Invasive fungal infections among organ transplant recipients: results of the Transplant-Associated Infection Surveillance Network (TRANSNET)

Antifungal agents use in a French administrative region

BACKGROUND

The increased use of new costly antifungal agents has led to a considerable increase in pharmaceutical expenditure. In December 2011, the Lorraine Regional Health Agency commissioned the Antibiolor network to evaluate costly antifungal agent stewardship using as reference regional, French, and international recommendations.

METHODS

We performed a regional retrospective multicenter study. The criteria for evaluation were the appropriateness of the indication for treatment, the choice of the agent or of a combination, compliance with dose and treatment duration, and the absence of any alternative.

RESULTS

One hundred and fourteen prescriptions were analyzed, in 7 intensive care units, 4 hematology units, and 1 infectious diseases unit. The indication for costly antifungal treatment was appropriate in 110 cases (96.5%), the choice of the antifungal agent in 102 cases (93%), the dose in 98 cases (89%), treatment duration in 102 cases (93%), and an alternative antifungal treatment was possible in 10 cases (9%). Eighty-two prescriptions (74.5%) complied with the marketing authorization, 19 (17%) were related to a protocol for temporary use, and 9 (8%) were considered as inappropriate.

CONCLUSION

Our results show a high rate of appropriate prescriptions. The easily accessible and regularly updated local recommendations probably resulted in the standardization and optimization of costly antifungal agent prescriptions.

High-dose weekly liposomal amphotericin b antifungal prophylaxis in patients undergoing liver transplantation: a prospective phase II trial

BACKGROUND

To assess the safety and tolerability of high-dose weekly (10 mg/kg) liposomal amphotericin B (LamB) for antifungal prophylaxis in liver transplantation (LT) recipients with predefined risk factors for invasive fungal infection (IFI), a prospective phase II noncomparative trial was performed at our center over a 4-year period.

METHODS

In the selected LT recipients, LamB was administered weekly until hospital discharge after LT for minimum 2 weeks. Criteria for early discontinuing prophylaxis were: (i) any adverse event (AE); (ii) suspicion of IFI. Safety and tolerability were assessed according to the incidence of grades 3 to 4 AEs based on Common Toxicity Criteria (CTC) classification. Post-LT follow-up was of 180 days.

RESULTS

Overall, 76 patients were included. Liposomal amphotericin B was started within a median of 1 (interquartile range, 1-4) day after LT. Overall, 66 of 76 (86.8%) patients completed the prophylaxis, 10 discontinued the study protocol: 6 for infusion-related AE, 4 for suspected IFI. Adverse events consisted of five cases of lumbar pain and one case of thoracic pain which occurred after a median of 1.5 (interquartile range, 1-2) LamB infusions. None of the patients reported CTC grades 3 to 4 hypokalemia, three reported CTC grade 3 acute renal injury, none of which were deemed directly attributable to LamB. No drug-drug interactions with immunosuppressive drugs were reported, and no episode of rejection occurred during the prophylaxis. In only two of the four patients with suspected IFI was the diagnosis of invasive candidiasis confirmed.

CONCLUSION

Our results suggest high-dose weekly LamB may be a safe prophylactic strategy for high-risk LT recipients.

Mononuclear phagocyte-mediated antifungal immunity: the role of chemotactic receptors and ligands

Over the past two decades, fungal infections have emerged as significant causes of morbidity and mortality in patients with hematological malignancies, hematopoietic stem cell or solid organ transplantation and acquired immunodeficiency syndrome. Besides neutrophils and CD4(+) T lymphocytes, which have long been known to play an indispensable role in promoting protective antifungal immunity, mononuclear phagocytes are now being increasingly recognized as critical mediators of host defense against fungi. Thus, a recent surge of research studies has focused on understanding the mechanisms by which resident and recruited monocytes, macrophages and dendritic cells accumulate and become activated at the sites of fungal infection. Herein, we critically review how a variety of G-protein coupled chemoattractant receptors and their ligands mediate mononuclear phagocyte recruitment and effector function during infection by the most common human fungal pathogens.

Opportunistic yeast pathogens: reservoirs, virulence mechanisms, and therapeutic strategies

Life-threatening invasive fungal infections are becoming increasingly common, at least in part due to the prevalence of medical interventions resulting in immunosuppression. Opportunistic fungal pathogens of humans exploit hosts that are immunocompromised, whether by immunosuppression or genetic predisposition, with infections originating from either commensal or environmental sources. Fungal pathogens are armed with an arsenal of traits that promote pathogenesis, including the ability to survive host physiological conditions and to switch between different morphological states. Despite the profound impact of fungal pathogens on human health worldwide, diagnostic strategies remain crude and treatment options are limited, with resistance to antifungal drugs on the rise. This review will focus on the global burden of fungal infections, the reservoirs of these pathogens, the traits of opportunistic yeast that lead to pathogenesis, host genetic susceptibilities, and the challenges that must be overcome to combat antifungal drug resistance and improve clinical outcome.

Could Histoplasma capsulatum Be Related to Healthcare-Associated Infections?

