of baseline characteristics. The univariate analysis of risk factors identified the treatment with azole as a predictor of mortality, while treatments that containing amphotericin B were associated with reduced mortality. In addition, the survival rate on day 30 was observed in 60.7% (17/28) of patients who were initially treated with echinocandins, while this was observed in 86.4% (19/22, P=0.039) and 100% (13/13, P=0.024) of patients treated with amphotericin B plus echinocandins and amphotericin B, respectively.

Conclusion

These data indicate for the first time that the initial therapy with amphotericin B-based agents was associated with a better survival rate and could be assessed as the optimal strategy for the treatment of Candida tropicalis fungemia in patients with neutropenia.

Candidemia in a Portuguese tertiary care hospital: Analysis of a 2-year period

BACKGROUND

Candidemia is a nosocomial infection of increasing importance, associated with high morbidity and mortality. The aim of this study is to describe the species distribution, risk factors, management and outcomes of patients with candidemia.

METHODS

We conducted a retrospective study at Centro Hospitalar Universitário de São João, Portugal, between January 2016 and December 2017.

RESULTS

A total of 117 candidemia episodes (n=114 patients) were included. Median age was 65 years, with an increased prevalence of older ages. Candida albicans (51.3%) was the most prevalent species, followed by C. glabrata (22.2%), C. parapsilosis (15.4%), C. tropicalis (4.3%) and C. lusitaniae (2.6%). Forty-two patients (35.9%) did not receive antifungal drugs after diagnosis of candidemia. Echinocandins were used as first-line drug therapy in half of the treated patients (50.7%). The median EQUAL Candida Score was 6/17 (IQR 6-9) for patients without central venous catheter (CVC) and 11/20 (IQR 6-14) for patients with CVC. The 30 days-mortality was 31,6% and was not significantly associated with the timing of antifungal therapy and the EQUAL Candida Score.

CONCLUSION

The distribution of Candida species has changed in recent years, with an increase in the proportion of C. albicans and C. glabrata. Rapid diagnostic tests, empiric antifungal therapy and source control are essential to improve the prognosis of patients with candidemia. More multicentric prospective studies are needed to evaluate the association of mortality with the timing of antifungal therapy or the EQUAL Candida Score.

The epidemiology and management of candidemia in Northern Ireland during 2002-2011, including a 12-month enhanced case review

In Northern Ireland there are concerns about candidaemia, with rates higher than those reported in England and Wales. Our aim was to explore the epidemiology of candidaemia during a 10 year period and the clinical management upon suspicion of cases during a one year enhanced investigation in Northern Ireland.Candidaemia reports to the Public Health Agency were validated during 2002-2011 and used to examine incidence and antifungal sensitivity trends (during 2007-2011). A clinical proforma was used to collate information for all patients with candidaemia in 2011.The majority (96%) of isolates were captured through voluntary laboratory reporting. There was a year-on-year increase in candidaemia from 2002-2011, from 80 to 131 episodes (incidence rate ratio 1.09 95% CI 1.05-1.13). Rates were highest in males under 1 year and over 75 years. 83/98 (85%) of case notes were available from candidaemia patients during 2011. The most prevalent risk factors were patients on total parenteral nutrition (26 people, 31.3%), surgery in the two months prior to the candidaemia (25 people, 30.1%), significant steroid use in the previous 3 months (24 people, 28.9%) and active neoplastic disease (23 people, 27.7%),This study confirmed an increase in candidaemia rates over time, with the observed incidence in 2011 higher than England and Wales. We identified areas for improvement around the clinical management of candidaemia. We recommend raising the awareness of guidelines for fundoscopy, echocardiography and central venous catheter removal.

