Epidemiology and predictors of mortality in cases of Candida bloodstream infection: results from population-based surveillance, barcelona, Spain, from 2002 to 2003

Antifungal drug resistance among Candida species: mechanisms and clinical impact

The epidemiology of Candida infections has changed in recent years. Although Candida albicans is still the main cause of invasive candidiasis in most clinical settings, a substantial proportion of patients is now infected with non-albicans Candida species. The various Candida species vary in their susceptibility to the most commonly used antifungal agents, and the intrinsic resistance to antifungal therapy seen in some species, along with the development of acquired resistance during treatment in others, is becoming a major problem in the management of Candida infection. A better understanding of the mechanisms and clinical impact of antifungal drug resistance is essential for the efficient treatment of patients with Candida infection and for improving treatment outcomes. Herein, we report resistance to the azoles and echinocandins among Candida species.

Comparison of E,E-Farnesol Secretion and the Clinical Characteristics of Candida albicans Bloodstream Isolates from Different Multilocus Sequence Typing Clades

Using multilocus sequence typing (MLST), Candida albicans can be subdivided into 18 different clades. Farnesol, a quorum-sensing molecule secreted by C. albicans, is thought to play an important role in the development of C. albicans biofilms and is also a virulence factor. This study evaluated whether C. albicans bloodstream infection (BSI) strains belonging to different MLST clades secrete different levels of E,E-farnesol (FOH) and whether they have different clinical characteristics. In total, 149 C. albicans BSI isolates from ten Korean hospitals belonging to clades 18 (n = 28), 4 (n = 23), 1 (n = 22), 12 (n = 17), and other clades (n = 59) were assessed. For each isolate, the FOH level in 24-hour biofilms was determined in filtered (0.45 μm) culture supernatant using high-performance liquid chromatography. Marked differences in FOH secretion from biofilms (0.10–6.99 μM) were observed among the 149 BSI isolates. Clade 18 isolates secreted significantly more FOH than did non-clade 18 isolates (mean ± SEM; 2.66 ± 0.22 vs. 1.69 ± 0.10 μM; P < 0.001). Patients with isolates belonging to clade 18 had a lower mean severity of illness than other patients, as measured using the “acute physiology and chronic health evaluation” (APACHE) III score (14.4 ± 1.1 vs. 18.0 ± 0.7; P < 0.05). This study provides evidence that C. albicans BSI isolates belonging to the most prevalent MLST clade (clade 18) in Korea are characterized by increased levels of FOH secretion and less severe illness.

Epidemiology, risk factor, species distribution, antifungal resistance and outcome of Candidemia at a single French hospital: a 7-year study

Candidemia remains a major cause of disease worldwide and is associated with a high mortality rate. We conducted a retrospective study of candidemia at Nantes Hospital, France, between 2004 and 2010. A total of 191 episodes (n = 188 patients) were reviewed. Incidence, demographics, risk factors, antifungal management, species identification, in vitro susceptibility and 12 weeks survival were analysed. Global incidence of candidemia was 0.37‰ admissions. Higher incidences were observed in haematology (6.65‰) and intensive care units (2‰). Central venous catheter and antibiotic exposure were the most frequent risk factors (77% and 76% respectively). Candida albicans was the predominant species (51.8%) followed by C. parapsilosis (14.5%), C. glabrata (9.8%), C. tropicalis (9.8%) and C. krusei (4.1%). However, species distribution differed significantly between medical units with frequency of C. tropicalis being higher in haematology compared to other medical units. Fluconazole and caspofungin were the main antifungals given as first-line therapy. Although not significant, 12 weeks mortality rate was 30.9%, being higher for C. tropicalis (44.4%) than for C. parapsilosis (16%). Acquired azole or echinocandin resistance was noted in some isolates, underlining the need for systematic antifungal susceptibility testing in patients with candidemia. These epidemiological findings will be of interest for antifungal stewardship at our hospital.

Distribution and antifungal susceptibility of Candida species in patients with increased risk for fungal infections

Candida species are opportunistic yeasts that can be a serious threat for immunocompromised and critically ill patients, and a cause for increased morbidity and mortality in hospitalized patients. The aim of this study was to determine the frequency and distribution of different Candida species in clinical specimens in patients with increased risk for fungal infections, and to determine the antifungal susceptibility profile of invasive Candida species to antifungal agents. During a two year period, clinical specimens from 120 patients divided into 4 groups were analysed at the Institute of microbiology and parasitology, Faculty of Medicine, Skopje, Republic of Macedonia. Each of these 4 groups consisted of specimens from 30 patients, with primary immune deficiency, critically ill patients treated in the intensive care units (ICU), patients with mucosal candidiasis only, and patients with cystic fibrosis. All specimens were investigated with conventional mycological methods. Identification of Candida species was performed with VITEK-2 system (bioMérieux, France). E-test strips of fluconazole, voriconazole, amphotericin B and caspofungin (AB bioMerieux, France) were used for determination of the antifungal susceptibility profile. In this study, a total of 115 isolates of Candida species were confirmed in different clinical specimens (91 isolates from mucosal surfaces and 24 isolates from blood culture). Colonisation of mucosal membranes of gastrointestinal, respiratory and/or urinary tracts was registered in 56.67% (17/30), 56.67% (17/30), 90% (27/30) and 100% (30/30) of the specimens in the first, second, third and fourth group respectively. In all four groups of patients, the following Candida species were confirmed: C. albicans - 55%, C. glabrata - 17.6%, C. parapsilosis - 7.7%, C. tropicalis - 6.6%, unidentified Candida species - 4.4%, C. dubliniensis - 3.3%, C. kefyr - 2.2%, and one isolate of C. rugosa, C. pelliculosa and C. krusei each. Positive blood culture was registered in 23.33% specimens from the first group, 43.33% in the second group, 23.08% of the third group, and in one specimen of the fourth group. The most frequent isolates from blood culture were C. tropicalis and C. krusei, followed by C. albicans, C. parapsilosis and C. tropicalis, and in the second group C. albicans and C. pelliculosa were equally distributed, followed by C. parapsilosis and C. glabrata. All invasive isolates of Candida species were susceptible to amphotericin B, voriconazole and caspofungin. Resistance to fluconazole was registered in 8.3% (2/24) of all confirmed Candida species. Dose-dependent susceptibility to fluconazole was confirmed in 46% (11/24) of the isolates. Our study confirms high prevalence of colonisation and candidemia with non-albicans Candida species. Resistance to antifungal agents was registered only in two isolates of C. krusei. An epidemiological study is necessary for surveillance of dynamics of candidemia and antifungal susceptibility profile of invasive isolates of Candida species in our patients.

Novel strategies against Candida biofilms: interest of synthetic compounds

A biofilm is a consortium of microbial cells that are attached to a substratum or an interface. It should be considered a reservoir that may induce serious infections. Indeed, Candidaspp. biofilms may be involved in the persistence or worsening of some chronic inflammatory diseases as well as in systemic infections, which may lead to high morbidity and mortality rates. New strategies are currently being explored, utilizing several synthetic compounds to prevent or fight these Candida biofilms. This article focuses on active synthetic compounds classified with regards to their modes of action: inhibition of early adherence phase, inhibition or control of biofilm maturation and finally elimination of already formed biofilms. Some of them show promise in fighting biofilm.

