Breakthrough pulmonary Aspergillus fumigatus infection with multiple triazole resistance in a Spanish patient with chronic myeloid leukemia

BackgroundAn allogeneic hematopoietic cell transplantation (allo-HCT) patient presented with chronic pulmonary aspergillosis associated to pulmonary graft versus host disease (GVHD) and was treated for a long time with several antifungal agents that were administered as prophylaxis, combination therapies, and maintenance treatment. The patient suffered from a breakthrough invasive pulmonary aspergillosis due to Aspergillus fumigatus after long-term antifungal therapy.Material and methodsSeveral isolates were analyzed. First isolates were susceptible in vitro to all azole agents. However, after prolonged treatment with itraconazole and voriconazole a multiple azole resistant A. fumigatus isolate was cultured from bronchoalveolar lavage (BAL) when the patient was suffering from an invasive infection, and cavitary lesions were observed.ResultsAnalysis of the resistant mechanisms operating in the last strain led us to report the first isolation in Spain of an azole resistant A. fumigatus strain harboring the L98H mutation in combination with the tandem repeat (TR) alteration in CYP51A gene (TR-L98H). Long-term azole therapy may increase the risk of resistance selecting strains exhibiting reduced susceptibility to these compounds. However, since the isolates were genetically different the suggestion that could be made is that the resistance was not induced during the prolonged azole therapy but the patient might simply have acquired this resistant isolate from the environment, selected by the therapy.ConclusionsThese findings suggest that in all long-term treatments with antifungal agents, especially with azoles, repeated sampling and regular susceptibility testing of strains isolated is necessary as resistant isolates could be selected.     

Identification of resistance-associated proteins in closely-related maize lines varying in aflatoxin accumulation

Aspergillus flavus infection of maize and subsequent contamination with carcinogenic aflatoxins poses serious health concerns, especially in developing countries. Maize lines resistant to A. flavus infection have been identified; however, the development of commercially-useful aflatoxin-resistant maize lines has been hindered due to a lack of breeding markers. To identify maize resistance-associated proteins (RAPs) as potential markers for breeding, 52 BC1S4 lines developed from crosses between five African maize inbreds and five temperate aflatoxin-resistant lines were screened using the kernel screening assay. Five pairs of closely-related lines that had 75?C94% genetic similarity within each pair and which varied within each pair in aflatoxin accumulation were selected for proteomic investigation. Kernel embryo and endosperm protein profile differences within the pair and across pairs were compared using two-dimensional polyacrylamide gel electrophoresis. Differentially expressed (??1.5-fold) RAPs were sequenced through tandem mass spectrometry and were identified as antifungal, stress-related, storage or regulatory proteins. Sequence homology analysis highlighted several proteins in maize that confer resistance to A. flavus infection and/or aflatoxin production.     

Refractory disseminated fusariosis by Fusarium verticillioides in a patient with acute myeloid leukaemia relapsed after allogeneic hematopoietic stem cell transplantation: A case report and literature review

BackgroundFusarium species are among the leading fungal pathogens to cause invasive mould infections in patients with hematopoietic malignancy. The Fusarium species most frequently involved in human infections are Fusarium solani, Fusarium oxysporum and Fusarium verticillioides. However, identification is a cumbersome and time-consuming task. Fusarium is resistant in vitro to many of the antifungal agents and the management of fusariosis is not well defined.ObjectivesTo emphasise the difficulty of identifying Fusarium spp. by conventional methods and the need of new rapid molecular tests to achieve earlier diagnosis and appropriate therapy.MethodsA disseminated Fusarium infection due to F. verticillioides was documented in a neutropenic refractory patient with acute myeloid leukaemia, relapsed after allogeneic hematopoietic stem cell transplantation.ResultsThe patient died despite liposomal amphotericin B and voriconazole combination and “in vitro” susceptibility of agents employed. Morphological and molecular identification of F. verticillioides was obtained only after the death of the patient.ConclusionsThis case highlights the poor outcome of an invasive fungal disease caused by Fusarium in aplastic patients. Identification of members of Fusarium genus remains restricted to selected laboratories and should be introduced into routine mycological diagnostics. In immunocompromised patients, diagnosis of fusariosis is directly related to prompt diagnosis and to patient's status. Current diagnosis methods and therapeutic options are discussed.     