Candida parapsilosis: from Genes to the Bedside

Patients with suppressed immunity are at the highest risk for hospital-acquired infections. Among these, invasive candidiasis is the most prevalent systemic fungal nosocomial infection. Over recent decades, the combined prevalence of non-albicans Candida species outranked Candida albicans infections in several geographical regions worldwide, highlighting the need to understand their pathobiology in order to develop effective treatment and to prevent future outbreaks. Candida parapsilosis is the second or third most frequently isolated Candida species from patients. Besides being highly prevalent, its biology differs markedly from that of C. albicans, which may be associated with C. parapsilosis' increased incidence. Differences in virulence, regulatory and antifungal drug resistance mechanisms, and the patient groups at risk indicate that conclusions drawn from C. albicans pathobiology cannot be simply extrapolated to C. parapsilosis Such species-specific characteristics may also influence their recognition and elimination by the host and the efficacy of antifungal drugs. Due to the availability of high-throughput, state-of-the-art experimental tools and molecular genetic methods adapted to C. parapsilosis, genome and transcriptome studies are now available that greatly contribute to our understanding of what makes this species a threat. In this review, we summarize 10 years of findings on C. parapsilosis pathogenesis, including the species' genetic properties, transcriptome studies, host responses, and molecular mechanisms of virulence. Antifungal susceptibility studies and clinician perspectives are discussed. We also present regional incidence reports in order to provide an updated worldwide epidemiology summary.

ECIL-6 guidelines for the treatment of invasive candidiasis, aspergillosis and mucormycosis in leukemia and hematopoietic stem cell transplant patients

The European Conference on Infections in Leukemia (ECIL) provides recommendations for diagnostic strategies and prophylactic, pre-emptive or targeted therapy strategies for various types of infection in patients with hematologic malignancies or hematopoietic stem cell transplantation recipients. Meetings are held every two years since 2005 and evidence-based recommendations are elaborated after evaluation of the literature and discussion among specialists of nearly all European countries. In this manuscript, the ECIL group presents the 2015-update of the recommendations for the targeted treatment of invasive candidiasis, aspergillosis and mucormycosis. Current data now allow a very strong recommendation in favor of echinocandins for first-line therapy of candidemia irrespective of the underlying predisposing factors. Anidulafungin has been given the same grading as the other echinocandins for hemato-oncological patients. The beneficial role of catheter removal in candidemia is strengthened. Aspergillus guidelines now recommend the use of either voriconazole or isavuconazole for first-line treatment of invasive aspergillosis, while first-line combination antifungal therapy is not routinely recommended. As only few new data were published since the last ECIL guidelines, no major changes were made to mucormycosis recommendations.

Molecular characterization of Candida isolates from intensive care unit patients, Krakow, Poland

BACKGROUND

Over the last decades, Candida species have emerged as important pathogens in immunocompromised patients. Nosocomial infections are mainly of endogenous origin. Nevertheless, some cases of exogenous candidiasis have also been reported.

AIMS

The aim of this study was to evaluate the genetic relatedness between Candida albicans, Candida glabrata, Candida tropicalis, Candida krusei and Candida kefyr isolates recovered from intensive care unit (ICU) patients.

METHODS

A total of 132 Candida clinical isolates (62 C. albicans, 40 C. glabrata, 13 C. tropicalis, 11 C. krusei, 6 C. kefyr), obtained from specimens of endotracheal aspirate, urine and blood taken from patients of a tertiary hospital in Poland, were included in the study. Species identification was performed by PCR method and genetic relatedness was assessed by randomly amplified polymorphic DNA assay (RAPD) with five primers.

RESULTS

The RAPD analysis revealed high genetic diversity among the studied Candida isolates, indicating that most of the strains were from endogenous sources. Only two clonal strains of C. glabrata isolated from different patients were observed, suggesting a possible cross-transmission of these pathogens.

CONCLUSIONS

Our study confirmed the high discriminatory power of the RAPD assay. This genotyping method can be applied to local epidemiological studies of Candida species.

A Genome-Wide Transcriptional Analysis of Yeast-Hyphal Transition in Candida tropicalis by RNA-Seq

Candida tropicalis is considered as the leading pathogen in nosocomial fungemia and hepatosplenic fungal infections in patients with cancer, particularly in leukemia. The yeast-filament transition is required for virulent infection by Candida. Several studies have explored the genome-wide transcription profile of Candida, however, no report on the transcriptional profile of C. tropicalis under yeast-filament transition has been published.

In this study, the transcriptomes of three C. tropicalis isolates with different adhesion and biofilm formation abilities, identified in our previous studies, were analyzed in both the yeast and filament states using RNA-Seq. Differentially expressed genes were found for each isolate during the transition. A total of 115 genes were up- or down- regulated in the two hyphal-producing isolates (ZRCT 4 and ZRCT 45). Among these differentially expressed genes, only two were down-regulated during the yeast-filament transition. Furthermore, six filament-associated genes were up-regulated in the hyphae-producing isolates. According to Candida Hypha Growth Database established in this study, 331 hyphae- related genes were discovered in C. tropicalis. ALS1 and ALS3 were down-regulated and up-regulated, respectively, during filamentous growth of C. tropicalis. These findings proved a better understanding of gene expression dynamics during the yeast-filament transition in C. tropicalis.