Candida albicans Shaving to Profile Human Serum Proteins on Hyphal Surface

Candida albicans is a human opportunistic fungus and it is responsible for a wide variety of infections, either superficial or systemic. C. albicans is a polymorphic fungus and its ability to switch between yeast and hyphae is essential for its virulence. Once C. albicans obtains access to the human body, the host serum constitutes a complex environment of interaction with C. albicans cell surface in bloodstream. To draw a comprehensive picture of this relevant step in host-pathogen interaction during invasive candidiasis, we have optimized a gel-free shaving proteomic strategy to identify both, human serum proteins coating C. albicans cells and fungi surface proteins simultaneously. This approach was carried out with normal serum (NS) and heat inactivated serum (HIS). We identified 214 human and 372 C. albicans unique proteins. Proteins identified in C. albicans included 147 which were described as located at the cell surface and 52 that were described as immunogenic. Interestingly, among these C. albicans proteins, we identified 23 GPI-anchored proteins, Gpd2 and Pra1, which are involved in complement system evasion and 7 other proteins that are able to attach plasminogen to C. albicans surface (Adh1, Eno1, Fba1, Pgk1, Tdh3, Tef1, and Tsa1). Furthermore, 12 proteins identified at the C. albicans hyphae surface induced with 10% human serum were not detected in other hypha-induced conditions. The most abundant human proteins identified are involved in complement and coagulation pathways. Remarkably, with this strategy, all main proteins belonging to complement cascades were identified on the C. albicans surface. Moreover, we identified immunoglobulins, cytoskeletal proteins, metabolic proteins such as apolipoproteins and others. Additionally, we identified more inhibitors of complement and coagulation pathways, some of them serpin proteins (serine protease inhibitors), in HIS vs. NS. On the other hand, we detected a higher amount of C3 at the C. albicans surface in NS than in HIS, as validated by immunofluorescence.

Consumption of systemic antifungal agents among acute care hospitals in Catalonia (Spain), 2008-2013

Objective To know the patterns and consumption trends (2008-2013) of antifungal agents for systemic use in 52 acute care hospitals affiliated to VINCat Program in Catalonia (Spain). Methods Consumption was calculated in defined daily doses (DDD)/100 patient-days and analyzed according to hospital size and complexity and clinical departments. Results Antifungal consumption was higher in intensive care units (ICU) (14.79) than in medical (3.08) and surgical departments (1.19). Fluconazole was the most consumed agent in all type of hospitals and departments. Overall antifungal consumption increased by 20.5%during the study period (p = 0.066); a significant upward trend was observed in the consumption of both azoles and echinocandins. In ICUs, antifungal consumption increased by 12.4% (p = 0.019). Conclusions The study showed a sustained increase in the overall consumption of systemic antifungals in a large number of acute care hospitals of different characteristics in Catalonia. In ICUs there was a trend towards the substitution of older agents by the new ones.

Cost-effectiveness of three echinocandins and fluconazole in the treatment of candidemia and/or invasive candidiasis in nonneutropenic adult patients

OBJECTIVE

To estimate the cost-effectiveness of three echinocandins (anidulafungin, caspofungin, and micafungin) and generic fluconazole in the treatment of nonneutropenic adult patients with candidemia and/or invasive candidiasis in intensive care units in Spain.

MATERIALS AND METHODS

A decision-tree model was applied. The success and safety (hepatic and renal adverse effects) of first-line treatments were obtained from meta-analyses and systematic reviews of clinical trials. In the case of failure, a second-line treatment (liposomal amphotericin B after the echinocandins, or one of the echinocandins after fluconazole) was administered. The duration of the treatments (14 days total) was established by a panel of clinical experts using the Delphi method and according to Infectious Diseases Society of America guidelines. The cost of the medications and renal toxicity were considered. Deterministic and probabilistic sensitivity analysis using Monte Carlo simulations were carried out.

RESULTS

The total cost of the treatment of candidemia and/or invasive candidiasis with anidulafungin, caspofungin, micafungin, and fluconazole was €5,483, €5,968, €6,231, and €2,088, respectively. Anidulafungin was the dominant treatment (more effective, less expensive) compared to micafungin and caspofungin. The cost of achieving one more patient successfully treated with anidulafungin, caspofungin, and micafungin compared to fluconazole was €17,199, €23,962, and €27,339, respectively. The result remained stable, despite modification of the duration of the first-line and second-line treatments, as well as most of the dosing regimens. The probabilistic analysis also remained stable.

CONCLUSION

In accordance with this economic study, anidulafungin would produce savings and would be the dominant treatment compared with micafungin and caspofungin in nonneutropenic adult patients with candidemia and/or invasive candidiasis in intensive care units in Spain.

Candida parapsilosis Resistance to Fluconazole: Molecular Mechanisms and In Vivo Impact in Infected Galleria mellonella Larvae

Candida parapsilosis is the main non-albicans Candida species isolated from patients in Latin America. Mutations in the ERG11 gene and overexpression of membrane transporter proteins have been linked to fluconazole resistance. The aim of this study was to evaluate the molecular mechanisms in fluconazole-resistant strains of C. parapsilosis isolated from critically ill patients. The identities of the nine collected C. parapsilosis isolates at the species level were confirmed through molecular identification with a TaqMan qPCR assay. The clonal origin of the strains was checked by microsatellite typing. The Galleria mellonella infection model was used to confirm in vitro resistance. We assessed the presence of ERG11 mutations, as well as the expression of ERG11 and two additional genes that contribute to antifungal resistance (CDR1 and MDR1), by using real-time quantitative PCR. All of the C. parapsilosis (sensu stricto) isolates tested exhibited fluconazole MICs between 8 and 16 μg/ml. The in vitro data were confirmed by the failure of fluconazole in the treatment of G. mellonella infected with fluconazole-resistant strains of C. parapsilosis. Sequencing of the ERG11 gene revealed a common mutation leading to a Y132F amino acid substitution in all of the isolates, a finding consistent with their clonal origin. After fluconazole exposure, overexpression was noted for ERG11, CDR1, and MDR1 in 9/9, 9/9, and 2/9 strains, respectively. We demonstrated that a combination of molecular mechanisms, including the presence of point mutations in the ERG11 gene, overexpression of ERG11, and genes encoding efflux pumps, are involved in fluconazole resistance in C. parapsilosis.

Nosocomial Candidiasis: Antifungal Stewardship and the Importance of Rapid Diagnosis

Candidemia and other forms of candidiasis are associated with considerable excess mortality and costs. Despite the addition of several new antifungal agents with improved spectrum and potency, the frequency of Candida infection and associated mortality have not decreased in the past two decades. The lack of rapid and sensitive diagnostic tests has led to considerable overuse of antifungal agents resulting in increased costs, selection pressure for resistance, unnecessary drug toxicity, and adverse drug interactions. Both the lack of timely diagnostic tests and emergence of antifungal resistance pose considerable problems for antifungal stewardship. Whereas antifungal stewardship with a focus on nosocomial candidiasis should be able to improve the administration of antifungal therapy in terms of drug selection, proper dose and duration, source control and de-escalation therapy, an important parameter, timeliness of antifungal therapy, remains a victim of slow and insensitive diagnostic tests. Fortunately, new proteomic and molecular diagnostic tools are improving the time to species identification and detection. In this review we will describe the potential impact that rapid diagnostic testing and antifungal stewardship can have on the management of nosocomial candidiasis.