Possible Trichosporon asahii urinary tract infection in a critically ill COVID-19 patient

BackgroundTrichosporon asahii, an emerging fungal pathogen, has been frequently associated with invasive infections in critically ill patients.Case reportA 74-year-old male patient diagnosed with COVID-19 was admitted to an Intensive Care Unit (ICU). During hospitalization, the patient displayed episodes of bacteremia by Staphylococcus haemolyticus and a possible urinary tract infection by T. asahii. While the bacterial infection was successfully treated using broad-spectrum antibiotics, the fungal infection in the urinary tract was unsuccessfully treated with anidulafungin and persisted until the patient died.ConclusionsWith the evolving COVID-19 pandemic, invasive fungal infections have been increasingly reported, mainly after taking immunosuppressant drugs associated with long-term broad-spectrum antibiotic therapy. Although Candida and Aspergillus are still the most prevalent invasive fungi, T. asahii and other agents have emerged in critically ill patients. Therefore, a proper surveillance and diagnosing any fungal infection are paramount, particularly in COVID-19 immunocompromised populations.     

Quantitative trait locus mapping of resistance to Aspergillus flavus infection using a recombinant inbred line population in maize

Aflatoxin contamination of maize (Zea mays L.) grain caused by Aspergillus flavus is a serious health hazard to animals and humans. Development of maize varieties resistant to A. flavus infection and/or aflatoxin production can reduce this contamination. This study was conducted to identify quantitative trait loci (QTL) associated with resistance to A. flavus infection. A recombinant inbred line population was developed derived from RA, a maize inbred line resistant to A. flavus infection, and M53, a susceptible inbred line. After inoculation with A. flavus under controlled conditions, the kernels from each plant line grown in three different environments were evaluated for infection level. Categorical inoculation data were collected for each plant line based on the percentage of the kernel surface covered by fungal conidia. Significant genotypic variation in infection level was observed in all environments. Based on a genetic map containing 916 polymorphic simple sequence repeat and single nucleotide polymorphism markers, the resistance QTL were initially analyzed by composite interval mapping (CIM) separately for each environment. One QTL in bin 5.03 was detected in all environments, and seven other QTL were identified in one environment. Next, a mixed model based on CIM (MCIM) was employed for QTL analysis using data from the three environments simultaneously. Significant epistasis and epistasis × environment interaction to A. flavus infection were revealed. The QTL in bin 5.03 was repeatedly detected by the MCIM. This QTL explained the largest phenotypic variation among all of the detected QTL and could be considered as a major QTL for use in breeding for A. flavus resistance.     

Cutaneous fusariosis by a species of the Fusarium dimerum species complex in a patient with acute mieloblastic leukemia

BackgroundFusariosis is an emergent opportunistic hyalohyphomycosis produced by fungi belonging to the genus Fusarium. These molds are capable of producing life-threatening diseases in immunocompromised hosts, especially in those suffering from leukemia. It has also been described in immunocompetent patients, where it usually causes non-invasive localized lesions. Fusariosis in immunocompromised individuals has a high morbidity and mortality mainly because of the low sensitivity of these fungi to the antifungal drugs available.Case reportWe describe here the case of a patient with acute mieloblastic leukemia who developed fusariosis by a species of the Fusarium dimerum species complex. The early diagnosis was made on the basis of microscopic observation of samples from cutaneous lesions, and voriconazole treatment was prescribed. A subsequent complete study of the fungal isolate by culture and molecular methods allowed the identification of F. dimerum, a species rarely described as a human pathogen. The sensitivity of the strain was tested using the Sensititre YeastOne^® commercial system, which showed sensitivity to voriconazole and posaconazole, as well as to amphotericin B. The patient died after 7 days at hospital due to an hemodynamic failure.ConclusionsComplete identification of new isolates of Fusarium and their antifungal susceptibility patterns is of high interest to improve our knowledge about the epidemiology of the disease and how to best manage patients.     

