Fusarium, a Significant Emerging Pathogen in Patients With Hematologic Malignancy: Ten Years' Experience at a Cancer Center and Implications for Management

Non-Aspergillus mould lung infections

Non-Aspergillus filamentous fungi causing invasive mould infections have increased over the last years due to the widespread use of anti-Aspergillus prophylaxis and increased complexity and survival of immunosuppressed patients. In the few studies that have reported on invasive mould infection epidemiology, Mucorales are the most frequently isolated group, followed by either Fusarium spp. or Scedosporium spp. The overall incidence is low, but related mortality is exceedingly high. Patients with haematological malignancies and haematopoietic stem cell transplant recipients comprise the classical groups at risk of infection for non-Aspergillus moulds due to profound immunosuppression and the vast use of anti-Aspergillus prophylaxis. Solid organ transplant recipients also face a high risk, especially those receiving lung transplants, due to direct exposure of the graft to mould spores with altered mechanical and immunological elimination, and intense, associated immunosuppression. Diagnosing non-Aspergillus moulds is challenging due to unspecific symptoms and radiological findings, lack of specific biomarkers, and low sensitivity of cultures. However, the advent of molecular techniques may prove helpful. Mucormycosis, fusariosis and scedosporiosis hold some differences regarding clinical paradigmatic presentations and preferred antifungal therapy. Surgery might be an option, especially in mucormycosis. Finally, various promising strategies to restore or enhance the host immune response are under current evaluation.

Outcomes of antifungal prophylaxis for newly diagnosed AML patients treated with a hypomethylating agent and venetoclax

Antifungal prophylaxis (AFP) is recommended for acute myeloid leukemia (AML) patients receiving the combination of venetoclax (VEN) and a hypomethylating agent (HMA), but the benefit of this practice is unclear. We identified 131 patients with newly diagnosed AML who received frontline VEN/HMA and evaluated the use of AFP and its association with invasive fungal infections (IFIs) and AML outcomes. Seventeen percent of our patients received AFP at any time. Overall incidence of any IFI ('possible,' 'probable,' or 'proven' infection, as defined by the European Mycoses Study Group) was 13%, and the incidence did not differ based on AFP use (p=.74). Median overall survival did not differ based on AFP use or lack thereof (8.1 vs. 12.5 months, respectively; p=.14). Our findings suggest that, at an institution where the incidence of fungal infections is low, there does not appear to be a role for AFP in newly diagnosed AML patients receiving VEN/HMA.

Invasive Fusariosis in Pediatric Hematology/Oncology and Stem Cell Transplant Patients: A Report from the Israeli Society of Pediatric Hematology-Oncology

Invasive Fusarium species infections in immunocompromised patients occur predominantly in those with hematological malignancies. Survival rates of 20−40% were reported in adults, but data in children are limited. Our retrospective, nationwide multicenter study of invasive fusariosis in pediatric hematology/oncology and stem cell transplant (SCT) patients identified twenty-two cases. Underlying conditions included hematological malignancies (n = 16; 73%), solid tumors (n = 2), and non-malignant hematological conditions (n = 4). Nineteen patients (86%) were neutropenic, nine (41%) were SCT recipients, and seven (32%) received corticosteroids. Sixteen patients (73%) had disseminated fusariosis, five had local infection, and one had isolated fungemia. Fifteen patients (68%) had skin involvement and eight (36%) had a bloodstream infection. Four patients (18%) presented with osteoarticular involvement and four with pulmonary involvement. Nineteen patients (86%) received combination antifungal therapy upfront and three (14%) received single-agent treatment. Ninety-day probability of survival was 77%: four of the five deaths were attributed to fusariosis, all in patients with relapsed/refractory acute leukemias. Ninety-day probability of survival for patients with relapsed/refractory underlying malignancy was 33% vs. 94% in others (p < 0.001). Survival rates in this largest pediatric population-based study were strikingly higher than those reported in adults, demonstrating that invasive fusariosis is a life-threatening but salvageable condition in immunosuppressed children.

Emergency management of fever and neutropenia in children with cancer: A review

INTRODUCTION

Care of pediatric cancer patients is increasingly being provided by physicians in community settings, including general emergency departments. Guidelines based on current evidence have standardized the care of children undergoing chemotherapy or hematopoietic stem cell transplantation (HSCT) presenting with fever and neutropenia (FN).

OBJECTIVE

This narrative review evaluates the management of pediatric patients with cancer and neutropenic fever and provides comparison with the care of the adult with neutropenic fever in the emergency department.

DISCUSSION

When children with cancer and FN first present for care, stratification of risk is based on a thorough history and physical examination, baseline laboratory and radiologic studies and the clinical condition of the patient, much like that for the adult patient. Prompt evaluation and initiation of intravenous broad-spectrum antibiotics after cultures are drawn but before other studies are resulted is critically important and may represent a practice difference for some emergency physicians when compared with standardized adult care. Unlike adults, all high-risk and most low-risk children with FN undergoing chemotherapy require admission for parenteral antibiotics and monitoring. Oral antibiotic therapy with close, structured outpatient monitoring may be considered only for certain low-risk patients at pediatric centers equipped to pursue this treatment strategy.