In vitro activity of essential oils extracted from condiments against fluconazole-resistant and -sensitive Candida glabrata

In the present study, the antifungal activity of essential oils obtained from Origanum vulgare (oregano), Cinnamomum zeylanicum (cinnamon), Lippia graveolens (Mexican oregano), Thymus vulgaris (thyme), Salvia officinalis (sage), Rosmarinus officinalis (rosemary), Ocimum basilicum (basil) and Zingiber officinale (ginger) were assessed against Candida glabrata isolates. One group contained 30 fluconazole-susceptible C. glabrata isolates, and the second group contained fluconazole-resistant isolates derived from the first group after the in vitro induction of fluconazole-resistance, for a total of 60 tested isolates. The broth microdilution methodology was used. Concentrations of 50μg/mL, 100μg/mL, 200μg/mL, 400μg/mL, 800μg/mL, 1600μg/mL and 3200μg/mL of the essential oils were used, and the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined. Thyme, sage, rosemary, basil and ginger essential oils showed no antifungal activity at the tested concentrations. Antimicrobial activity less than or equal to 3200μg/mL was observed for oregano, Mexican oregano and cinnamon essential oils. Both the oregano and Mexican oregano essential oils showed high levels of antifungal activity against the fluconazole-susceptible C. glabrata group, whereas the cinnamon essential oil showed the best antifungal activity against the fluconazole-resistant C. glabrata isolates.

Candida species epidemiology 2000-2013: a laboratory-based report

OBJECTIVE

To describe a prospective laboratory-based surveillance of Candida species that were collected from different anatomical sites of patients admitted to the University of Malaya Medical Centre, Malaysia, from the year 2000 to 2013.

METHODS

Conventional (culture, microscopic examination and carbohydrate assimilation test) and molecular (PCR amplification and DNA sequencing) techniques were used to identify Candida species.

RESULTS

A total of 16 Candida species isolated from 34 392 clinical samples were from the oral cavity (oral swabs and throat swabs), blood, respiratory tract (sputum, tracheal secretions, nasopharyngeal aspirates, bronchoalveolar lavage), high vaginal swab, pus and urine. C. albicans (66.70%, 22 941/34 392), C. glabrata (11.71%, 4029/34 392), C. parapsilopsis (10.74%, 3692/34 392), C. tropicalis (9.19%, 3162/34 392) and C. krusei (1.15%, 396/34 392) were the five predominant Candida species. C. albicans was the predominant species isolated from the oral cavity, respiratory tract and high vaginal swab; while the Candida species isolated from blood, urine and pus were predominant non-albicans Candida. Uncommon Candida species, such as C. lusitaniae, C. haemulonii, C. humicola, Pichia ohmeri and C. ciferrii, were also isolated in this study.

CONCLUSION

Our study expands the current knowledge of the epidemiology of non-invasive and invasive candidiasis in Malaysia. The variability of the Candida species distribution from different anatomical sites highlights the significance of local epidemiology in disease management and selection of antifungal agents.

Sensitive and rapid RT-qPCR quantification of pathogenic Candida species in human blood

For accurate diagnosis and appropriate treatment of candidiasis, we developed a highly sensitive quantitative RT-PCR (RT-qPCR) system for five Candida species that have been reported to be the major causes of bloodstream fungal infection (Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei), together with a system for all pathogenic Candida species. Cells of each fungal species spiked into human peripheral blood (PB) were specifically detected at a lower detection limit of 10(0) cell/1 mL PB by this system using the newly developed specific primer sets targeting 18S or 26S rRNA of the five Candida species, together with the existing group primer set. The total count of the five Candida spp. as the sum of those obtained by using the five species primer sets was equivalent to the count obtained by using the group primer set, indicating that the group set covered the major five Candida spp. in human blood with the same degree of accuracy as the species primer sets. The RT-qPCR counts of the Candida species were in good agreement with CFU counts obtained by their culture on CHROMagar™, with a lower detection limit of 10(0)cell/mL of PB. Candida rRNA molecules were stably stored for at least 7 days at 4°C by keeping the blood specimens in an RNA stabilizing reagent. These results strongly suggest that this sensitive system is useful for accurate and rapid diagnosis of Candida bloodstream infections.

Twenty-two years of candidaemia surveillance: results from a Norwegian national study

Several studies have reported an increased incidence of candidaemia and a redistribution of species, with a decrease in the number of Candida albicans isolates. In Norway, a prospective, national surveillance study of candidaemia has been ongoing since 1991. Data from the period 1991-2003 have been published previously. The aim of this study was to follow up the incidence, species distribution and antifungal susceptibility of Candida species isolates from blood cultures in the period 2004-2012, and compare them with the corresponding findings from the period 1991-2003. Blood culture isolates of Candida species from all medical microbiological laboratories in Norway were identified and susceptibility tested at the Norwegian Mycological Reference Laboratory. A total of 1724 isolates were recovered from 1653 patients in the period 2004-2012. Comparison of the two periods showed that the average incidence of candidaemia episodes per 100 000 inhabitants increased from 2.4 (1991-2003) to 3.9 (2004-2012). The increase in incidence in the latter period was significantly higher in patients aged >40 years (p 0.001), and a marked increase was observed in patients aged >60 years (p < 0.001). In conclusion, the average incidence in Norway over a period of 22 years modestly increased from 2.4 to 3.9 per 100,000 inhabitants, this being mainly accounted for by candidaemia in the elderly. The species distribution was stable, and the rate of acquired resistance was low.

Analysis of clinical and environmental Candida parapsilosis isolates by microsatellite genotyping--a tool for hospital infection surveillance

Candida parapsilosis emerged as an important opportunistic pathogen, causing candidaemia worldwide. Nosocomial outbreaks triggered by this species have been frequently described, particularly in cancer patients. For a better understanding of its epidemiology, several typing methods are used and microsatellite analysis has been reported as highly discriminant. The main objective of this work was to study C. parapsilosis isolates by application of microsatellite genotyping to distinguish epidemiologically related strains, compare clinical and environmental isolates and determine possible routes of dispersion of the isolates in the hospital setting. A total of 129 C. parapsilosis isolates from different origins, including hospital environment and hands of healthcare workers, were genotyped using four microsatellite markers. The isolates were recovered from different health institutions. Analysis of C. parapsilosis isolates from hospital environment showed great genotypic diversity; however, the same or very similar genotypes were also found. The same multilocus genotype was shared by isolates recovered from the hand of a healthcare worker, from the hospital environment and from patients of the same healthcare institution, suggesting that these could be possible routes of transmission and that infections due to C. parapsilosis may be mainly related with exogenous transmission to the patient. Examination of sequential isolates from the same patients showed that colonizing and bloodstream isolates had the same multilocus genotype in the majority of cases. We demonstrate that this typing method is able to distinguish clonal clusters from genetically unrelated genotypes and can be a valuable tool to support epidemiologic investigations in the hospital setting.