Central venous catheter (CVC) removal for patients of all ages with candidaemia

BACKGROUND

Candida bloodstream infections most often affect those already suffering serious, potentially life-threatening conditions and often cause significant morbidity and mortality. Most affected persons have a central venous catheter (CVC) in place. The best CVC management in these cases has been widely debated in recent years, while the incidence of candidaemia has markedly increased.

OBJECTIVES

The main purpose of this review is to examine the impact of removing versus retaining a CVC on mortality in adults and children with candidaemia who have a CVC in place.

SEARCH METHODS

We searched the following databases from inception to 3 December 2015: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid SP), EMBASE (Ovid SP), the Commonwealth Agricultural Bureau (CAB), Web of Science and the Cumulative Index to Nursing and Allied Health Literature (CINAHL). We searched for missed, unreported and ongoing trials in trial registries and in reference lists of excluded articles.

SELECTION CRITERIA

We searched for randomized controlled trials (RCTs) and quasi-RCTs involving adults and children with candidaemia and in which participants were randomized for removal of a CVC (the intervention under study), irrespective of publication status, date of publication, blinding status, outcomes published or language.However, two major factors make the conduct of RCTs in this population a difficult task: the large sample size required to document the impact of catheter removal in terms of overall mortality; and lack of economic interest from the industry in conducting such a trial.

DATA COLLECTION AND ANALYSIS

Our primary outcome measure was mortality. Several secondary outcome measures such as required time for clearance of blood cultures for Candida species, frequency of persistent candidaemia, complications, duration of mechanical ventilation and length of stay in the intensive care unit (ICU) and in the hospital were planned, as were various subgroup and sensitivity analyses, according to our protocol. We assessed papers and abstracts for eligibility and resolved disagreements by discussion. However, we were not able to include any RCTs or quasi-RCTS in this review and, as a result, have carried out no meta-analyses. However, we have chosen to provide a brief overview of excluded observational studies.

MAIN RESULTS

We found no RCT and thus no available data for evaluation of the primary outcome (mortality) nor secondary outcomes or adverse effects. Therefore, we conducted no statistical analysis.A total of 73 observational studies reported on various clinically relevant outcomes following catheter removal or catheter retention. Most of these excluded, observational studies reported a beneficial effect of catheter removal in patients with candidaemia. None of the observational studies reported results in favour of retaining a catheter. However, the observational studies were very heterogeneous with regards to population, pathogens and interventions. Furthermore, they suffered from confounding by indication and an overall high risk of bias. As a consequence, we are not able to provide recommendations or to draw firm conclusions because of the difficulties involved in interpreting the results of these observational studies (very low quality of evidence, GRADE - Grades of Recommendation, Assessment, Development and Evaluation Working Group).

AUTHORS' CONCLUSIONS

Despite indications from observational studies in favour of early catheter removal, we found no eligible RCTs or quasi-RCTs to support these practices and therefore could draw no firm conclusions. At this stage, RCTs have provided no evidence to support the benefit of early or late catheter removal for survival or other important outcomes among patients with candidaemia; no evidence with regards to assessment of harm or benefit with prompt central venous catheter removal and subsequent re-insertion of new catheters to continue treatment; and no evidence on optimal timing of insertion of a new central venous catheter.

Interferon-gamma Immunotherapy in a Patient With Refractory Disseminated Candidiasis

Despite advances in supportive care and novel antifungal agents, mortality caused by invasive Candida infection is high. A 3-year-old boy with disseminated Candida dubliniensis infection during induction chemotherapy for acute lymphoblastic leukemia deteriorated despite resolution of neutropenia and appropriate antifungal treatment. Monocyte human leukocyte antigen-DR expression was extremely low, suggesting immunoparalysis. Adjuvant immunotherapy with interferon-gamma restored the immune response, which was accompanied by clinical and radiographic recovery.

