Emerging evidence of selection of fluconazole-tolerant fungi in surgical intensive care units

Invasive Fungal Breakthrough Infections under Targeted Echinocandin Prophylaxis in High-Risk Liver Transplant Recipients

Invasive fungal infections (IFIs) are frequent and outcome-relevant complications in the early postoperative period after orthotopic liver transplantation (OLT). Recent guidelines recommend targeted antimycotic prophylaxis (TAP) for high-risk liver transplant recipients (HR-LTRs). However, the choice of antimycotic agent is still a subject of discussion. Echinocandins are increasingly being used due to their advantageous safety profile and the increasing number of non-albicans Candida infections. However, the evidence justifying their use remains rather sparse. Recently published data on breakthrough IFI (b-IFI) raise concerns about echinocandin efficacy, especially in the case of intra-abdominal candidiasis (IAC), which is the most common infection site after OLT. In this retrospective study, we analyzed 100 adult HR-LTRs undergoing first-time OLT and receiving echinocandin prophylaxis between 2017 and 2020 in a tertiary university hospital. We found a breakthrough incidence of 16%, having a significant impact on postoperative complications, graft survival, and mortality. The reasons for this may be multifactorial. Among the pathogen-related factors, we identified the breakthrough of Candida parapsilosis in 11% of patients and one case of persistent IFI due to the development of a secondary echinocandin resistance of an IAC caused by Candida glabrata. Consequently, the efficacy of echinocandin prophylaxis in liver transplantation should be questioned. Further studies are necessary to clarify the matter of breakthrough infections under echinocandin prophylaxis.

Incidence of Invasive Fungal Infections in Liver Transplant Recipients under Targeted Echinocandin Prophylaxis

Invasive fungal infections (IFIs) are one of the most important infectious complications after liver transplantation, determining morbidity and mortality. Antimycotic prophylaxis may impede IFI, but a consensus on indication, agent, or duration is still missing. Therefore, this study aimed to investigate the incidence of IFIs under targeted echinocandin antimycotic prophylaxis in adult high-risk liver transplant recipients. We retrospectively reviewed all patients undergoing a deceased donor liver transplantation at the Medical University of Innsbruck in the period from 2017 to 2020. Of 299 patients, 224 met the inclusion criteria. We defined patients as being at high risk for IFI if they had two or more prespecified risk factors and these patients received prophylaxis. In total, 85% (190/224) of the patients were correctly classified according to the developed algorithm, being able to predict an IFI with a sensitivity of 89%. Although 83% (90/109) so defined high-risk recipients received echinocandin prophylaxis, 21% (23/109) still developed an IFI. The multivariate analysis identified the age of the recipient (hazard ratio-HR = 0.97, p = 0.027), split liver transplantation (HR = 5.18, p = 0.014), massive intraoperative blood transfusion (HR = 24.08, p = 0.004), donor-derived infection (HR = 9.70, p < 0.001), and relaparotomy (HR = 4.62, p = 0.003) as variables with increased hazard ratios for an IFI within 90 days. The fungal colonization at baseline, high-urgency transplantation, posttransplant dialysis, bile leak, and early transplantation showed significance only in a univariate model. Notably, 57% (12/21) of the invasive Candida infections were caused by a non-albicans species, entailing a markedly reduced one-year survival. The attributable 90-day mortality rate of an IFI after a liver transplant was 53% (9/17). None of the patients with invasive aspergillosis survived. Despite targeted echinocandin prophylaxis, there is still a notable risk for IFI. Consequently, the prophylactic use of echinocandins must be critically questioned regarding the high rate of breakthrough infections, the increased occurrence of fluconazole-resistant pathogens, and the higher mortality rate in non-albicans Candida species. Adherence to the internal prophylaxis algorithms is of immense importance, bearing in mind the high IFI rates in case algorithms are not followed.

Candiduria: Evidence-based approach to management, are we there yet?

Candiduria is considered one of the most controversial issues in patient management. Neither the diagnosis nor the optimal treatment options are standardized. This is further complicated by lack of defined laboratory criteria for diagnosis as most of the studies were set for bacterial rather than fungal urinary tract infection (UTI). Furthermore, since Candida species is a known commensal of the genitourinary tract its presence in the urine sample adds ambiguity to making a definitive diagnosis of candidal UTI. Guidelines for diagnosis and management of candiduria have changed considerably over the past decades. In 1960s, the condition was believed to be benign with no intervention required. However, over the years new dimensions were added to address the issues associated with candiduria until the latest Infectious Diseases Association of America (IDSA) guidelines were published in 2009, which indicated that there was an increase in the incidence of candiduria caused by more resistant non-Candida albicans species. Further complicating the issue is the observation that candiduria may be the only indicator of a more serious invasive candidiasis, especially in immunocompromised patients. Long-term urinary catheterization is considered to be the most significant risk factor for candiduria followed by antibiotic use and diabetes. Strategies for management are based on the evaluation of candiduria in the context of the clinical setting to determine its relevance and make an appropriate decision about the need for antifungal therapy. Fluconazole is the main drug used for its efficacy and least complications. Other options include bladder irrigation with amphotericin B, flucytosine or parenteral amphotericin B. Since azoles other than fluconazole and all echinocandins are poorly excreted in urine they have been found to be less effective in candiduric patients.

First isolation of Candida wangnamkhiaoensis from the blood of immunocompromised paediatric patient

Candida wangnamkhiaoensis is a species clustered under the Hyphopichia clade has not ever been isolated from any clinical specimens. To the best of our knowledge, this is the first report of C. wangnamkhiaoensis associated with fungaemia in immunocompromised paediatric patient. The isolate was assigned a strain name as UZ1679/14, in which the identification was confirmed by a polymerase chain reaction-sequencing of the internal transcribed spacer (ITS) and large subunit (LSU) regions of the rRNA gene. Antifungal susceptibility pattern showed that the isolate was sensitive to anidulafungin, caspofungin, fluconazole and voriconazole. The patient clinically improved after the antifungal treatment with caspofungin.

Temporal Trends in Blood Stream Infection Isolates from Surgical Patients

BACKGROUND

Blood stream infections (BSIs) are a common source of morbidity and death in hospitalized patients. We hypothesized that the proportions of bacteremia from gram-positive and fungal pathogens have decreased over time, whereas rates of gram-negative bacteremia have increased as a result of better central venous catheter management.

METHODS

All U.S. Centers for Disease Control and Prevention-defined BSIs in patients treated on the general surgery and trauma services at our institution between January 1, 1998, and December 31, 2009 were identified prospectively. These cases were analyzed on a yearly basis to compare rates of various infections over time. The Cochran-Armitage test for trend was used to evaluate categorical data, whereas the Jonckheere-Terpstra test for ordered values was used to analyze continuous data.

RESULTS

A total of 1,040 patients had 1,441 episodes of BSI caused by 1,632 strains of bacteria or fungi. There was no difference over time in the proportion of BSI among overall infections. Rates of BSI for gram-negative and fungal pathogens increased over time (p=0.03 and<0.0001, respectively), whereas rates of gram-positive BSI decreased (p<0.0001). Positive changes in anaerobic BSI approached statistical significance.

CONCLUSION

Although our hypothesis was only partly true, over the last 12 y, our institution clearly has witnessed a shift in the types of organisms causing BSIs. There was a decrease in the rates of BSI caused by gram-positive pathogens with an associated increase in the rates of BSI of infections by fungal and gram-negative pathogens. Interventions to reduce institutional rates of BSI should include targeted therapies based on historical institutional trends.

Outcomes associated with routine systemic antifungal therapy in critically ill patients with Candida colonization

PURPOSE

To assess the evolution of patient deep colonization by Candida spp. in a surgical ICU over an 8-year period.