CONCLUSIONS

Although there are many similarities between the emergency approach to FN in children and adults with cancer, there are differences that every emergency physician should know. This review provides strategies to optimize the care of FN in children with cancer in all emergency practice settings.

How different is invasive fusariosis in pediatric patients than in adults? A systematic review

PURPOSE OF REVIEW

To investigate the peculiarities of invasive fusariosis (IF) in pediatric patients.

METHODS

We conducted a systematic literature review to identify human cases of locally invasive and systemic fusariosis documented in children (up to 18 years) published between 1973 (first case report) and 2021.

RECENT FINDINGS

One hundred and six cases were retrieved, and hematologic malignancy was reported in 64% (68/106) of the cases. The most frequent anatomic sites involved were skin 66% (70/106), blood 47% (50/106), and lungs 35% (37/106), bone and joint (8%, 09/106), and eye/central nervous system involvement (8%, 9/106). Fusarium solani, followed by Fusarium oxysporum, were the most commonly reported species. In disseminated fusariosis, relapsed or refractory baseline disease (P < 0.001, OR=10.555, CI 95% 3.552-31.365) was associated with poor outcome, whereas voriconazole-based therapy was associated with better prognosis (P  = 0.04, OR = 0.273, CI 95% 0.076-0.978).

SUMMARY

Hematologic malignancies and solid tumors requiring intensive immunosuppression are the main conditions related to IF in children where other organs than skin, blood, and lungs were frequently involved. Voriconazole therapy appears to be also effective in children with IF, despite the wide pharmacokinetic variability of this triazole in pediatric patients.

Invasive Fusariosis in Patients with Hematologic Diseases

Fusarium species are filamentous fungi widely encountered in nature, and may cause invasive disease in patients with hematologic conditions. Patients at higher risk are those with acute leukemia receiving induction remission chemotherapy or allogeneic hematopoietic cell transplant recipients. In these hosts, invasive fusariosis presents typically with disseminated disease, fever, metastatic skin lesions, pneumonia, and positive blood cultures. The prognosis is poor and the outcome is largely dependent on the immune status of the host, with virtually a 100% death rate in persistently neutropenic patients, despite monotherapy or combination antifungal therapy. In this paper, we will review the epidemiology, clinical manifestations, diagnosis, and management of invasive fusariosis affecting patients with hematologic diseases.

Disseminated Geosmithia argillacea Infection in a Patient with Ph-Positive Acute Lymphoblastic Leukemia. Case Report and Literature Review

Invasive fungal infection (IFI) remains the major complication in patients with either acute leukemia, allogeneic stem cell transplantation setting, or both, especially regarding pulmonary localization. We report an experience of a 74-year-old Caucasian male with a Philadelphia-positive (BCR-ABL p190) Common B-acute lymphoblastic leukemia (ALL) who developed a pulmonary infection due to Geosmithia argillacea. Furthermore, we describe the management of this complication and the results of microbiological tests useful to guide the treatment. All cases reported show failure of voriconazole treatment. In the majority of cases a good susceptibility to posaconazole has been reported, which seems to have a good clinical impact; however, only L-AmB shows a clinical effect to produce quick clinical improvement and so it should be a drug of choice. A literature revision shows that only a few papers have thus far described this infection, at present only one case was reported in a hematological setting like a gastrointestinal graft versus host disease in an allogeneic HSCT recipient. The severity of clinical conditions in hematological malignancy settings requires improving the management of this emerging invasive fungal infection. Indeed, a molecular diagnostic approach with a tight laboratory collaboration and targeted therapy should become the gold standard.

Clinical Features and Outcomes of Invasive Fusariosis: A Case Series in a Single Center with Literature Review

Fusarium species, which are commonly found in soil, water, and organic substrates, can cause serious infections especially in immunocompromised patients. Fusarium infection is notoriously difficult to treat, because of their inherently high minimum inhibitory concentrations (MICs) to most antifungal agents. There have been limited data on invasive fusariosis in Korea. We identified 57 patients with culture-proven fusariosis at Samsung Medical Center, Seoul, Korea, from September 2003 through January 2017. Invasive fusariosis was defined as any case with at least one positive blood culture or with concurrent involvement of 2 or more non-contiguous sites. Superficial infections such as keratitis and onychomycosis were excluded. We reported 14 cases of invasive fusariosis categorized according to the European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria, of which 6 cases were fusarium fungemia. Hematologic malignancies (7/14, 50%), solid organ transplantation (2/14, 14.2%), or immunosuppressive therapy (2/14, 14.2%), were the predominant underlying conditions. The overall mortality rate was 37%, however, that of disseminated fusariosis was up to 83%. Antifungal treatment with voriconazole or liposomal amphotericin B was commonly administered. In this report, we described the clinical characteristics and treatment outcomes of invasive fusariosis in Korea. Given the high mortality in disseminated cases, invasive fusariosis is becoming a therapeutic challenge to clinicians treating immunocompromised patients.