Healthcare-associated infections (HAI) are described in diverse settings. The main etiologic agents of HAI are bacteria (85%) and fungi (13%). Some factors increase the risk for HAI, particularly the use of medical devices; patients with severe cuts, wounds, and burns; stays in the intensive care unit, surgery, and hospital reconstruction works. Several fungal HAI are caused by Candida spp., usually from an endogenous source; however, cross-transmission via the hands of healthcare workers or contaminated devices can occur. Although other medically important fungi, such as Blastomyces dermatitidis, Paracoccidioides brasiliensis, and Histoplasma capsulatum, have never been considered nosocomial pathogens, there are some factors that point out the pros and cons for this possibility. Among these fungi, H. capsulatum infection has been linked to different medical devices and surgery implants. The filamentous form of H. capsulatum may be present in hospital settings, as this fungus adapts to different types of climates and has great dispersion ability. Although conventional pathogen identification techniques have never identified H. capsulatum in the hospital environment, molecular biology procedures could be useful in this setting. More research on H. capsulatum as a HAI etiologic agent is needed, since it causes a severe and often fatal disease in immunocompromised patients.

Two cases of transplant renal artery thrombosis and spontaneous rupture caused by mucormycosis

Mucormycosis is an uncommon infectious complication after renal transplantation and is associated with fatal outcomes. We report 2 cases of transplant renal artery thrombosis and spontaneous rupture caused by mucormycosis. As stenosis, thrombosis, and spontaneous rupture of the transplant renal artery began to occur in both cases after renal transplantation, nephrectomy of the transplanted kidney was performed. Postoperative pathological findings in the transplanted kidney revealed an invasive mucormycosis infection in the renal artery. One patient survived, but the other patient died. This report also presents the diagnosis and treatment processes used for this transplant complication.

Preventing Cryptococcosis-Shifting the Paradigm in the Era of Highly Active Antiretroviral Therapy

Cryptococcosis remains a significant cause of morbidity and mortality among HIV-infected patients, especially in sub-Saharan Africa where it causes up to 20 % of AIDS-related deaths in HIV programs. A new, highly sensitive, and affordable point of care diagnostic test for cryptococcal infection, the lateral flow assay, can detect early sub-clinical cryptococcosis especially in areas with limited laboratory infrastructure. With a prevalence of detectable sub-clinical cryptococcal infection averaging 7.2 % (95 % CI 6.8-7.6 %) among 36 cohorts with CD4 <100 cells/μL in Africa, together with data showing that preemptive fluconazole prevents overt cryptococcal disease in this population, implementing a screen and treat strategy as part of HIV care practice among patients with CD4 <100 cells/μL could prevent the incidence of often fatal cryptococcal meningitis in the setting of the HIV pandemic.

Isavuconazole: a new extended spectrum triazole for invasive mold diseases

ABSTRACT 

Isavuconazole is the first broad spectrum prodrug triazole with efficacy against invasive fungal diseases including aspergillosis and mucormycosis. Characteristics include linear dose-proportional pharmacokinetics, intravenous and oral formulations allowing therapeutic streamlining, once daily dosing, absence of nephrotoxic solubilizing agents and excellent oral bioavailability independent of prandial status and gastric acidity. An open label noncomparator study demonstrated encouraging results for isavuconazole as primary or salvage therapy for a range of fungi including mucormycosis. Isavuconazole had fewer premature drug discontinuations and adverse events in the eye, hepatobiliary and psychiatry systems than the comparator agent, voriconazole in a randomized double-blind clinical trial. Cross-resistance of isavuconazole best correlates with voriconazole. In vitro resistance is not invariably predictive of clinical failure. Isavuconazole signals progress in pharmacokinetics, bioavailability and toxicity/tolerability supported by clinical efficacy from Phase III trials.

Fungal infections in renal transplant patients

Organ transplantation has always been considered to be the standard therapeutic interventions in patients with end-stage organ failure. In 2008, more than 29,000 organ transplants were performed in US. Survival rates among transplant recipients have greatly improved due to better understanding of transplant biology and more effective immunosuppressive agents. After transplant, the extent of the immune response is influenced by the amount of interleukin 2 (IL-2) being produced by the T-helper cells. Transplant immunosuppressive therapy primarily targets T cell-mediated graft rejection. Calcineurin inhibitor, which includes cyclosporine, pimecrolimus and tacrolimus, impairs calcineurin-induced up-regulation of IL-2 expression, resulting in increased susceptibility to invasive fungal diseases. This immunosuppressive state allows infectious complication, leading to a high mortality rate. Currently, overall mortality due to invasive fungal infections (IFIs) in solid organ transplant recipients ranges between 25% and 80%. The risk of IFI following renal transplant is associated with the dosage of immunosuppressive agents given, environmental factors and post-transplant duration. Most fungal infections occur in the first 6 months after transplant because of the use of numerous immunosuppressors. Candida spp. and Cryptococcus spp. are the yeasts most frequently isolated, while most frequent filamentous fungi (molds) isolated are Aspergillus spp. The symptoms of systemic fungal infections are non-specific and early detection of fungal infections and proper therapy are important in improving survival and reducing mortality. This article will provide an insight on the risk factors and clinical presentation, compare variation in treatment of IFIs in renal transplant patients, and evaluate the role of prophylactic therapy in this group of patients. We also report the course and management of two renal transplant recipients admitted to Staten Island University Hospital, both of whom developed pulmonary complications secondary to Aspergillus infection.