METHODS

This retrospective, observational study included all patients hospitalized for more than 2 days in a surgical and trauma ICU of a university hospital, from 2005 to 2012. Mycological samples were monitored weekly from five sites (oropharyngeal, rectal, gastric, tracheal and urinary). Preemptive fluconazole therapy was started in patients highly colonized with Candida albicans. The evolution in Candida spp. involved in the deep colonization sites distribution over the study period (main outcome measure, trend chi-square and time-series analysis), antifungal consumption, ICU-acquired candidemia and mortality were determined.

RESULTS

Among the 3029 patients with ICU stay >48 h, 2651 had at least one set of mycological sampling. Thirty percent of the 31,171 samples were positive to Candida spp. Caspofungin consumption increased over the years, whereas fluconazole consumption decreased. No trend in C. albicans colonization was observed, after adjusting on colonization risk-factors. A significant increase of acquired C. glabrata colonization was observed, whereas the clearing of C. parapsilosis colonization significantly decreased. No significant shift of colonization to other Candida spp. and mortality was observed.

CONCLUSIONS

Preemptive strategy of antifungal drug prescriptions in highly colonized ICU patients induced an increase in C. glabrata colonization without significant shift of colonization to other Candida spp. in surgical ICU patients. However, the potential detrimental impact of fluconazole on Candida ecology in ICU and/or on Candida susceptibility to antifungal drugs should be considered, and deserves further studies.

Resistant pathogens, fungi, and viruses

Although originally described in Staphylococcus aureus, resistance among bacteria has now become a race to determine which classes of bacteria will become more resistant. Availability of antibacterial agents has allowed the development of entirely new diseases caused by nonbacterial pathogens, related largely to fungi that are inherently resistant to antibacterials. This article presents the growing body of knowledge of the herpes family of viruses, and their occurrence and consequences in patients with concomitant surgical disease or critical illness. The focus is on previously immunocompetent patients, as the impact of herpes viruses in immunosuppressed patients has received thorough coverage elsewhere.

Early state research on antifungal natural products

Nosocomial infections caused by fungi have increased greatly in recent years, mainly due to the rising number of immunocompromised patients. However, the available antifungal therapeutic arsenal is limited, and the development of new drugs has been slow. Therefore, the search for alternative drugs with low resistance rates and fewer side effects remains a major challenge. Plants produce a variety of medicinal components that can inhibit pathogen growth. Studies of plant species have been conducted to evaluate the characteristics of natural drug products, including their sustainability, affordability, and antimicrobial activity. A considerable number of studies of medicinal plants and alternative compounds, such as secondary metabolites, phenolic compounds, essential oils and extracts, have been performed. Thus, this review discusses the history of the antifungal arsenal, surveys natural products with potential antifungal activity, discusses strategies to develop derivatives of natural products, and presents perspectives on the development of novel antifungal drug candidates.

Aggressive versus conservative initiation of antimicrobial treatment in critically ill surgical patients with suspected intensive-care-unit-acquired infection: a quasi-experimental, before and after observational cohort study

BACKGROUND

Antimicrobial treatment in critically ill patients can either be started as soon as infection is suspected or after objective data confirm an infection. We postulated that delaying antimicrobial treatment of patients with suspected infections in the surgical intensive care unit (SICU) until objective evidence of infection had been obtained would not worsen patient mortality.

METHODS

We did a 2-year, quasi-experimental, before and after observational cohort study of patients aged 18 years or older who were admitted to the SICU of the University of Virginia (Charlottesville, VA, USA). From Sept 1, 2008, to Aug 31, 2009, aggressive treatment was used: patients suspected of having an infection on the basis of clinical grounds had blood cultures sent and antimicrobial treatment started. From Sept 1, 2009, to Aug 31, 2010, a conservative strategy was used, with antimicrobial treatment started only after objective findings confirmed an infection. Our primary outcome was in-hospital mortality. Analyses were by intention to treat.

FINDINGS

Admissions to the SICU for the first and second years were 762 and 721, respectively, with 101 patients with SICU-acquired infections during the aggressive year and 100 patients during the conservative year. Compared with the aggressive approach, the conservative approach was associated with lower all-cause mortality (13/100 [13%] vs 27/101 [27%]; p=0·015), more initially appropriate therapy (158/214 [74%] vs 144/231 [62%]; p=0·0095), and a shorter mean duration of therapy (12·5 days [SD 10·7] vs 17·7 [28·1]; p=0·0080). After adjusting for age, sex, trauma involvement, acute physiology and chronic health evaluation (APACHE) II score, and site of infection, the odds ratio for the risk of mortality in the aggressive therapy group compared with the conservative therapy group was 2·5 (95% CI 1·5-4·0).

INTERPRETATION

Waiting for objective data to diagnose infection before treatment with antimicrobial drugs for suspected SICU-acquired infections does not worsen mortality and might be associated with better outcomes and use of antimicrobial drugs.

FUNDING

National Institutes of Health.

Economic considerations of antifungal prophylaxis in patients undergoing surgical procedures

Fungi are a frequent cause of nosocomial infections, with an incidence that has increased significantly in recent years, especially among critically ill patients who require intensive care unit (ICU) admission. Among ICU patients, postsurgical patients have a higher risk of Candida infections in the bloodstream. In consideration of the high incidence of fungal infections in these patients, their strong impact on mortality rate, and of the difficulties in Candida diagnosis, some experts suggest the use of antifungal prophylaxis in critically ill surgical patients. A clinical benefit from this strategy has been demonstrated, but the economic impact of the use of antifungal prophylaxis in surgical patients has not been systematically evaluated, and its cost-benefit ratio has not been defined. Whereas the costs associated with treating fungal infections are very high, the cost of antifungal drugs varies from affordable (ie, the older azoles) to expensive (ie, echinocandins, polyenes, and the newer azoles). Adverse drug-related effects and the possibly increased incidence of fluconazole resistance and of isolates other than Candida albicans must also be taken into account. From the published studies of antifungal prophylaxis in surgical patients, a likely economic benefit of this strategy could be inferred, but its usefulness and cost-benefits should be evaluated in light of local data, because the available evidence does not permit general recommendations.

Impact of the transcriptional regulator, Ace2, on the Candida glabrata secretome

Candida glabrata is a major fungal pathogen of humans, and the virulence of C. glabrata is increased by inactivation of the transcription factor, Ace2. Our previous examination of the effects of Ace2 inactivation upon the intracellular proteome suggested that the hypervirulence of C. glabrata ace2 mutants might be caused by differences in the secretome. Therefore in this study we have characterised the C. glabrata secretome and examined the effects of Ace2 inactivation upon this extracellular proteome. We have identified 31 distinct proteins in the secretome of wild-type C. glabrata cells by MS/MS of proteins that were precipitated from the growth medium and enriched by affinity chromatography on concanavalin A. Most of these proteins are predicted to be cell wall proteins, cell wall modifying enzymes and aspartyl proteinases. The endochitinase Cts1 and the endoglucanase Egt2 were not detected in the C. glabrata secretome following Ace2 inactivation. This can account for the cell separation defect of C. glabrata ace2 cells. Ace2 inactivation also resulted in the detection of new proteins in the C. glabrata secretome. The release of such proteins might contribute to the hypervirulence of ace2 cells.

To treat or not to treat--critically ill patients with candiduria

The prevalence of candiduria has increased in patients admitted to intensive care units (ICUs) and it has emerged as a common nosocomial infection among critically ill patients. Generally, urinary candidiasis should be regarded as a risk factor for invasive candidiasis, but not as a disease that needs to be treated on its own. However, decision-making in critically ill patients with candiduria may become a balancing act, because candiduria may be the only indication for invasive candidaemia with significant morbidity and mortality. Of further concern, there is a worldwide increase in the incidence of non-albicans spp. isolated from urine with highly variable susceptibility to fluconazole, which has been the first-line therapy for Candida infections during the last decades. This article discusses everyday problems with urinary candidiasis in interdisciplinary ICUs.

