Antifungal Susceptibility Pattern of Candida glabrata from a Referral Center and Reference Laboratory: 2012-2022

The prevalence of invasive candidiasis caused by non-Candida albicans has rapidly increased. Candida glabrata (Nakaseomyces glabrata) is an important pathogen associated with substantial mortality. Our study examined the antifungal temporal susceptibility of C. glabrata and cross-resistance/non-wild-type patterns with other azoles and echinocandins. Laboratory data of all adult patients with C. glabrata isolated from clinical specimens at the Mayo Clinic, Rochester, from 2012 to 2022 were collected. Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints were used. We obtained 1046 C. glabrata isolates from 877 patients. Using CLSI and EUCAST breakpoints, 187 (17.9%) isolates and 256 (24.5%) isolates were fluconazole-resistant, respectively. Focusing on C. glabrata bloodstream infections, fluconazole-resistance ranged from 16 to 22%. Among those 187 fluconazole-resistant isolates, 187 (100%) and 184 (98.4%) isolates were also voriconazole and posaconazole non-wild-type, respectively, with 97 (51.9%) isolates deemed non-wild type for itraconazole. The fluconazole susceptibility pattern has not changed over the past decade. The proportion of fluconazole-resistant C. glabrata is relatively high, which could be due to the complexity of patients and fluconazole exposure. Itraconazole appears to be a compelling step-down therapy for fluconazole-resistant C. glabrata, given the high proportion of wild-type isolates. Further research to examine clinical outcomes is warranted.

Candidemia in Patients With Cardiovascular Implantable Electronic Devices: Uncertainty in Management Based on Current International Guidelines

Background

In contrast to bloodstream infection due to a variety of bacteria in patients with cardiovascular implantable electronic devices (CIED), there are limited data regarding candidemia and risk of CIED infection.

Methods

All patients with candidemia and a CIED at Mayo Clinic Rochester between 2012 and 2019 were reviewed. Cardiovascular implantable electronic device infection was defined by (1) clinical signs of pocket site infection or (2) echocardiographic evidence of lead vegetations.

Results

A total of 23 patients with candidemia had underlying CIED; 9 (39.1%) cases were community onset. None of the patients had pocket site infection. The duration between CIED placement and candidemia was prolonged (median 3.5 years; interquartile range, 2.0-6.5). Only 7 (30.4%) patients underwent transesophageal echocardiography and 2 of 7 (28.6%) had lead masses. Only the 2 patients with lead masses underwent CIED extraction, but device cultures were negative for Candida species. Two (33.3%) of 6 other patients who were managed as candidemia without device infection subsequently developed relapsing candidemia. Cardiovascular implantable electronic device removal was done in both patients and device cultures grew Candida species. Although 17.4% of patients were ultimately confirmed to have CIED infection, CIED infection status was undefined in 52.2%. Overall, 17 (73.9%) patients died within 90 days of diagnosis of candidemia.

Conclusions

Although current international guidelines recommend CIED removal in patients with candidemia, the optimal management strategy remains undefined. This is problematic because candidemia alone is associated with increased morbidity and mortality as seen in this cohort. Moreover, inappropriate device removal or retention can both result in increased patient morbidity and mortality.

Role of the T2Dx magnetic resonance assay in patients with suspected bloodstream infection: a single-centre real-world experience

BACKGROUND

T2Dx was approved by the US Food and Drug Administration for the rapid detection of a modified panel of ESKAPE bacterial species or Candida spp. causing bloodstream infection (BSI).

PATIENTS AND METHODS

We performed a retrospective, observational study from January 1, 2018 to December 31, 2019 of all hospitalised patients with suspected BSI who underwent assessment using T2Dx in addition to standard blood culture (BC). T2-positive patients (cases) were compared to a matched group of patients with BSI documented only by BC (1:2 ratio) to investigate the possible impact of T2Dx on the appropriateness of empirical antimicrobial therapy and 21-day mortality.

RESULTS

In total, 78 T2Dx-analysed samples (49 patients) were analysed. The T2Dx assay result was positive for18 patients and negative for 31 patients. The concordance rates of the T2Bacteria Panel and T2Candida Panel results with those of standard BC were 74.4% and 91.4%, respectively. In the matched analysis, inappropriate empiric antimicrobial therapy administration was significantly less frequent in cases than in comparators (5.5% vs. 38.8%). The 21-day mortality rate was twofold lower in cases than in comparators (22.2% vs. 44.4%), although the difference was not significant. No other analysed variables were significantly different between the two groups.

CONCLUSIONS

This study illustrated that T2Dx might be associated with an increase in the appropriateness of empiric antimicrobial therapy in patients with BSI. Further studies are needed to evaluate whether the T2Dx assay can improve patient outcomes.

Risk factors for isolation of fluconazole and echinocandin non-susceptible Candida species in critically ill patients

Introduction. Resistance rates to azoles and echinocandins of Candida spp. increased over the last decade.Hypothesis/Gap Statement. Widespread use of antifungals could lead to development and dissemination of resistant Candida spp.Aim. To identify risk factors for isolation of Candida spp. non-susceptible to either fluconazole or echinocandins.Methodology. All patients hospitalized in the Intensive Care Unit (ICU) of the University General Hospital of Patras, Greece with Candida spp. isolated from clinical specimens during a ten-year period (2010-19) were included. Candida isolates were identified using Vitek-2 YST card. Consumption of antifungals was calculated.Results. During the study period, 253 isolates were included. C. non-albicans predominated (64.4 %) with C. parapsilosis being the most commonly isolated (42.3 %) followed by C. glabrata (nomenclatural change to Nakaseomyces glabrataa; 8.7 %) and C. tropicalis (11.9 %). Among all isolates, 45.8 and 28.5 % were non-susceptible and resistant to fluconazole, respectively. Concerning echinocandins, 8.7 % of isolates were non-susceptible to at least one echinocandin (anidulafungin or micafungin) and 3.1 % resistant. Multivariate analysis revealed that hospitalization during 2015-19, as compared to 2010-14, isolate being non-albicans or non-susceptible to at least one echinocandin was associated with isolation of fluconazole non-susceptible isolate. Administration of echinocandin, isolate being C. glabrata or C. tropicalis, or Candida spp. non-susceptible to fluconazole were independently associated with isolation of Candida spp. non-susceptible to at least one echinocandin. Fluconazole's administration decreased during the study period, whereas liposomal-amphotericin B's and echinoncandins' administration remained stable.Conclusion. Fluconazole's non-susceptibility increased during the study period, despite the decrease of its administration. Although echinocandins' administration remained stable, non-susceptibility among Candida spp. increased.