Interplay between β herpesviruses and fungal infections in transplant patients: from the bench to the bedside

ABSTRACT 

The studies on the interplay between β-herpesviruses (CMV, human herpes viruses 6 and 7) and fungi in immunocompromised hosts, have demonstrated that a detailed knowledge of the interaction between the host and the above infectious agents may have a significant clinical relevance. β-herpesviruses may directly be associated to different pathological conditions and may indirectly be involved in the development of opportunistic infections (e.g., fungal infections), allograft rejection and decreased patient survival. Recent in vitro and in vivo studies have pointed out the importance of the microbiome, exposure to microbes and the innate immune system in determining the risk of developing infections; such microbial interactions may modulate the expression of the infection, change the microbial pathogenicity, or increase the immunosuppression.

Lung transplantation for cystic fibrosis: results, indications, complications, and controversies

Survival in patients with cystic fibrosis (CF) has improved dramatically over the past 30 to 40 years, with mean survival now approximately 40 years. Nonetheless, progressive respiratory insufficiency remains the major cause of mortality in CF patients, and lung transplantation (LT) is eventually required. Timing of listing for LT is critical, because up to 25 to 41% of CF patients have died while awaiting LT. Globally, approximately 16.4% of lung transplants are performed in adults with CF. Survival rates for LT recipients with CF are superior to other indications, yet LT is associated with substantial morbidity and mortality (∼50% at 5-year survival rates). Myriad complications of LT include allograft failure (acute or chronic), opportunistic infections, and complications of chronic immunosuppressive medications (including malignancy). Determining which patients are candidates for LT is difficult, and survival benefit remains uncertain. In this review, we discuss when LT should be considered, criteria for identifying candidates, contraindications to LT, results post-LT, and specific complications that may be associated with LT. Infectious complications that may complicate CF (particularly Burkholderia cepacia spp., opportunistic fungi, and nontuberculous mycobacteria) are discussed.

Causes of death in a contemporary cohort of patients with invasive aspergillosis

Information regarding the processes leading to death in patients with invasive aspergillosis (IA) is lacking. We sought to determine the causes of death in these patients, the role that IA played in the cause, and the timing of death. The factors associated with IA-related mortality are also analyzed. We conducted a multicenter study (2008-2011) of cases of proven and probable IA. The causes of death and whether mortality was judged to be IA-related or IA-unrelated were determined by consensus using a six-member review panel. A multivariate analysis was performed to determine risk factors for IA-related death. Of 152 patients with IA, 92 (60.5%) died. Mortality was judged to be IA-related in 62 cases and IA-unrelated in 30. The most common cause of IA-related death was respiratory failure (50/62 patients), caused primarily by Aspergillus infection, although also by concomitant infections or severe comorbidities. Progression of underlying disease and bacteremic shock were the most frequent causes of IA-unrelated death. IA-related mortality accounted for 98% and 87% of deaths within the first 14 and 21 days, respectively. Liver disease (HR 4.54; 95% CI, 1.69-12.23) was independently associated with IA-related mortality, whereas voriconazole treatment was associated with reduced risk of death (HR 0.43; 95% CI, 0.20-0.93). In conclusion, better management of lung injury after IA diagnosis is the main challenge for physicians to improve IA outcomes. There are significant differences in causes and timing between IA-related and IA-unrelated mortality and these should be considered in future research to assess the quality of IA care.

Lymphocyte depletion after alemtuzumab induction disrupts intestinal fungal microbiota in cynomolgus monkeys

BACKGROUND

The interactions of specific fungal phylotypes with immune cells have been recently documented; however, little is known whether gut fungal microbiota is influenced by aberrant immune response in immunosuppressive state. This study aimed to define the biologic impact of lymphocyte depletion on gut fungal microbiota and their relationship.

METHODS

Fifteen male cynomolgus monkeys with CD52 antigen negative on erythrocytes were administered intravenously with a single dose (3.0 mg kg body weight) of alemtuzumab. Depletion and repopulation of circulating and mucosal lymphocytes were determined. The dynamic variations of intestinal fungal microbiota were characterized using 18S ribosomal DNA-based molecular techniques.

RESULTS

The fungal microbiota in colonal mucosa was perturbed during lymphocyte depletion, characterized by increased diversity and colonization of Candida albicans, Aspergillus clavatus, and Saccharomyces cerevisiae. The diversity of the fecal fungal population decreased markedly after mucosal lymphocyte depletion, and specific fungal phylotypes, especially Candida albicans, Saccharomyces cerevisiae, and Botryotinia fuckeliana, were expanded (P<0.05). After reconstitution of mucosal lymphocytes, the composition and diversity of the gut fungal microbiota were both recovered. A close association of the community diversity and Candida albicans colonization with T lymphocyte subsets was also identified.