[Role of anidulafungin in critically ill patients]

The most frequent invasive fungal infections in critically ill patients are invasive candidiasis, among which is candidemia. In the last few years, these infections have become more common in intensive care units (ICU), including those produced by species other than Candida albicans. This phenomenon may lead to the development of species resistant to antifungal agents. To start the most appropriate treatment, early diagnosis of the infection is essential, which would reduce empirical antibiotic treatment and increase the proportion of advanced or directed antibiotic therapy. Given the poor reliability of the available diagnostic techniques, new strategies are currently being employed in the ICU, such as the use of scores to evaluate the presence of fungal infections. The therapeutic arsenal against these infections has been increased and the introduction of anidulafungin represents the addition of a highly appropriate drug for the treatment of invasive candidiasis in immunocompetent critically ill patients.

Risk factors for albicans and non-albicans candidemia in the intensive care unit

OBJECTIVE

To determine risk factors for bloodstream infections (BSI) with Candida non-albicans (C-NA) species and Candida albicans (CA) among critically ill patients.

DESIGN

Case-control study.

SETTING

Adult medical and surgical intensive care units (ICUs) at two university hospitals.

PATIENTS

Consecutive patients with C-NA and CA BSIs from 1995-2005 formed the two case groups. Controls were patients without candidemia who were randomly selected in a ratio of 5:1 and matched by study hospital, ICU type (medical vs. surgical) and by ICU admission date within a 3-month period.

INTERVENTIONS

Data collected included demographics, comorbidities, exposure to antibiotics and antifungals, and ICU factors such as total parenteral nutrition (TPN), blood product transfusions, invasive procedures, central venous catheters, hemodialysis, and mechanical ventilation. We built multivariable logistic regression models, which identified risk factors for C-NA or CA BSIs compared with controls. Variables were adjusted for time-at-risk.

MEASUREMENTS AND MAIN RESULTS

There were 67 patients with C-NA BSIs, 79 patients with CA BSIs, and 780 controls. In multivariable models, factors associated with an increased risk of C-NA compared with controls included major pre-ICU operations [odds ratio; (95% confidence interval)] [2.12; (1.14-3.97)], gastrointestinal procedures [2.24; (1.49-3.38)], enteric bacteremia [3.43; (1.39-8.48)], number of hemodialysis days [6.20; (2.67-14.4)], TPN duration [2.87; (1.40-5.90)], and mean number of red blood cell transfusions [2.72; (1.33-5.58)]. Factors associated with an increased risk of CA BSIs compared to controls were very similar and included major ICU operations [1.26; (1.14-3.97)], enteric bacteremia [3.45; (1.38-8.63)], number of hemodialysis days [3.84; (1.75-8.40)], TPN duration [11.0; (5.52-21.7)] and mean number of red blood cell transfusions [1.97; (0.98-3.99)].

CONCLUSIONS

We found multiple common risk factors for both non-C. albicans and C. albicans BSIs, however we could not differentiate between these two groups based on clinical characteristics alone.

Management of Candida infections in the adult intensive care unit

The epidemiology of Candida infection in intensive care units (ICUs) and the management strategies for such infections in non-neutropenic intensive care patients are discussed in this review. Candida species are one of the leading causes of nosocomial bloodstream infections and a significant cause of morbidity in patients admitted to the ICU. Prophylactic, pre-emptive and empiric treatment strategies for Candida infections have been explored in ICU patients. Routine prophylaxis should not be administered to the whole population of ICU patients, because the concerns about the selection of azole-resistant Candida strains or the induction of resistance are justified. Treatment of fungal infections is now possible with newer antifungal agents, including newer azoles (e.g., voriconazole, posaconazole) and echinocandins (e.g., micafungin, anidulafungin). However, there is a critical need for improvement in diagnosis of invasive Candida infection in order to provide clinicians the opportunity to intervene earlier in the diseases course.

A Prospective Observational Study of Risk Factors for Candida glabrata in an SICU: Role of Fluconazole

Background

Candida glabrata has emerged as a serious nosocomial pathogen, particularly in surgical intensive care units (SICU).

Purpose

To determine potential risk factors for the emergence of C. glabrata colonization or infection (C/I) in the SICU.

Methods

A prospective observational study was conducted collecting and analyzing variables associated with the development of C/I with C. glabrata versus non- glabrata Candida species in our SICU.

Results

Fourteen patients developed C/I with C. glabrata (cases), while 21 patients developed C/I with non- glabrata Candida species (controls). Univariate analyses identified the following continuous variables as being statistically significant for the development of C/I with C. glabrata: number of days prior to antifungal or penicillin class therapy. The following categorical variables were significant by univariate analyses: any prior use of piperacillin/tazobactam, penicillin class, or fluconazole, or at least 5 days of use of fluconazole. Any prior use of levofloxacin was found to be statistically significant for controls. Multivariate-logistic regression analysis identified more than 5 days of fluconazole use and no prior use of levofloxacin as independent risk factors for the development of C. glabrata C/I in the SICU.

Conclusions

Prior fluconazole use was identified as an independent risk factor for development of C. glabrata C/I.

Surgical critical care: Fungal infections in surgical patients

OBJECTIVE

To review the epidemiology, risk factors, diagnosis, treatment, and prevention of Candida infections in surgical intensive care unit patients.

DESIGN

: Selected review of the literature.

SETTING

Critically ill patients either in an intensive care unit or having undergone a major surgical procedure.

INTERVENTIONS

None.

MAIN RESULTS

Candida infections are the third most common cause of bloodstream infection in the intensive care unit, with increasing numbers of infections due to nonalbicans species. The diagnosis of an invasive fungal infection is difficult, and the risk factors must be recognized and minimized. There is no general consensus about what signs, symptoms, and cultures define a fungal infection. A new 1,3 beta-glucan blood test may assist is the definition of invasive fungal infection. Treatment of fungal infections is now possible with a variety of antifungal agents, with different spectrums of activity, mechanisms of action, and adverse events. Prevention (prophylaxis) is a reasonable strategy in highly selected patients with a significant risk of fungal infection.

CONCLUSION

New antifungal agents and diagnostic tests may improve the outcome of surgical intensive care unit patients with invasive fungal infections. However, agreement about definitions of fungal infection makes study and conclusions of prevention and treatment trials difficult to interpret.

Systematic review and meta-analysis of antifungal agents for preventing fungal infections in liver transplant recipients

A systematic review and meta-analysis was performed to evaluate the benefits and harms of antifungal prophylaxis in liver transplant recipients. Ten randomised trials comparing any prophylactic antifungal regimen with no antifungal agent or with another antifungal regimen were identified from Medline, EMBASE, the Cochrane Library, and other sources. Together, the studies included a total of 1,106 patients. In general, results were consistent across trials despite clinical and methodological heterogeneity. Antifungal prophylaxis did not reduce total mortality (RR 0.84, 95% CI: 0.54-1.3). Fluconazole prophylaxis reduced invasive fungal infections by about 75% (RR 0.28, 95% CI: 0.13-0.57). Although fewer data on prophylactic itraconazole and liposomal amphotericin B were available, indirect comparisons and three direct comparative trials suggested similar efficacy. Fluconazole prophylaxis did not significantly increase colonisation or infection with azole-resistant fungi, although data were limited. A subgroup analysis suggested a dose and duration effect. In conclusion, fluconazole prophylaxis significantly reduces invasive fungal infections in liver transplant recipients and should be instituted in patients at increased risk in the early postoperative period.