Caspofungin PK in critically ill patients after the first and fourth doses: suggestions for therapeutic drug monitoring?

We describe caspofungin pharmacokinetics (PK) after the first and fourth doses in 20 critically ill septic patients. Monte Carlo simulation was used to analyze the probability of target attainment (PTA) (AUC/MIC > 865) for Candida spp. Caspofungin concentrations were analyzed by HPLC in plasma and urine. A great variability in PK parameters was observed after both doses. Patients were divided in two groups according to their AUC values (AUC ≤ 75 mg h/L cut-off). In the low-AUC group Cmax, Cmin and AUC were lower, while Vd and Cl were higher than in the high-AUC group (p < 0.05, both at day 1 and 4). The mean 24-h urinary recovery of the drug was 8 ± 6.3% (day1) and 9.8 ± 6.3 (day4). Monte Carlo simulation analysis (0.03-1 mg/L MIC-range) showed that PTA was guaranteed only for MICs ≤ 0.03 mg/L in the low-AUC group, and for MICs ≤ 0.06 mg/L in the high-AUC group. No group had a PTA ≥ 90% for 0.125 mg/L MIC (the epidemiological cut-off). Mortality was higher in low-AUC group (p < 0.01). In our 'real-world' population, no clinical data can predict which patient will have lower, suboptimal caspofungin exposure, therefore we suggest TDM to optimize caspofungin therapy and reduce the risk of selecting resistances (CEAVC, 32366/2015; OSS.15.114, NCT03798600).

Synthesis, antimicrobial activity, and determination of the lipophilicity of ((cyclohex-3-enylmethylene)hydrazinyl)thiazole derivatives

Synthesis and investigation of antimicrobial activity of fifteen novel thiazoles containing cyclohexene moiety are presented. Among the derivatives, compounds 3a–3d, 3f, 3n, and 3o showed very strong activity against the reference Candida spp. strains with MIC = 0.015–3.91 µg/ml. The activity of these compounds is similar and even higher than the activity of nystatin used as positive control. Compounds 3d, 3f, 3n, 3o showed the highest activity with very strong effect towards most of yeasts isolated from clinical materials with MIC = 0.015–7.81 µg/ml. The cytotoxicity studies for the most active compounds showed that Candida spp. growth was inhibited at noncytotoxic concentrations for the mammalian L929 fibroblast. In addition, a good correlation was obtained between lipophilicity of compounds determined using reversed phase thin-layer chromatography and their antifungal activity.

Attenuating the emergence of anti-fungal drug resistance by harnessing synthetic lethal interactions in a model organism

Drug resistance is a rapidly emerging concern, thus prompting the development of novel therapeutics or combinatorial therapy. Currently, combinatorial therapy targets are based on knowledge of drug mode of action and/or resistance mechanisms, constraining the number of target proteins. Unbiased genome-wide screens could reveal novel genetic components within interaction networks as potential targets in combination therapies. Testing this, in the context of antimicrobial resistance, we implemented an unbiased genome-wide screen, performed in Saccharomyces cerevisiae expressing a Candida glabrata PDR1+ gain-of-function allele. Gain-of-function mutations in this gene are the principal mediators of fluconazole resistance in this human fungal pathogen. Eighteen synthetically lethal S. cerevisiae genetic mutants were identified in cells expressing C. glabrata PDR1+. One mutant, lacking the histone acetyltransferase Gcn5, was investigated further. Deletion or drug-mediated inhibition of Gcn5 caused a lethal phenotype in C. glabrata cells expressing PDR1+ alleles. Moreover, deletion or drug-mediated inactivation of Gcn5, inhibited the emergence of fluconazole-resistant C. glabrata isolates in evolution experiments. Thus, taken together, the data generated in this study provides proof of concept that synthetically lethal genetic screens can identify novel candidate proteins that when therapeutically targeted could allow effective treatment of drug-resistant infections.

Mechanisms of azole resistance in clinical isolates of Candida glabrata from two hospitals in China

Purpose: Candida glabrata has emerged as the second or third most common non-albicans species responsible for an increasing number of systemic infections. Moreover, its high-level of resistance to azole is associated with a high mortality rate. This study aimed to evaluate nosocomial infections and resistance characteristics of C. glabrata and to explore the mechanism of azole resistance in C. glabrata.

Patients and methods: Fifty-nine clinical C. glabrata isolates were collected from two hospitals in China. The susceptibility of the strains to antifungal agents was determined by both the ATB Fungus 3 strip and CLSI M27 broth microdilution method. Efflux of rhodamine 6G was examined to evaluate the effects of efflux pumps. The expression levels of CgCDR1, CgCDR2, CgSNQ2, CgERG11, and CgPDR1 were examined by real-time PCR. The sequences of CgERG11 and CgPDR1 were determined by PCR-based DNA sequencing.

Results: All 59 isolates of C. glabrata were susceptible to flucytosine and amphotericin B. Twelve (20.3%) isolates were determined to be fluconazole-resistant, whereas 13 (22.0%) and 27 (45.7%) isolates were categorized as non-wild-type for itraconazole and voriconazole, respectively. Efflux pumps in azole-resistant isolates showed stronger effects than those in azole-susceptible-dose dependent isolates, which is consistent with the significant upregulation of CgCDR1 and CgCDR2 (P<0.05), whereas no obvious differences were found for CgSNQ2, CgERG11, and CgPDR1 (P>0.05). Sequencing of CgERG11 showed no alteration favoring the hypothesis that CgERG11 is not involved in the azole resistance of C. glabrata. Four CgPDR1 missense mutations were found in azole-resistant isolates, of which the high frequency of the CgPDR1 mutation, A848V, has not been reported previously.

Conclusion: Efflux pump function is the main mechanism of resistance to fluconazole in our collected clinical isolates of C. glabrata, and further studies of the related gene disruption and genome-wide expression are needed to verify the function.

Sequence modification of the master regulator Pdr1 interferes with its transcriptional autoregulation and confers altered azole resistance in Candida glabrata

The transcriptional regulator Pdr1 plays a positive role in regulating azole drug resistance in Candida glabrata. Previous studies have shown the importance of the carboxyl (C)-terminal sequence of Pdr1 in fulfilling its function, as this region mediates interactions between Pdr1 and the co-activator Gal11A and is crucial for activation of Pdr1 targets. However, mechanisms of how Pdr1 is regulated, especially implication of its C-terminus in the regulatory activity, remain uncharacterized. In this study, we unexpectedly observed that the C-terminal modification of Pdr1 in an azole-resistant clinical isolate harboring a single GOF mutation, resulted in adverse effects such as decreased expression levels of Pdr1, downregulation of Pdr1 targets and azole hypersensitivity. Importantly, the C-terminal 3 × FLAG tagging significantly decreased the binding of Pdr1 to the pleiotropic drug response elements in its own promoter, promoted an irregular cellular mislocalization and thereby disrupted the transcriptional autoregulation of this master regulator. Unexpectedly, the aberrant cytoplasmic localization caused a non-functional interaction with Gal11A, a co-activator involved in drug resistance. Based on these findings, we proposed that C-terminal sequence of Pdr1 is vital for its stability and functionality, and targeting regulation of this region may represent a promising future strategy for combating C. glabrata infection and drug resistance.