Multilocus microsatellite markers for molecular typing of Candida tropicalis isolates

Background

Candida tropicalis is considered to be the leading pathogen causing nosocomial fungemia and hepatosplenic fungal infections in patients with cancer, particularly those with leukemia. Microsatellite-based typing methods using sets of genetic markers have been developed and reported for population structure analysis of C. albicans, C. glabrata, and C. parapsilosis, but no studies have been published for genetic analysis of C. tropicalis. The objective of this study was to develop new microsatellite loci that have the ability to distinguish among C. tropicalis isolates.

Results

DNA sequences containing over 10 bi- or tri-nucleotide repeats were selected from the C. tropicalis genome database. Thirty PCR primers sets specific for the microsatellite loci were designed and tested using eight clinically independent isolates. According to the amplification efficiency, specificity, and observed polymorphisms, eight markers were selected for further population structure analysis and molecular typing. Sixty-five independent C. tropicalis isolates were genotyped using these 8 markers. Based on these analyses, six microsatellite loci were confirmed, although two loci were found to be with unstable flanking areas. The six polymorphic loci displayed 4–22 alleles and 7–27 genotypes. The discriminatory power of the six loci ranged from 0.70 to 0.95. Genotyping results obtained by microsatellite analysis were compared to PCR-fingerprinting and multi-locus sequence typing (MLST). The comparisons showed that microsatellite analysis and MLST had the similar discriminatory power for C. tropicalis, which were more powerful than PCR-fingerprinting.

Conclusions

This is the first attempt to develop new microsatellite loci for C. tropicalis. These newly developed markers will be a valuable resource for the differentiation of C. tropicalis isolates. More C. tropicalis isolates will need to be sequenced and analyzed in order to fully show the potential of these newly developed microsatellite markers.

Candidaemia observed at a university hospital in Milan (northern Italy) and review of published studies from 2010 to 2014

BACKGROUND

Candida species represent the fourth leading cause of nosocomial bloodstream infections (BSI) worldwide. However, candidaemia rates and species involved vary geographically.

OBJECTIVES

To evaluate the epidemiological pattern, risk factors for mortality and antifungal therapy of Candida BSI over a 5-year period (2008-2012) in a university hospital in northern Italy together with a review of the recent literature concerning candidaemia.

METHODS

A retrospective cohort study cross-linked with microbiology database was performed.

RESULTS

A total of 89 Candida BSI were identified in 42 males (47 %) and 47 females (52.8 %). The median age was 69 years (interquartile range 55-78) with 61.8 % of patients being older than 65 years. Considering all hospitalized patients, the overall incidence rate of candidaemia increased significantly from 2008 to 2012 (from 0.4 to 1.68 episodes per 10,000 patient/days) (p = 0.0001) with a mean linear increase in 5 new cases per year. Candida albicans was the predominant species isolated (64 %) followed by C. glabrata (19.1 %). The latter species was observed with significantly higher frequency in Internal Medicine and Intensive Care Units (ICU). In-hospital crude mortality was 41.6 %.

CONCLUSIONS

Candidaemia is an increasing BSI in our university hospital, in accordance with that observed in northern Italy, and it is still associated with high in-hospital crude mortality.

Species distribution and in vitro antifungal susceptibility profiles of yeast isolates from invasive infections during a Portuguese multicenter survey

This is the first Portuguese multicenter observational and descriptive study that provides insights on the species distribution and susceptibility profiles of yeast isolates from fungemia episodes. Ten district hospitals across Portugal contributed by collecting yeast isolates from blood cultures and answering questionnaires concerning patients' data during a 12-month period. Molecular identification of cryptic species of Candida parapsilosis and C. glabrata complex was performed. The susceptibility profile of each isolate, considering eight of the most often used antifungals, was determined. Both Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) protocols were applied. The incidence of 240 episodes of fungemia was 0.88/1,000 admissions. Fifteen different species were found, with C. albicans (40 %) being the most prevalent, followed by C. parapsilosis (23 %) and C. glabrata (13 %). Most isolates were recovered from patients admitted to surgical wards or intensive care units, with 57 % being males and 32 % aged between 41 and 60 years. For both the CLSI and EUCAST protocols, the overall susceptibility rates ranged from 74 to 97 % for echinocandins and from 84 to 98 % for azoles. Important resistance rate discrepancies between protocols were observed in C. albicans and C. glabrata for echinocandins and in C. parapsilosis and C. tropicalis for azoles. Death associated with fungemia occurred in 25 % of the cases, with more than half of C. glabrata infections being fatal. The great number of Candida non-albicans is noteworthy despite a relatively low antifungal resistance rate. Studies like this are essential in order to improve empirical treatment guidelines.