The Effect on mortality of fluconazole or echinocandins treatment in candidemia in internal medicine wards [corrected]

The incidence of candidemia has increased over the past two decades, with an increased number of cases in Internal Medicine and a prevalence ranging from 24% to 57%. This single-center retrospective study was performed to evaluate the epidemiology and the risk factors associated with mortality of candidemia in patients admitted to Internal Medicine wards (IMWs) of the City of Health and Sciences, Molinette Hospital, Turin, from January 2004 to December 2012. For each patient, demographic, clinical and microbiological data were collected. A case of candidemia was defined as a patient with at least one blood culture positive for Candida spp. Amongst 670 episodes of candidemia, 274 (41%) episodes occurred in IMWs. The mortality was 39% and was associated at multivariate analysis with sepsis, cirrhosis and neurologic diseases, whilst removal of central venous catheter ≤48h was significantly associated with survival. In the 77 patients treated with early antifungal therapy the mortality was 29% and was not significantly different with caspofungin or fluconazole, whilst in patients with definitive therapy the mortality was significantly lower with echinocandins compared to fluconazole (11.7% Vs. 39%; p=0.0289), a finding confirmed by multivariate analysis. The mortality was significantly associated with sepsis, cirrhosis and neurologic diseases, whilst CVC removal ≤48h was associated with survival. In patients with early therapy, fluconazole or caspofungin were equally effective. However, echinocandins were significantly more effective as definitive treatment, a finding not explained by differences in treatment delays. Further studies are needed to understand the full potential of these different therapeutic strategies in IMWs.

Susceptibility of Candida spp. isolated from blood cultures as evaluated using the M27-A3 and new M27-S4 approved breakpoints

The high mortality rates associated with candidemia episodes and the emergence of resistance to antifungal agents necessitate the monitoring of the susceptibility of fungal isolates to antifungal treatments. The new, recently approved, species-specific clinical breakpoints (SS-CBPs)(M27-S4) for evaluating susceptibility require careful interpretation and comparison with the former proposals made using the M27-A3 breakpoints, both from CLSI. This study evaluated the susceptibility of the different species of Candida that were isolated from candidemias based on these two clinical breakpoints. Four hundred and twenty-two isolates were identified and, among them, C. parapsilosis comprised 46.68%, followed by C. albicans (35.78%), C. tropicalis (9.71%), C. glabrata (3.55%), C. lusitaniae (1.65%), C. guilliermondii (1.65%) and C. krusei (0.94%). In accordance with the M27-A3 criteria, 33 (7.81%) non-susceptible isolates were identified, of which 16 (3.79%) were resistant to antifungal agents. According to SS-CBPs, 80 (18.95%) isolates were non-susceptible, and 10 (2.36%) of these were drug resistant. When the total number of non-susceptible isolates was considered, the new SS-CBPs detected 2.4 times the number of isolates that were detected using the M27-A3 interpretative criteria. In conclusion, the detection of an elevated number of non-susceptible species has highlighted the relevance of evaluating susceptibility tests using new, species-specific clinical breakpoints (SS-CBPs), which could impact the profile of non-susceptible Candida spp. to antifungal agents that require continuous susceptibility monitoring.

Clinico-microbiological study of candidemia in a tertiary care hospital of southern part of India

BACKGROUND AND OBJECTIVES

Over the last two decades, both the incidence of nosocomial candidaemia and the proportion of blood stream infection due to Candida spp. other than Candida albicans have increased. The aims of this study was to identify different species of Candida and risk factors associated with bloodstream infection and detection of biofilm production.

MATERIALS AND METHODS

This study was conducted in an 840 bedded tertiary care hospital, over a period of one year. All blood isolates received from patients during this period were screened for candidemia prospectively. Speciation was carried out by standard microbiological method. Biofilm production detection was done by Brachini et al method.

RESULT

A total of 80 cases of candidemia were identified. Most important risk factor was placement of vascular access devices in all the age groups. Candida albicans accounted for 22 isolates (27.5%) whereas non-albicans Candida spp. accounted for 58 isolates (72.5%). Biofilm production was found in 31 strains (38.75%). Biofilm production was seen more in non-albicans Candidaspp. (83.87%) especially in C. tropicalis (66.67%, 8 of 12).

CONCLUSIONS

Non-albicansspecies of Candida were most frequently recovered in our study. So, the epidemiology of Candida infection is changing. Non-albicans Candida spp have the capacity to produce significant amount of biofilm which may be the cause of their reduced susceptibility to antifungal agents.

Terminal-stage prognostic analysis in candidemia

BACKGROUND

Candidemia has an extremely high mortality rate but is not always the direct cause of death. Therefore, determining the effect of candidemia on death is extremely difficult.

METHODS

We investigated prognostic factors in patients with culture-proven candidemia at 2 Japanese university teaching hospitals from April 2009 through May 2013. To examine the effects of comorbid conditions, the Charlson comorbidity index was determined, and patients were subjectively classified into 3 clinical prognostic stages (terminal [death expected within 1 month], semiterminal [death expected within 6 months], and nonterminal [expected to live more than 6 months]). The Cox proportional hazard model was used for univariate and multivariate analyses of factors possibly affecting survival.

RESULTS

On univariate analysis, factors identified as associated with an increased mortality rate were: admission to an internal medicine department, Candida glabrata, immunosuppression, hypotension, hypoxemia, and a terminal prognostic stage. Factors associated with a decreased mortality rate were: serum albumin, endophthalmitis investigation, and nonterminal prognostic stage. The mortality rate was significantly related to the prognostic stage on multivariate analysis (P < 0.0001), was increased by age (P = 0.0014), and was decreased by a delayed start of antifungal therapy (P = 0.0374).

CONCLUSION

In contrast to earlier studies, the present study has found that later antifungal usage is associated with a decreased mortality rate in cases of candidemia. More important than candidemia in causing the deaths of patients with candidemia were the patients' background and comorbidity status. Therefore, rigorous methods should be used when investigating causes of death in terminally ill patients with candidemia.

Analysis of Independent Risk Factors for Death Among Pediatric Patients With Candidemia and a Central Venous Catheter in Place

Objective.

To use multivariate analysis to determine risk factors for death among pediatric patients with candidemia and a central venous catheter in place.

Design.

Retrospective cohort study conducted at Santa Casa Complexo Hospitalar, a 1,200-bed teaching hospital in southern Brazil.

Methods.

All cases of candidemia in pediatric patients (age, ≤ 13 years) at our medical center over a 9-year period were reviewed. A diagnosis of sepsis was required for inclusion in the study. Severity of illness was confirmed by the presence of hypotension requiring inotropes and according to the following scores: the Pediatric Risk of Mortality (PRISM) II score, the PRISM III score, and the Pediatric Logistic Organic Dysfunction score. The following 2 outcomes were evaluated: early death, defined as death occurring within 7 days after candidemia was diagnosed, and late death, defined as death 8-30 days after candidemia was diagnosed.

Results.