Disseminated Amphotericin-Resistant Fusariosis in Acute Leukemia Patients: Report of Two Cases

Disseminated fusariosis has emerged as a significant, usually fatal infection in immunocompromised hosts despite antifungal treatment. We describe here two patients with acute leukemia who developed disseminated amphotericin-resistant fusariosis, and review of six studies of cases series in the literature. Two Fusarium solani strains were isolated from blood and skin cultures of one patient, and one strain from the blood culture of the second patient. Both patients died despite antifungal treatment. Strains were identified by sequencing of ITS1 and ITS4 regions. Random amplified polymorphic DNA analysis of the three F. solani isolates showed a low degree of similarity. Screening for Fusarium spp. contaminants within our facility was negative. Using the CLSI M-38-A2 broth dilution method and E tests^®, we found that the MICs were low for voriconazole (0.12 and 0.5 mg/L, respectively), unexpectedly high for amphotericin B (≥8 and ≥32 μg/mL, respectively) and itraconazole (≥16 mg/ml). Patients with leukemia or persistent neutropenia should be assessed for disseminated fungal infections, including biopsy and skin cultures. Antifungal susceptibility tests are important due to the possibility of the strains being amphotericin resistant. Treatments must be aggressive, with high doses of antifungals or combined therapy.     

Sclerotium formation in an Aspergillus flavus wound infection

A patient studied at autopsy was found to have a post-operative wound infection with Aspergillus flavus in which there was the formation of fungal structures resembling sclerotia. The ability of Aspergillus to form sclerotia in tissue appears to be rare and is related to the strain of Aspergillus flavus. Since sclerotia are considered as structures capable of withstanding dramatic shifts in the environment, the production of these in tissue may affect the efficacy of antifungal therapy.     

Invasive scedosporiosis in lung transplant recipients: A nine-year retrospective study in a tertiary care hospital

BackgroundScedosporium species and Lomentospora prolificans (Sc/Lp) are emerging molds that cause invasive disease associated with a high mortality rate. After Aspergillus, these molds are the second filamentous fungi recovered in lung transplant (LT) recipients.AimsOur objective was to evaluate the incidence, risk factors and outcome of Sc/Lp infections in LT recipients at a tertiary care hospital with a national reference LT program.MethodsA nine-year retrospective study was conducted.ResultsDuring this period, 395 LT were performed. Positive cultures for Sc/Lp were obtained from twenty-one LT recipients. Twelve patients (incidence 3.04%) developed invasive scedosporiosis (IS). In 66.7% of the patients with IS the invasive infection was defined as a breakthrough one. The main sites of infection were lungs and paranasal sinuses. Most of the patients received combination antifungal therapy. The IS crude mortality rate after 30 days was 16.7%, and 33.3% after a year.ConclusionsOur study highlights improved survival rates associated with combination antifungal therapy in LT recipients and underlines the risk of breakthrough infections in patients with allograft dysfunction on nebulized lipidic amphotericin B prophylaxis. In addition to pretransplant colonization, acute or chronic organ dysfunctions seem to be the main risk factors for IS.     

Selection and characterization of two monoclonal antibodies specific for the Aspergillus flavus major antigenic cell wall protein Aflmp1

Aspergillus flavus is a major fungal pathogen of plants and an opportunistic pathogen of humans. In addition to the direct impact of infection, it produces immunosuppressive and carcinogenic aflatoxins. The early detection of A. flavus is therefore necessary to diagnose and monitor fungal infection, to prevent aflatoxin contamination of food and feed, and for effective antifungal therapy. Aspergillus-specific monoclonal antibodies (mAbs) are promising as diagnostic and therapeutic reagents for the tracking and treatment of Aspergillus infections, respectively. However, A. flavus has a complex cell wall composition and dynamic morphology, hindering the discovery of mAbs with well-characterized targets. Here we describe the generation and detailed characterization of mAb5.52 (IgG2aκ) and mAb17.15 (IgG1κ), which bind specifically to the highly immunogenic cell wall antigen A. flavus mannoprotein 1 (Aflmp1). Both mAbs were generated using hybridoma technology following the immunization of mice with a recombinant truncated version of Aflmp1 (ExD, including the homologous CR4 domain) produced in bacteria. We show that mAb5.52 and mAb17.15 bind specifically to A. flavus and A. parasiticus cell wall fragments (CWFs), with no cross-reaction to CWFs from other fungal pathogens. Immunofluorescence microscopy revealed that both mAbs bind to the surface of Aspergillus hyphae and that mAb17.15 also binds to spores. The epitope for both mAbs is localized within the CR4 region of the Aflmp1 protein. These Aspergillus-specific mAbs may be useful for the early detection of fungal infection in food/feed crops, for serodiagnosis in patients with invasive aspergillosis caused by A. flavus infection and for the development of antibody-expressing disease-resistant crops.     