Evolutionary Emergence of Drug Resistance in Candida Opportunistic Pathogens

Fungal infections, such as candidiasis caused by Candida, pose a problem of growing medical concern. In developed countries, the incidence of Candida infections is increasing due to the higher survival of susceptible populations, such as immunocompromised patients or the elderly. Existing treatment options are limited to few antifungal drug families with efficacies that vary depending on the infecting species. In this context, the emergence and spread of resistant Candida isolates are being increasingly reported. Understanding how resistance can evolve within naturally susceptible species is key to developing novel, more effective treatment strategies. However, in contrast to the situation of antibiotic resistance in bacteria, few studies have focused on the evolutionary mechanisms leading to drug resistance in fungal species. In this review, we will survey and discuss current knowledge on the genetic bases of resistance to antifungal drugs in Candida opportunistic pathogens. We will do so from an evolutionary genomics perspective, focusing on the possible evolutionary paths that may lead to the emergence and selection of the resistant phenotype. Finally, we will discuss the potential of future studies enabled by current developments in sequencing technologies, in vitro evolution approaches, and the analysis of serial clinical isolates.

Thiazoles with cyclopropyl fragment as antifungal, anticonvulsant, and anti-Toxoplasma gondii agents: synthesis, toxicity evaluation, and molecular docking study

Synthesis and investigation of antifungal, anticonvulsant and anti-Toxoplasma gondii activities of ten novel (2-(cyclopropylmethylidene)hydrazinyl)thiazole 3a-3j are presented. Among the derivatives, compounds 3a-3d and 3f-3j possess very high activity against Candida spp. ATCC with MIC = 0.015-7.81 µg/ml. Compounds 3a-3d and 3f-3j possess also very high activity towards most of strains of Candida spp. isolated from clinical materials with MIC = 0.015-7.81 µg/ml. The activity of these compounds is similar and even higher than the activity of nystatin used as positive control. Additionally, compounds 3c and 3e showed interesting anticonvulsant activities in the MES test, whereas compounds 3f and 3i demonstrated the anticonvulsant activity in PTZ-induced seizures. Noteworthy, none of these compounds impaired animals' motor skills in the rotarod test. Moreover, thiazoles 3a, 3h, and 3j showed significant anti-Toxoplasma gondii activity, with IC50 values 31-52 times lower than those observed for sulfadiazine. The results of the cytotoxicity evaluation, anti-Candida spp. and anti-Toxoplasma gondii activity studies showed that Candida spp. and Toxoplasma gondii growth was inhibited at non-cytotoxic concentrations for the mouse L929 fibroblast and the African green monkey kidney (VERO) cells. Molecular docking studies indicated secreted aspartic proteinase (SAP) as possible antifungal target.

Diabetes, malignancy and age as predictors of Candida glabrata bloodstream infection: A re-evaluation of the risk factors

OBJECTIVE

Echinocandins and azoles are widely used in the treatment of candidaemia. Guidelines of the Infectious Diseases Society of America recommend commencing treatment with an echinocandin in candidaemic patients with risk factors for Candida glabrata i.e. patients who are elderly, or who have diabetes or malignancy, or those with recent prescription of azoles. We attempted to validate whether age, diabetes and malignancy are associated with C. glabrata candidaemia.

PATIENTS, MATERIALS AND METHODS

Information in relation to demographics, patient associated risk factors, and laboratory parameters were collected from the casenotes and the laboratory information system. We then analysed the distribution of the risk factors (age, diabetes, and malignancy) in candidaemic patients with C. glabrata and patients with species other than C. glabrata (excluding Candida krusei).

RESULTS

Over a 42-month period (April 2011-September 2017), 124 patients had candidaemia. We analysed data for 119 patients of whom 33 (27.7%) had C. glabrata and the remaining 86 (72.2%) were infected with other species. Sixty-five patients were elderly (age≥65), 40 had some form of malignancy, 34 had diabetes, and 4 patients were prescribed azoles in the 30 days prior to candidaemia (many patients had multiple risk factors). Comparing patients with C. glabrata to patients infected with other species, we found no association with diabetes (39.3% vs. 24.4%, P=0.1), malignancy (36.3 vs. 32.5%, P=0.69), and age (54.5% vs. 54.6%, P=0.99).

CONCLUSIONS

Diabetes, malignancy and age are not reliable predictors of candidaemia due to C. glabrata.

Identification and antifungal susceptibility of Candida species isolated from the urine of patients in a university hospital in Brazil

The aim of this study was to identify Candida spp. isolated from candiduria episodes at a tertiary hospital in the Midwest region of Brazil, and to determine their susceptibility profiles to antifungal compounds. From May 2011 to April 2012, Candida spp. isolated from 106 adult patients with candiduria admitted to the University Hospital of the Federal University of Mato Grosso do Sul were evaluated. Both, species identification and susceptibility testing with fluconazole-FLC, voriconazole-VRC, and amphotericin B-AmB were carried out using the Vitek 2. To discriminate species of the C. parapsilosis complex, a RAPD-PCR technique using the RPO2 primer was performed. From the total of 106 isolates, 42 (39.6%) C. albicans and 64 (60.4%) Candida non-albicans (CNA) - 33 C. tropicalis, 18 C. glabrata, 5 C. krusei, 4 C. parapsilosis sensu stricto, 2 C. kefyr, 1 C. lusitaniae, and 1 C. guilliermondii were identified. All isolates were susceptible to AmB and VRC, whereas all C. glabrata isolates presented either resistance (5.6%) or dose-dependent susceptibility (94.4%) to FLC. The study of Candida spp. and their resistance profiles may help in tailoring more efficient therapeutic strategies for candiduria.