A total of 61 patients were included in the study, including 14 neonates. Most (63.9%) of these patients were girls, and the median age was 0.3 years. A total of 80.3% of candidemia cases were due to species other than Candida albicans, primarily Candida parapsilosis (32.8% of cases) and Candida tropicalis (24.6% of cases). Using multivariate analysis, we demonstrated that failure to remove the central venous catheter was an independent risk factor for early death among pediatric patients with candidemia. However, patients whose catheters were retained were sicker than patients whose catheters were removed, and catheter removal had no impact on late death. Instead, severity of illness determined using the PRISM III score was also an independent predictor of late death.

Conclusions.

Results from this study suggest that systematic removal of catheters from pediatric patients with candidemia does not reduce the occurrence of late death.

Extracellular DNA release confers heterogeneity in Candida albicans biofilm formation

Background

Biofilm formation by Candida albicans has shown to be highly variable and is directly associated with pathogenicity and poor clinical outcomes in patients at risk. The aim of this study was to test the hypotheses that the extracellular DNA release by C. albicans is strain dependent and is associated with biofilm heterogeneity.

Results

Initially, biofilm formed by C. albicans high biofilm formers (HBF) or low biofilm formers (LBF) were treated with DNase to find whether eDNA play a role in their biofilm formation. Digestion of biofilm eDNA significantly reduced the HBF biofilm biomass by five fold compared to untreated controls. In addition, quantification of eDNA over the period of biofilm formation by SYBR green assay demonstrate a significantly higher level of 2 to 6 fold in HBF compared to LBF. Biochemical and transcriptional analyses showed that chitinase activity and mRNA levels of chitinase genes, a marker of autolysis, were upregulated in 24 h biofilm formation by HBF compared to LBF, indicating autolysis pathway possibly involved in causing variation. The biofilm biomass and eDNA release by single (∆cht2, ∆cht3) and double knockout (∆cht2/∆cht3) chitinase mutants were significantly less compared to their parental strain CA14, confirming the role of chitinases in eDNA release and biofilm formation. Correlation analysis found a positive correlation between chitinases and HWP1, suggesting eDNA may release during the hyphal growth. Finally, we showed a combinational treatment of biofilms with DNase or chitinase inhibitor (acetazolamide) plus amphotericin B significantly improved antifungal susceptibility by 2 to 8 fold.

Conclusions

Collectively, these data show that eDNA release by C. albicans clinical isolates is variable and is associated with differential biofilm formation. Digestion of biofilm eDNA by DNase may provide a novel therapeutic strategies to destabilise biofilm growth and improves antifungal sensitivity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-014-0303-6) contains supplementary material, which is available to authorized users.

Catheter-related Candida bloodstream infection in intensive care unit patients: a subgroup analysis of the China-SCAN study

Background

In patients hospitalized in intensive care units (ICU), Candida infections are associated with increased morbidity, mortality and costs. However, previous studies reported confused risk factors for catheter-related Candida bloodstream infection (CRCBSI). The objective was to describe the risk factors, microbiology, management and outcomes of CRCBSI in the China-SCAN population.

Methods

Patients with ≥1 Candida-positive peripheral blood culture were selected from the China-SCAN study. Peripheral and catheter blood samples were collected for Candida isolation. Patients with the same strain of Candida in peripheral and catheter blood samples were considered as being with CRCBSI, while patients with Candida-positive peripheral blood cultures only or different strains were considered as non-CRCBSI. Data were collected from the China-SCAN study.

Results

CRCBSI incidence in ICU was 0.03% (29/96,060), accounting for 9.86% of all candidemia observed in ICU (29/294). The proportion of CRCBSI due to Candida parapsilosis reached 33.3%, more than that of Candida albicans (28.6%). In univariate analyses, older age (P = 0.028) and lower body weight (P = 0.037) were associated with CRCBSI. Multivariate analysis showed that the sequential organ failure assessment (SOFA) score was independently associated with CRCBSI (odds ratio (OR) = 1.142, 95% confidence interval = 1.049-1.244, P = 0.002). Catheter removal and immune enhancement therapy were often used for CRCBSI treatment.

Conclusions

In China, CRCBSI was more likely to occur in old patients with low body weight. SOFA score was independently associated with CRCBSI. Candida parapsilosis accounted for a high proportion of CRCBSI, but the difference from non-CRCBSI was not significant.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0594-0) contains supplementary material, which is available to authorized users.

Burden of serious fungal infections in Spain

Estimates of the incidence and prevalence of serious fungal infections, based on epidemiological data, are essential in order to inform public health priorities given the lack of resources dedicated to the diagnosis and treatment of these serious fungal diseases. However, epidemiology of these infections is largely unknown, except for candidaemia and cryptococcosis. The aim of this work is to calculate the burden of serious fungal infections in Spain. All published epidemiology papers reporting fungal infection rates from Spain were identified. Where no data existed, we used specific populations at risk and fungal infection frequencies in those populations to estimate national incidence or prevalence, depending on the condition. Around 8.1 million people suffer a fungal infection every year. Most of them are skin or mucosal infections causing no deaths. Candidaemia is more common than in other European countries and has risen by 1.88-fold in frequency in the last decade (8.1 cases × 100,000). Good estimates of invasive aspergillosis (2.75 cases × 100,000) and mucormycosis (0.04 × 100,000) are available. Fungal infections with a high mortality such as invasive aspergillosis, candidaemia, Pneumocystis pneumonia and mucormycosis are not numerous in Spain, but they affect those with severe underlying diseases and are therefore linked to poor outcomes. Additional studies are required, especially for high burden diseases such as recurrent thrush in women (∼9000 cases × 100,000 women), allergic bronchopulmonary aspergillosis (126 cases × 100,000) and severe asthma with fungal sensitisation (198 cases × 100,000).

Epidemiology and prognostic factors of candidemia in elderly patients

AIM

The present retrospective study was carried out to investigate the epidemiological characteristics and the prognostic factors of candidemia among elderly patients.

METHODS

From 2009 to 2012, elderly patients with candidemia were identified at the Chi Mei medical center, a 900-bed regional hospital in southern Taiwan, and their medical records retrospectively reviewed.

RESULTS

During the 4-year period, a total of 175 episodes of candidemia among elderly patients were identified. The patients ranged in age from 65 to 98 years (mean 76.4 years) and the mean (±standard deviation) Charlson Comorbidity Index score was 7.6 (±2.7). Cancer was the most common underlying disease (n = 127, 72.6%), followed by diabetes mellitus (n = 69, 39.4%). Candida albicans (n = 96, 54.9%) was the most common pathogen, followed by C. tropicalis (n = 39, 22.3%), C. parapsilosis (n = 24, 13.7%), C. glabrata (n = 22, 12.6%), C. guilliermondii (n = 2, 1.1%) and Candida species (n = 3, 1.7%). The ratio of C. albicans causing candidemia was significantly higher in young-old than old-old patients (64.1% vs 47.4%, P = 0.027). The overall in-hospital mortality was 50.3%. Multivariate analysis showed that the in-hospital mortality was only significantly associated with jaundice (P = 0.004), no use of antifungal agent (P = 0.021) and intensive care unit admission (P < 0.001).

CONCLUSIONS

Candidemia can develop in elderly patients, especially patients with cancer or other risk factors. C. albicans is the most common Candida species causing candidemia among elderly patients, followed by C. tropicalis. The mortality of candidemia among elderly patients remains high.