Caspofungin at catheter lock concentrations eradicates mature biofilms of Candida lusitaniae and Candida guilliermondii

The antibiofilm activities of caspofungin, anidulafungin, micafungin, and liposomal amphotericin B were studied against Candida lusitaniae, Candida guilliermondii, and a Candida albicans control strain. While anidulafungin and micafungin (0.007 to 2,048 mg/liter) showed reduced activity against biofilms of both test species, caspofungin displayed concentration-dependent antibiofilm activity, reaching complete and persistent eradication at concentrations achievable during lock therapy (512 to 2,048 mg/liter, P < 0.05). Although liposomal amphotericin B strongly inhibited mature biofilms, it possessed lower antibiofilm activity than caspofungin (P < 0.05).

Epidemiology and risk factors for invasive candidiasis

The number of immunosuppressive patients has increased significantly in recent years. These patients are at risk for opportunistic infections, especially fungal infections. Candidiasis is one of the most frequent fungal infections determined in these immunosuppressive patients and its epidemiology has changed over the last two decades. Recently, new antifungal agents and new therapy strategies such as antifungal prophylaxis, secondary prophylaxis, and preemptive therapy have come into use. These changes resulted in the alteration of Candida species causing invasive infections. The incidence of Candida albicans was decreased in many countries, especially among patients with immunosuppressive disorders, while the incidence of species other than C. albicans was increased. In this review, incidence, risk factors, and species distribution of invasive candidiasis are discussed.

Antifungal step-down therapy based on hospital intravenous to oral switch policy and susceptibility testing in adult patients with candidaemia: a single centre experience

AIMS

Echinocandins are recommended for the treatment of candidaemia in moderately severe to severely ill patients. Step-down or de-escalation from echinocandin to fluconazole is advised in patients who are clinically stable but data in relation to step-down therapy are sparse. Using our hospital intravenous to oral switch therapy (IVOST) policy to guide antifungal de-escalation in patients with candidaemia, we aimed to determine what proportion of patients are de-escalated to fluconazole, the timescale to step-down, associated reduction in consumption of echinocandins and antifungal cost savings.

METHODOLOGY

Patients with candidaemia were followed from April 2011 to March 2013.

RESULTS

A total of 37 episodes of candidaemia were documented during the study period. Twenty-seven patients were commenced on an echinocandin or voriconazole and 19 (70.3%) were de-escalated to fluconazole based on the IVOST policy. The mean and median number of days to de-escalation of therapy was 4.6 and 5 days, respectively. One patient whose therapy was de-escalated relapsed. The overall 30 day crude mortality was 37.1%. The step-down approach led to significant saving in antifungal drug cost of £1133.88 per candidaemic episode and £2208.08 per de-escalation.

CONCLUSION

Implementation of IVOST policy led to streamlining of antifungal therapy.

Epidemiology of candidemia in Qatar, the Middle East: performance of MALDI-TOF MS for the identification of Candida species, species distribution, outcome, and susceptibility pattern

INTRODUCTION

Bloodstream infections (BSIs) due to Candida spp. constitute the predominant group of hospital-based fungal infections worldwide. A retrospective study evaluated the performance of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the identification of BSI Candida isolates. The epidemiology, risk factors, demographic features, species distribution, and clinical outcome associated with candidemia in patients admitted to a single tertiary-care hospital in Qatar, were analyzed.

METHODS

A single-center, retrospective analysis covering the period from January 1, 2004 to December 31, 2010 was performed. Molecular identification used sequence analysis of the D1/D2 domains of the large subunit ribosomal DNA (LSU rDNA) and the ITS1/2 regions of the rDNA. MALDI-TOF MS-based identification of all yeast isolates was performed with the ethanol/formic acid extraction protocol according to Bruker Daltonics (Bremen, Germany). The susceptibility profiles of 201 isolates to amphotericin B, itraconazole, fluconazole, voriconazole, anidulafungin, caspofungin, posaconazole, and isavuconazole were tested using CLSI standard broth microdilution method (M27-A3 and M27 S4) guidelines. Statistical analyses were performed with the statistical package SPSS 19.0.

