Emerging moulds: Fusarium, Scedosporium and Zygomycetes in transplant recipients

Misleading subcutaneous mycosis: a case report of subsequent clinical mycetoma-like and histological chromoblastomycosis-like lesions

Hyalohyphomycosis and phaeohyphomycosis are groups of mycoses caused by several agents and show different clinical manifestations. We report a case of an immunocompromised patient who presented rare manifestations of opportunistic mycoses: mycetoma-like hyalohyphomycosis on his right foot caused by Colletotrichum gloeosporioides, followed by cutaneous phaeohyphomycosis on his right forearm caused by Exophiala oligosperma. Further to the rarity of this case, the patient's lesion on the foot shows that the clinical aspects of mycetomas could falsely appear in other fungal infections similar to hyalohyphomycosis. We also show that the muriform cells that were seen in the direct and anatomopathological examination of the skin are not pathognomonic of chromoblastomycosis, as observed in the lesion of the patient's forearm.

Recurrent Scedosporium apiospermum Cutaneous Infection in a Patient with Rheumatoid Arthritis: The Potent Role of IL-6 Signaling Pathway Blockade: A Case-Based Review

Rheumatoid arthritis (RA) patients deal with a higher risk of bacterial and fungal infections compared to the general population because of their dysregulated immune system as well as the immunosuppressive therapy they usually receive. Scedosporium spp. is a fungal pathogen responsible for cutaneous, lung, central nervous system, and eye infections, mostly in immunocompromised patients, leading to death in disseminated cases. We report the case of an 81-year-old woman with rheumatoid arthritis treated with steroids and an IL-6 inhibitor who was diagnosed with scedosporiosis of the upper limb. She was treated with voriconazole for one month, which was discontinued due to adverse events, and when scedosporiosis relapsed, she switched to itraconazole. We also reviewed the current literature on RA patients presenting with Scedosporium infections. Early and accurate diagnosis of scedosporiosis has therapeutic and prognostic implications, as traditionally this fungus is resistant to commonly used antifungals. Clinical alertness regarding uncommon infections, including fungal, in patients with autoimmune diseases on immunomodulatory agents is essential for effective treatment.

A Dual-Readout High-Throughput Screening Assay for Small Molecules Active Against Aspergillus Fumigatus

Human fungal infections caused by molds have been on the rise in recent years. These infections have high mortality rates compared to other fungal infections, and yet treatment options are limited due to resistance to clinical antifungals and lack of broad-spectrum activity against molds. Technical challenges associated with molds have limited large-throughput screening efforts for anti-mold compounds: therefore, we adapted an assay for use with A. fumigatus to help fill the gap in robust screening platforms for these organisms. This assay measures the release of the cytosolic enzyme adenylate kinase (AK) as a measure of fungal cell lysis and can also detect inhibition of germination as a reduction in the secretion of AK during vegetative growth. The ability to detect both lysis and inhibition of germination facilitates the identification of a wide range of compounds with different mechanisms of action, creating a strong screening platform for the identification of novel, anti-mold compounds.

Invasive Mold Infections in Allogeneic Hematopoietic Cell Transplant Recipients in 2020: Have We Made Enough Progress?

Background

Despite progress in diagnostic, prevention, and treatment strategies, invasive mold infections (IMIs) remain the leading cause of mortality in allogeneic hematopoietic cell transplant (allo-HCT) recipients.

Methods

We describe the incidence, risk factors, and mortality of allo-HCT recipients with proven/probable IMI in a retrospective single-center 10-year (01/01/2010–01/01/2020) cohort study.