Correlation between microdilution, E-test, and disk diffusion methods for antifungal susceptibility testing of posaconazole against Candida spp

Agar-based antifungal susceptibility testing is an attractive alternative to the microdilution method. We examined the correlation between the microdilution, E-test, and disk diffusion methods for posaconazole against Candida spp. A total of 270 bloodstream isolates of Candida spp. with a broad range of posaconazole MICs were tested using the CLSI M27-A2 method for microdilution, as well as the M-44A method and E-test methods for agar-based testing on Mueller-Hinton agar supplemented with 2% glucose and 0.5 microg of methylene blue. MICs and inhibitory zone diameters at the prominent growth reduction endpoint were recorded at 24 and 48 h. The Candida isolates included Candida albicans (n = 124), C. parapsilosis (n = 44), C. tropicalis (n = 41), C. glabrata (n = 36), C. krusei (n = 20), C. lusitaniae (n = 3), and C. dubliniensis (n = 2). The overall concordance (i.e., the percentage of isolates within two dilutions) between the E-test and microdilution was 64.8% at 24 h and 82.6% at 48 h. When we considered an arbitrary breakpoint of < or = 1 microg/ml, the agreement between the E-test and microdilution methods was 87.8% at 24 h and 93.0% at 48 h. The correlation of MICs with disk diffusion zone diameters was better for the E-test than the microdilution method. Zone correlation for diameters produced by the disks of two manufacturers was high, with a Pearson test value of 0.941 at 24 h. The E-test and microdilution MICs show good concordance and interpretative agreement. The disk diffusion zone diameters are highly reproducible and correlate well with both the E-test and the microdilution method, making agar-based methods a viable alternative to microdilution for posaconazole susceptibility testing.

Antifungal prophylaxis in liver transplant patients: a systematic review and meta-analysis

We performed a meta-analysis to determine whether antifungal prophylaxis decreases infectious morbidity and mortality in liver transplant patients. We searched for randomized trials dealing with prophylaxis with systemic antifungal agents. We used a fixed effect model, with risk ratio (RR) and 95% confidence interval (CI); we assessed study quality for heterogeneity and publication bias. Six studies (5 double-blind), for a total of 698 patients, compared fluconazole, itraconazole, or liposomal amphotericin to placebo (5 studies) or oral nystatin. Prophylaxis reduced colonization (RR, 0.45; CI, 0.37-0.55), total proven fungal infections (RR, 0.31; CI, 0.21-0.46), which included both superficial (RR, 0.27; CI, 0.16-0.45) and invasive (RR, 0.33; CI, 0.18-0.59) infections, and mortality attributable to fungal infection (RR, 0.30; CI, 0.12-0.75). Prophylaxis did not affect overall mortality (RR, 1.06; CI, 0.69-1.64) or empiric treatment for suspected fungal infection (RR, 0.80; CI, 0.39-1.67). The beneficial effect of antifungal prophylaxis was predominantly associated with the reduction of Candida albicans infection and mortality attributable to C. albicans. Compared to controls, however, patients receiving prophylaxis experienced a higher proportion of episodes of non-albicans Candida, and in particular of C. glabrata. No beneficial effect on invasive Aspergillus infection was observed. In conclusion, our analysis shows a clear, though limited, beneficial effect of antifungal prophylaxis in liver transplant patients. Concerns about the selection of triazole-resistant Candida strains, however, are realistic, and the potential disadvantages of prophylaxis should be weighed against the established benefits.

The Other Fungi: It's Not Just Candida albicans Anymore

BACKGROUND

Candida albicans continues to be the fungus most often causing disease in surgical patients, but with the treatment of an increasing number of critically ill and immunosuppressed patients, other candidal and non-candidal fungal pathogens are becoming more common.

METHODS

Review of current practice and guidelines.

RESULTS

The presentation and management of non-C. albicans fungal infections differs depending on the genus and species. The availability of newer anti-fungal agents has in many cases improved outcomes or decreased toxicities associated with these diseases.

CONCLUSIONS

Although such infections are still relatively uncommon, a working knowledge of infections with non-C. albicans fungi may be beneficial for surgeons, who are likely to encounter such patients both primarily and in consultation. Prompt recognition and treatment of these diseases should improve outcomes.

Antifungal agents for preventing fungal infections in non-neutropenic critically ill and surgical patients: systematic review and meta-analysis of randomized clinical trials

OBJECTIVES

This study aims to systematically identify and summarize the effects of antifungal prophylaxis in non-neutropenic critically ill adult patients on all-cause mortality and the incidence of invasive fungal infections.

METHODS

Systematic review and meta-analysis of randomized controlled trials in all languages comparing the prophylactic use of any antifungal agent or regimen with placebo, no antifungal or another antifungal agent or regimen in non-neutropenic critically ill adult patients. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2005), MEDLINE (1966 to 2 September 2005) and EMBASE (1980 to week 36, 2005). We also hand-searched reference lists, abstracts of conference proceedings and scientific meetings (1998-2004) and contacted authors of included studies and pharmaceutical manufacturers. The primary outcomes assessed were all-cause mortality and proven invasive fungal infections. Two reviewers independently applied selection criteria, performed quality assessment and extracted data using an intention-to-treat approach. Data were synthesized using the random effects model and expressed as relative risk with 95% confidence intervals.

RESULTS

Twelve unique trials (eight comparing fluconazole and four ketoconazole with no antifungal or a non-absorbable agent) involving 1606 randomized patients were included. For both outcomes of total mortality and invasive fungal infections, almost all trials of fluconazole and ketoconazole separately showed a non-significant risk reduction with prophylaxis. When combined, fluconazole/ketoconazole reduced total mortality by one-quarter (relative risk 0.76, 95% confidence interval 0.59-0.97) and invasive fungal infections by about one-half (relative risk 0.46, 95% confidence interval 0.31-0.68). No significant increase in the incidence of infection or colonization with the azole-resistant fungal pathogens Candida glabrata or Candida krusei was demonstrated, although the confidence intervals of the summary effect measures were wide. Adverse effects requiring treatment discontinuation were not more common amongst patients receiving prophylaxis. Results across all trials were homogeneous despite considerable heterogeneity in clinical and methodological characteristics.

CONCLUSIONS

Prophylaxis with fluconazole or ketoconazole in critically ill patients reduces invasive fungal infections by one-half and total mortality by one-quarter. Although no significant increase in azole-resistant Candida species associated with prophylaxis was demonstrated, trials were not powered to exclude such an effect. In patients at increased risk of invasive fungal infections, antifungal prophylaxis with fluconazole should be considered.

Antifungal agents for preventing fungal infections in non-neutropenic critically ill patients

BACKGROUND

Invasive fungal infections, important causes of morbidity and mortality in critically ill patients, may be preventable with the prophylactic administration of antifungal agents.

OBJECTIVES

This study aims to systematically identify and summarize the effects of antifungal prophylaxis in non-neutropenic critically ill adult patients on all-cause mortality and the incidence of invasive fungal infections.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), (The Cochrane Library, Issue 3, 2005), MEDLINE (1966 to 2 September 2005), and EMBASE (1980 to week 36, 2005). We also handsearched reference lists, abstracts of conference proceedings and scientific meetings (1998 to 2004), and contacted authors of included studies and pharmaceutical manufacturers.

SELECTION CRITERIA

We included randomized controlled trials in all languages comparing the prophylactic use of any antifungal agent or regimen with placebo, no antifungal, or another antifungal agent or regimen in non-neutropenic critically ill adult patients.

DATA COLLECTION AND ANALYSIS

Two authors independently applied selection criteria, performed quality assessment, and extracted data using an intention-to-treat approach. We resolved differences by discussion. We synthesized data using the random effects model and expressed results as relative risk with 95% confidence intervals.