Cutaneous Fusariosis in a Patient with Job’s (Hyper-IgE) Syndrome

Fusarium is a filamentous fungus that is ubiquitous in nature and can cause severe opportunistic infections in immunocompromised hosts. The association between Fusarium and hyper-IgE syndrome is exceedingly rare and has only been documented in a single report previously. A 44-year-old male, working as marijuana grower, with prior diagnosis of hyper-IgE syndrome and recurrent infections presented with enlarging right knee ulcer that did not respond to antimicrobial treatment. The patient was diagnosed with cutaneous fusariosis, confirmed with punch biopsy and positive wound cultures. The patient was managed with extended antifungal therapy (i.e., posaconazole) and surgical debridement resulting in remarkable improvement with wound healing leaving a pale scar. Fusarium should be considered in differential for cutaneous and invasive fungal infections in presence of cutaneous manifestations. Exposure to Cannabis plants is a noticeable risk factor. Multimodal approach involving systemic antifungals and wound debridement is essential for favorable outcome. Posaconazole was demonstrated to be a highly efficacious antifungal choice.

Immune response and Raman scattering assessment in rats skin after contact with Fusarium oxysporum metabolites

The secondary metabolites produced by Fusarium can cause disease and death when consumed and produce biological responses even in the absence of the microorganism. The IL-6, TNF-α and TGF-β1 cytokines immune reactivity was associated with histopathological and physico-chemical changes in skin of immune competent rats after administration of Fusarium oxysporum crude extract. Rats were intradermally injected with 50 μl of 0.5 mg/ml crude extract and were euthanized at 3, 6, 12 and 24 h after injection. The inflammatory response was quantified by enzyme myeloperoxidase activity and by immunohistochemical method to detect the IL-6, TNF-α and TGF-β1. Physico-chemical analysis was performed using FT-Raman Spectroscopy. The inflammatory response was most intense at 6 and 12 h after crude extract administration and the most significant histopathological changes were observed in the dermis. Myeloperoxidase activity was intense from 3 to 24 h after injection. The immunostaining of pro-inflammatory cytokines IL-6 and TNF-α peaked at 6 h. Immunostaining for TGF-β1 was highest at 12 and 24 h. FT-Raman spectral analysis showed both, the most intense Fusarium interaction with the skin at 6 h, as revealed by the changes in the stretching of -CH bands (3100-2800 cm^-1) in the dermis, and skin recovery trending after 12 h after crude extract injection. The results showed that secondary metabolites stimulated histopathologic changes and inflammatory responses even in the absence of the fungus, increasing myeloperoxidase activity and pro-inflammatory cytokine expression besides promoting physico-chemical changes.

The genome of opportunistic fungal pathogen Fusarium oxysporum carries a unique set of lineage-specific chromosomes

Fusarium oxysporum is a cross-kingdom fungal pathogen that infects plants and humans. Horizontally transferred lineage-specific (LS) chromosomes were reported to determine host-specific pathogenicity among phytopathogenic F. oxysporum. However, the existence and functional importance of LS chromosomes among human pathogenic isolates are unknown. Here we report four unique LS chromosomes in a human pathogenic strain NRRL 32931, isolated from a leukemia patient. These LS chromosomes were devoid of housekeeping genes, but were significantly enriched in genes encoding metal ion transporters and cation transporters. Homologs of NRRL 32931 LS genes, including a homolog of ceruloplasmin and the genes that contribute to the expansion of the alkaline pH-responsive transcription factor PacC/Rim1p, were also present in the genome of NRRL 47514, a strain associated with Fusarium keratitis outbreak. This study provides the first evidence, to our knowledge, for genomic compartmentalization in two human pathogenic fungal genomes and suggests an important role of LS chromosomes in niche adaptation.

Zhang, Yang et al. compare a Fusarium oxysporum isolate obtained clinically to a phytopathogenic strain to examine transfer of lineage-specific chromosomes in determining host specificity. They find four unique lineage-specific chromosomes that seem to contribute to fungal adaptation to human hosts.

Fusarium species intramedullary spinal cord fungus ball: case report

The Fusarium species are one of the most common opportunistic fungal infections occurring in immunocompromised patients and are associated with high morbidity and mortality. Common sites of infection include blood, skin, nasal passages, lungs, bone, and other visceral organs. There is a paucity of literature on Fusarium infections in the brain, and the true nature and extent of central nervous system involvement is not well described. To the authors' knowledge, there have been no reported cases of Fusarium infection of the spine. The authors report the case of a man with acute myeloblastic leukemia and resultant pancytopenia who presented with fungal sinusitis, upper- and lower-extremity weakness, and cardiopulmonary arrest. Imaging studies revealed a spinal cervical intramedullary ring-enhancing lesion. Because of the progressive nature of his symptoms, neurosurgical intervention involving a C2-3 laminectomy and drainage of the lesion was performed. Intraoperative cultures and histopathology results were positive for Fusarium species and, along with intraoperative findings, were consistent with a fungus ball. The patient was placed on a regimen of intravenous and intrathecal antifungal therapy. Unfortunately, his clinical condition declined postoperatively, and he ultimately died of disseminated infection.