RESULTS

A total of 187 patients with 201 episodes of candidemia were identified. Candida albicans was the most common species isolated (33.8 %; n = 68), whereas non-albicans Candida species represented 66.2 % (n = 133) of the episodes. The species distribution and outcome of candidemia showed a difference in the crude mortality between patients infected with C. albicans (n = 30; 45.5 %) and non-albicans Candida species. For example, C. parapsilosis candidemia was associated with the lowest mortality rate (40.6 %), and patients with other non-albicans species had the highest mortality rate (68-71.4 %). High mortality rates were observed among pediatric (<1 year of age) and elderly patients (>60 years of age). All strains showed low minimum inhibitory concentrations (MICs) (MIC90 of 0.063 μg/ml) to isavuconazole. The overall resistance to voriconazole in vitro antifungal activity was 2.5 %. C. glabrata (n = 38) had an MIC90 of 8 μg/ml for fluconazole. Most yeast isolates were susceptible to anidulafungin (>99.5 %) and 81.1 % to caspofungin. Resistance to anidulafungin was detected in 1/8 (12.5 %) isolates of C. orthopsilosis. According to new Clinical and Laboratory Standards Institute (CLSI) breakpoints, C. glabrata (n = 38) showed 100 % resistance, and 37/68 (54.4 %) C. albicans isolates were susceptible dose dependent (SDD) to caspofungin. Identification by MALDI-TOF MS was in 100 % concordance with molecular identification.

CONCLUSION

The Middle East epidemiology of candidemia has a unique species distribution pattern distinct from other parts of the globe. High mortality rates were observed among pediatric (<1 year of age) and elderly patients (>60 years of age). All strains were susceptible to isavuconazole. All isolates of C.glabrata were resistant to caspofungin based on M27 S4. MALDI-TOF MS is a highly useful method for the routine identification of yeast isolates in clinical setting to achieve successful therapeutic treatment.

Candida species distribution and antifungal susceptibility testing according to European Committee on Antimicrobial Susceptibility Testing and new vs. old Clinical and Laboratory Standards Institute clinical breakpoints: a 6-year prospective candidaemia survey from the fungal infection network of Switzerland

We analyzed the species distribution of Candida blood isolates (CBIs), prospectively collected between 2004 and 2009 within FUNGINOS, and compared their antifungal susceptibility according to clinical breakpoints defined by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) in 2013, and the Clinical and Laboratory Standards Institute (CLSI) in 2008 (old CLSI breakpoints) and 2012 (new CLSI breakpoints). CBIs were tested for susceptiblity to fluconazole, voriconazole and caspofungin by microtitre broth dilution (Sensititre® YeastOne™ test panel). Of 1090 CBIs, 675 (61.9%) were C. albicans, 191 (17.5%) C. glabrata, 64 (5.9%) C. tropicalis, 59 (5.4%) C. parapsilosis, 33 (3%) C. dubliniensis, 22 (2%) C. krusei and 46 (4.2%) rare Candida species. Independently of the breakpoints applied, C. albicans was almost uniformly (>98%) susceptible to all three antifungal agents. In contrast, the proportions of fluconazole- and voriconazole-susceptible C. tropicalis and F-susceptible C. parapsilosis were lower according to EUCAST/new CLSI breakpoints than to the old CLSI breakpoints. For caspofungin, non-susceptibility occurred mainly in C. krusei (63.3%) and C. glabrata (9.4%). Nine isolates (five C. tropicalis, three C. albicans and one C. parapsilosis) were cross-resistant to azoles according to EUCAST breakpoints, compared with three isolates (two C. albicans and one C. tropicalis) according to new and two (2 C. albicans) according to old CLSI breakpoints. Four species (C. albicans, C. glabrata, C. tropicalis and C. parapsilosis) represented >90% of all CBIs. In vitro resistance to fluconazole, voriconazole and caspofungin was rare among C. albicans, but an increase of non-susceptibile isolates was observed among C. tropicalis/C. parapsilosis for the azoles and C. glabrata/C. krusei for caspofungin according to EUCAST and new CLSI breakpoints compared with old CLSI breakpoints.