Ochroconis humicola Coexisting with Esthesioneuroblastoma: An Incidental Coloniser or Allergen?

Ochroconis humicola, a fish pathogen, is rarely reported to cause disease in human. We report its first isolation from nasal tissue of a human immunodeficiency virus-positive young female patient. Histopathologically, the nasal mass was diagnosed as esthesioneuroblastoma. She presented with right-sided nasal obstruction and bleeding for two and half months. Computed tomography scan showed the nasal mass filling the whole right nasal cavity, maxillary, ethmoid and sphenoid sinuses. The direct microscopy of the nasal tissue and mucin demonstrated the presence of septate hyphae. On culture, O. humicola was isolated from the same tissue and the fungus was identified by morphologic, physiologic and molecular data including sequencing of ITS and 28S rDNA regions. No antifungal was prescribed, and the whole mass was resected out by endoscopic surgery. The patient was treated further by radical radiotherapy. After 1 year of follow-up, patient is stable with no recurrence of tumour. The role of this fungus was not clear, as it may be bystander or producing allergic fungal rhinosinusitis.     

Cytokine milieu in renal cavities of immunocompetent mice in response to intravenous challenge of Aspergillus flavus leading to aspergillosis

Investigations in mice have demonstrated that Aspergillus flavus is more virulent than all other Aspergillus species except A. tamari. However, there is a complete lack of information on the immune responses elicited by A. flavus in systemic model. This communication reports the progression of infection and cytokine profile in BALB/c mice in response to intravenous challenge of A. flavus. The pathogenesis of infection was evaluated morphologically and by the analysis of Colony Forming Units (CFUs) in kidney homogenates. The kinetics of regulated cytokines was determined in kidneys by cytokine-specific murine ELISA. During the initial phase of infection the rate of clearance of A. flavus was high, most likely through recruited neutrophils and the resident renal macrophages with concurrent significant release of pro-inflammatory cytokines (IFN-γ, TNF-α, IL-12/IL-23p40, IL-6) indicating antifungal innate immune response to be active at the site. However, at 24 h PI there was a significant rise of IL-17 and IL-23 suggesting the activation of IL-17/IL-23 axis of inflammation resulting in rise of CFU. The lack of significant induction in the anti-inflammatory cytokines like IL-4 and IL-10 confirmed the absence of Th2 type of response. In the late phase, after 3 days post-infection, there was a rise in the number of pathogen in the kidneys as determined by histopathology and CFU counts. The A. flavus hyphae were evident in the renal pelvis and ureter and we propose the production of blastoconidia by metamorphosed hyphae.     

Primary Cutaneous Mucormycosis Presenting as a Giant Plaque: Uncommon Presentation of a Rare Mycosis

Mucormycosis is an uncommon opportunistic fungal infection caused by Zygomycetes. It usually affects immunocompromised, diabetic and trauma patients with infected wounds. We report a case of disseminated infection secondary to facial cutaneous mucormycosis caused by Saksenaea vasiformis in a diabetic patient who had a farming accident causing him severe head injury. The patient was treated with a combination of surgical debridement and antifungal therapy with liposomal amphotericin B, but he had a slow and fatal outcome. In cases of tissue necrosis following trauma involving wound contact with soil (i.e., potential fungal contamination), testing for the presence of Zygomycetes fungi such as S. vasiformis in both immunocompetent and immunocompromised patients is crucial. The reason is that this infection usually has a rapid progression and may be fatal if appropriate treatment is not administered.     