Results

Among 515 allo-HCT recipients, 48 (9.3%) patients developed 51 proven/probable IMI: invasive aspergillosis (IA; 34/51, 67%), mucormycosis (9/51, 18%), and other molds (8/51, 15%). Overall, 35/51 (68.6%) breakthrough IMIs (bIMIs) were identified: 22/35 (62.8%) IA and 13/35 (37.1%) non-IA IMI. One-year IMI cumulative incidence was 7%: 4.9% and 2.1% for IA and non-IA IMI, respectively. Fourteen (29.2 %), 10 (20.8%), and 24 (50.0%) patients were diagnosed during the first 30, 31–180, and >180 days post-HCT, respectively. Risk factors for IMI included prior allo-HCT (sub hazard ratio [SHR], 4.06; P = .004) and grade ≥2 acute graft-vs-host disease (aGvHD; SHR, 3.52; P < .001). All-cause 1-year mortality was 33% (170/515): 48% (23/48) and 31.5% (147/467) for patients with and without IMI (P = .02). Mortality predictors included disease relapse (hazard ratio [HR], 7.47; P < .001), aGvHD (HR, 1.51; P = .001), CMV serology–positive recipients (HR, 1.47; P = .03), and IMI (HR, 3.94; P < .001). All-cause 12-week mortality for patients with IMI was 35.4% (17/48): 31.3% (10/32) for IA and 43.8% (7/16) for non-IA IMI (log-rank P = .47). At 1 year post–IMI diagnosis, 70.8% (34/48) of the patients were dead.

Conclusions

IA mortality has remained relatively unchanged during the last 2 decades. More than two-thirds of allo-HCT recipients with IMI die by 1 year post–IMI diagnosis. Dedicated intensified research efforts are required to further improve clinical outcomes.

A Unique Dual-Readout High-Throughput Screening Assay To Identify Antifungal Compounds with Aspergillus fumigatus

Treatment of invasive mold infections is limited by the lack of adequate drug options that are effective against these fatal infections. High-throughput screening of molds using traditional antifungal assays of growth is problematic and has greatly limited our ability to identify new mold-active agents. Here, we present a high-throughput screening platform for use with Aspergillus fumigatus, the most common causative agent of invasive mold infections, for the discovery of novel mold-active antifungals. This assay detects cell lysis through the release of the cytosolic enzyme adenylate kinase and, thus, is not dependent on changes in biomass or metabolism to detect antifungal activity. The ability to specifically detect cell lysis is a unique aspect of this assay that allows identification of molecules that disrupt fungal cell integrity, such as cell wall-active molecules. We also found that germinating A. fumigatus conidia release low levels of adenylate kinase and that a reduction in this background allowed us to identify molecules that inhibit conidial germination, expanding the potential for discovery of novel antifungal compounds. Here, we describe the validation of this assay and proof-of-concept pilot screens that identified a novel antifungal compound, PIK-75, that disrupts cell wall integrity. This screening assay provides a novel platform for high-throughput screens with A. fumigatus for the identification of anti-mold drugs.

IMPORTANCE Fungal infections caused by molds have the highest mortality rates of human fungal infections. These devastating infections are hard to treat and available antifungal drugs are often not effective. Therefore, the identification of new antifungal drugs with mold activity is critical. Drug screening with molds is challenging and there are limited assays available to identify new antifungal compounds directly with these organisms. Here, we present an assay suitable for use for high-throughput screening with a common mold pathogen. This assay has exciting future potential for the identification of new drugs to treat these fatal infections.

Advances in Supportive Care for Acute Lymphoblastic Leukemia

PURPOSE OF REVIEW

Tremendous advances have been made in the treatment armamentarium for acute lymphoblastic leukemia in recent years, which have substantially improved outcomes for these patients. At the same time, unique toxicities have emerged, and without early intervention, are life-threatening. This article will review the novel therapies in acute leukemias and highlight the clinically relevant supportive care advances.

RECENT FINDINGS

The American Society for Transplantation and Cellular Therapy (ASTCT) has put forth the most recent recommendations in managing the cytokine release syndrome and neurotoxicity after chimeric antigen receptor T cells (CAR-T) and blinatumomab. The hepatic injury incurred by inotuzumab, and the vascular toxicity of tyrosine kinase inhibitors, other relatively novel agents, require subspecialist intervention and multidisciplinary care. Asparaginase, a long-established and key element of pediatric regimens, has made a comeback in the young adult leukemia population. Updated guidelines have been outlined for management of asparaginase thrombotic complications. Lastly, although there have been few changes in the applications of growth factor, antimicrobial prophylaxis, and management of neuropathy, these encompass exceedingly important aspects of care. While the rapidly changing treatment paradigms for acute lymphoblastic leukemia have transformed leukemia-specific outcomes, treatment emergent toxicities have forced much necessary attention to better definitions of these toxicities and on improving supportive care guidelines in acute lymphoblastic leukemia.