Study of Microbial Interaction Formed by "Candida krusei" and "Candida glabrata": "In Vitro" and "In Vivo" Studies

Abstract Recently, the non-albicans Candida species have become recognized as an important source of infection and oral colonization by association of different species in a large number of immunosuppressed patients. The objective of this study was to evaluate the interactions between C. krusei and C. glabrata in biofilms formed in vitro and their ability to colonize the oral cavity of mouse model. Monospecies and mixed biofilms were developed of each strain, on 96-well microtiter plates for 48 h. These biofilms were analyzed by counting colony-forming units (CFU/mL) and by determining cell viability, using the XTT hydroxide colorimetric assay. For the in vivo study, twenty-four mice received topical applications of monospecie or mixed suspensions of each strain. After 48 h, yeasts were recovered from the mice and quantified by CFU/mL count. In the biofilm assays, the results for the CFU/mL count and the XTT assay showed that the two species studied were capable of forming high levels of in vitro monospecie biofilm. In mixed biofilm, the CFU of C. krusei increased (p=0.0001) and C. glabrata decreased (p=0.0001). The metabolic activity observed in XTT assay of mixed biofilm was significantly reduced compared with a single C. glabrata biofilm (p=0.0001). Agreeing with CFU in vitro count, C. glabrata CFU/mL values recovered from oral cavity of mice were statistically higher in the group with single infection (p=0.0001) than the group with mixed infection. We concluded that C. krusei inhibits C. glabrata and takes advantage to colonize the oral cavity and to form biofilms.

Multidrug-Resistant Candida: Epidemiology, Molecular Mechanisms, and Treatment

Invasive Candida infections remain an important cause of morbidity and mortality, especially in hospitalized and immunocompromised or critically ill patients. A limited number of antifungal agents from only a few drug classes are available to treat patients with these serious infections. Resistance can be either intrinsic or acquired. Resistance mechanisms are not exchanged between Candida; thus, acquired resistance either emerges in response to an antifungal selection pressure in the individual patient or, more rarely, occur due to horizontal transmission of resistant strains between patients. Although multidrug resistance is uncommon, increasing reports of multidrug resistance to the azoles, echinocandins, and polyenes have occurred in several Candida species, most notably Candida glabrata and more recently Candida auris. Drivers are overall antifungal use, subtherapeutic drug levels at sites of infection/colonization, drug sequestration in the biofilm matrix, and, in the setting of outbreaks, suboptimal infection control. Moreover, recent research suggests that DNA mismatch repair gene mutations may facilitate acquisition of resistance mutations in C. glabrata specifically. Diagnosis of antifungal-resistant Candida infections is critical to the successful management of patients with these infections. Reduction of unnecessary use of antifungals via antifungal stewardship is critical to limit multidrug resistance emergence.

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.

High Recovery Rate of Non-albicans Candida Species Isolated From Burn Patients With Candidemia in Iran

Background:

Blood stream infections (BSIs) are major causes of morbidity and mortality in burn patients. Microorganisms responsible for BSI are generally bacteria; however, Candida spp. are the infection agents in as many as 8% of all cases. Burn wound colonization and infections are generally the first steps to systemic infection. Candidemia in burn patients has been associated with high mortality and a prolonged hospital stay.

Objectives:

Candidemia in burn patients has been defined as a preterminal event, leading to high morbidity and mortality rates among these patients. The aim of this study was to establish the incidence of candidemia in burn patients in Iran.

Patients and Methods:

We consecutively collected 405 blood samples from 113 burn patients. The yeast isolates were identified to the species level using conventional procedures. In vitro antifungal susceptibility of the Candida isolates to amphotericin B, fluconazole, voriconazole and caspofungin was performed using the Etest.

Results:

Twenty-seven samples (6.7%) of the blood cultures from 13 patients (12%) were positive for Candida species. Candidaparapsilosis (38%) and C. tropicalis (38%) were the most commonly found Candida species, followed by C. albicans (15%) and C. guilliermondii (15%) in the patients. The incidence of candidemia was significantly correlated with increased duration of hospitalization, increased time of stay in the intensive care unit, and higher mortality. The antifungal susceptibility tests demonstrated that amphotericin B and voriconazole had the lowest minimum inhibitory concentrations (MICs) against Candida spp.

Conclusions:

Non-albicans Candida should be considered as significant pathogens in burned patients with candidemia.

Antifungal susceptibility profiles of bloodstream yeast isolates by Sensititre YeastOne over nine years at a large Italian teaching hospital

Sensititre YeastOne (SYO) is an affordable alternative to the Clinical and Laboratory Standards Institute (CLSI) reference method for antifungal susceptibility testing. In this study, the MICs of yeast isolates from 1,214 bloodstream infection episodes, generated by SYO during hospital laboratory activity (January 2005 to December 2013), were reanalyzed using current CLSI clinical breakpoints/epidemiological cutoff values to assign susceptibility (or the wild-type [WT] phenotype) to systemic antifungal agents. Excluding Candida albicans (57.4% of all isolates [n = 1,250]), the most predominant species were Candida parapsilosis complex (20.9%), Candida tropicalis (8.2%), Candida glabrata (6.4%), Candida guilliermondii (1.6%), and Candida krusei (1.3%). Among the non-Candida species (1.9%), 7 were Cryptococcus neoformans and 17 were other species, mainly Rhodotorula species. Over 97% of Candida isolates were susceptible (WT phenotype) to amphotericin B and flucytosine. Rates of susceptibility (WT phenotype) to fluconazole, itraconazole, and voriconazole were 98.7% in C. albicans, 92.3% in the C. parapsilosis complex, 96.1% in C. tropicalis, 92.5% in C. glabrata, 100% in C. guilliermondii, and 100% (excluding fluconazole) in C. krusei. The fluconazole-resistant isolates consisted of 6 C. parapsilosis complex isolates, 3 C. glabrata isolates, 2 C. albicans isolates, 2 C. tropicalis isolates, and 1 Candida lusitaniae isolate. Of the non-Candida isolates, 2 C. neoformans isolates had the non-WT phenotype for susceptibility to fluconazole, whereas Rhodotorula isolates had elevated azole MICs. Overall, 99.7% to 99.8% of Candida isolates were susceptible (WT phenotype) to echinocandins, but 3 isolates were nonsusceptible (either intermediate or resistant) to caspofungin (C. albicans, C. guilliermondii, and C. krusei), anidulafungin (C. albicans and C. guilliermondii), and micafungin (C. albicans). However, when the intrinsically resistant non-Candida isolates were included, the rate of echinocandin nonsusceptibility reached 1.8%. In summary, the SYO method proved to be able to detect yeast species showing antifungal resistance or reduced susceptibility.