CONCLUSION

Our findings demonstrate that mucosal lymphocyte depletion leads to the dysbiosis of gut fungal microbiota, suggesting its role in maintaining host-fungus homeostasis. The pathophysiologic consequences of this altered fungal colonization might provide novel clues to uncover the underlying mechanism of enteric fungal infection in immunosuppressive therapies.

Fungal diversity and presence of potentially pathogenic fungi in a hospital hot water system treated with on-site monochloramine

Currently, our knowledge of fungal ecology in engineered drinking water systems is limited, despite the potential for these systems to serve as a reservoir for opportunistic pathogens. In this study, hot water samples were collected both prior to and following the addition of monochloramine as an on-site disinfectant in a hospital hot water system. Fungal ecology was then analyzed by high throughput sequencing of the fungal ITS1 region. The results demonstrate that the genera Penicillium, Aspergillus, Peniophora, Cladosporium and Rhodosporidium comprised the core fungal biome of the hospital hot water system. Penicillium dominated the fungal community with an average relative abundance of 88.89% (±6.37%). ITS1 sequences of fungal genera containing potential pathogens such as Aspergillus, Candida, and Fusarium were also detected in this study. No significant change in fungal community structure was observed before and after the initiation of on-site monochloramine water treatment. This work represents the first report of the effects of on-site secondary water disinfection on fungal ecology in premise plumbing system, and demonstrates the necessity of considering opportunistic fungal pathogens during the evaluation of secondary premise plumbing disinfection systems.

Population-based analysis of invasive fungal infections, France, 2001-2010

These infections are underrecognized as a cause of death in the general population and high-risk groups.

To determine the epidemiology and trends of invasive fungal infections (IFIs) in France, we analyzed incidence, risk factors, and in-hospital death rates related to the most frequent IFIs registered in the national hospital discharge database during 2001–2010. The identified 35,876 IFI cases included candidemia (43.4%), Pneumocystis jirovecii pneumonia (26.1%), invasive aspergillosis (IA, 23.9%), cryptococcosis (5.2%), and mucormycosis (1.5%). The overall incidence was 5.9/100,000 cases/year and the mortality rate was 27.6%; both increased over the period (+1.5%, +2.9%/year, respectively). Incidences substantially increased for candidemia, IA, and mucormycosis. Pneumocystis jirovecii pneumonia incidence decreased among AIDS patients (−14.3%/year) but increased in non-HIV–infected patients (+13.3%/year). Candidemia and IA incidence was increased among patients with hematologic malignancies (>+4%/year) and those with chronic renal failure (>+10%/year). In-hospital deaths substantially increased in some groups, e.g., in those with hematologic malignancies. IFIs occur among a broad spectrum of non–HIV-infected patients and should be a major public health priority.

Nosocomial bloodstream infections in a nationwide study: comparison between solid organ transplant patients and the general population

BACKGROUND

The incidence of bloodstream infection (BSI) varies according to the transplanted organ. Mortality can be as high as 24%, with a significant impact on graft survival. Transplantation is a risk factor for multidrug-resistant (MDR) organisms, but comparison with a non-transplanted population in a single large cohort has not been described.

METHODS

This is a prospective nationwide study (16 centers) reporting data on 2364 monomicrobial nosocomial BSIs, comparing 83 episodes in solid organ transplant patients with 2447 BSIs occurring in the general hospital population.

RESULTS

The prevalence of groups of infecting organisms (gram-positive, gram-negative, and fungi) was similar between transplant patients and the general population and a similar crude mortality rate was observed (34.9% in transplant vs. 43.3% in non-transplant patients). Staphylococcus aureus was the single most frequently isolated organism in both groups, and Acinetobacter species was more frequently isolated in the general population. Regarding MDR organisms, Klebsiella species, and Enterobacter species resistant to cefepime, as well as Acinetobacter species resistant to meropenem, were significantly more frequent in transplant patients.

CONCLUSION

Antimicrobial resistance is higher, particularly among gram-negative bacteria in the transplant population, although the overall mortality rate between transplant and non-transplant patients with nosocomial BSI is similar.

Molecular and nonmolecular diagnostic methods for invasive fungal infections

Invasive fungal infections constitute a serious threat to an ever-growing population of immunocompromised individuals and other individuals at risk. Traditional diagnostic methods, such as histopathology and culture, which are still considered the gold standards, have low sensitivity, which underscores the need for the development of new means of detecting fungal infectious agents. Indeed, novel serologic and molecular techniques have been developed and are currently under clinical evaluation. Tests like the galactomannan antigen test for aspergillosis and the β-glucan test for invasive Candida spp. and molds, as well as other antigen and antibody tests, for Cryptococcus spp., Pneumocystis spp., and dimorphic fungi, have already been established as important diagnostic approaches and are implemented in routine clinical practice. On the other hand, PCR and other molecular approaches, such as matrix-assisted laser desorption ionization (MALDI) and fluorescence in situ hybridization (FISH), have proved promising in clinical trials but still need to undergo standardization before their clinical use can become widespread. The purpose of this review is to highlight the different diagnostic approaches that are currently utilized or under development for invasive fungal infections and to identify their performance characteristics and the challenges associated with their use.