Clinical and epidemiological characteristics and risk factors for mortality in patients with candidemia in hospitals from Bogotá, Colombia

Background

Bloodstream infection by Candida species has a high mortality in Latin American countries. The aim of this study was to describe the characteristics of patients with documented bloodstream infections caused by Candida species in third level hospitals and determine the risk factors for in-hospital-mortality.

Methods

Patients from seven tertiary-care hospitals in Bogotá, Colombia, with isolation of a Candida species from a blood culture were followed prospectively from March 2008 to March 2009. Epidemiologic information, risk factors, and mortality were prospectively collected. Isolates were sent to a reference center, and fluconazole susceptibility was tested by agar-based E-test. The results of susceptibility were compared by using 2008 and 2012 breakpoints. A multivariate analysis was used to determinate risk factors for mortality.

Results

We identified 131 patients, with a median age of 41.2 years. Isolates were most frequently found in the intensive care unit (ICU). Candida albicans was the most prevalent species (66.4% of the isolates), followed by C. parapsilosis (14%). Fluconazole resistance was found in 3.2% and 17.6% of the isolates according to the 2008 and 2012 breakpoints, respectively. Fluconazole was used as empirical antifungal therapy in 68.8% of the cases, and amphotericin B in 22%. Hospital crude mortality rate was 35.9%. Mortality was associated with age and the presence of shock at the time of Candida detection. Fluconazole therapy was a protective factor for mortality.

Conclusions

Candidemia is associated with a high mortality rate. Age and shock increase mortality, while the use of fluconazole was shown to be a protective factor. A higher resistance rate with new breakpoints was noted.

Worrisome trends in incidence and mortality of candidemia in intensive care units (Paris area, 2002-2010)

Purpose

To analyze trends in incidence and mortality of candidemia in intensive care units (ICUs) vs. non-ICU hospitalized patients and to determine risk factors for infection by specific species and for death.

Methods

Active hospital-based surveillance program of incident episodes of candidemia due to common species in 24 tertiary care hospitals in the Paris area, France between October 2002 and September 2010.

Results

Among 2,507 adult cases included, 2,571 Candida isolates were collected and species were C. albicans (56 %), C. glabrata (18.6 %), C. parapsilosis (11.5 %), C. tropicalis (9.3 %), C. krusei (2.9 %), and C. kefyr (1.8 %). Candidemia occurred in ICU in 1,206 patients (48.1 %). When comparing ICU vs. non-ICU patients, the former had significantly more frequent surgery during the past 30 days, were more often preexposed to fluconazole and treated with echinocandin, and were less frequently infected with C. parapsilosis. Risk factors and age remained unchanged during the study period. A significant increased incidence in the overall population and ICU was found. The odds of being infected with a given species in ICU was influenced by risk factors and preexposure to fluconazole and caspofungin. Echinocandins initial therapy increased over time in ICU (4.6 % first year of study, to 48.5 % last year of study, p < 0.0001). ICU patients had a higher day-30 death rate than non-ICU patients (odds ratio [OR] 2.12; 95 % confidence interval [CI] 1.66–2.72; p < 0.0001). The day-30 and early (<day 8) death rates increased over time in ICU (from 41.5 % the first to 56.9 % the last year of study (p = 0.001) and 28.7–38.8 % (p = 0.0292), respectively). Independent risk factors for day-30 death in ICU were age, arterial catheter, Candida species, preexposure to caspofungin, and lack of antifungal therapy at the time of blood cultures results (p < 0.05).

Conclusions

The availability of new antifungals and the publication of numerous guidelines did not prevent an increase of candidemia and death in ICU patients in the Paris area.

Per-species risk factors and predictors of invasive Candida infections in patients admitted to pediatric intensive care units: development of ERICAP scoring systems

BACKGROUND

Prediction rules for invasive Candida infection (ICI) are available for adult but not for infants and children managed in pediatric intensive care units (PICU).

METHODS

Observational study in 24 PICU with prospective phase (all children admitted during 1 year) and retrospective review of ICI records. Four logistic regression models were performed using ICI by Candida spp., Candida albicans, Candida parapsilosis or Candida tropicalis as dependent variables. Scores were constructed.

RESULTS

One hundred and twenty five ICI (47 C. albicans, 37 C. parapsilosis, 19 C. tropicalis and 22 others) and 1022 controls were included. Incidence (cases/100 PICU admissions): 4.22 (all Candida), 2.44 (C. albicans), 1.41 (C. parapsilosis), 0.19 (C. tropicalis). ICI was associated [Area under the receiver operating characteristics curve (AUC) = 0.764, 95% confidence interval (CI) = 0.719-0.809, P < 0.001] with pre-PICU hospitalization ≥ 15 days [odds ratio (OR) = 3.3; score: +3], fever (OR = 2.6; +2), thrombopenia (OR = 2.0; +1) and parenteral nutrition (OR=2.4; +2). Additionally, the following associations were noted: C. albicans ICI (AUC = 0.716, 95% CI = 0.640-0.792, P < 0.001) with chronic metabolic disease (OR = 10.7; score:+4), surgical digestive process (OR = 2.8; +1), fever (OR = 2.8; +1) and parenteral nutrition (OR = 2.3; +1); C. parapsilosis ICI (AUC = 0.808, 95% CI = 0.739-0.877, P < 0.001) with previous colonization (OR = 7.1; score:+3), tracheostomy (OR = 5.1; +2), parenteral nutrition (OR = 4.3; +2), thrombopenia (OR = 3.6; +1) and previous bacterial infection (OR = 3.0; +1) and ICI by C. tropicalis (AUC = 0.941, 95% CI=0.886-0.995, P < 0.001) with thrombopenia (OR = 53.8; score: +10), neutropenia (OR = 7.2; +1), pre-PICU hospitalization ≥ 15 days (OR = 17.2; +3) and hematologic (OR = 22.4; +4) and cardiovascular infectious processes (OR = 5.5; +1). Specificity was >90% for cut offs of 5 (all Candida), 3 (C. albicans), 3 (C. parapsilosis) and 11 (C. tropicalis).

CONCLUSIONS

Once validated, these scores may help for identification of ICI by specific species allowing adequate empiric/prophylactic treatment.

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.

Analysis of the protein domain and domain architecture content in fungi and its application in the search of new antifungal targets

Over the past several years fungal infections have shown an increasing incidence in the susceptible population, and caused high mortality rates. In parallel, multi-resistant fungi are emerging in human infections. Therefore, the identification of new potential antifungal targets is a priority. The first task of this study was to analyse the protein domain and domain architecture content of the 137 fungal proteomes (corresponding to 111 species) available in UniProtKB (UniProt KnowledgeBase) by January 2013. The resulting list of core and exclusive domain and domain architectures is provided in this paper. It delineates the different levels of fungal taxonomic classification: phylum, subphylum, order, genus and species. The analysis highlighted Aspergillus as the most diverse genus in terms of exclusive domain content. In addition, we also investigated which domains could be considered promiscuous in the different organisms. As an application of this analysis, we explored three different ways to detect potential targets for antifungal drugs. First, we compared the domain and domain architecture content of the human and fungal proteomes, and identified those domains and domain architectures only present in fungi. Secondly, we looked for information regarding fungal pathways in public repositories, where proteins containing promiscuous domains could be involved. Three pathways were identified as a result: lovastatin biosynthesis, xylan degradation and biosynthesis of siroheme. Finally, we classified a subset of the studied fungi in five groups depending on their occurrence in clinical samples. We then looked for exclusive domains in the groups that were more relevant clinically and determined which of them had the potential to bind small molecules. Overall, this study provides a comprehensive analysis of the available fungal proteomes and shows three approaches that can be used as a first step in the detection of new antifungal targets.