Insights into the antimicrobial properties of hepcidins: advantages and drawbacks as potential therapeutic agents

The increasing frequency of multi-drug resistant microorganisms has driven research into alternative therapeutic strategies. In this respect, natural antimicrobial peptides (AMPs) hold much promise as candidates for the development of novel antibiotics. However, AMPs have some intrinsic drawbacks, such as partial degradation by host proteases or inhibition by host body fluid composition, potential toxicity, and high production costs. This review focuses on the hepcidins, which are peptides produced by the human liver with a known role in iron homeostasis, as well by numerous other organisms (including fish, reptiles, other mammals), and their potential as antibacterial and antifungal agents. Interestingly, the antimicrobial properties of human hepcidins are enhanced at acidic pH, rendering these peptides appealing for the design of new drugs targeting infections that occur in body areas with acidic physiological pH. This review not only considers current research on the direct killing activity of these peptides, but evaluates the potential application of these molecules as coating agents preventing biofilm formation and critically assesses technical obstacles preventing their therapeutic application.

Relationship of fluconazole prophylaxis with fungal microbiology in hospitalized intra-abdominal surgery patients: a descriptive cohort study

INTRODUCTION

Historically, Candida albicans has represented the most common cause of candidemia. However, the proportion of bloodstream infections due to non-albicans Candida species has increased. Because of the risk for candidemia in intra-abdominal surgical patients, some experts advocate the use of fluconazole prophylaxis. The impact of this practice on the distribution of Candida species isolated in breakthrough fungal infections in this population is unknown. We examined the association of fluconazole prophylaxis with the distribution of Candida species in intra-abdominal surgery patients.

METHODS

We retrospectively identified cases with a positive blood culture (BCx) for Candida among hospitalized adult intra-abdominal surgery patients between July 2005 and October 2012. Distribution of Candida species isolated represented our primary endpoint. Qualifying surgical cases were determined based on a review of discharge International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Patients receiving low-dose fluconazole prior to the positive BCx with a known indication for prophylaxis including neutropenia, ICU exposure or history of organ transplantation were classified as prophylaxis. Appropriateness of fungal treatment was determined by the timing and selection of antifungal agent based on fungal isolate.

RESULTS

Among 10,839 intra-abdominal surgery patients, 227 had candidemia. The most common Candida species isolated was C. albicans (n = 90, 39.6%) followed by C. glabrata (n = 81, 35.7%) and C. parapsilosis (n = 38, 16.7%). Non-albicans Candida accounted for 57.7% of isolates among the 194 non-prophylaxis patients and 75.8% among the 33 prophylaxis patients (P = 0.001). C. glabrata, the most common non-C. albicans species, was more prevalent than C. albicans in persons given prophylaxis, but not in those without prophylaxis. A total of 63% of those with candidemia were treated inappropriately based on the timing and selection of antifungal administration.

CONCLUSIONS

Selection pressure from fluconazole prophylaxis in at-risk surgical patients may be associated with a drift toward fluconazole-resistant species in subsequent candidemia. Tools are needed to guide appropriate treatment through the prompt recognition and characterization of candidemia.

Association of clinical and demographic factors in invasive candidiasis caused by fluconazole-resistant Candida species: a study in 15 hospitals, Medellín, Colombia 2010-2011

Candida is the most important agent of fungal infections. Several risk factors have been described associated with invasive infection by fluconazole-resistant Candida spp. A prospective cross-sectional study with case-control analysis was conducted. Case group patients with fluconazole-resistant Candida isolate were included; control group were patients with fluconazole-susceptible Candida spp. A multivariate logistic regression model was performed. Three hundred isolates of Candida spp. were analyzed. Most frequent species were Candida albicans/Candida dubliniensis (48.3%) and Candida tropicalis (22.3%). Posaconazole susceptibility was 93.7%; voriconazole, 84%; and fluconazole, 78.7%. Susceptibility to anidulafungin and caspofungin was 92.7% and 92.3%, respectively. Neutropenia (adjusted odds ratio [aOR] 6.5, 95% confidence interval [CI] 1.0-43.1), antifungal exposure (aOR 5.1, 95% CI 2.3-11.2), and antituberculosis therapy (aOR 7.7, 95% CI 1.4-43.2) were associated to fluconazole resistance. Susceptibility results are useful to guide the selection of empiric antifungal treatment and the design of local therapeutic guidelines. Previous antifungal exposure suggests possible resistance to fluconazole, pointing towards the selection of a different class of antifungal agents.

Proteomic Analysis of Cellular and Membrane Proteins in Fluconazole-Resistant Candida glabrata

Objectives

Candida glabrata is one of the most common causes of Candida bloodstream infections worldwide. Some isolates of C glabrata may be intermediately resistant to azoles, with some strains developing resistance during therapy or prophylaxis with fluconazole. In this study, we used a proteomic approach to identify differentially expressed proteins between fluconazoleresistant and -susceptible strains.

Methods

Membrane and cellular proteins were extracted from fluconazolesusceptible and fluconazole-resistant C glabrata strains. Differentially expressed proteins were compared using two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis. Proteins with >1.5-fold difference in expression were identified by liquid chromatography tandem mass spectrometry (LC-MS/MS).

Results

A total of 65 proteins were differentially expressed in the cellular and membrane fractions. Among the 39 cellular proteins, 11 were upregulated and 28 were downregulated in fluconazole-resistant strains in comparison with fluconazole-susceptible strains. In the membrane fraction, a total of 26 proteins were found, of which 19 were upregulated and seven were downregulated. A total of 31 proteins were identified by LC-MS/MS that are involved in glycolysis, carbohydrate transport, energy transfer, and other metabolic pathways. Heat shock proteins were identified in various spots.

Conclusion

Heat shock and stress response proteins were upregulated in the membrane fraction of the fluconazole-resistant C glabrata strain. Compared with susceptible strains, fluconazole-resistant strains showed increased expression of membrane proteins and decreased expression of cellular proteins.

Proteomic Analysis of Intracellular and Membrane Proteins From Voriconazole-Resistant Candida glabrata

Objectives

The proteomic analysis of voriconazole resistant Candida glabrata strain has not yet been investigated. In this study, differentially expressed proteins of intracellular and membrane fraction from voriconazole-susceptible, susceptible dose-dependent (S-DD), resistant C. glabrata strains were compared with each other and several proteins were identified.

Methods

The proteins of intracellular and membrane were isolated by disrupting cells with glass bead and centrifugation from voriconazole susceptible, S-DD, and resistant C. glabrata strains. The abundance of expressed proteins was compared using two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis and proteins showing continuous twofold or more increase or reduction of expression in resistant strains compared to susceptible and S-DD strain were analyzed by liquid chromatography/mass spectrometry-mass spectrometry method.