Broad-range PCR Application in a Large Academic Pediatric Center: Clinical Value and Challenges in Diagnosis of Infectious Diseases

BACKGROUND

Broad-range polymerase chain reaction (BR-PCR) detects infectious pathogens from clinical specimens using targets for bacteria (16S rRNA), fungi (28S rDNA), and mycobacteria (fluorescence resonance energy transfer and heat shock protein 65 gene) with reported diagnostic sensitivity and specificity ranging from 43% to 100% and 100%, respectively. We describe our experience when applying BR-PCR to clinical samples submitted for conventional infectious disease testing [conventional testing (CT)] from pediatric patients with concern for infection.

METHODS

Retrospective analysis of clinical samples obtained from Nationwide Children's Hospital microbiology laboratory from January 2011 to December 2014 and sent for BR-PCR. Medical record review collected data on patient characteristics, clinical manifestations, laboratory results and antimicrobials prescribed, and a determination of clinical value of BR-PCR was assigned.

RESULTS

There were 247 clinical samples from 163 patients identified; 71 (44%) patients were immunocompromised and 192 (78%) samples reflected pretreatment with antimicrobials. A clinically significant putative organism was identified for 59 samples (24%) between all diagnostic modalities. Conventional testing identified organisms in 41 (17%) samples, 17 of which were corroborated by BR-PCR. Broad-range polymerase chain reaction identified an organism in an additional 18 samples with negative CT results and was considered to provide additional important clinical information. Broad-range polymerase chain reaction detected a bacterial or fungal organism more frequently from tissue samples than from bronchoalveolar lavage or other fluid samples (P = 0.0096, χ).

CONCLUSIONS

In our cohort, BR-PCR was an important adjunctive diagnostic in identifying bacteria and fungi in complex clinical situations. Additional data are needed to define the optimal clinical circumstances and specimen type in which BR-PCR can provide the highest diagnostic yield.

Successful treatment of disseminated fusariosis in a patient with acute lymphoblastic leukemia: A case report and literature review

RATIONALE

Fusarium is the second most common cause of fungi infections in the immunocompromised patients with the mortality rate over 80%. Early identification and appropriate selection of antifungal drugs is the key to successful treatment.

PATIENT CONCERNS

A 31-year-old female was diagnosed with acute lymphocytic leukemia (pro-B ALL). She developed a high fever and presented with typical painful purple nodules with central necrosis formed on the upper and lower limbs during the induction chemotherapy.

DIAGNOSIS

Combining clinical manifestations with results of blood culture testing and sequencing methods, it was consistent with the diagnosis of disseminated fusariosis.

INTERVENTIONS

The patient was treated with the combination of tigecycline and antifungal agents (Liposomal Amphotericin B and Voriconazole), OUTCOMES:: The skin lesions generally healed with some scar left after treating with antifungal agents for 6 weeks. The final date of follow-up was 1.5 years later, and the patient was alive with no diseases.

LESSONS

This case highlights the importance of the typical cutaneous lesions for early diagnosis and proper treatment to decrease the mortality rate of this severe infection. This patient was successfully treated with the combination of tigecycline and antifungal agents, which may be the first clinical confirmation of tigecycline that improved the effectiveness of antifungal agents against fusariosis, but it requires more studies to verify. We reviewed 62 cases from literature and analyzed using logistic regression and recognized the high-risk factor for fusariosis mortality in patients with acute leukemia was non-remission of underlying disease.

Successful Combination Therapy of Liposomal Amphotericin B and Caspofungin for Disseminated Fusariosis in a Pediatric Patient With Acute Lymphoblastic Leukemia

Disseminated fusariosis is a fatal infection in immunocompromised hosts. However, the optimal antifungal treatment for disseminated fusariosis has not yet been established. We report a case of disseminated fusariosis after chemotherapy for acute lymphoblastic leukemia, presenting with multiple skin, lung and kidney lesions and cerebrospinal fluid invasion. The combination therapy of liposomal amphotericin B and caspofungin resolved disseminated fusariosis successfully.

Disseminated cutaneous fusariosis in human immunodeficiency virus-infected patient and dramatic response with oral itraconazole

Fusarium species are known to cause disseminated cutaneous lesions in immunocompromised patients. Some cases of fusariosis are reported in patients infected with the human immunodeficiency virus. There are two reports in such patients with systemic comorbidities like lymphoma, neutropenia and infective port-a-catheter. Another reported patient had systemic fusariosis, without skin involvement. Diagnosis and treatment of cutaneous fusariosis is difficult and resistance to antifungals is a problem. Our patient was at an advanced human immunodeficiency virus infection stage with disseminated cutaneous fusariosis, without any systemic involvement, who responded completely to oral itraconazole.