Dramatic improvement of severe cryptococcosis-induced immune reconstitution syndrome with adalimumab in a renal transplant recipient

In solid organ transplant recipients, immune reconstitution inflammatory syndrome (IRIS) is a rare complication of cryptococcosis, which may require steroids in its most severe forms. Here, we report the case of a renal transplant recipient who developed severe cryptococcal meningitis-associated IRIS 1 week after immunosuppression reduction. High-dose steroids failed to improve the disease. Finally, a recombinant human monoclonal tumor necrosis factor-α (TNF-α) antagonist, adalimumab, was prescribed, and the patient rapidly experienced dramatic neurological improvement. No IRIS relapse occurred within 14 months following adalimumab discontinuation.

Rate of cyp51A mutation in Aspergillus fumigatus among lung transplant recipients with targeted prophylaxis

OBJECTIVES

The most common mechanism of azole (itraconazole and voriconazole) resistance in Aspergillus fumigatus is a mutation at the cyp51A locus. The aim of our study was to determine the rate of cyp51A mutations in lung transplant recipients (LTR) undergoing targeted antifungal prophylaxis with 12 weeks of voriconazole.

METHODS

We conducted a prospective study that included 22 LTR with A. fumigatus between October 2008 and November 2011. Of those, 10 LTR were colonized with A. fumigatus and 12 had invasive pulmonary aspergillosis.

RESULTS

Four patients were found to have A. fumigatus isolates with a cyp51A mutation, two had colonization and two had invasive pulmonary aspergillosis. The remaining 18 LTR had WT cyp51A A. fumigatus isolates. All A. fumigatus isolates (except one due to mixed growth) were tested for antifungal susceptibility. A total of nine LTR were exposed to azoles prior to A. fumigatus isolation for a median duration of 249 (IQR 99-524) days. Azole exposure preceded the isolation of two mutant isolates and seven WT isolates. None of the cyp51A mutant isolates conferred phenotypic resistance to azoles.

CONCLUSIONS

Targeted antifungal prophylaxis in LTR did not lead to cyp51A resistance mutations in this cohort. Data on larger cohorts who receive universal antifungal prophylaxis are needed.

Burden of fungal disease in Ireland

Our objective was to estimate the burden of fungal disease on the island of Ireland, as part of a coordinated project estimating the global burden. Published epidemiology data describing fungal infection in Ireland were identified. Population and underlying disease data were collected for 2010 and a structured set of assumptions were applied to estimate burden of fungal disease based on immunosuppression, chronic disease, and other demographic information indicating predisposition to fungal infection. From Ireland's population of 6.4 million, we estimate 117, 000 patients develop significant fungal disease each year. By far the most common fungal disease is recurrent Candida vaginitis, with an estimated 95, 000 episodes annually (3000 per 100 000 women). Other fungal diseases which may be less well recognized are severe asthma with fungal sensitization and allergic bronchopulmonary aspergillosis, with estimated episodes per year of 11, 700 and 9000, respectively (182 and 140 per 100, 000 population, respectively). The model also estimates 450 episodes of invasive aspergillosis, 200 of chronic pulmonary aspergillosis, 600 of oesophageal candidiasis and 450 of candidaemia per year (7, 3, 9 and 6 episodes per 100, 000 population, respectively). This is, we believe, the first attempt to estimate the burden of fungal disease in our population and provides a basis for estimating its impact on human health and resource use.

Successful long-term management of invasive cerebral fungal infection following liver transplantation

Central nervous system (CNS) infections after liver transplantation may be fungal in aetiology, with involvement from either common organisms such as Cryptococcus neoformans and Aspergillus spp. as well as less common organisms, such as the Mucorales and Scedosporium spp. Although the mortality of CNS fungal infections was nearly 100% in early series, more recent data has suggested that good outcomes can be achieved. This may be due to both improved diagnostic capabilities, such as the ability to obtain fungal susceptibilities and therapeutic drug levels, and improved therapeutic options, such as the newer triazoles- voriconazole and posaconazole. Due to improved outcomes, issues have now arisen around the long-term tolerability of these agents. The following two cases of invasive cerebral fungal infections following liver transplantation, one with Aspergillus flavus, and the other with Scedosporium boydii/apiospermum highlight the success that can be seen with the modern management of a previously fatal diagnosis. In particular, we highlight the issues around therapeutic monitoring and discontinuation of therapy.