Invasive Scedosporium and Lomentosora infections in the era of antifungal prophylaxis: A 20-year experience from a single centre in Spain

BACKGROUND

Non-Aspergillus mould infections such as those caused by Scedosporium apiospermum or Lomentospora prolificans are an emerging threat. Few studies have monitored their long-term incidence.

OBJECTIVES

To analyse the epidemiology, risk factors, clinical features and incidence of patients with proven and probable infections.

PATIENTS/METHODS

Patients admitted to Gregorio Marañón Hospital between 1998 and 2017 and from whom Scedosporium/Lomentospora was isolated were studied. Subjects were classified as having a probable/proven invasive fungal infection or colonization. Molecular identification and antifungal susceptibility testing of isolates causing infection were performed, as well as a description of the patients and incidence of infection.

RESULTS

One or more Scedosporium/Lomentospora isolates were identified in 67 patients. Sixteen (23.9%) patients had developed infection: 11 scedosporiosis and 5 lomentosporiosis. Stable incidence was observed throughout the study period. Most patients were immunosuppressed and the most common underlying diseases were haematologic malignancy (25%), solid organ transplantation (25%) and chronic corticoid therapy (25%). Breakthrough infection occurred in four patients, 2/11 (18.2%) cases of scedosporiosis and 2/5 (40%) of lomentosporiosis. Overall mortality was 54.5% (6/11) and 80% (4/5) in subjects with scedosporiosis and lomentosporiosis, respectively. High MICs of amphotericin B and remarkable inter-species susceptibility variability to triazoles was observed for most isolates.

CONCLUSIONS

In contrast to previous studies, the incidence of scedosporiosis and lomentosporiosis has not increased at our hospital over the years. The tendency to cause disseminated infection and a reduced susceptibility to most antifungal agents leads to high mortality.

Review of the Novel Investigational Antifungal Olorofim

The incidence of invasive fungal infections caused by molds and endemic fungi is increasing. There is also concern regarding increased rates of reduced susceptibility or frank resistance among Aspergillus and Coccidioides species, while Scedosporium species, Lomentospora prolificans, and Fusarium species are inherently less susceptible or intrinsically resistant to clinically available antifungals. Olorofim (formerly F901318) is the first member of the orotomide class of antifungals to be evaluated clinically for the treatment of invasive mold infections. This agent inhibits dihydroorotate dehydrogenase, a key enzyme in the biosynthesis of pyrimidines. Olorofim has activity against many molds and thermally dimorphic fungi, including species that are resistant to azoles and amphotericin B, but lacks activity against yeasts and the Mucorales. It is currently being developed for both oral and intravenous administration. Although published clinical outcome data have been limited to case reports to date, the results against invasive and refractory infections are promising. This review describes the mechanism of action of olorofim, its in vitro spectrum of activity, and what is currently known about its pharmacokinetic profile and clinical efficacy.

Fungal Infections of the Stem Cell Transplant Recipient and Hematologic Malignancy Patients

Despite advances in chemotherapy and supportive care, morbidity and mortality remain high for patients with hematologic malignancies (HMs). Those who require hematopoietic stem cell transplantation (HSCT) often require significant immunosuppression and are subject to a variety of complications. These patients carry multiple risk factors for infectious complications, including the development of invasive fungal infections, compared with the general population. Because antifungal prophylaxis has been widely adopted, there has been a shift away from invasive candidiasis toward invasive mold infections, including breakthrough infections. For patients with HM and HSCT, we outline the epidemiology, manifestations, diagnosis, and treatment of invasive fungal infections.

Caenorhabditis elegans as a model animal for investigating fungal pathogenesis

The morbidity and mortality associated with systemic fungal infections in humans cannot be underestimated. The nematode Caenorhabditis elegans has become popular for the in vivo study of the pathogenesis of human fungal pathogens and as an antifungal drug-screening tool. C. elegans offers many advantages as a model organism for the study of human fungal diseases, including lack of ethics requirements, easy maintenance in the laboratory, fully sequenced genome, availability of genetic mutants, and the possibility of liquid assays for high-throughput antifungal screening. Its major drawbacks include the inability to grow at 37 °C and absence of an adaptive immune response. However, several virulence factors involved in the pathogenesis of medically important fungal pathogens have been identified using the C. elegans model, consequently providing new leads for drug discovery and potential drug targets. We review the use of C. elegans as a model animal to understand the pathogenesis of medically important human fungal pathogens and the discovery of novel antifungal compounds. The review makes a case for C. elegans as a suitable invertebrate model for a plethora of practical applications in the investigation of fungal pathogenesis as well as its amenability for liquid-based high-throughput screening of potential antifungal compounds.