Necrotizing fungal gingivitis in a patient with Acute Myelogenous Leukemia: visible yet obscure

Oral fungal infections present with atypical and varied manifestations, and distinguishing them from other entities including leukemic infiltration can be diagnostically challenging. In this report, we describe a 62 year old female with acute myeloid leukemia who presented, towards the end of her second treatment cycle of decitabine in a prolonged neutropenic state, with a month of painful, necrotic-appearing marginal gingival lesions. She was duly initiated on empiric broad spectrum antifungal treatment but did not show a clinical response with the appearance of new skin lesions concerning for progressive fungemia. Concurrent gingival and cutaneous biopsy showed fungal invasion with Fusarium. Despite changing antifungal treatment the lesions progressed, and white blood cell (WBC) transfusions were instituted. The patient had an impressive response with gradual resolution of the skin lesions and regression in gingival lesions over a week of therapy. This case illustrates the highly atypical, confounding appearance of oral fungal infections in immunocompromised hematological malignancy patients. Maxillary and mandibular marginal gingival involvement, although extremely rare, should be recognized as potential sites of fungal involvement. Accurate diagnosis entails a biopsy especially in ambiguous clinical scenarios, as presented here. The role of WBC transfusions in the management of these rare fungal pathogenic infections needs to re-established.

Bloodstream Infections

Bacteremia and sepsis are conditions associated with high mortality and are of great impact to health care operations. Among the top causes of mortality in the United States, these conditions cause over 600 fatalities each day. Empiric, broad-spectrum treatment is a common but often a costly approach that may fail to effectively target the correct microbe, may inadvertently harm patients via antimicrobial toxicity or downstream antimicrobial resistance. To meet the diagnostic challenges of bacteremia and sepsis, laboratories must understand the complexity of diagnosing and treating septic patients, in order to focus on creating algorithms that can help direct a more targeted approach to antimicrobial therapy and synergize with existing clinical practices defined in new Surviving Sepsis Guidelines. Significant advances have been made in improving blood culture media; as yet no molecular or antigen-based method has proven superior for the detection of bacteremia in terms of limit of detection. Several methods for rapid molecular identification of pathogens from blood cultures bottles are available and many more are on the diagnostic horizon. Ultimately, early intervention by molecular detection of bacteria and fungi directly from whole blood could provide the most patient benefit and contribute to tailored antibiotic coverage of the patient early on in the course of the disease. Although blood cultures remain as the best means of diagnosing bacteremia and candidemia, complementary testing with antigen tests, microbiologic investigations from other body sites, and histopathology can often aid in the diagnosis of disseminated disease, and application of emerging nucleic acid test methods and other new technology may greatly impact our ability to bacteremic and septic patients, particularly those who are immunocompromised.

Antimold Prophylaxis May Reduce the Risk of Invasive Fusariosis in Hematologic Patients with Superficial Skin Lesions with Positive Culture for Fusarium

Hematologic patients with superficial skin lesions on admission growing Fusarium spp. are at a high risk for developing invasive fusariosis during neutropenia. We evaluated the impact of primary prophylaxis with a mold-active azole in preventing invasive fusariosis in these patients. Between August 2008 and December 2014, patients with acute leukemia or aplastic anemia and recipients of hematopoietic cell transplants were screened on admission with dermatologic and direct exams and fungal cultures of superficial skin lesions. Until November 2009, no interventions were made. Beginning in December 2009, patients with baseline skin lesions and a direct exam and/or culture suggestive of the presence of Fusarium spp. received prophylaxis with voriconazole or posaconazole. Skin lesions in the extremities (mostly onychomycosis and interdigital intertrigo) were present on admission in 88 of 239 episodes (36.8%); 44 lesions had hyaline septate hyphae identified by direct exam, and cultures from 11 lesions grew Fusarium spp. Antimold prophylaxis was given for 20 episodes (voriconazole for 17 and posaconazole for 3). Invasive fusariosis was diagnosed in 14 episodes (5.8%). Among patients with baseline skin lesions with positive cultures for Fusarium spp., 4 of 5 without antimold prophylaxis developed invasive fusariosis versus 0 of 6 with antimold prophylaxis (P = 0.01; 95% confidence interval for the difference between proportions, 22% to 96%). Primary antifungal prophylaxis with an antimold azole may prevent the occurrence of invasive fusariosis in high-risk hematologic patients with superficial skin lesions on admission growing Fusarium spp.

Itraconazole and Terbinafine Treatment of Some Nondermatophyte Molds Causing Onychomycosis of the Toes and a Review of the Literature

Background:

Onychomycosis may be caused by dermatophytes (which form the majority of organisms), Candida species, and nondermatophyte molds.

Objective:

To evaluate the efficacy and safety of itraconazole and terbinafine in the treatment of some nondermatophyte molds that cause toe onychomycosis and to review the literature on the treatment of nondermatophyte mold toe onychomycosis using the oral antifungal agents.

Patients and Methods:

Patients with nondermatophyte mold toe onychomycosis were treated in an open, prospective manner with either itraconazole (pulse) or terbinafine therapy. In each instance, light microscopic examination was consistent with the diagnosis of a nondermatophyte mold. For each patient, mycological evaluation of the target nail resulted in 3 or more successive cultures yielding growth of the mold alone.