MAIN RESULTS

We included 12 unique trials (eight comparing fluconazole and four ketoconazole with no antifungal or a nonabsorbable agent) involving 1606 randomized patients. For both outcomes of total mortality and invasive fungal infections, almost all trials of fluconazole and ketoconazole separately showed a non-significant risk reduction with prophylaxis. When combined, fluconazole/ketoconazole reduced total mortality by about 25% (relative risk 0.76, 95% confidence interval 0.59 to 0.97) and invasive fungal infections by about 50% (relative risk 0.46, 95% confidence interval 0.31 to 0.68). We identified no significant increase in the incidence of infection or colonization with the azole-resistant fungal pathogens Candida glabrata or C. krusei, although the confidence intervals of the summary effect measures were wide. Adverse effects were not more common amongst patients receiving prophylaxis. Results across all trials were homogeneous despite considerable heterogeneity in clinical and methodological characteristics.

AUTHORS' CONCLUSIONS

Prophylaxis with fluconazole or ketoconazole in critically ill patients reduces invasive fungal infections by one half and total mortality by one quarter. Although no significant increase in azole-resistant Candida species associated with prophylaxis was demonstrated, trials were not powered to exclude such an effect. In patients at increased risk of invasive fungal infections, antifungal prophylaxis with fluconazole should be considered.

Prior antimicrobial therapy and risk for hospital-acquired Candida glabrata and Candida krusei fungemia: a case-case-control study

The incidence of infections caused by Candida glabrata and Candida krusei, which are generally more resistant to fluconazole than Candida albicans, is increasing in hospitalized patients. However, the extent to which prior exposure to specific antimicrobial agents increases the risk of subsequent C. glabrata or C. krusei candidemia has not been closely studied. A retrospective case-case-control study was performed at a university hospital. From 1998 to 2003, 60 patients were identified with hospital-acquired non-C. albicans candidemia (C. glabrata or C. krusei; case group 1). For comparison, 68 patients with C. albicans candidemia (case group 2) and a common control group of 121 patients without candidemia were studied. Models were adjusted for demographic and clinical risk factors, and the risk for candidemia associated with exposure to specific antimicrobial agents was assessed. After adjusting for both nonantimicrobial risk factors and receipt of other antimicrobial agents, piperacillin-tazobactam (odds ratio [OR], 4.15; 95% confidence interval [CI], 1.04 to 16.50) and vancomycin (OR, 6.48; CI, 2.20 to 19.13) were significant risk factors for C. glabrata or C. krusei candidemia. For C. albicans candidemia, no specific antibiotics remained a significant risk after adjusted analysis. Prior fluconazole use was not significantly associated with either C. albicans or non-C. albicans (C. glabrata or C. krusei) candidemia. In this single-center study, exposure to antibacterial agents, specifically vancomycin or piperacillin-tazobactam, but not fluconazole, was associated with subsequent hospital-acquired C. glabrata or C. krusei candidemia. Further studies are needed to prospectively analyze specific antimicrobial risks for nosocomial candidemia across multiple hospital centers.

Proteomic changes associated with inactivation of the Candida glabrata ACE2 virulence-moderating gene

Inactivation of the gene encoding the transcriptional activator Ace2 in the fungal pathogen Candida glabrata results in an almost 200-fold increase in virulence characterised by acute mortality and a massive over-stimulation of the pro-inflammatory arm of the innate immune system. In this study we have adopted a proteomics approach to identify cellular functions regulated by C. glabrata Ace2 that might contribute to this increase in virulence. A two-dimensional polyacrylamide gel electrophoresis map of the C. glabrata proteome was constructed. We identified a total of 123 proteins, 61 of which displayed reproducible and statistically significant alterations in their levels following inactivation of ACE2. Of these, the levels of 32 proteins were elevated, and 29 were reduced in ace2 cells. These data show that Ace2 influences metabolism, protein synthesis, folding and targeting, and aspects of cell growth and polarisation. Some of these functions are likely to contribute to the effects of Ace2 upon the virulence of C. glabrata.

Clinical trials of antifungal prophylaxis among patients in surgical intensive care units: concepts and considerations

BACKGROUND

Fungal infections are important clinical infections in patients in surgical intensive care units. In some institutions, antifungal prophylaxis has become commonplace, and increasing resistance has been reported. However, trials of antifungal prophylaxis are hampered by difficulties in trial design, and the findings may not be generalizable.

METHODS

Issues in clinical trial design are reviewed from existing and theoretical perspectives.

RESULTS

Identification of a primary hypothesis with a sound epidemiological basis is essential. The study must include institutions where fungal infections have a high and well-studied incidence. A high-risk patient population should be identified and enrolled. The agent selected should have an appropriate spectrum, be easily delivered to the population selected, and be cost effective with few adverse events. At present, fluconazole appears to be the best agent for targeted prophylaxis. The primary end point of the study should be based on an easily measured outcome, for example, days free from fungal infection rather than death due to fungal infection.

CONCLUSIONS

Trials of antifungal prophylaxis for patients in surgical intensive care units have had problems in design, and several issues in the conceptual basis of future clinical trials must be addressed.

Prophylaxis of Candida infections in adult trauma and surgical intensive care patients: a systematic review and meta-analysis

OBJECTIVE

To determine whether systemic antifungal prophylaxis decreases infectious morbidity and mortality in nonneutropenic, critically ill, trauma and surgical intensive care unit (ICU) adult patients.

DESIGN

Systematic review and meta-analysis of randomized clinical trials. We used a fixed effect model, with risk ratio (RR) and 95% confidence intervals (CI).

PARTICIPANTS

Patients admitted to ICU after surgery or trauma, with multiple risk factors for fungal infections.

INTERVENTIONS

Nine studies (seven double blind) with a total of 1,226 patients compared ketoconazole (three) or fluconazole (six) to placebo (eight) or no treatment (one).

RESULTS

Prophylaxis with azole was associated with reduced rates of candidemia (RR 0.30, 95% CI 0.10-0.82), mortality attributable to Candida infection (RR 0.25, 95% CI 0.08-0.80), and overall mortality (RR 0.60, 95% CI 0.45-0.81). Time to event analysis showed a significantly lower probability of fungal infections in treated patients. There was no evidence of statistical heterogeneity between studies, and publication bias assessment gave a negative results. There was, however, wide variability in the definition and reporting of some relevant clinical outcomes (e.g., confirmed or suspected infections, colonization) and pooling of these outcome measures was not feasible.

CONCLUSIONS

Prophylaxis of candidal infection among critically ill ICU patients has beneficial effect on certain outcome measures, but additional data from well designed clinical trials and long-term epidemiological observations are needed to provide firm recommendations for the selection of subgroups of patients who would most benefit from prophylaxis and to determine the effect of prophylaxis on fungal resistance patterns.

Impact of selective decontamination of the digestive tract on fungal carriage and infection: systematic review of randomized controlled trials

OBJECTIVE

To determine the impact of the antifungal component of selective decontamination of the digestive tract on fungal carriage, infection and fungaemia.

DESIGN

Meta-analysis of randomized controlled trials of selective decontamination of the digestive tract.

STUDY SELECTION

Data sources included Medline, Embase, Cochrane Register of Controlled Trials, previous meta-analyses, personal communications and conference proceedings, without restriction of language or publication status. All randomized trials were selected that compared oropharyngeal and/or intestinal administration of antifungals amphotericin B or nystatin, as part of selective decontamination protocol, with no treatment in the controls. There were 42 randomized controlled trials with a total of 6,075 critically ill patients.

METHODS

Three reviewers independently applied selection criteria, performed quality assessment and extracted the data. The main outcome measures were patients with fungal carriage, patients with fungal infections and patients with fungaemia. Odds ratios were pooled with the random effect model.