Utilization of voriconazole drug monitoring in the treatment of cutaneous Scedosporium apiospermum infection

We report the use of voriconazole troughs to achieve appropriate therapeutic levels in treatment of a cutaneous Scedosporium apiospermum infection. Following heart transplantation, a 63-year-old immunocompromised patient presented with post-traumatic nodular lesions on his right shin. Pathology showed fungal yeasts with culture revealing Scedosporium apiospermum. According to therapeutic drug monitoring, initial voriconazole treatment was subtherapeutic requiring increased dosing until appropriate therapeutic trough levels were attained, and resolution of the fungal infection was achieved.

Molecular Identification and Susceptibility Testing of Molds Isolated in a Prospective Surveillance of Triazole Resistance in Spain (FILPOP2 Study)

Antifungal resistance is increasing by the emergence of intrinsically resistant species and by the development of secondary resistance in susceptible species. A previous study performed in Spain revealed levels of azole resistance in molds of between 10 and 12.7%, but secondary resistance in Aspergillus fumigatus was not detected. We used itraconazole (ITZ)-supplemented medium to select resistant strains. A total of 500 plates supplemented with 2 mg/liter of ITZ were sent to 10 Spanish tertiary hospitals, and molecular identification and antifungal susceptibility testing were performed. In addition, the cyp51A gene in those A. fumigatus strains showing azole resistance was sequenced. A total of 493 isolates were included in the study. Sixteen strains were isolated from patients with an infection classified as proven, 104 were isolated from patients with an infection classified as probable, and 373 were isolated from patients with an infection classified as colonization. Aspergillus was the most frequent genus isolated, at 80.3%, followed by Scedosporium-Lomentospora (7.9%), Penicillium-Talaromyces (4.5%), Fusarium (2.6%), and the order Mucorales (1%). Antifungal resistance was detected in Scedosporium-Lomentospora species, Fusarium, Talaromyces, and Mucorales Three strains of A. fumigatus sensu stricto were resistant to azoles; two of them harbored the TR₃₄+L98H mechanism of resistance, and the other one had no mutations in cyp51A The level of azole resistance in A. fumigatus remains low, but cryptic species represent over 10% of the isolates and have a broader but overall higher range of antifungal resistance.

Successful treatment of bilateral endogenous Fusarium solani endophthalmitis in a patient with acute lymphocytic leukaemia

Fusarium spp. are an uncommon cause of fungaemia in immunocompromised and neutropenic patients that may hematogenously disseminate to the eyes. Herein, we describe a patient with acute lymphoblastic leukaemia and a prior history of extensive corticosteroid exposure who developed disseminated Fusarium solani infection following chemotherapy despite posaconazole prophylaxis. She was successfully treated with combination liposomal amphotericin B and voriconazole, intraocular injections of voriconazole, topical amphotericin B and bilateral vitrectomy. We also review published literature describing the management of endogenous Fusarium endophthalmitis in immunocompromised hosts.

Antifungal resistance: current trends and future strategies to combat

Antifungal resistance represents a major clinical challenge to clinicians responsible for treating invasive fungal infections due to the limited arsenal of systemically available antifungal agents. In addition current drugs may be limited by drug-drug interactions and serious adverse effects/toxicities that prevent their prolonged use or dosage escalation. Fluconazole resistance is of particular concern in non-Candida albicans species due to the increased incidence of infections caused by these species in different geographic locations worldwide and the elevated prevalence of resistance to this commonly used azole in many institutions. C. glabrata resistance to the echinocandins has also been documented to be rising in several US institutions, and a higher percentage of these isolates may also be azole resistant. Azole resistance in Aspergillus fumigatus due to clinical and environmental exposure to this class of agents has also been found worldwide, and these isolates can cause invasive infections with high mortality rates. In addition, several species of Aspergillus, and other molds, including Scedosporium and Fusarium species, have reduced susceptibility or pan-resistance to clinically available antifungals. Various investigational antifungals are currently in preclinical or clinical development, including several of them that have the potential to overcome resistance observed against the azoles and the echinocandins. These include agents that also target ergosterol and b-glucan biosynthesis, as well as compounds with novel mechanisms of action that may also overcome the limitations of currently available antifungal classes, including both resistance and adverse effects/toxicity.