Results:

All 15 patients had onychomycosis of the toes which was of the distal and lateral type. The patients were treated with itraconazole given as the standard 3 pulses with additional pulses administered depending upon the response exhibited by the toe onychomycosis in the patient. Similarly, terbinafine was given for 12 weeks with additional therapy administered as dictated by the response. Efficacy parameters were mycological cure (MC) and clinical cure (CC). Mycological cure was negative light microscopic examination (KOH) and culture. Clinical cure was the appearance of a completely normal-looking nail. At month 12 from the start of treatment, the response was as follows: Scopulariopsis brevicaulis: itraconazole (MC 4/4, CC 2/4) and terbinafine (MC 0/1, CC 0/1), Fusarium species: itraconazole (MC 1/1, CC 1/1) and terbinafine (MC 0/1, CC 0/1), Aspergillus species: itraconazole (MC 5/6, CC 3/6), Alternaría alternata: itraconazole (MC 0/1, CC 0/1), and Onychocola canadensis: itraconazole (MC 1/1, CC 0/1). There were no significant clinical or laboratory adverse effects.

Conclusions:

In the present series itraconazole demonstrated efficacy against onychomycosis of the toenails caused by 5. brevicaulis and Aspergillus species. A review of the literature confirms our experience with itraconazole and further suggests that terbinafine may also demonstrate efficacy against cases of S. brevicaulis and Aspergillus toe onychomycosis. Additionally, reports in the literature suggest that pedal onychomycosis caused by Fusarium species may also show response to itraconazole and terbinafine. For the other species, there are fewer data, making it difficult to draw conclusions.

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.

Development of cycling probe-based real-time PCR system to detect Fusarium species and Fusarium solani species complex (FSSC)

In the present study, we developed a new real-time PCR system based on the cycling probe technology (CPT), which is composed of two single tube real-time PCR assays: the Fusarium genus-specific assay and the Fusarium solani species complex (FSSC)-specific assay with primers targeting the 28s ribosomal RNA gene. The Fusarium genus-specific assay was shown to be highly specific, detecting all reference Fusarium strains with no cross-reaction with other reference fungal strains, such as Aspergillus spp. and human DNA. The FSSC-specific assay also reacted very specifically with FSSC, except for a cross-reaction with Fusarium lunatum. To validate the real-time PCR system, we tested 87 clinical isolates of Fusarium spp. Identification results from the real-time PCR system were found to be 100% concordant with those from DNA sequencing of EF-1α gene. The sensitivity testing also demonstrated high sensitivity, enabling detection of one copy of standard DNA with good reproducibility. Furthermore, both assays were shown to be extremely sensitive even when fungal cells were mixed with human cells, detecting 3 germinated conidia spiked in 3mL of human blood. To apply our new real-time PCR system to the molecular diagnosis of fusariosis, we evaluated its efficacy using a mouse model of invasive F. solani infection. Plasma and whole blood samples of infected mice were tested using the real-time PCR system. The sensitivity of the real-time PCR system was found to be 100% (n=4) in plasma samples. In contrast, no amplification signal was detected in whole blood samples. This system could provide a rapid and precise diagnostic tool for early diagnosis, which is necessary for appropriate treatment and improvement of prognosis of disseminated fusariosis.

Fusarium infection: report of 26 cases and review of 97 cases from the literature

Fusarium species is a ubiquitous fungus that causes opportunistic infections. We present 26 cases of invasive fusariosis categorized according to the European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria of fungal infections. All cases (20 proven and 6 probable) were treated from January 2000 until January 2010. We also review 97 cases reported since 2000. The most important risk factors for invasive fusariosis in our patients were compromised immune system, specifically lung transplantation (n = 6) and hematologic malignancies (n = 5), and burns (n = 7 patients with skin fusariosis), while the most commonly infected site was the skin in 11 of 26 patients. The mortality rates among our patients with disseminated, skin, and pulmonary fusariosis were 50%, 40%, and 37.5%, respectively. Fusarium solani was the most frequent species, isolated from 49% of literature cases. Blood cultures were positive in 82% of both current study and literature patients with disseminated fusariosis, while the remaining 16% had 2 noncontiguous sites of infection but negative blood cultures. Surgical removal of focal lesions was effective in both current study and literature cases. Skin lesions in immunocompromised patients should raise the suspicion for skin or disseminated fusariosis. The combination of medical monotherapy with voriconazole or amphotericin B and surgery in such cases is highly suggested.

Immunotherapy against invasive mold infections

Invasive infections due to filamentous fungi, such as Aspergillus spp., Zygomycetes, Scedosporium and Fusarium spp., cause significant morbidity and mortality in immunocompromised patients with hematological malignancies, recipients of hematopoietic stem cell transplants and those with chronic granulomatous disease. Despite antifungal therapy, the outcome is often unfavorable in these patients; immune restoration is considered as the cornerstone of successful treatment. Important aspects of human immune response against fungi include effective innate immune response expressed as effective phagocytic functions and a balance between proinflammatory and regulatory adaptive immune responses. A number of immunomodulatory approaches, including the administration of enhancing cytokines, adoptive transfer of pathogen-specific T lymphocytes and granulocyte transfusions have been investigated as adjunctive treatments against serious mold infections. Despite encouraging in vitro and in vivo data, current clinical evidence is not sufficient to allow firm recommendations on the use of these immunomodulatory modalities in serious mold infections.