MEASUREMENTS AND RESULTS

Enteral antifungals significantly reduced fungal carriage (odds ratio 0.32, 95% confidence interval 0.19-0.53) and overall fungal infections (0.30, 0.17-0.53). Fungaemia was not significantly reduced in the treatment group (0.89, 0.16-4.95).

CONCLUSIONS

Antifungals, as part of selective decontamination of the digestive tract, reduce fungal carriage and infection but not fungaemia in critically ill patients and may justify the inclusion of an antifungal component in the decontamination protocol.

Candida spp. colonization significance in critically ill medical patients: a prospective study

OBJECTIVE

Multiple-site colonization with Candida species is commonly recognized as a major risk factor for invasive fungal infection in critically ill patients. The fungal colonization density could be of predictive value for the diagnosis of systemic candidiasis in high-risk surgical patients. Little is known about it in the medical ICU setting.

DESIGN AND SETTING

Prospective observational study in the eight-bed medical intensive care unit of a teaching hospital.

SUBJECTS

92 consecutive nonneutropenic patients hospitalized for more than 7 days.

MEASUREMENTS AND RESULTS

The colonization index (ratio of the number of culture-positive surveillance sites for Candida spp. to the number of sites cultured) was calculated weekly upon ICU admission until death or discharge. The 0.50 threshold was reached in 36 (39.1%) patients, almost exclusively in those with detectable fungal colonization upon ICU admission. The duration of broad-spectrum antibiotic therapy was found to be the main factor that independently promoted fungal growth as measured through the colonization index.

CONCLUSIONS

Candida spp. multiple-site colonization is frequently met among the critically ill medical patients. Broad-spectrum antibiotic therapy was found to promote fungal growth in patients with prior colonization. Since most of the invasive candidiasis in the ICU setting are thought to be subsequent to colonization in high-risk patients, reducing antibiotic use could be useful in preventing fungal infections.

Inactivation of transcription factor gene ACE2 in the fungal pathogen Candida glabrata results in hypervirulence

During an infection, the coordinated orchestration of many factors by the invading organism is required for disease to be initiated and to progress. The elucidation of the processes involved is critical to the development of a clear understanding of host-pathogen interactions. For Candida species, the inactivation of many fungal attributes has been shown to result in attenuation. Here we demonstrate that the Candida glabrata homolog of the Saccharomyces cerevisiae transcription factor gene ACE2 encodes a function that mediates virulence in a novel way. Inactivation of C. glabrata ACE2 does not result in attenuation but, conversely, in a strain that is hypervirulent in a murine model of invasive candidiasis. C. glabrata ace2 null mutants cause systemic infections characterized by fungal escape from the vasculature, tissue penetration, proliferation in vivo, and considerable overstimulation of the proinflammatory arm of the innate immune response. Compared to the case with wild-type fungi, mortality occurs much earlier in mice infected with C. glabrata ace2 cells, and furthermore, 200-fold lower doses are required to induce uniformly fatal infections. These data demonstrate that C. glabrata ACE2 encodes a function that plays a critical role in mediating the host-Candida interaction. It is the first virulence-moderating gene to be described for a Candida species.

Assessment of preemptive treatment to prevent severe candidiasis in critically ill surgical patients(*)

OBJECTIVE

To assess the efficacy of a preemptive antifungal therapy in preventing proven candidiasis in critically ill surgical patients.

DESIGN

Before/after intervention study, with 2-yr prospective and 2-yr historical control cohorts.

SETTING

Surgical intensive care unit (SICU) in a university-affiliated hospital.

PATIENTS

Nine hundred and thirty-three patients, 478 in the prospective group and 455 in the control group, with SICU stay > or =5 days.

INTERVENTIONS

During the prospective period, systematic mycological screening was performed on all patients admitted to the SICU, immediately at admittance and then weekly until discharge. A corrected colonization index was used to assess intensity of Candida mucosal colonization. Patients with corrected colonization index > or =0.4 received early preemptive antifungal therapy (fluconazole intravenously: loading dose 800 mg, then 400 mg/day for 2 wks).

MEASUREMENTS AND MAIN RESULTS

End points of this study were the frequency of proven candidiasis, especially SICU-acquired candidiasis. During the retrospective period, 32 patients of 455 (7%) presented with proven candidiasis: 22 (4.8%) were imported and 10 (2.2%) were SICU-acquired cases. During the prospective period, 96 patients with corrected colonization index > or =0.4 of 478 received preemptive antifungal treatment and only 18 cases (3.8%) of proven candidiasis were diagnosed; all were imported infections. Candida infections occurred more frequently in the control cohort (7% vs. 3.8%; p = .03). Incidence of SICU-acquired proven candidiasis significantly decreased from 2.2% to 0% (p < .001, Fisher test). Incidence of proven imported candidiasis remained unchanged (4.8% vs. 3.8%; p = .42). No emergence of azole-resistant Candida species (especially Candida glabrata, Candida krusei) was noted during the prospective period.

CONCLUSIONS

Targeted preemptive strategy may efficiently prevent acquisition of proven candidiasis in SICU patients. Further studies are being performed to assess cost-effectiveness of this strategy and its impact on selection of azole-resistant Candida strains on a long-term basis.

Impact of fluconazole administration on outcomes in critically ill patients

BACKGROUND

Serious infections caused by Candida spp. are an increasingly important cause of morbidity and mortality in critically ill patients. It is unclear which patients will benefit from therapy and at what point to institute treatment.

OBJECTIVE

To evaluate the impact of administration of fluconazole therapy in critically ill trauma patients on mortality, length of hospital stay, incidence of deep-seated fungal infection, and positive fungal cultures from any site.

METHODS

We conducted a retrospective, matched case-control study of 116 critically ill surgical trauma patients who did or did not receive fluconazole. Patients were followed until hospital discharge or death. A consecutive sample of 58 patients who received fluconazole was selected. A parallel group of patients was evaluated, from which 58 were matched with fluconazole-treated patients based on age (+/- 5 y), gender, and APACHE II score (+/- 3).

RESULTS

The groups of patients were well matched, with the exception of central venous catheter placement and broad-spectrum antibiotic use. We found no difference between groups in hospital mortality (21% vs 26%; p = 0.661) or incidence of deep-seated fungal infection (0% vs 2%; p = NS). However, patients receiving fluconazole had a significantly longer stay in both the intensive care unit (ICU) (18 +/- 13 vs 7 +/- 11 days; p < 0.001) and hospital (25 +/- 15 vs 9 +/- 11 days; p < 0.001). Fluconazole patients were significantly more likely to have Candida cultured from sites associated with colonization (43% vs 2%; p < 0.001), possibly explaining why they received fluconazole.

CONCLUSIONS

We were unable to detect a benefit from use of fluconazole in our surgical trauma patient population. Isolation of Candida from the mouth or throat alone, in the absence of correlating clinical signs of infection, should not lead to initiation of fluconazole therapy. Fluconazole use should be reserved for carefully selected patients in the trauma ICU setting.

Potential risk factors for infection with Candida spp. in critically ill patients

The incidence, risk factors and prognostic factors for candidal infection were determined in a prospective study of 280 infected patients. Thirty-one (11%) patients were infected with Candida spp., sub-divided into 18 (58%) with C. albicans, and 13 (42%) with non-albicans spp. (six C. glabrata, three C. parapsilosis, and one each of C. krusei, C. tropicalis, C. guilliermondii and C. lusitaniae). Infection with Candida spp. was always associated with concurrent bacterial infection. By univariate logistic regression analysis, the degree of morbidity and the duration of mechanical ventilation were independent predictive factors for death, but infection with Candida spp., was not. Factors associated with Candida spp. infection were the degree of morbidity, intensive care unit length of stay, alterations of immune response, and the number of medical devices involved. By multivariate logistic regression analysis, the only independent risk factor for candidal infection was intensive care unit length of stay.