Six-year trend analysis of nosocomial candidemia and risk factors in two intensive care hospitals in Mato Grosso, midwest region of Brazil

We conducted this cross-sectional retrospective study using clinical and laboratory data from two tertiary hospitals in Cuiabá, Mato Grosso, Brazil, in order to explore the risk factors and estimate mortality, prevalence and lethality of candidemia between 2006 and 2011. A total of 130 episodes of candidemia were identified. The prevalence of candidemia was 1.8 per 1,000 admissions, the mortality rate was 0.9 per 1,000 admissions, and the lethality was 49.2 %. The main agent in this population was Candida parapsilosis (n = 50), followed by C. albicans (n = 45). Comparison between the numbers of episodes in the two triennia revealed that the non-albicans group grew by 48.2 %. The distribution of yeast species of Candida per hospital unit revealed that C. albicans was more prevalent than C. parapsilosis in the adult ICU and C. parapsilosis was more prevalent than C. albicans in the neonatal ICU. Patients remained hospitalized for an average of 53.5 days. Central venous catheters, parenteral nutrition and age were the variables that proved to be independent in the multivariate analysis and that maintained a statistically significant association with the incidence of death in patients with candidemia. The annual prevalence of candidemia showed a significant increase in the second triennium (2009-2011) compared with the first (2006-2008) probably due to increased exposure to risk factors: central venous catheter, H2 blockers, nutrition parenteral corticosteroids and mean hospital duration.

Epidemiology of candidemia in Latin America: a laboratory-based survey

Background

The epidemiology of candidemia varies depending on the geographic region. Little is known about the epidemiology of candidemia in Latin America.

Methods

We conducted a 24-month laboratory-based survey of candidemia in 20 centers of seven Latin American countries. Incidence rates were calculated and the epidemiology of candidemia was characterized.

Results

Among 672 episodes of candidemia, 297 (44.2%) occurred in children (23.7% younger than 1 year), 36.2% in adults between 19 and 60 years old and 19.6% in elderly patients. The overall incidence was 1.18 cases per 1,000 admissions, and varied across countries, with the highest incidence in Colombia and the lowest in Chile. Candida albicans (37.6%), C. parapsilosis (26.5%) and C. tropicalis (17.6%) were the leading agents, with great variability in species distribution in the different countries. Most isolates were highly susceptible to fluconazole, voriconazole, amphotericin B and anidulafungin. Fluconazole was the most frequent agent used as primary treatment (65.8%), and the overall 30-day survival was 59.3%.

Conclusions

This first large epidemiologic study of candidemia in Latin America showed a high incidence of candidemia, high percentage of children, typical species distribution, with C. albicans, C. parapsilosis and C. tropicalis accounting for the majority of episodes, and low resistance rates.

Analysis of the clonality of Candida tropicalis strains from a general hospital in Beijing using multilocus sequence typing

Multilocus sequence typing (MLST) based on six loci was used to analyze the relationship of 58 Candida tropicalis isolates from individual patients in a general hospital in Beijing, China. A total of 52 diploid sequence types (DSTs) were generated by the MLST, all of which were new to the central database. Unweighted Pair Group Method with Arithmetic Mean (UPGMA) dendrograms were constructed, which showed that the 58 isolates were distributed robustly and 6 main groups were clustered regardless of the specimen source and medical department. The minimum spanning tree (MST) of the 58 isolates (52 DSTs) and all 401 isolates (268 DSTs) in the C. tropicalis central database (http://pubmlst.org/ctropicalis/) indicated that the isolates in this study clustered in three relative pure clonal complexes, and 2 clustered with isolates from Taiwan, Belgium, Brazil, and the US. This study presents the first MLST analysis of C. tropicalis isolates from Mainland China, which may be useful for further studies on the similarity, genetic relationship, and molecular epidemiology of C. tropicalis strains worldwide.

Prevention and management of central line-associated bloodstream infections in hospital practice

In this article aimed at hospitalists, we examine the literature on preventive measures for central line-associated bloodstream infections (CLABSIs) and optimal management once a CLABSI has been established. We focus on a number of core preventive measures and the contemporary approach of bundling these measures for maximal impact in reducing infection rates. We then discuss empiric and pathogen-specific antibiotic therapy, including the role of newer antimicrobial agents, as well as the management of an infected central venous catheter.