Results

Of 34 intracellular proteins, 15 proteins showed expression increase or reduction (twofold or more). The identified proteins included regulation, energy production, carbohydrate transport, amino acid transport, and various metabolism related proteins. The increase of expression of heat shock protein 70 was found. Among membrane proteins, 12, 31 proteins showed expression increase or decrease in the order of susceptible, S-DD, and resistant strains. This expression included carbohydrate metabolism, amino acid synthesis, and response to stress-related proteins. In membrane fractions, the change of expression of 10 heat shock proteins was observed, and 9 heat shock protein 70 (Hsp70) showed the reduction of expression.

Conclusion

The expression of Hsp70 protein in membrane fraction is related to voriconazole resistant C. glabrata strains.

Changing epidemiology of candidemia in a medical center in middle Taiwan

BACKGROUND

Candidemia remains a major cause of morbidity and mortality in the health care setting, and the epidemiology of Candida infection is changing.

METHODS

Clinical and laboratory data from patients with candidemia were collected retrospectively at a tertiary medical center in Taiwan from July 1, 2009 to June 30, 2012 (a 36-month period). Demographics, clinical characteristics, and drug susceptibility of the invading Candida species of patients at the onset of candidemia were analyzed and compared with previous study from January 1, 2001 to June 30, 2003 (a 30-month period).

RESULTS

A total of 209 episodes of candidemia in 205 patients were identified in this study period. When compared with the previous study period, more patients were admitted for medical conditions at percentages ranging from 49.5% to 69.8%; the incidence rate of health care-associated candidemia increased from 0.76 to 1.14 per 1000 discharges; the proportion of Candida albicans in patients with candidemia decreased from 64.8% to 43.6% whereas the proportion of Candida glabrata increased greatly from 1.1% to 21.6% and the proportions of Candida tropicalis and Candida parapsilosis were slightly elevated (19.8-22.0% and 2.2-7.3%, respectively). All of the C. albicans isolates remained susceptible to fluconazole, whereas 66.7% of C. glabrata isolates were dose-dependent susceptible, and 4.4% of C. glabrata isolates and 11.6% C. tropicalis isolates were resistant. There was one C. glabrata and one Candida guilliermondii resistant to echinocandin. The predictors for 30-day mortality included the high Acute Physiology and Chronic Health Evaluation II (APACHE II) score, use of parenteral nutrition, underlying malignancy, liver cirrhosis, and neutropenia whereas candidemia by C. parapsilosis or C. glabrata is a favorable predictor when compared with C. albicans.

CONCLUSION

The distribution of Candida species in candidemia was changed. Although C. albicans remained the major species, the isolation of non-C. albicans spp., especially C. glabrata, increased. Patients with candidemia still had high mortalities due to severity of illness and underlying conditions.

MALDI-TOF mass spectrometry in the clinical mycology laboratory: identification of fungi and beyond

MALDI-TOF mass spectrometry (MS) is becoming essential in most clinical microbiology laboratories throughout the world. Its successful use is mainly attributable to the low operational costs, the universality and flexibility of detection, as well as the specificity and speed of analysis. Based on characteristic protein spectra obtained from intact cells - by means of simple, rapid and reproducible preanalytical and analytical protocols - MALDI-TOF MS allows a highly discriminatory identification of yeasts and filamentous fungi starting from colonies. Whenever used early, direct identification of yeasts from positive blood cultures has the potential to greatly shorten turnaround times and to improve laboratory diagnosis of fungemia. More recently, but still at an infancy stage, MALDI-TOF MS is used to perform strain typing and to determine antifungal drug susceptibility. In this article, the authors discuss how the MALDI-TOF MS technology is destined to become a powerful tool for routine mycological diagnostics.

Mortality in patients with early- or late-onset candidaemia

OBJECTIVES

Although candidaemia is a well-known complication of hospital stay and has a crude mortality of ∼40%, few data are available for episodes diagnosed within 10 days after hospital admission. In this paper, we compared the risk factors for mortality according to the onset of candidaemia.

METHODS

This was a retrospective study of hospitalized patients with early-onset candidaemia (EOC; ≤ 10 days) or late-onset candidaemia (LOC; >10 days) to identify any distinct clinical characteristics and risk factors for 30 day mortality in two Italian academic centres.

RESULTS

A total of 779 patients were included in the study: 183 EOC and 596 LOC. Mortality was significantly lower in EOC (71/183, 38.8% versus 283/596, 47.5%, P=0.03). In EOC, multivariate analysis showed that inadequate initial antifungal therapy (IIAT) (P=0.005, OR 3.02, 95% CI 1.40-6.51), Candida albicans aetiology (P=0.02, OR 2.17, 95% CI 1.11-4.26) and older age (P<0.001, OR 1.05, 95% CI 1.02-1.07) were independent risk factors for mortality. In LOC, liver disease (P=0.003, OR 2.46, 95% CI 1.36-4.43), IIAT (P=0.002, OR 2.01, 95% CI 1.28-3.15) and older age (P<0.001, OR 1.03, 95% CI 1.02-1.04) were independently associated with a fatal outcome, while treatment with caspofungin was associated with survival (P<0.001, OR 0.42, 95% CI 0.26-0.67).

CONCLUSIONS

EOC has different clinical characteristics and risk factors for mortality compared with LOC. Although EOC mortality is significantly lower, the rate of inappropriate antifungal treatment is higher. Treatment with caspofungin is significantly associated with survival in patients with LOC. Efforts are needed to improve the diagnosis and treatment of EOC.

Fluconazole exposure rather than clonal spreading is correlated with the emergence of Candida glabrata with cross-resistance to triazole antifungal agents

The emergence of antifungal resistance in Candida species has raised concern in recent years, especially resistance toward triazole. Several newer triazole antifungal agents have been introduced which have a broader spectrum for fungal infections, such as voriconazole. However, cross-resistance among triazoles is a major concern with regard to their clinical application. Antifungal susceptibility was performed using E-test for 166 clinical isolates (29 blood and 137 nonblood isolates) in 2003 and 2004. We applied pulsed-field gel electrophoresis for genotyping. Ninety isolates of C. albicans, 47 isolates of C. tropicalis, 27 isolates of C. glabrata, and two isolates of C. krusei were included. All isolates were susceptible to amphotericin B. Eleven (40.7%) of the 27 C. glabrata had intermediate resistance to caspofungin. Forty-seven (28.3%) of the 166 isolates were not susceptible to fluconazole, including two C. albicans, 16 C. tropicalis, 27 C. glabrata, and two C. krusei isolates. All except seven of the C. glabrata isolates were susceptible to voriconazole. All the triazole drugs had a positive correlation among their minimum inhibitory concentrations (MICs). Fluconazole MIC was a good predictor for susceptibility to voriconazole, as determined using a receiver operating characteristic curve. Furthermore, a high diversity of pulsotypes for the 27 clinical isolates of C. glabrata was observed. Previous fluconazole exposure within 3 months was associated with reduced triazole susceptibility for C. glabrata. We demonstrated a significant positive correlation of MIC values among the four tested triazole drugs. No amphotericin B and caspofungin resistant isolates were found in this study. The cross-resistance to triazole among C. glabrata isolates was associated with previous fluconazole exposure as opposed to clonal spreading. Selection pressure due to fluconazole use may play a major role in triazole cross-resistance.