Fusarium falciforme vertebral abscess and osteomyelitis: case report and molecular classification

Fusarium is a ubiquitous mold that can cause superficial infections such as keratitis and onychomycosis in immunocompetent humans; however, infections in immunocompromised hosts can be fatal. We report an unusual case of epidural abscess and vertebral osteomyelitis in a patient with an autoimmune disorder who was on long-term glucocorticoids. Multilocus DNA sequence-based typing revealed that the infection was caused by a novel three-locus haplotype of Fusarium falciforme designated FSSC 3+4qqq.

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.

Identification of Fusarium species in formalin-fixed and paraffin-embedded sections by in situ hybridization using peptide nucleic acid probes

Fusarium has recently emerged as an opportunistic pathogen of humans, but the histological differentiation of Fusarium from Aspergillus and Scedosporium is particularly difficult because these fungi may induce similar clinical features and exhibit filamentous development in host tissues. Thus, there is a need to establish rapid and reliable methods that are applicable to pathological diagnoses. The aim of this study was to evaluate and establish in situ hybridization (ISH) using peptide nucleic acid (PNA) probes targeting the 28S rRNA to identify Fusarium species in tissue sections. This technique was validated using both formalin-fixed and paraffin-embedded pulmonary tissues from mice infected with seven different species of fungi and cell blocks from fungal cultures of 30 strains. As a result, strong positive signals were observed within fungal organisms present in tissues of the lung from mice infected with Fusarium solani. Furthermore, this probe reacted strongly with both F. solani and Fusarium oxysporum in sections from cell blocks. Although some cross-reactivity occurred with the Pseudallescheria boydii in sections from cell blocks, the signal intensity was low and most hyphae were not reactive. In conclusion, it was confirmed that ISH with PNA probes is accurate and is a valuable tool for identifying Fusarium spp. among organisms that have identical morphological features in formalin-fixed and paraffin-embedded sections.

Efficacy of posaconazole as treatment and prophylaxis against Fusarium solani

Invasive fusariosis is a highly aggressive fungal infection associated with high mortality in heavily immunocompromised patients. Although posaconazole is efficacious as salvage therapy against infections caused by Fusarium species, concerns remain regarding this agent in the setting of reduced potency. To evaluate the efficacy of posaconazole as treatment or prophylaxis against invasive fusariosis caused by Fusarium solani, we utilized a neutropenic murine model of disseminated disease. ICR mice were administered escalating doses of posaconazole (6.25, 12.5, 25, or 50 mg/kg of body weight twice daily [BID]) by oral gavage beginning 2 days prior to inoculation in the prophylaxis studies or beginning 12 h after inoculation as treatment. Therapy was continued until day 9 postinoculation, and animals were monitored off therapy until day 15 for survival. Fungal burden was assessed as CFU in the kidneys. A clear dose-response relationship was observed, as the highest dose of posaconazole (50 mg/kg) was the most effective in prolonging survival and reducing tissue fungal burden both as prophylaxis and as treatment. This dose response was associated with high posaconazole serum concentrations as measured by bioassay. However, the extent of efficacy was also dependent on the infecting inoculum, as greater increases in survival and reductions in fungal burden were observed with the lower inocula tested. In this model high dosages of posaconazole were effective as treatment and prophylaxis against disseminated fusariosis caused by F. solani.

Fusarium proliferatum soft tissue infection at the site of a puncture by a plant: recovery, isolation, and direct molecular identification

After allogeneic stem cell transplantation, a 49-year-old man developed fever and inflammation at the site of a plant puncture on a finger. A hyalohyphomycete was recovered by incubating the plant spine fragment following surgery. Amplification of the internal transcribed spacer region and 5.8S rRNA, beta-tubulin, and translation elongation factor coding genes identified Fusarium proliferatum, which was confirmed later by culture.

Interactions between triazoles and amphotericin B in treatment of disseminated murine infection by Fusarium oxysporum

We have evaluated and compared the efficacies of high doses of amphotericin B (AMB; 3 mg/kg of body weight/day), voriconazole (60 mg/kg), and posaconazole (PSC; 100 mg/kg) alone and combined in a murine model of disseminated infection by Fusarium oxysporum. The combination of AMB with PSC showed the best results, prolonging the survival of mice and reducing their organ fungal loads. This combination might constitute a therapeutic option for those infections where monotherapies fail.

Imaging of pulmonary fusariosis in patients with hematologic malignancies

OBJECTIVE

The purpose of this study was to assess the radiographic features of pulmonary fusariosis, an increasingly encountered cause of severe opportunistic mold pneumonia.