Necrotizing encephalitis caused by disseminated Aspergillus infection after orthotopic liver transplantation

Liver transplantation is the only available treatment for some patients with end-stage liver disease. Despite reduction in mortality rates due to advances related to surgical techniques, intensive medical management and immunosuppressive therapy, invasive fungal infections remain a serious complication in orthotopic liver transplantation. We report the case of an 18-year-old male diagnosed with autoimmune cirrhosis in 2009 who was assessed and listed for liver transplantation for massive variceal hemorrhage. One year after listing a successful orthotopic liver transplantation was performed. Uneventful early recovery was achieved; however, he developed pulmonary and neurological Aspergillus infection 23 and 40 days after surgery, respectively. Antibiotic therapy with voriconazole and amphotericin was started early, with no major response. Neuroimaging revealed multiple right frontal and right parietal lesions with perilesional edema; surgical management of the brain abscesses was performed. A biopsy with periodic acid-Schiff and Gomori stains revealed areas with mycotic microorganisms morphologically consistent with Aspergillus, later confirmed by culture. The patient developed necrotizing encephalitis secondary to aspergillosis and died. Necrotizing encephalitis as a clinical presentation of Aspergillus infection in an orthotopic liver transplant is not common, and even with adequate management, early diagnosis and prompt antifungal treatment, mortality rates remain high.

Antifungal activity of compounds targeting the Hsp90-calcineurin pathway against various mould species

OBJECTIVES

Invasive mould infections are associated with a high mortality rate and the emergence of MDR moulds is of particular concern. Calcineurin and its chaperone, the heat shock protein 90 (Hsp90), represent an important pathway for fungal virulence that can be targeted at different levels. We investigated the antifungal activity of compounds directly or indirectly targeting the Hsp90-calcineurin axis against different mould species.

METHODS

The in vitro antifungal activity of the anticalcineurin drug FK506 (tacrolimus), the Hsp90 inhibitor geldanamycin, the lysine deacetylase inhibitor trichostatin A and the Hsp70 inhibitor pifithrin-μ was assessed by the standard broth dilution method against 62 clinical isolates of Aspergillus spp. and non-Aspergillus moulds (Mucoromycotina, Fusarium spp., Scedosporium spp., Purpureocillium/Paecilomyces spp. and Scopulariopsis spp.)

RESULTS

FK506 had variable antifungal activity against different Aspergillus spp. and was particularly active against Mucor spp. Geldanamycin had moderate antifungal activity against Fusarium spp. and Paecilomyces variotii. Importantly, trichostatin A had good activity against the triazole-resistant Aspergillus ustus and the amphotericin B-resistant Aspergillus terreus as well as the MDR Scedosporium prolificans. Moreover, trichostatin A exhibited synergistic interactions with caspofungin against A. ustus and with geldanamycin against Rhizopus spp. for which none of the other agents showed activity. Pifithrin-μ exhibited little antifungal activity.

CONCLUSIONS

Targeting the Hsp90-calcineurin axis at different levels resulted in distinct patterns of susceptibility among different fungal species. Lysine deacetylase inhibition may represent a promising novel antifungal strategy against emerging resistant moulds.

Overcoming antifungal resistance

Fungal infections have become one of the major causes of morbidity and mortality in immunocompromised patients. Despite increased awareness and improved treatment strategies, the frequent development of resistance to the antifungal drugs used in clinical settings contributes to the increasing toll of mycoses. Although a natural phenomenon, antifungal drug resistance can compromise advances in the development of effective diagnostic techniques and novel antifungals. In this review, we will discuss the advent of cellular-micro- arrays, microfluidics, genomics, proteomics and other state-of-the art technologies in conquering antifungal drug resistance.

Divergent targets of Aspergillus fumigatus AcuK and AcuM transcription factors during growth in vitro versus invasive disease

In Aspergillus nidulans, the AcuK and AcuM transcription factors form a complex that regulates gluconeogenesis. In Aspergillus fumigatus, AcuM governs gluconeogenesis and iron acquisition in vitro and virulence in immunosuppressed mice. However, the function of AcuK was previously unknown. Through in vitro studies, we found that A. fumigatus ΔacuK single and ΔacuK ΔacuM double mutants had impaired gluconeogenesis and iron acquisition, similar to the ΔacuM mutant. Also, the ΔacuK, ΔacuM, and ΔacuK ΔacuM mutants had similar virulence defects in mice. However, the ΔacuK mutant had a milder defect in extracellular siderophore activity and induction of epithelial cell damage in vitro than did the ΔacuM mutant. Moreover, overexpression of acuM in the ΔacuK mutant altered expression of 3 genes and partially restored growth under iron-limited conditions, suggesting that AcuM can govern some genes independently of AcuK. Although the ΔacuK and ΔacuM mutants had very similar transcriptional profiles in vitro, their transcriptional profiles during murine pulmonary infection differed both from their in vitro profiles and from each other. While AcuK and AcuM governed the expression of only a few iron-responsive genes in vivo, they influenced the expression of other virulence-related genes, such as hexA and dvrA. Therefore, in A. fumigatus, while AcuK and AcuM likely function as part of the same complex, they can also function independently of each other. Furthermore, AcuK and AcuM have different target genes in vivo than in vitro, suggesting that in vivo infection stimulates unique transcriptional regulatory pathways in A. fumigatus.

Early invasive pulmonary aspergillosis in a kidney transplant recipient caused by Aspergillus lentulus: first Brazilian report

We report the first Brazilian case of pulmonary invasive aspergillosis caused by Aspergillus lentulus, a new opportunistic Aspergillus species included in the section fumigati that is usually resistant to amphotericin B and azoles.