Risk factors and outcomes of candidemia caused by biofilm-forming isolates in a tertiary care hospital

Background

Very few data exist on risk factors for developing biofilm-forming Candida bloodstream infection (CBSI) or on variables associated with the outcome of patients treated for this infection.

Methods and Findings

We identified 207 patients with CBSI, from whom 84 biofilm-forming and 123 non biofilm-forming Candida isolates were recovered. A case-case-control study to identify risk factors and a cohort study to analyze outcomes were conducted. In addition, two sub-groups of case patients were analyzed after matching for age, sex, APACHE III score, and receipt of adequate antifungal therapy. Independent predictors of biofilm-forming CBSI were presence of central venous catheter (odds ratio [OR], 6.44; 95% confidence interval [95% CI], 3.21–12.92) or urinary catheter (OR, 2.40; 95% CI, 1.18–4.91), use of total parenteral nutrition (OR, 5.21; 95% CI, 2.59–10.48), and diabetes mellitus (OR, 4.47; 95% CI, 2.03–9.83). Hospital mortality, post-CBSI hospital length of stay (LOS) (calculated only among survivors), and costs of antifungal therapy were significantly greater among patients infected by biofilm-forming isolates than those infected by non-biofilm-forming isolates. Among biofilm-forming CBSI patients receiving adequate antifungal therapy, those treated with highly active anti-biofilm (HAAB) agents (e.g., caspofungin) had significantly shorter post-CBSI hospital LOS than those treated with non-HAAB antifungal agents (e.g., fluconazole); this difference was confirmed when this analysis was conducted only among survivors. After matching, all the outcomes were still favorable for patients with non-biofilm-forming CBSI. Furthermore, the biofilm-forming CBSI was significantly associated with a matched excess risk for hospital death of 1.77 compared to non-biofilm-forming CBSI.

Conclusions

Our data show that biofilm growth by Candida has an adverse impact on clinical and economic outcomes of CBSI. Of note, better outcomes were seen for those CBSI patients who received HAAB antifungal therapy.

Frequency of decreased susceptibility and resistance to echinocandins among fluconazole-resistant bloodstream isolates of Candida glabrata

The echinocandin class of antifungal agents is considered to be the first-line treatment of bloodstream infections (BSI) due to Candida glabrata. Recent reports of BSI due to strains of C. glabrata resistant to both fluconazole and the echinocandins are of concern and prompted us to review the experience of two large surveillance programs, the SENTRY Antimicrobial Surveillance Program for the years 2006 through 2010 and the Centers for Disease Control and Prevention population-based surveillance conducted in 2008 to 2010. The in vitro susceptibilities of 1,669 BSI isolates of C. glabrata to fluconazole, voriconazole, anidulafungin, caspofungin, and micafungin were determined by CLSI broth microdilution methods. Fluconazole MICs of ≥64 μg/ml were considered resistant. Strains for which anidulafungin and caspofungin MICs were ≥0.5 μg/ml and for which micafungin MICs were ≥0.25 μg/ml were considered resistant. A total of 162 isolates (9.7%) were resistant to fluconazole, of which 98.8% were nonsusceptible to voriconazole (MIC > 0.5 μg/ml) and 9.3%, 9.3%, and 8.0% were resistant to anidulafungin, caspofungin, and micafungin, respectively. There were 18 fluconazole-resistant isolates that were resistant to one or more of the echinocandins (11.1% of all fluconazole-resistant isolates), all of which contained an acquired mutation in fks1 or fks2. By comparison, there were no echinocandin-resistant strains detected among 110 fluconazole-resistant isolates of C. glabrata tested in 2001 to 2004. These data document the broad emergence of coresistance over time to both azoles and echinocandins in clinical isolates of C. glabrata.

Fungicidal activity of the human peptide hepcidin 20 alone or in combination with other antifungals against Candida glabrata isolates

Candida glabrata infections are often difficult to eradicate due to the intrinsically low susceptibility to azoles of this species. In addition, C. glabrata has also been shown to be insensitive to several cationic peptides, which have been shown to be promising novel therapeutic candidates for the treatment of fungal infection. In this study, the in vitro fungicidal activity of the human cationic peptide hepcidin 20 (Hep-20) was evaluated against clinical isolates of C. glabrata with different levels of fluconazole susceptibility. Interestingly, all isolates were susceptible to Hep-20 (100-200 μg/ml) at pH 7.4, whereas the fungicidal effect of the peptide was higher (50 μg/ml) at acidic pH values. In addition, an increased antifungal activity was observed for Hep-20 with amphotericin B and a synergistic effect was demonstrated for the Hep-20/fluconazole and Hep-20/caspofungin combinations.

Genotypic, phenotypic, and proteomic characterization of Candida glabrata during sequential fluconazole exposure

AIM

Candida glabrata is a major pathogen in humans known to be intrinsically resistant to fluconazole. However, genotypic, phenotypic, and proteomic changes associated with reduced susceptibility to fluconazole are not properly understood. The aim of this study was to observe specific phenotypic, chromosomal, and proteomic alterations in a Candida glabrata strain sequentially exposed to fluconazole.

METHODS

Candida glabrata was exposed to increased concentrations of fluconazole in RPMI for 55 days. Phenotypic changes were evaluated using standard assays. Molecular/proteomic changes in C. glabrata were analyzed by contour-clamped homogeneous electric field electrophoresis, reverse transcription-polymerase chain reaction, and mass spectrometry.

RESULTS

  Candida glabrata demonstrated increased fluconazole resistance (>256 μg/mL), with extensive cross-resistance to ketoconazole (0.38-3.0 μg), itraconazole (8 to >32 μg), and voriconazole (0.125-1.5 μg). Morphologically dissimilar colonies on RPMI/fluconazole agar demonstrated variable chromosomal profiles compared with the control isolate. Stable chromosomal changes were associated with a significantly higher (P<0.05) mRNA level of the hemolysin gene compared with the control. Phenotypic switching on CuSO4 agar was associated with variable metallothionein mRNA transcription levels. The proteome analysis of a fluconazole-resistant offshoot demonstrated a total of 98 protein spots, 25 showing a twofold upregulation.

