Disseminated Aspergillus terreus infection in immunocompromised hosts

A Repertoire of Clinical Non-Dermatophytes Moulds

Humans are constantly exposed to micromycetes, especially filamentous fungi that are ubiquitous in the environment. In the presence of risk factors, mostly related to an alteration of immunity, the non-dermatophyte fungi can then become opportunistic pathogens, causing superficial, deep or disseminated infections. With new molecular tools applied to medical mycology and revisions in taxonomy, the number of fungi described in humans is rising. Some rare species are emerging, and others more frequent are increasing. The aim of this review is to (i) inventory the filamentous fungi found in humans and (ii) provide details on the anatomical sites where they have been identified and the semiology of infections. Among the 239,890 fungi taxa and corresponding synonyms, if any, retrieved from the Mycobank and NCBI Taxonomy databases, we were able to identify 565 moulds in humans. These filamentous fungi were identified in one or more anatomical sites. From a clinical point of view, this review allows us to realize that some uncommon fungi isolated in non-sterile sites may be involved in invasive infections. It may present a first step in the understanding of the pathogenicity of filamentous fungi and the interpretation of the results obtained with the new molecular diagnostic tools.

Effect of reduced oxygen on the antifungal susceptibility of clinically relevant aspergilli

The influence of hypoxia on the in vitro activities of amphotericin B, azoles, and echinocandins against Aspergillus spp. was evaluated by comparing MICs, minimal fungicidal concentrations (MFCs), and epidemiological cutoffs (ECOFFs). Changes of MIC distributions due to hypoxia largely depend on the method, the species, and the growth ability under hypoxia. The activities of antifungals were not significantly altered under hypoxia, except for Aspergillus terreus, for which the activity changed from fungicidal to fungistatic.

In vitro susceptibility testing in Aspergillus species: an update

Aspergillus species are the most common causes of invasive mold infections in immunocompromised patients. The introduction of new antifungal agents and recent reports of resistance emerging during treatment of Aspergillus infections have highlighted the need for in vitro susceptibility testing. Various testing procedures have been proposed, including macro- and micro-dilution, disk diffusion, Etest (AB Biodisk, Sweden) and other commercial tests. Although Aspergillus species are generally susceptible to various compounds, intrinsic and acquired resistance has been documented. Amphotericin B has limited activity against Aspergillus terreus and Aspergillus nidulans. Not surprisingly, continued use of azole-based drugs has the undesirable consequence of elevating the resistance of subsequent isolates from these patients. Several species in the Aspergillus fumigatus complex appear to be resistant to azoles; there is evidence of in vitro and in vivo correlation. Each in vitro susceptibility testing method has its own advantages and disadvantages. Etest is easy to perform and use on a daily basis, yet it is expensive. Disk diffusion is the most attractive alternative method to date, yet we lack sufficient data for aspergilli. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical Laboratory Standard Institute (CLSI) have produced reproducible reference testing methods. This article reviews the available methods for antifungal susceptibility testing in Aspergillus spp. as well as the scant data regarding the clinical implications of in vitro testing.

Activities of antifungal agents against yeasts and filamentous fungi: assessment according to the methodology of the European Committee on Antimicrobial Susceptibility Testing

We compared the activities of antifungal agents against a wide range of yeasts and filamentous fungi. The methodology of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) for yeasts and spore-forming molds was applied; and a total of 349 clinical isolates of Candida spp., other yeast species, Aspergillus spp., and nondermatophyte non-Aspergillus spp. were investigated. The average geometric mean (GM) of the MICs of the various drugs for Candida spp. were as follows: amphotericin B (AMB), 0.55 microg/ml; liposomal amphotericin B (l-AMB); 0.35 microg/ml; itraconazole (ITC), 0.56 microg/ml; voriconazole (VRC), 0.45 microg/ml; posaconazole (POS), 0.44 microg/ml; and caspofungin (CPF), 0.45 microg/ml. The data indicated that the majority of Candida spp. were susceptible to the traditional and new antifungal drugs. For Aspergillus spp., the average GM MICs of AMB, l-AMB, ITC, VRC, POS, and CPF were 1.49 microg/ml, 1.44 microg/ml, 0.65 microg/ml, 0.34 microg/ml, 0.25 microg/ml, and 0.32 microg/ml, respectively. For the various zygomycetes, the average GM MICs of AMB, l-AMB, ITC, and POS were 1.36 microg/ml, 1.42 microg/ml, 4.37 microg/ml, and 1.65 microg/ml, respectively. Other yeastlike fungi and molds displayed various patterns of susceptibility. In general, the minimal fungicidal concentrations were 1 to 3 dilutions higher than the corresponding MICs. POS, AMB, and l-AMB showed activities against a broader range of fungi than ITC, VRC, and CPF did. Emerging pathogens such as Saccharomyces cerevisiae and Fusarium solani were not killed by any drug. In summary, the EUCAST data showed that the in vitro susceptibilities of yeasts and filamentous fungi are variable, that susceptibility occurs among and within various genera and species, and that susceptibility depends on the antifungal drug tested. AMB, l-AMB, and POS were active against the majority of pathogens, including species that cause rare and difficult-to-treat infections.