Oral versus intravenous therapy in the treatment of systemic mycosis

The great majority of systemic fungal infections require long-term therapy that often extends 6-12 months, particularly in immunosuppressed patients. It can be difficult to comply with this requirement when the drug to be used is only available for intravenous administration, because problems related to maintaining a permeable venous pathway for long periods arise. The availability of an intravenously (IV) and orally (PO) administered drug can solve this problem by making sequential therapy possible. Voriconazole is a new antifungal agent that, apart from satisfying this requirement because it has a high oral bioavailability, presents a broad spectrum of antifungal activity that makes its use possible, a priori, in the initial and/or sequential IV/PO treatment of any systemic mycotic infection. Based on current costs there is potential for savings compared with liposomal amphotericin B.

Antifungal agents for preventing fungal infections in solid organ transplant recipients

BACKGROUND

Invasive fungal infections (IFIs) are important causes of morbidity and mortality in solid organ transplant recipients.

OBJECTIVES

This study aims to systematically identify and summarise the effects of antifungal prophylaxis in solid organ transplant recipients.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (Issue 3, 2003), MEDLINE (1966-June 2003), and EMBASE (1980-June 2003) were searched. Reference lists, abstracts of conference proceedings and scientific meetings (1998-2003) were handsearched. Authors of included studies and pharmaceutical manufacturers were contacted.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in all languages comparing the prophylactic use of any antifungal agent or regimen with placebo, no antifungal, or another antifungal agent or regimen.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied selection criteria, performed quality assessment, and extracted data using an intention-to-treat approach. Differences were resolved by discussion. Data were synthesised using the random effects model and expressed as relative risk (RR) with 95% confidence intervals (95% CI).

MAIN RESULTS

Fourteen unique trials with 1497 randomised participants were included. Antifungal prophylaxis did not reduce mortality (RR 0.90, 95% CI 0.57 to 1.44). In liver transplant recipients, a significant reduction in IFIs was demonstrated for fluconazole (RR 0.28, 95% CI 0.13 to 0.57). Although less data were available for itraconazole and liposomal amphotericin B, indirect comparisons and one direct comparative trial suggested similar efficacy. Fluconazole prophylaxis did not significantly increase invasive infections or colonisation with fluconazole-resistant fungi. In renal and cardiac transplant recipients, neither ketoconazole nor clotrimazole significantly reduced invasive infections. Overall, the strength and precision of comparisons however were limited by a paucity of data.

REVIEWERS' CONCLUSIONS

For liver transplant recipients, antifungal prophylaxis with fluconazole significantly reduces the incidence of IFIs with no definite mortality benefit. Given a 10% incidence of IFI, 14 liver transplant recipients would require fluconazole prophylaxis to prevent one infection. In transplant centres where the incidence of IFIs is high, or in situations where the individual risk is great, antifungal prophylaxis should be considered.

Candidemia: The Impact of Antifungal Prophylaxis in a Surgical Intensive Care Unit

BACKGROUND

Candidemia is fourfold more common in 1990 compared to 1980. In addition, a shift to non-albicans species has occurred in some institutions. Antifungal prophylaxis (AP) is effective in high-risk patients including critically ill surgical patients, but its use has been attributed to a resultant shift to non-albicans candida species. We hypothesized that the use of fluconazole prophylaxis would lead to a decreased incidence of candidemia but a possible increased incidence of resistant species of Candida, especially Candida glabrata (CG).

METHODS

From 1990 to 2002, all patients with candidemia (C) in the surgical intensive care unit (SICU) of a large tertiary care hospital were identified and reviewed retrospectively. Antifungal prophylaxis began in 2000 for high-risk patients. The periods were separated into PRE (1990-2000), and POST prophylaxis (2000-2002).

RESULTS

Excluding the year of the trial studying prophylaxis, (1998; five cases of C) a total of 83 patients developed candidemia: 69 PRE (83%) (1.94/1000 patient days) and 14 POST (17%) (0.76/1000 patient days) (OR 0.44; 95% CI 0.25, 0.78; p = 0.004). In the PRE period C. albicans (45%) and CG (30%) were predominant, whereas in the POST period, CG (9/14, 64%) (p = 0.05), and C. albicans (3/14, 21%) were common. Non-albicans species were 38/69 (55%) PRE and 11/14 (79%) POST, p = 0.14. Mortality in the group was 43/83 (52%) and did not differ PRE/POST or based on treatment. Predictors of SICU mortality (model r2 = 0.61) included hospital length of stay (LOS) (OR 1.14, CI 1.04, 1.25), fever (OR 51.2, CI 2.46, 1064), and broad-spectrum antibiotics (OR 69.7, CI 2.08, 2351), whereas post-transplantation status (OR 0.005, CI 0.00, 0.56), blood sugar <180 mg/dL (OR 0.03, CI 0.01, 0.81), and fungal prophylaxis (OR 0.03, CI 0.01, 0.58) were associated with a decreased risk of mortality.

CONCLUSIONS

Unfortunately, the mortality of candidemia remains high in SICU patients (52%). In the SICU, risk factors for candidemia and mortality are common. However, antifungal prophylaxis has significantly decreased the annual incidence of candidemia without a statistically significant shift to non-albicans pathogens.

Changes in the spectrum and risk factors for invasive candidiasis in liver transplant recipients: prospective, multicenter, case-controlled study

BACKGROUND

This study determines whether the spectrum, risk factors, and outcome of invasive candidiasis in liver transplant recipients have changed.

METHODS

Thirty-five consecutive liver transplant recipients with invasive candidiasis were prospectively studied in a case-controlled, multicenter study. One control was matched with the case for duration of hospitalization and the other for antibiotic use so that risk factors unique in liver transplantation could be elicited.

RESULTS

In matched-pair analysis, antibiotic prophylaxis for spontaneous bacterial peritonitis (odds ratio [OR] 8.3, P=0.002), posttransplant dialysis (OR 7.6, P=0.0009), and retransplantation (OR 16.4, P=0.0018) were independently significant predictors of invasive candidiasis. Candida spp. included C. albicans in 65% of patients, C. glabrata in 21%, C. tropicalis in 9%, C. parapsilosis in 3%, and C. guilliermondii in 3%. Patients with C. albicans infections were less likely to have received antifungal prophylaxis than those with non-albicans Candida infections (13.6% vs. 50%, P=0.04). The mortality rate was 36.1% for the cases and 2.8% for the controls (OR 25.0, 95% confidence interval, 6.2-100.5, P=0.0002). Non-albicans Candida infections (P=0.04) and prior antifungal prophylaxis (P=0.05) correlated with poorer outcome in the cases.

CONCLUSIONS

Our study has identified predictors for Candida infections in the current era that have implications relevant for targeting the prophylaxis toward the high-risk patients. Routine use of antifungal prophylaxis warrants concern given the emergence of non-albicans Candida spp. as significant pathogens after liver transplantation and higher mortality in patients with these infections.

Shifting patterns in the epidemiology of nosocomial Candida infections

The incidence of candidemia--a common and potentially fatal nosocomial infection--has risen dramatically, and this increase has been accompanied by a shift in the infecting pathogen away from Candida albicans to treatment-resistant non-albicans species. Prophylactic azole antifungals, such as fluconazole, may play an important role not only in the management of candidemia but also in the proliferation of hard-to-treat Candida species. In a variety of acute nosocomial settings, IV fluconazole, 400 mg/d, has reduced Candida colonization and infection. A growing body of evidence supports the still controversial contention that the increasing use of azole antifungals is at least partially responsible for the proliferation of treatment-resistant, non-albicans isolates, especially Candida glabrata. Thus, selecting the most appropriate candidates for prophylactic antifungal intervention--ie, those with the highest risk for candidemia--may be indispensable, not only in preventing candidemia, but also in reducing antifungal overuse, which may contribute to the emergence of treatment-resistant Candida isolates.