CONCLUSION

Fluconazole exposure initiates the chance evolution of a new colonizing population with specific virulence traits.

Host iron withholding demands siderophore utilization for Candida glabrata to survive macrophage killing

The fungal pathogen Candida glabrata has risen from an innocuous commensal to a major human pathogen that causes life-threatening infections with an associated mortality rate of up to 50%. The dramatic rise in the number of immunocompromised individuals from HIV infection, tuberculosis, and as a result of immunosuppressive regimens in cancer treatment and transplant interventions have created a new and hitherto unchartered niche for the proliferation of C. glabrata. Iron acquisition is a known microbial virulence determinant and human diseases of iron overload have been found to correlate with increased bacterial burden. Given that more than 2 billion people worldwide suffer from iron deficiency and that iron overload is one of the most common single-gene inherited diseases, it is important to understand whether host iron status may influence C. glabrata infectious disease progression. Here we identify Sit1 as the sole siderophore-iron transporter in C. glabrata and demonstrate that siderophore-mediated iron acquisition is critical for enhancing C. glabrata survival to the microbicidal activities of macrophages. Within the Sit1 transporter, we identify a conserved extracellular SIderophore Transporter Domain (SITD) that is critical for siderophore-mediated ability of C. glabrata to resist macrophage killing. Using macrophage models of human iron overload disease, we demonstrate that C. glabrata senses altered iron levels within the phagosomal compartment. Moreover, Sit1 functions as a determinant for C. glabrata to survive macrophage killing in a manner that is dependent on macrophage iron status. These studies suggest that host iron status is a modifier of infectious disease that modulates the dependence on distinct mechanisms of microbial Fe acquisition.

Candida glabrata is a major human pathogen due to its low susceptibility to conventional antifungal drugs and the dramatic increase in the number of immunocompromised individuals suffering from HIV AIDS, cancer, and diabetes. Iron overload is one of the most common genetically inherited diseases and reports suggest increased susceptibility of these patients to bacterial infection. The ability of microorganisms to obtain iron from their environment is a major determinant in their fitness and hence in their ability to cause infectious disease. Here we demonstrate that the siderophore iron carrier is critical for C. glabrata survival after ingestion by mouse and human macrophage immune effector cells. Through the generation of macrophage models of human iron overload disease we demonstrate that ingested C. glabrata cells sense altered macrophage iron levels, and that the Sit1 siderophore-iron transporter functions as a critical determinant in the ability of C. glabrata to survive macrophage killing in a manner that is dependent on macrophage iron status. Our results reveal a role for siderophore-iron as a source of iron during C. glabrata infection, suggest additional therapeutic intervention strategies, and support a pivotal contribution for a common human iron overload disease in the mechanisms used for Fe acquisition in C. glabrata.

Clinical and economic outcomes of decreased fluconazole susceptibility in patients with Candida glabrata bloodstream infections

BACKGROUND

The impact of reduced fluconazole susceptibility on clinical and economic outcomes in patients with Candida glabrata bloodstream infections (BSI) is unknown.

METHODS

A retrospective cohort study was conducted to evaluate 30-day inpatient mortality and postculture hospital charges in patients with C glabrata BSI with decreased fluconazole susceptibility (minimum inhibitory concentration [MIC] ≥ 16 μg/mL) versus fluconazole-susceptible C glabrata BSI (MIC ≤ 8 μg/mL). These analyses were adjusted for demographics, comorbidities, and time at risk. Secondary analyses limited the C glabrata group with decreased fluconazole susceptibility to MIC ≥ 64 μg/mL.

RESULTS

There were 45 (31%) deaths among 144 enrolled patients: 19 deaths (25%) among 76 patients with C glabrata BSI with decreased fluconazole susceptibility and 26 deaths (38%) among 68 patients with fluconazole-susceptible C glabrata BSI. Decreased fluconazole susceptibility was not independently associated with increased 30-day inpatient mortality (adjusted odds ratio, .60; 95% confidence interval (CI): .26-1.35; P = 0.22) or hospital charges (multiplicative change in hospital charges, .93; 95% CI: .60-1.43; P = 0.73). Older age was associated with increased mortality and increased time at risk was associated with increased hospital charges.

CONCLUSION

Crude mortality rates remain high in patients with C glabrata BSI. However, decreased fluconazole susceptibility was not associated with increased mortality or hospital charges.

Risk factors for fluconazole resistance in patients with Candida glabrata bloodstream infection: potential impact of control group selection on characterizing the association between previous fluconazole use and fluconazole resistance

BACKGROUND

Although Candida glabrata is an emerging infection, risk factors for fluconazole resistance in patients with C glabrata bloodstram infection (BSI) have not been well elucidated.

METHODS

A case-control study was conducted to evaluate the primary risk factor of interest, previous fluconazole use, adjusting for demographics, comorbidities, time at risk, and antimicrobial exposure and assessing for effect modification. Secondary analyses were performed limiting the case group to C glabrata BSIs with a minimum inhibitory concentration (MIC) > or =64 microg/mL.

RESULTS

Previous fluconazole use was not a significant risk factor for fluconazole-resistant C glabrata BSI in primary analysis (adjusted odds ratio [aOR], 1.5; 95% confidence interval [CI], 0.7-3.2) but was borderline significant in secondary analysis (aOR, 3.2; 95% CI, 0.9-11.3). Increased time at risk was an independent risk factor in primary (aOR, 1.02; 95% CI, 1.002-1.04) and secondary analyses (aOR, 1.03; 95% CI, 1.004-1.06).

CONCLUSION

Increased time at risk was the only significant risk factor for fluconazole resistance. Future studies are needed to further evaluate the relationship between previous fluconazole use and fluconazole-resistant C glabrata BSI isolates with MIC > or =64 microg/mL.

Candida in the ICU

Invasive Candida infections are becoming increasingly recognized in critically ill patients. These infections result in serious morbidity, can be life threatening, and are expensive to manage. Early suspicion of Candida infection and the use of timely and proper antifungal treatment can improve outcome. Although treatment of documented, deep-seated Candida infections in nonneutropenic patients has been studied extensively, guidelines for the management of suspected but undocumented cases of invasive Candida infections in critically ill patients have not been clearly established. Future work should focus on better delineation of the sector of critically ill patients who have suspected invasive Candida infection and who could benefit from the use of empiric antifungal therapy, and on the investigation of novel approaches for the potential salvage of devices infected with Candida species.