Some fungi have become pathogenic to plants and in a lesser extent to animals. Under certain conditions their presence in the human body can prove a threat for human health, especially for immunocompromised patients. Yet, some fungi can also infect healthy individuals. The low sensitivity of the antifungal drugs available together with the clinically observed resistance of some fungi raises the demand for new alternative treatments. Proteins are biological molecules which perform essential functions within the living organisms. Many of those functions are attributed to the varying folded structure of each protein. These configurations are composed of functional units -also called domains- each one independently responsible for a fraction of the overall biological function. Understanding how the different block combinations are distributed across members of the same or similar families of organisms is important. For instance, exclusive domain combinations can hold particular acquired functions. Blocks displaying a high mobility can play major roles for the organism's survival. The biological goal of this study was to analyse the functional implications of protein domains and domain combinations in the available fungal proteomes. This information can be used to highlight proteins and pathways that could be potentially used as drug targets.

Impact of therapeutic strategies on the prognosis of candidemia in the ICU

OBJECTIVES

To determine the epidemiology of Candida bloodstream infections, variables influencing mortality, and antifungal resistance rates in ICUs in Spain.

DESIGN

Prospective, observational, multicenter population-based study.

SETTING

Medical and surgical ICUs in 29 hospitals distributed throughout five metropolitan areas of Spain.

PATIENTS

Adult patients (≥ 18 yr) with an episode of Candida bloodstream infection during admission to any surveillance area ICU from May 2010 to April 2011.

INTERVENTIONS

Candida isolates were sent to a reference laboratory for species identification by DNA sequencing and susceptibility testing using the methods and breakpoint criteria promulgated by the European Committee on Antimicrobial Susceptibility Testing. Prognostic factors associated with early (0-7 d) and late (8-30 d) mortality were analyzed using logistic regression modeling.

MEASUREMENTS AND MAIN RESULTS

We detected 773 cases of candidemia, 752 of which were included in the overall cohort. Among these, 168 (22.3%) occurred in adult ICU patients. The rank order of Candida isolates was as follows: Candida albicans (52%), Candida parapsilosis (23.7%), Candida glabrata (12.7%), Candida tropicalis (5.8%), Candida krusei (4%), and others (1.8%). Overall susceptibility to fluconazole was 79.2%. Cumulative mortality at 7 and 30 days after the first episode of candidemia was 16.5% and 47%, respectively. Multivariate analysis showed that early appropriate antifungal treatment and catheter removal (odds ratio, 0.27; 95% CI, 0.08-0.91), Acute Physiology and Chronic Health Evaluation II score (odds ratio, 1.11; 95% CI, 1.04-1.19), and abdominal source (odds ratio, 8.15; 95% CI, 1.75-37.93) were independently associated with early mortality. Determinants of late mortality were age (odds ratio, 1.04; 95% CI, 1.01-1.07), intubation (odds ratio, 7.24; 95% CI, 2.24-23.40), renal replacement therapy (odds ratio, 6.12; 95% CI, 2.24-16.73), and primary source (odds ratio, 2.51; 95% CI, 1.06-5.95).

CONCLUSIONS

Candidemia in ICU patients is caused by non-albicans species in 48% of cases, C. parapsilosis being the most common among these. Overall mortality remains high and mainly related with host factors. Prompt adequate antifungal treatment and catheter removal could be critical to decrease early mortality.

Biofilms formed by Candida albicans bloodstream isolates display phenotypic and transcriptional heterogeneity that are associated with resistance and pathogenicity

BACKGROUND

Candida albicans infections have become increasingly recognised as being biofilm related. Recent studies have shown that there is a relationship between biofilm formation and poor clinical outcomes in patients infected with biofilm proficient strains. Here we have investigated a panel of clinical isolates in an attempt to evaluate their phenotypic and transcriptional properties in an attempt to differentiate and define levels of biofilm formation.

RESULTS

Biofilm formation was shown to be heterogeneous; with isolates being defined as either high or low biofilm formers (LBF and HBF) based on different biomass quantification. These categories could also be differentiated using a cell surface hydrophobicity assay with 24 h biofilms. HBF isolates were more resistance to amphotericin B (AMB) treatment than LBF, but not voriconazole (VRZ). In a Galleria mellonella model of infection HBF mortality was significantly increased in comparison to LBF. Histological analysis of the HBF showed hyphal elements intertwined indicative of the biofilm phenotype. Transcriptional analysis of 23 genes implicated in biofilm formation showed no significant differential expression profiles between LBF and HBF, except for Cdr1 at 4 and 24 h. Cluster analysis showed similar patterns of expression for different functional classes of genes, though correlation analysis of the 4 h biofilms with overall biomass at 24 h showed that 7 genes were correlated with high levels of biofilm, including Als3, Eap1, Cph1, Sap5, Plb1, Cdr1 and Zap1.

CONCLUSIONS

Our findings show that biofilm formation is variable amongst C. albicans isolates, and categorising isolates depending on this can be used to predict how pathogenic the isolate will behave clinically. We have shown that looking at individual genes in less informative than looking at multiple genes when trying to categorise isolates at LBF or HBF. These findings are important when developing biofilm-specific diagnostics as these could be used to predict how best to treat patients infected with C. albicans. Further studies are required to evaluate this clinically.

Candida albicans and cancer: Can this yeast induce cancer development or progression?

There is currently increasing concern about the relation between microbial infections and cancer. More and more studies support the view that there is an association, above all, when the causal agents are bacteria or viruses. This review adds to this, summarizing evidence that the opportunistic fungus Candida albicans increases the risk of carcinogenesis and metastasis. Until recent years, Candida spp. had fundamentally been linked to cancerous processes as it is an opportunist pathogen that takes advantage of the immunosuppressed state of patients particularly due to chemotherapy. In contrast, the most recent findings demonstrate that C. albicans is capable of promoting cancer by several mechanisms, as described in the review: production of carcinogenic byproducts, triggering of inflammation, induction of Th17 response and molecular mimicry. We underline the need not only to control this type of infection during cancer treatment, especially given the major role of this yeast species in nosocomial infections, but also to find new therapeutic approaches to avoid the pro-tumor effect of this fungal species.