Detection of seven Candida species using the Light-Cycler system

Due to the limitations of classical methods for the detection of systemic fungal infections and the high mortality rates associated with these infections, it has become essential to develop a quick, sensitive and specific detection assay. By using the Idaho Technologies Light-Cycler system, a qualitative real-time PCR system has been developed for the detection of the leading causes of systemic infection within the genus Candida. The sensitivity of the assay was comparable to previously described PCR methods (1-5 c.f.u. ml(-1)) and, by the use of a single Candida probe, it was able to detect, but not differentiate between, seven species of Candida (Candida albicans, Candida dubliniensis, Candida glabrata, Candida kefyr, Candida krusei, Candida parapsilosis and Candida tropicalis). Single-round amplification on the Light-Cycler allowed rapid turn-around of clinical samples (within one working day) and it was shown to be more sensitive than classical procedures, exposing 39 possible systemic infections that were not detected by blood culture.

Development and evaluation of the nuclisens basic kit NASBA for the detection of RNA from Candida species frequently resistant to antifungal drugs

We describe a Nucleic Acid Sequence Based Amplification (NASBA) protocol to detect 6 different Candida species (Candida krusei, Candida glabrata, Candida inconspicua, Candida dubliniensis, Candida norvegensis, Candida lusitaniae) and compare it to a PCR assay. NASBA showed a sensitivity of 1 Colony Forming Unit and detected RNA from all 6 Candida species within 1 working day. All 5 patients with documented candidiasis showed identical results by both methods. This assay offers a sensitive, specific and fast possibility to detect yeast RNA.

Antifungal drug resistance

The increasing incidence of invasive fungal infections is the result of many factors, including an increasing number of patients with severe immunosuppression. Although new drugs have been introduced to combat this problem, the development of resistance to antifungal drugs has become increasingly apparent, especially in patients who require long-term treatment or who are receiving antifungal prophylaxis, and there is growing awareness of shifts of flora to more-resistant species. The frequency, interpretation, and, in particular, mechanism of resistance to current classes of antifungal agents, particularly the azoles (where resistance has climbed most prominently) are discussed in this review.

Control of morphogenesis in the human fungal pathogen Penicillium marneffei

Fungal pathogens are an increasing threat to human health due to the increasing population of immunocompromised individuals and the increased incidence of treatment-derived infections. Penicillium marneffei is an emerging fungal pathogen endemic to South-east Asia, where it is AIDS defining. Like many other fungal pathogens, P. marneffei is capable of alternating between a filamentous and a yeast growth form, known as dimorphic switching, in response to environmental stimuli. P. marneffei grows in the filamentous form at 25 degrees C and in the yeast form at 37 degrees C. During filamentous growth and in response to environmental cues, P. marneffei undergoes asexual development to form complex multicellular structures from which the infectious agents, the conidia, are produced. At 37 degrees C, P. marneffei undergoes the dimorphic switching program to produce the pathogenic yeast cells. These yeast cells are found intracellularly in the mononuclear phagocyte system of the host and divide by fission, in contrast to the budding mode of division exhibited by most other fungal pathogens. In addition, P. marneffei is evolutionarily distinct from most other dimorphic fungal pathogens and is the only known Penicillium species which exhibits dimorphic growth. The unique evolutionary history of P. marneffei and the rapidly increasing incidence of infection, coupled with the presence of both complex asexual development and dimorphic switching programs in one organism, makes this system a valuable one for the study of morphogenesis and pathogenicity. Recent development of molecular genetic techniques for P. marneffei, including DNA-mediated transformation, have greatly facilitated the study of these two important morphogenetic programs, asexual development and dimorphic switching, and we are beginning to uncover important determinants which control these events. Understand these programs is providing insights into the biology of P. marneffei and its pathogenic capacity.

Candida glabrata, an emerging fungal pathogen, exhibits superior relative cell surface hydrophobicity and adhesion to denture acrylic surfaces compared with Candida albicans

Oral candidosis is a common opportunistic infection in debilitated individuals and Candida glabrata is the second most frequently isolated species from this condition, after Candida albicans. Candidal adherence to various biological or non-biological surfaces is considered a prerequisite for colonization, and pathogenesis of candidal infections, and their relative cell surface hydrophobicity (CSH) is likely to be a possible contributory force involved in this process. Whereas a large body of data on the latter features of C. albicans is available, there is surprisingly little information on C. glabrata. As a comprehensive database on the relative adhesion and CSH of Candida spp. is instructive and useful, we investigated in vitro the latter attributes of 34 oral isolates of C. glabrata and 15 isolates of C albicans. There were remarkable intraspecies differences in both the CSH and the adhesive ability of C. glabrata strains (p < 0.001). Compared with C. albicans, C glabrata demonstrated a four-fold greater CSH value (30.63 +/- 11.20% vs 7.23+/-3.56%, p < 0.0001) and a two-fold greater tendency to adhere to denture acrylic surfaces (75.18 +/- 39.96 vs 30.36+/-9.21, p < 0.0001). A significant positive correlation between CSH and adhesion was also noted for both C. glabrata (r=0.674, p < 0.0001) and C. albicans ( r = 0.636, p < 0.05). When the effect of different incubation conditions on the relative CSH and adherence of C. glabrata was examined, CSH and the adherence to acrylic surfaces of four of six C. glabrata isolates were significantly affected by a reduction of the culture temperature (from 37 degrees C to 25 degrees C). A positive relationship also emerged when the temperature-induced variations in the adherence values were correlated with their relative CSH. These data provide hitherto unavailable archival information on important pathogenic attributes of the two most common oral Candida species that may help explain their predominance in this milieu.

Candidemia as a cause of septic shock and multiple organ failure in nonimmunocompromised patients

OBJECTIVE

To describe outcomes of septic shock and multiple organ failure arising from candidemia.

DESIGN

Secondary cohort analysis of data from the placebo arm of the North American Septic Shock Trial (NORASEPT II), the largest prospective, randomized, double-blind, controlled multiple center study of septic shock conducted to date, with predetermined end point analysis of outcomes.

SETTING

Adult intensive care units in 105 hospitals in the United States and Canada.

SUBJECTS

A cohort of ten purely candidemic patients in septic shock were compared with a cohort of 376 purely bacteremic patients in septic shock. Patients were not immunocompromised, because patients on corticosteroids, with neutropenia, or posttransplantation were excluded from enrollment in NORASEPT II.

MEASUREMENTS AND MAIN RESULTS

Demographic variables, baseline characteristics, 28-day mortality rates, and multiple organ failure were compared for the two cohorts. Candidemic patients were more likely to have a history of underlying renal failure at baseline and to require dialysis at onset of septic shock. Both causes of septic shock are associated with an extremely high severity of illness (Acute Physiology and Chronic Health Evaluation II: candidemic septic shock, 32 +/- 10; bacteremic septic shock, 30 +/- 8; p =.44). More than 70% of patients with candidemia and septic shock were in multiple organ failure at days 3, 7, and 14; patients with candidemic septic shock sustained persistent multiple organ failure and showed delayed recovery from multiple organ failure compared with patients with bacteremic septic shock. Mortality rate at 28 days was 60% in candidemic septic shock and 46% in bacteremic septic shock (p =.38).

CONCLUSIONS

Candidemia with septic shock is infrequent in nonimmunocompromised patients but has a very high mortality rate, a high likelihood of associated multiple organ failure, and possibly a delayed recovery from multiple organ failure. Patients with candidemic septic shock are more likely to have underlying renal failure at baseline.