Randomized trial of micafungin for the prevention of invasive fungal infection in high-risk liver transplant recipients

In this randomized clinical trial comparing micafungin 100 mg with standard-care antifungal prophylaxis (fluconazole, liposomal amphotericin B, or caspofungin) in high-risk liver transplant patients, micafungin 100 mg was noninferior and had a better kidney safety profile.

Background. Invasive fungal infection (IFI) following liver transplant is associated with significant morbidity and mortality. Antifungal prophylaxis is rational for liver transplant patients at high IFI risk.

Methods. In this open-label, noninferiority study, patients were randomized 1:1 to receive intravenous micafungin 100 mg or center-specific standard care (fluconazole, liposomal amphotericin B, or caspofungin) posttransplant. The primary endpoint was clinical success (absence of a proven/probable IFI and no need for additional antifungals) at end of prophylaxis (EOP). Noninferiority (10% margin) of micafungin vs standard care was assessed in the per protocol and full analysis sets. Safety assessments included adverse events and liver and kidney function tests.

Results. The full analysis set comprised 344 patients (172 micafungin; 172 standard care). Mean age was 51.2 years; 48.0% had a Model for End-Stage Liver Disease score ≥20. At EOP (mean treatment duration, 17 days), clinical success was 98.6% for micafungin and 99.3% for standard care (Δ standard care – micafungin [95% confidence interval], 0.7% [−2.7% to 4.4%]) in the per protocol set and 96.5% and 93.6%, respectively (−2.9% [−8.0% to 1.9%]), in the full analysis set. Incidences of drug-related adverse events for micafungin and standard care were 11.6% and 16.3%, leading to discontinuation in 6.4% and 11.6% of cases, respectively. At EOP, liver function tests were similar but creatinine clearance was higher in micafungin- vs standard care–treated patients.

Conclusions. Micafungin was noninferior to standard care as antifungal prophylaxis in liver transplant patients at high risk for IFI. Adverse event profiles and liver function at EOP were similar, although kidney function was better with micafungin.

Clinical Trials Registration. NCT01058174.

Contribution of (1,3)-beta-D-glucan to diagnosis of invasive candidiasis after liver transplantation

Invasive candidiasis (IC) causes high morbidity and mortality rates after liver transplantation, in part due to delayed diagnosis. The fungal cell wall component (1,3)-beta-d-glucan (BG) could be an early biomarker of IC. This preliminary prospective study was designed to evaluate the contribution of BG measurements to the diagnosis of IC after liver transplantation. All consecutive patients who underwent liver transplantation at Henri Mondor Hospital in France between January and June 2013 were enrolled prospectively in the study. They were monitored weekly for colonization by Candida, and colonization index values were calculated. Serum samples were tested for BG (Fungitell; Cape Cod Inc.) at least weekly between liver transplantation and discharge from the hospital. A total of 52 patients (including 39 male patients) were enrolled, with a median age of 55 years (range, 31 to 69 years). The median Model for End-Stage Liver Disease (MELD) score was 27 (range, 6 to 40). Cultures from 42 patients (81%) yielded Candida spp., with the most common Candida species isolated being Candida glabrata (47%). Six cases of documented IC were found for four of the 52 patients. On the day the clinical diagnosis of IC was made, analysis based on combining two sequential BG-positive samples (>146 pg/ml) and a colonization index of ≥0.5 revealed sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) results of 83%, 89%, 50%, and 97.6%, respectively. The detection of BG associated with Candida colonization may be a promising tool based on a high NPV that can rule out IC among high-risk patients.

Efficacy and safety of echinocandins versus triazoles for the prophylaxis and treatment of fungal infections: a meta-analysis of RCTs

Echinocandins and triazoles were proven to be effective antifungal drugs against invasive fungal infections (IFI), which may cause significant morbidity and mortality in immunocompromised patients. The aim of this study was to compare the efficacy and safety between echinocandins and triazoles for the prophylaxis and treatment of fungal infections. PubMed, Embase, and the Cochrane Library were searched to identify relevant randomized controlled trials (RCTs) up to July 2014. The quality of trials was assessed with the Jadad scoring system. The primary outcomes of interest were treatment success, microbiological success, breakthrough infection, drug-related adverse events (AEs), withdrawals due to AEs, and all-cause mortality. Ten RCTs, involving 2,837 patients, were included, as follows: caspofungin versus fluconazole (n = 1), caspofungin versus itraconazole (n = 1), anidulafungin versus fluconazole (n = 1), micafungin versus fluconazole (n = 4), micafungin versus voriconazole (n = 2), and micafungin versus itraconazole (n = 1). Echinocandins and triazoles showed similar effects in terms of favorable treatment success rate [relative risk (RR) = 1.02, 95 % confidence interval (CI), 0.97–1.08], microbiological success rate (RR = 0.98, 95 % CI, 0.90–1.15), breakthrough infection (RR = 1.09; 95 % CI, 0.59–2.01), drug-related AEs (RR = 0.94; 95 % CI, 0.71–1.15), and all-cause mortality (RR = 0.85; 95 % CI, 0.66–1.10) in the prophylaxis and treatment of fungal infections. Additionally, echinocandins were more effective than triazoles for prophylaxis in patients undergoing hematologic malignancies or those who received hematopoietic stem cell transplantation (HSCT; RR = 1.08; 95 % CI, 1.02–1.15). Echinocandins significantly decreased the AE-related withdrawals rate compared with triazoles (RR = 0.47; 95 % CI, 0.33–0.67). This meta-analysis revealed that echinocandins are as effective and safe as triazoles for the prophylaxis and treatment of patients with fungal infections.