Invasive fungal infection in patients with hematologic disorders in a Brazilian tertiary care hospital

INTRODUCTION:

Invasive fungal infections (IFIs) are an important complication in immunocompromised individuals, particularly neutropenic patients with hematological malignancies. In this study, we aimed to verify the epidemiology and diagnosis of IFIs in patients with hematologic problems at a tertiary hospital in Goiânia-GO, Brazil.

METHODS:

Data from 117 patients, involving 19 cases of IFIs, were collected. The collected data included diagnosis methods, demographics, clinical characteristics, and in vitro susceptibility to different antifungal agents. Among the 19 cases, 12 were classified as proven IFI and 7 as probable invasive aspergillosis with detection of galactomannan in blood and presence of lung infiltrates in radiographic images. Logistic regression analysis showed that the proven and probable IFIs were associated with increased risk of death. Statistical analysis demonstrated that age, sex, and underlying disease were not independently associated with risk of death in IFI patients.

RESULTS:

Most bloodstream isolates of Candida spp. exhibited low minimum inhibitory concentrations (MICs) to all antifungal agents tested. Voriconazole and amphotericin had the lowest MICs for Aspergillus spp. and Fusarium spp., but Fusarium spp. showed the least susceptibility to all antifungals tested. Amphotericin B, fluconazole, and itraconazole were found to be inactive in vitro against Acremonium kiliense; but this fungus was sensitive to voriconazole.

CONCLUSIONS:

Considering the high number of IFI cases, with crude mortality rate of 6%, we could conclude that IFIs remain a common infection in patients with hematological malignancies and underdiagnosed ante mortem. Thus, IFIs should be monitored closely.

Consensus guidelines for the treatment of invasive mould infections in haematological malignancy and haemopoietic stem cell transplantation, 2014

Mould species represent the pathogens most commonly associated with invasive fungal disease in patients with haematological malignancies and patients of haemopoietic stem cell transplants. Invasive mould infections in these patient populations, particularly in the setting of neutropenia, are associated with high morbidity and mortality, and significantly increase the complexity of management. While Aspergillus species remain the most prevalent cause of invasive mould infections, Scedosporium and Fusarium species and the Mucormycetes continue to place a significant burden on the immunocompromised host. Evidence also suggests that infections caused by rare and emerging pathogens are increasing within the setting of broad-spectrum antifungal prophylaxis and improved survival times placing immunosuppressed patients at risk for longer. These guidelines present evidence-based recommendations for the antifungal management of common, rare and emerging mould infections in both adult and paediatric populations. Where relevant, the role of surgery, adjunctive therapy and immunotherapy is also discussed.

Spectrum of Fusarium infections in tropical dermatology evidenced by multilocus sequencing typing diagnostics

Fusarium species are emerging causative agents of superficial, cutaneous and systemic human infections. In a study of the prevalence and genetic diversity of 464 fungal isolates from a dermatological ward in Thailand, 44 strains (9.5%) proved to belong to the genus Fusarium. Species identification was based on sequencing a portion of translation elongation factor 1-alpha (tef1-α), rDNA internal transcribed spacer and RNA-dependent polymerase subunit II (rpb2). Our results revealed that 37 isolates (84%) belonged to the Fusarium solani species complex (FSSC), one strain matched with Fusarium oxysporum (FOSC) complex 33, while six others belonged to the Fusarium incarnatum-equiseti species complex. Within the FSSC two predominant clusters represented Fusarium falciforme and recently described F. keratoplasticum. No gender differences in susceptibility to Fusarium were noted, but infections on the right side of the body prevailed. Eighty-nine per cent of the Fusarium isolates were involved in onychomycosis, while the remaining ones caused paronychia or severe tinea pedis. Comparing literature data, superficial infections by FSSC appear to be prevalent in Asia and Latin America, whereas FOSC is more common in Europe. The available data suggest that Fusarium is a common opportunistic human pathogens in tropical areas and has significant genetic variation worldwide.

Survival following lung resection in immunocompromised patients with pulmonary invasive fungal infection

OBJECTIVES

Pulmonary invasive fungal infections (IFIs) are associated with high mortality in patients being treated for haematological malignancy. There is limited understanding of the role for surgical lung resection and outcomes in this patient population.