UPC2A is required for high-level azole antifungal resistance in Candida glabrata

Candida glabrata, the second most common cause of Candida infections, is associated with high rates of mortality and often exhibits resistance to the azole class of antifungal agents. Upc2 and Ecm22 in Saccharomyces cerevisiae and Upc2 in Candida albicans are the transcriptional regulators of ERG11, the gene encoding the target of azoles in the ergosterol biosynthesis pathway. Recently two homologs for these transcription factors, UPC2A and UPC2B, were identified in C. glabrata. One of these, UPC2A, was shown to influence azole susceptibility. We hypothesized that due to the global role for Upc2 in sterol biosynthesis in S. cerevisiae and C. albicans, disruption of UPC2A would enhance the activity of fluconazole in both azole-susceptible dose-dependent (SDD) and -resistant C. glabrata clinical isolates. To test this hypothesis, we constructed mutants with disruptions in UPC2A and UPC2B alone and in combination in a matched pair of clinical azole-SDD and -resistant isolates. Disruption of UPC2A in both the SDD and resistant isolates resulted in increased susceptibility to sterol biosynthesis inhibitors, including a reduction in fluconazole MIC and minimum fungicidal concentration, enhanced azole activity by time-kill analysis, a decrease in ergosterol content, and downregulation of baseline and inducible expression of several sterol biosynthesis genes. Our results indicate that Upc2A is a key regulator of ergosterol biosynthesis and is essential for resistance to sterol biosynthesis inhibitors in C. glabrata. Therefore, the UPC2A pathway may represent a potential cotherapeutic target for enhancing azole activity against this organism.

Antifungal resistance to fluconazole and echinocandins is not emerging in yeast isolates causing fungemia in a Spanish tertiary care center

Accurate knowledge of fungemia epidemiology requires identification of strains to the molecular level. Various studies have shown that the rate of resistance to fluconazole ranges from 2.5% to 9% in Candida spp. isolated from blood samples. However, trends in antifungal resistance have received little attention and have been studied only using CLSI M27-A3 methodology. We assessed the fungemia epidemiology in a large tertiary care institution in Madrid, Spain, by identifying isolates to the molecular level and performing antifungal susceptibility testing according to the updated breakpoints of European Committee for Antimicrobial Susceptibility Testing (EUCAST) definitive document (EDef) 7.2. We studied 613 isolates causing 598 episodes of fungemia in 544 patients admitted to our hospital (January 2007 to December 2013). Strains were identified after amplification and sequencing of the ITS1-5.8S-ITS2 region and further tested for in vitro susceptibility to amphotericin B, fluconazole, posaconazole, voriconazole, micafungin, and anidulafungin. Resistance was defined using EUCAST species-specific breakpoints, and epidemiological cutoff values (ECOFFs) were applied as tentative breakpoints. Most episodes were caused by Candida albicans (46%), Candida parapsilosis (28.7%), Candida glabrata (9.8%), and Candida tropicalis (8%). Molecular identification enabled us to better detect cryptic species of Candida guilliermondii and C. parapsilosis complexes and episodes of polyfungal fungemia. The overall percentage of fluconazole-resistant isolates was 5%, although it was higher in C. glabrata (8.6%) and non-Candida yeast isolates (47.4%). The rate of resistance to echinocandins was 4.4% and was mainly due to the presence of intrinsically resistant non-Candida species. Resistance mainly affected non-Candida yeasts. The rate of resistance to fluconazole and echinocandins did not change considerably during the study period.

Candida empyema thoracis at a hospital in Taiwan

BACKGROUND

We conducted a study of the clinical manifestations and outcomes of empyema thoracis caused by Candida spp. in hospitalized patients.

METHODS

We identified patients who from January 2010 to June 2012 had signs of inflammation, such as fever and leukocytosis, and concomitant positive cultures of Candida spp. from specimens of pleural fluid. We reviewed retrospectively the medical records of all such patients.

RESULTS

Eight of the patients in whom we identified fever and leukocytosis with concomitant positive pleural fluid cultures of Candida spp. were found to have Candida empyema thoracis. Candida albicans was the most common species causing empyema (n=4), followed by C. glabrata (n=3) and C. tropicalis (n=1). Among the eight patients with Candida empyema thoracis, malignant disease was the most common underlying disease. Seven of the eight patients' episodes of Candida empyema thoracis (87.5%) were classified as health care-associated infections. One patient had a mixed infection with Candida spp. and Pseudomonas aeruginosa. None of the patients had concomitant candidemia. Fluconazole was the antifungal agent used most commonly in treating the patients, and all of the patients had drainage of pleural effusions, including tube thoracostomy in five patients and drainage through a pigtail catheter in three patients. One patient underwent video-assisted thoracic surgery for the management of empyema thoracis, and the patients' overall in-hospital mortality was 62.5%.

CONCLUSION

Although Candida empyema thoracis is encountered rarely, it can develop in immunocompromised patients and can be associated with a high mortality rate.

Aspergillus monitoring project in a large educational hospital using molecular assay

BACKGROUND

It is important to find reliable and accessible methods for the diagnosis and identification of fungal species causing hospital acquired infections. Our main objective was using a rapid and accessible molecular method for the monitoring of Aspergillus infections and identification of causing agents in the level of species.

MATERIAL AND METHODS

The study subjects were primarily clinical specimens collected from suspected HAI patients with clinical symptoms after hospitalization. Also some environmental specimens were collected from air and instruments of health care facilities for the investigation of Aspergillus sources in a university hospital of UMSU, Urmia. All specimens were transported to Medical Mycology Center for the detection and identification of Aspergillus species using morphological methods. Also molecular method, PCR-RFLP using single restriction enzyme as a rapid and available method was performed to investigate environmental sources of Aspergillus infections.

RESULTS

Total of 110 clinical fungal isolates included Candida and Aspergillus species and some other opportunistic fungi. Among the clinical Aspergillus findings, Aspergillus flavus (47%), Aspergillus fumigatus (29.4%) and Aspergillus niger (23.6%) were the most frequent species respectively and also Aspergillus niger (43.7%), Aspergillus flavus (41.8%), Aspergillus fumigatus (14.7%) were isolated as the most frequent species from environmental sources.

CONCLUSION

Because of accessibility, speed and high sensitivity of diagnosis, the PCR-RFLP was very useful for the identification of medically important Aspergillus species and epidemiological approaches.

Historical trends in the epidemiology of candidaemia: analysis of an 11-year period in a tertiary care hospital in Brazil

Candida species are an important cause of bloodstream infections (BSI). To evaluate the epidemiological, clinical and microbiological aspects of two cohorts {1994-1999 [period 1 (P1) ]; 2000-2004 [period 2 (P2) ]} of candidaemic patients, we performed a retrospective analysis from a laboratory-based survey. A total of 388 candidaemias were identified, with an incidence of 0.20/1,000 patient-days and a significant increase in P2 vs. P1 (0.25 vs. 0.15, p = 0.04). Cancer and prior antibiotic use were frequent and Candida albicans was the most prevalent species found (42.4%). Resistance to fluconazole was found in 2.47% of the strains. No differences were observed in the species distribution of Candida during the study periods. In the P2 cohort, there were higher prevalence of elderly individuals, cardiac, pulmonary and liver diseases, renal failure, central venous catheters and antibiotic therapy. In P1, there were higher prevalence of neurological diseases and chemotherapy. The crude mortality was 55.4%. In conclusion, our incidence rates remained high. Furthermore, the distribution pattern of Candida species and the fluconazole resistance profile remained unchanged. Moreover, we found a clear trend of higher prevalence of candidaemia among the elderly and among patients with comorbidities. Finally, it is necessary to discuss strategies for the prevention and control of Candida BSI in Brazil.