[Cerebral aspergillosis and liver transplantation: about one case]

Cerebral invasive aspergillosis is a rare but serious infection. Mortality is still high despite appropriate treatment. We report the case of a patient with liver transplantation in the context of alcoholic cirrhosis and transplanted back seven years later consequently to an ischemic cholangitis. Following an acquired active viral infection by HCV and treated by antiviral combination therapy the patient presented six months after this second operation a cerebral aspergillosis of tumour-like presentation. It rapidly evolved to an unfavourable outcome with intracranial hypertension state. If the therapeutic management is well established, the diagnosis is difficult. This observation allows us to discuss the various diagnostic criteria of cerebral aspergillosis.

Treatment of infections by cryptic Aspergillus species

The best treatment for patients with invasive aspergillosis caused by cryptic Aspergillus species remains uncertain, mainly due to the limited clinical data that have been published so far. In face of this limitation, patients should be treated with standard first-line therapy for invasive aspergillosis, with therapy being modified according to in vitro susceptibility testing. In this review, we summarize the importance of cryptic Aspergillus species in modern medicine, including their prevalence, methods for detection and response to antifungal drugs.

Antifungal prophylaxis in liver transplantation: a systematic review and network meta-analysis

Invasive fungal infections (IFIs) cause significant morbidity and mortality in liver transplant recipients, but the need and best agent for prophylaxis is uncertain. A comprehensive literature search was performed to identify randomized controlled trials comparing regimens for antifungal prophylaxis in liver transplant recipients. Direct comparisons were made between treatments using random-effects meta-analysis and a Bayesian network meta-analysis was performed for the primary end point of proven IFI. Fourteen studies met inclusion criteria, reporting comparisons of fluconazole, liposomal amphotericin B (L-AmB), itraconazole, micafungin and placebo. Overall, antifungal prophylaxis reduced the rate of proven IFI (odds ratio [OR] 0.37, confidence interval [CI] 0.19-0.72, p = 0.003), suspected or proven IFI (OR 0.40, CI 0.25-0.66, p = 0.0003) and mortality due to IFI (OR 0.32, CI 0.10-0.83, p = 0.02) when compared to placebo. All-cause mortality was not significantly affected. There was no difference in risk of adverse events requiring cessation of prophylaxis (OR 1.11, 95% CI 0.48-2.55, p = 0.81). In the network meta-analysis an equivalent reduction in the rate of IFI was seen with fluconazole (OR 0.21, CI 0.06-0.57) and L-AmB (OR 0.21, CI 0.05-0.71) compared with placebo. Routine prophylaxis with fluconazole or L-AmB reduces the incidence of IFI following liver transplantation, and the available evidence suggests that the two are equivalent in efficacy.

Bioactivity-guided isolation and structural characterization of the antifungal compound, plumbagin, from Nepenthes gracilis

CONTEXT

Despite several phytochemical studies of Nepenthes gracilis Korth (Nepenthaceae), the biological activities of this pitcher plant remain to be explored.

OBJECTIVE

This study evaluates the antifungal activity of N. gracilis extracts, isolates, and characterizes its bioactive compound and evaluates the cytotoxicity of the isolated compound.

MATERIALS AND METHODS

Fresh leaves of N. gracilis were sequentially extracted. The fungistatic and fungicidal activities of the extracts were evaluated against six species of fungi of medical importance using a colorimetric broth microdilution method. The most active extract was fractionated by liquid-liquid partitioning and further purified by a preparative thin layer chromatography. Structural elucidation was carried out using FT-IR, GC-MS, and NMR. Cytotoxicity testing against rhesus monkey kidney epithelial cells (LLC-MK2) was assessed by a neutral red uptake (NRU) assay.

RESULTS

The hexane extract, which showed the lowest minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), both at 20 μg/mL against Candida albicans, Issatchenkia orientalis, and Trichophyton mentagrophytes, was subjected to bioactivity-guided fractionation. The isolated compound exhibited potent activity with the MIC values ranging from 2 to 31 μg/mL against all the fungi. The active compound was identified as plumbagin (5-hydroxy-2-methyl-naphthalene-1,4-dione). The 50% cytotoxicity concentration (CC50) of plumbagin was 0.60 μg/mL.

DISCUSSION AND CONCLUSION

The selectivity indices of plumbagin against all the fungi were less than 1.0, indicating that plumbagin is more toxic to mammalian than fungal cells. This study provides information on the antifungal properties of N. gracilis leaf extracts, as well as the antifungal and cytotoxicity properties of plumbagin.