CONCLUSION

Pulmonary fusariosis has radiographic manifestations that are suggestive of an angioinvasive mold. Nodules or masses were the most common findings at CT, seen in 82% of patients compared with only 45% on chest radiography. The halo sign was not seen. Chest radiographs showed nonspecific findings in 30% of patients, and findings were normal at presentation in 25%. All of the patients had underlying hematologic malignancies. Thirteen of the 20 patients studied (65%) died within 1 month of diagnosis of pulmonary fusariosis. Because early initiation of intense antifungal therapy offers the best chance for survival in pulmonary fusariosis, early CT and appropriate microbiologic investigation should be obtained in severely immunocompromised patients.

Fusarium infections in immunocompromised patients

Fusarium species cause a broad spectrum of infections in humans, including superficial, locally invasive, and disseminated infections. The clinical form of fusariosis depends largely on the immune status of the host and the portal of entry, with superficial and localized disease occurring mostly in immunocompetent patients and invasive and disseminated disease affecting immunocompromised patients. Risk factors for severe fusariosis include prolonged neutropenia and T-cell immunodeficiency, especially in hematopoietic stem cell transplant recipients with severe graft-versus-host disease. The most frequent presentation of disseminated fusariosis is a combination of characteristic cutaneous lesions and positive blood cultures, with or without lung or sinus involvement. The prognosis is poor and is determined largely by degree of immunosuppression and extent of infection, with virtually a 100% death rate among persistently neutropenic patients with disseminated disease. These infections may be clinically suspected on the basis of a constellation of clinical and laboratory findings, which should lead to prompt therapy. Treatment options include the lipid formulations of amphotericin B, voriconazole, and posaconazole. Prevention of fusarial infection among high-risk patients should be considered.

Use of the Diversi Lab System for species and strain differentiation of Fusarium species isolates

Advances in molecular typing of fusariosis would facilitate the study of its epidemiology. We tested 26 such isolates by the commercially available Diversi Lab System. The system utilizes automated repetitive sequence-based PCR (rep-PCR) and web-based data analyses. rep-PCR dendrogram cluster analysis showed agreement with species sequence identification (elongation factor 1 alpha gene). Additionally, subtype differences within the same species were noted.

Fusarium verticillioides abscess of the nasal septum in an immunosuppressed child: case report and identification of the morphologically atypical fungal strain

Morphologically atypical Fusarium verticillioides causing a nasal abscess in a severely immunosuppressed child was successfully treated with repeated surgical intervention and liposomal amphotericin B, despite amphotericin B resistance in vitro. Definitive identification was achieved by sequencing the translation elongation factor alpha gene after ribosomal sequencing proved inadequate.

Invasive infections caused by Trichosporon species and Geotrichum capitatum in patients with hematological malignancies: a retrospective multicenter study from Italy and review of the literature

Trichosporonosis is an uncommon but frequently fatal mycosis in immunocompromised patients. A multicenter retrospective study was conducted to characterize cases of proven or probable invasive trichosporonosis diagnosed over the past 20 years in Italian patients with hematological diseases. Of the 52 cases identified, 17 were classified as Trichosporon sp. infections and 35 were attributed to Geotrichum capitatum. Acute myeloid leukemia accounted for 65.4% of the cases. The incidence rates of Trichosporon sp. and G. capitatum infections in acute leukemia patients were 0.4 and 0.5%, respectively. Overall, 76.9% of cases had positive blood cultures. Pulmonary involvement was documented in 26.9% of cases. Death was reported for 57.1% of G. capitatum infections and for 64.7% of Trichosporon sp. infections. A literature review on trichosporonosis in patients with any underlying disease or condition reveals G. capitatum as a predominantly European pathogen, particularly in certain Mediterranean areas, while Trichosporon sp. infections are seen with similar frequencies on all continents. The majority of published Trichosporon sp. and G. capitatum infections occurred in patients with hematological diseases (62.8 and 91.7%, respectively). Well over half of these were suffering from acute leukemia (68 and 84% of patients with Trichosporon sp. and G. capitatum infections, respectively). Crude mortality rates were 77% for Trichosporon spp. and 55.7% for G. capitatum. The optimal therapy for trichosporonosis has yet to be identified; however, in vitro experiences are providing encouraging evidence of the potential role of the new triazoles, in particular, voriconazole.

Fusarium dimerum infection in a stem cell transplant recipient treated successfully with voriconazole

We report the first case, to our knowledge, of a proven Fusarium dimerum soft-tissue infection in a stem cell transplant recipient treated successfully with voriconazole. There is a well-documented increase in the incidence, diversity and antifungal resistance of invasive mould infections in the immunocompromised patient population. The management of these infections is changing as new, more efficacious and less toxic antifungal agents become available. We present the case of a 19-year-old female diagnosed with a proven F. dimerum soft-tissue infection of the foot and possible pulmonary infection with the same organism 10 days following a sibling allogeneic stem cell transplant for severe aplastic anaemia. The infection developed despite treatment with 3 mg/kg AmBisome for a concurrent chest infection. She was treated successfully with voriconazole.