Fallo multiorgánico en paciente con fungemia por Saprochaete capitata

BackgroundThe significant increase in systemic fungal infections is mainly due to the increase in immunocompromised patients. The high morbimortality of these infections, along with the high hospitalization costs they generate, makes them a problem of great importance in our hospital practice. Saprochaete capitata is a rare fungus that causes invasive infections, usually in immunocompromised patients, and for which there is still no consensus on the treatment regimen to be used.Case reportWe present a case of disseminated infection by this fungus in a heavily immunosuppressed patient, who died as a result of multiple organ failure despite the life support measures taken and the wide spectrum antibiotics.ConclusionsIt is vital to begin the antibiotic treatment as soon as possible, as well as the monitoring and follow-up cultures to test for fungi in neutropenic patients.     

Schizophillum commune Causing Sinusitis with Nasal Polyposis in the Sub-Himalayan Region: First Case Report and Review

Schizophillum commune is an environmental fungus rarely causing human infections of diverse nature. Sinusitis occurs in immunocompromised persons and seldom in healthy subjects. Though easily isolated, the lack of awareness of its virulence is a bottleneck in the diagnosis of this infection. We report the first case of S. commune sinusitis with nasal polyps in an immunocompetent male from the sub-Himalayan region. The computerized tomography scan findings established the clinical diagnosis, and causative agent was confirmed as S. commune. A white, woolly mold with septate, hyaline hyphae and characteristic spicules but unclamped connections suggested a monokaryotic isolate. Patient was treated successfully with fiberoptic endoscopic sinus surgery, and no antifungal therapy was instituted. There was no recurrence at review after 1 year.     

Novel antifungal agents,targets or therapeutic strategies for the treatment of invasive fungal diseases: a review of the literature (2005-2009)

BackgroundThe incidence and prevalence of serious mycoses continues to be a public health problem. Despite aggressive treatment with new or more established licensed antifungal agents, these infections are an important cause of morbidity and mortality, especially in immunocompromised patients.AimsTo critically review the literature regarding important new developments in the field of antifungal therapy both in the English and Spanish versions.MethodsThe search of the literature focused on different antifungal targets or mechanisms of action as well as new agents or strategies that could improve antifungal therapy.ResultsThe review produced a huge amount of information on the use of virulent factors such as growth, filamentation, pathogen tissue clearance, among others, as putative targets of antifungal activity. More recently, the chemical-genetic relationships for licensed agents as well as for other compounds have been provided by the identification of the genes related to the mechanism of action.ConclusionsAlthough the antifungal activity of numerous compounds has been examined, most of them are at the in vitro or animal models of efficacy stages. Therefore, further investigation should be carried out to realize the true clinical utility of these compounds.     

The Epidemiology of Mould Infections in Argentina: Review and Experience

During the last decades, there has been an increasing proportion of patients susceptible to invasive fungal disease (IFD). The epidemiology of IFD varies mainly due to geography, antifungal exposure, and nosocomial reservoirs. We reviewed the Argentinean epidemiology of invasive mold disease (IMD) by analyzing laboratory and clinical data. Invasive mold disease was the second most prevalent IFD following the yeasts, with a prevalence that ranged from 0.98 to 1.31/100,000 population. The majority (60?C85?%) of IMD was caused by hyalohyphomycetes followed by Mucorales (6?C21?%) and phaeohyphomycetes (7?C13?%). The most prevalent genera were Aspergillus (40?C67?% of IMD) followed by Fusarium (10?C14?%). The most prevalent species were A. fumigatus (38?C50?%) followed by A. flavus (27?C43?%). In immunocompromised patients in Argentina the most prevalent agents of IMD are Aspergillus, followed by Fusarium and Mucorales, while the most prevalent Aspergillus species are A. fumigatus followed by A. flavus.     

Use of Voriconazole for the Treatment of Paecilomyces lilacinus Cutaneous Infections: Case Presentation and Review of Published Literature

The fungus Paecilomyces lilacinus is a rare but emerging pathogen that causes severe human infections, especially in immunocompromised hosts. It is an important organism to identify due to its poor susceptibility to conventional antifungal drugs, including amphotericin B, itraconazole, and fluconazole. Oculomycosis and cutaneous infections are the two most common manifestations of P. lilacinus infections. Voriconazole has been used successfully to treat P. lilacinus endophthalmitis, but reports of skin and soft tissue infections treated with voriconazole are limited to six prior publications. Our immunocompromised patient had a subcutaneous P. lilacinus infection successfully treated with 3 months of voriconazole therapy.