METHODS

This is a retrospective cohort of 50 immunocompromised patients who underwent lung resection for IFI. Patient charts were reviewed for details on primary malignancy and treatment course, presentation and work-up of IFI, reasons for surgery, type of resection and outcomes including postoperative complications, mortality, disease relapse and survival. Analysis was also performed on two subgroups based on year of surgery from 1990-2000 and 2001-2014.

RESULTS

The median age was 39 years (range: 5-64 years). Forty-seven patients (94%) had haematological malignancies and 38 (76%) underwent haematopoietic stem cell transplantation (HSCT). Surgical indications included haemoptysis, antifungal therapy failure and need for eradication before HSCT. The most common pathogen was Aspergillus in 34 patients (74%). Wedge resections were performed in 32 patients (64%), lobectomy in 9 (18%), segmentectomy in 2 (4%) and some combination of the 3 in 7 (14%) for locally extensive, multifocal disease. There were 9 (18%) minor and 14 (28%) major postoperative complications. Postoperative mortality at 30 days was 12% (n = 6). Acute respiratory distress syndrome was the most common cause of postoperative death. Overall 5-year survival was 19%. Patients who had surgery in the early period had a median survival of 24 months compared with 5 months for those who had surgery before 2001 (P = 0.046). At the time of death, 15 patients (30%) had probable or proven recurrent IFI. Causes of death were predominantly related to refractory malignancy, fungal lung disease or complications of graft versus host disease (GVHD). Patients who had positive preoperative bronchoscopy cultures had a trend towards worse survival compared with those with negative cultures (hazard ratio: 1.80, P = 0.087).

CONCLUSIONS

Surgical resection of IFI in immunocompromised patients is associated with high perioperative mortality. Long-term survival is limited by recurrent malignancy, persistent fungal infection and GVHD but has improved in recent years. Selection for surgical resection is difficult in this patient population, but should be carefully considered in those who are symptomatic, or have failed antifungal treatment.

Secondary antifungal prophylaxis in pediatric hematopoietic stem cell transplants

Invasive fungal infections (IFIs) constitute a leading cause of morbidity and infection-related mortality among hematopoietic stem cell transplant (HSCT) recipients. With the use of secondary prophylaxis, a history of IFI is not an absolute contraindication to allo-HSCT. However, still, IFI recurrence remains a risk factor for transplant-related mortality. In this study, of the 105 children undergoing HSCT between April 2010 and February 2013, 10 patients who had IFI history before transplantation and had undergone allo-HSCT were evaluated retrospectively to investigate results of secondary prophylaxis. In conclusion, our study shows that amphotericin B and caspofungin was successful as secondary antifungal prophylaxis agents with no relapse of IFI. In addition, after engraftment, secondary prophylaxis was continued with voriconazole orally in 4 patients that yielded good results.

ESCMID and ECMM joint guidelines on diagnosis and management of hyalohyphomycosis: Fusarium spp., Scedosporium spp. and others

Mycoses summarized in the hyalohyphomycosis group are heterogeneous, defined by the presence of hyaline (non-dematiaceous) hyphae. The number of organisms implicated in hyalohyphomycosis is increasing and the most clinically important species belong to the genera Fusarium, Scedosporium, Acremonium, Scopulariopsis, Purpureocillium and Paecilomyces. Severely immunocompromised patients are particularly vulnerable to infection, and clinical manifestations range from colonization to chronic localized lesions to acute invasive and/or disseminated diseases. Diagnosis usually requires isolation and identification of the infecting pathogen. A poor prognosis is associated with fusariosis and early therapy of localized disease is important to prevent progression to a more aggressive or disseminated infection. Therapy should include voriconazole and surgical debridement where possible or posaconazole as salvage treatment. Voriconazole represents the first-line treatment of infections due to members of the genus Scedosporium. For Acremonium spp., Scopulariopsis spp., Purpureocillium spp. and Paecilomyces spp. the optimal antifungal treatment has not been established. Management usually consists of surgery and antifungal treatment, depending on the clinical presentation.

Invasive fungal infections in transplant recipients

Invasive fungal infections are an important cause of morbidity and mortality in hematopoietic stem cell transplant and solid organ transplant recipients. Evolving transplant modalities and techniques, complex and extensive immunosuppressant strategies, and the increased use of broad spectrum antifungal prophylaxis has greatly impacted the epidemiology and temporal pattern of invasive fungal infections in the transplant population. The goal of this article is to provide an up-to-date review of the most commonly encountered invasive fungal infections seen in transplant recipients, including epidemiology, risk factors, clinical features, diagnostic dilemmas, management and their overall influence on outcomes.

Molecular analyses of Fusarium isolates recovered from a cluster of invasive mold infections in a Brazilian hospital

Background

Invasive fusariosis (IF) is a rare but often fatal fungal infection in immunosuppressed patients. In 2007, cases of IF above the expected epidemiologic baseline were detected in the hematology ward of a hospital in Rio de Janeiro, Brazil. Possible sources of infection were investigated by performing environmental sampling and patient isolate collection, followed by molecular typing. Isolates from dermatology patients with superficial fusariosis were included in the study for comparison to molecular types found in the community.

Methods

Environmental sampling focused on water-related sources in and around the hematology ward. Initially, we characterized 166 clinical and environmental isolates using the Fusarium translation elongation factor 1α (EF-1α) genetic locus. Isolates included 68 collected from water-related sources in the hospital environment, 55 from 18 hematology patients, and 43 from the skin/nails of 40 outpatients seen at the hospital dermatology clinic. Multi-locus sequence typing was performed on Fusarium solani species complex (FSSC) species 1 and 2 isolates to investigate their relatedness further.

Results

Most of the hematology samples were FSSC species 2, with species type FSSC 2-d the most commonly isolated from these patients. Most of the outpatient dermatology samples were also FSSC 2, with type 2-d again predominating. In contrast, environmental isolates from water sources were mostly Fusarium oxysporum species complex (FOSC) and those from air samples mostly Fusarium incarnatum-equiseti species complex (FIESC). A third of the environmental samples were FSSC, with species types FSSC 1-a and FSSC 1-b predominating.

Conclusions

Fusarium isolate species types from hematology patient infections were highly similar to those recovered from dermatology patients in the community. Four species types (FSSC 1-a, 1-b, 2-d and 2-f) were shared between hematology patients and the environment. Limitations in environmental sampling do not allow for nosocomial sources of infection to be ruled out. Future studies will focus on environmental factors that may have influenced the prevalence of FSSC fusariosis in this hematology ward.

Identification of clinical mold isolates by sequence analysis of the internal transcribed spacer region, ribosomal large-subunit D1/D2, and β-tubulin

Background

The identification of molds in clinical laboratories is largely on the basis of phenotypic criteria, the classification of which can be subjective. Recently, molecular methods have been introduced for identification of pathogenic molds in clinical settings. Here, we employed comparative sequence analysis to identify molds.

Methods

A total of 47 clinical mold isolates were used in this study, including Aspergillus and Trichophyton. All isolates were identified by phenotypic properties, such as growth rate, colony morphology, and reproductive structures. PCR and direct sequencing, targeting the internal transcribed spacer (ITS) region, the D1/D2 region of the 28S subunit, and the β-tubulin gene, were performed using primers described previously. Comparative sequence analysis by using the GenBank database was performed with the basic local alignment search tool (BLAST) algorithm.

Results

For Aspergillus, 56% and 67% of the isolates were identified to the species level by using ITS and β-tubulin analysis, respectively. Only D1/D2 analysis was useful for Trichophyton identification, with 100% of isolates being identified to the species level. Performances of ITS and D1/D2 analyses were comparable for species-level identification of molds other than Aspergillus and Trichophyton. In contrast, the efficacy of β-tubulin analysis was limited to genus identification because of the paucity of database information for this gene.

Conclusions

The molecular methods employed in this study were valuable for mold identification, although the different loci used had variable usefulness, according to mold genus. Thus, a tailored approach is recommended when selecting amplification targets for molecular identification of molds.

Graphium basitruncatum fungemia in an immunosuppressed child post stem-cell transplantation

Graphium basitruncatum is genetically and morphologically distinct from other Graphium and Scedosporium species, and has been reported only once previously as a cause of human disease. We report a case of Graphium basitruncatum fungemia in a two year old child with dyskeratosis congenita who underwent stem cell transplantation two months prior to infection.

Epidemiology of invasive fungal infections in the mediterranean area

Although Candida species remain the relevant cause of IFI, other fungi (especially moulds) have become increasingly prevalent. In particular, Aspergillus species are the leading cause of mould infections but also Glomeromycota (formerly Zygomycetes) and Fusarium species are increasing in frequency, and are associated with high mortality rates. Many of these emerging infections occur as breakthrough infections in patients treated with new antifungal drugs. The causative pathogens, incidence rate and severity are dependent on the underlying condition, as well as on the geographic location of the patient population. France and Italy show the highest incident rates of Fusarium infections in Europe, following the US, where numbers are still increasing. Scedosporium prolificans, which primarily is found in soil in Spain and Australia, is most frequently isolated from blood cultures in a Spanish hospital. Geotrichum capitatum represents another species predominantly found in Europe with especially high rates in Mediterranean countries. The increasing resistance to antifungal drugs especially of these new emerging pathogens is a severe problem for managing these IFIs.

Fusarium infection in lung transplant patients: report of 6 cases and review of the literature

Fusarium is a fungal pathogen of immunosuppressed lung transplant patients associated with a high mortality in those with severe and persistent neutropenia. The principle portal of entry for Fusarium species is the airways, and lung involvement almost always occurs among lung transplant patients with disseminated infection. In these patients, the immunoprotective mechanisms of the transplanted lungs are impaired, and they are, therefore, more vulnerable to Fusarium infection. As a result, fusariosis occurs in up to 32% of lung transplant patients. We studied fusariosis in 6 patients following lung transplantation who were treated at Massachusetts General Hospital during an 8-year period and reviewed 3 published cases in the literature. Cases were identified by the microbiology laboratory and through discharge summaries. Patients presented with dyspnea, fever, nonproductive cough, hemoptysis, and headache. Blood tests showed elevated white blood cell counts with granulocytosis and elevated inflammatory markers. Cultures of Fusarium were isolated from bronchoalveolar lavage, blood, and sputum specimens.Treatments included amphotericin B, liposomal amphotericin B, caspofungin, voriconazole, and posaconazole, either alone or in combination. Lung involvement occurred in all patients with disseminated disease and it was associated with a poor outcome. The mortality rate in this group of patients was high (67%), and of those who survived, 1 patient was treated with a combination of amphotericin B and voriconazole, 1 patient with amphotericin B, and 1 patient with posaconazole. Recommended empirical treatment includes voriconazole, amphotericin B or liposomal amphotericin B first-line, and posaconazole for refractory disease. High-dose amphotericin B is recommended for treatment of most cases of fusariosis. The echinocandins (for example, caspofungin, micafungin, anidulafungin) are generally avoided because Fusarium species have intrinsic resistance to them. Treatment should ideally be based on the Fusarium isolate, susceptibility testing, and host-specific factors. Prognosis of fusariosis in the immunocompromised is directly related to a patient's immune status. Prevention of Fusarium infection is recommended with aerosolized amphotericin B deoxycholate, which also has activity against other important fungi.

Antifungal activity of statins and their interaction with amphotericin B against clinically important Zygomycetes

The in vitro antifungal activity of different statins and the combinations of the two most effective ones (fluvastatin and rosuvastatin) with amphotericin B were investigated in this study on 6 fungal isolates representing 4 clinically important genera, namely Absidia, Rhizomucor, Rhizopus and Syncephalastrum . The antifungal effects of statins revealed substantial differences. The synthetic statins proved to be more effective than the fungal metabolites. All investigated strains proved to be sensitive to fluvastatin. Fluvastatin and rosuvastatin acted synergistically and additively with amphotericin B in inhibiting the fungal growth in clinically available concentration ranges. Results suggest that statins combined with amphotericin B have a therapeutic potential against fungal infections caused by Zygomycetes species.

Conazoles

This review provides a historical overview of the analog based drug discovery of miconazole and its congeners, and is focused on marketed azole antifungals bearing the generic suffix “conazole”. The antifungal activity of miconazole, one of the first broad-spectrum antimycotic agents has been mainly restricted to topical applications. The attractive in vitro antifungal spectrum was a starting point to design more potent and especially orally active antifungal agents such as ketoconazole, itraconazole, posaconazole, fluconazole and voriconazole. The chemistry, in vitro and in vivo antifungal activity, pharmacology, and clinical applications of these marketed conazoles has been described.