Aspergilloses au cours de maladies systémiques traitées par corticoïdes et/ou immunosuppresseurs : analyse de neuf cas et revue de la littérature

This is a multicentric retrospective study of aspergillosis in patients treated by corticosteroids and/or immunosuppressive drugs for systemic diseases and a review of the literature. Nine patients, 5 men and 4 women, mean age of 62.8 years old were included among which Horton's diseases (3 cases), systemic lupus erythematosus (2), polymyositis (1), microscopic polyangiitis (1), idiopathic thrombocytopenic purpura (1), rheumatoid polyarthritis (1). Aspergillosis occurred in average 28.4 month after the diagnosis of systemic disease, and 28 months after the beginning of its treatment: corticosteroids in all cases, at a dose of 50.8 mg/day (equivalent prednisone) in average, cyclophosphamide (2 cases), methotrexate (1), intravenous immunoglobulins (1), leflunomide (1). All cases were invasive or chronic pulmonary aspergillosis located in the lungs (6 cases), or in the brain (3). Revealing symptoms were mild and non specific. Lymphopenia was severe in most cases, in average 472 lymphocytes/mm3 and 283 CD4+/mm3. The diagnosis was confirmed 20.75 days after the first symptoms in invasive aspergillosis, and 18.5 months in the chronic pulmonary cases, by cultures in 7 cases (broncho-alveolar lavage: 4; cerebral biopsy: 3), and direct microscopy examination of broncho-alveolar lavage in 2 cases. Specific serology was positive in 4 cases. Patients were treated by voriconazole (4 cases), itraconazole (2), amphotericin B (1), association of caspofungin and voriconazole (1), successive voriconazole and itraconazole (1). Six patients recovered from aspergillosis with 10.8 months of following time, 3 patients died a few days after confirmation of the diagnosis. Fifty-four cases of the literature are analysed.

Nosocomial aspergillosis in outbreak settings

Nosocomial aspergillosis represents a serious threat for severely immunocompromised patients and numerous outbreaks of invasive aspergillosis have been described. This systematic review summarizes characteristics and mortality rates of infected patients, distribution of Aspergillus spp. in clinical specimens, concentrations of aspergillus spores in volumetric air samples, and outbreak sources. A web-based register of nosocomial epidemics (outbreak database), PubMed and reference lists of relevant articles were searched systematically for descriptions of aspergillus outbreaks in hospital settings. Fifty-three studies with a total of 458 patients were included. In 356 patients, the lower respiratory tract was the primary site of aspergillus infection. Species identified most often were Aspergillus fumigatus (154 patients) and Aspergillus flavus (101 patients). Haematological malignancies were the predominant underlying diseases (299 individuals). The overall fatality rate in these 299 patients (57.6%) was significantly greater than that in patients without severe immunodeficiency (39.4% of 38 individuals). Construction or demolition work was often (49.1%) considered to be the probable or possible source of the outbreak. Even concentrations of Aspergillus spp. below 1 colony-forming unit/m(3) were sufficient to cause infection in high-risk patients. Virtually all outbreaks of nosocomial aspergillosis are attributed to airborne sources, usually construction. Even small concentrations of spores have been associated with outbreaks, mainly due to A. fumigatus or A. flavus. Patients at risk should not be exposed to aspergilli.

Epidemiology and outcome of infections due to Aspergillus terreus: 10-year single centre experience

Aspergillus terreus, a less common pathogen, appears to be an emerging cause of infection at our institution, the Medical University Hospital of Innsbruck. Thus the epidemiology and outcome of A. terreus infections over the past 10 years was assessed. We analysed 67 cases of proven invasive aspergillosis (IA) according to the European Organisation for Research and Treatment of Cancer/Mycoses Study Group criteria, investigated antifungal susceptibility of amphotericin B (AMB), voriconazole and caspofungin and performed molecular typing of A. terreus. Patients with proven IA caused by A. terreus (n = 32) and non-A. terreus (n = 35) were evaluated. The two groups were comparable in terms of age, gender, underlying disease, antifungal prophylaxis and duration of neutropenia (P > 0.05). Leukaemia was the most common underlying malignancy. Fungal dissemination occurred in 63% of the patients. Aspergillus terreus infections were associated with a lower response rate to AMB therapy (20%), compared with 47% for patients with non-A. terreus infections (P < 0.05). In vitro, A. terreus was found to be resistant to AMB and molecular typing discriminated between patients isolates, showing a high strain diversity with 26 distinct types (I-XXVI) identified by combination of three primers. Aspergillus terreus infections displayed evidence of AMB resistance in vitro and in vivo and were associated with a high rate of dissemination and poor outcome; A. terreus causes systemic infections of endemic character in Tyrol, Austria. The onset of A. terreus infection depends not on the degree of immunosuppression but on environmental Aspergillus spp. exposure.

Epidemiology of Aspergillus terreus at a university hospital

Invasive fungal infections due to Aspergillus species have become a major cause of morbidity and mortality among immunocompromised patients. Aspergillus terreus, a less common pathogen, appears to be an emerging cause of infection at our institution, the University of Alabama hospital in Birmingham. We therefore investigated the epidemiology of A. terreus over the past 6 years by using culture data; antifungal susceptibility testing with amphotericin B, voriconazole, and itraconazole; and molecular typing with random amplification of polymorphic DNA-PCR (RAPD-PCR). During the study period, the percentage of A. terreus isolates relative to those of other Aspergillus species significantly increased, and A. terreus isolates frequently were resistant to amphotericin B. Molecular typing with the RAPD technique was useful in discriminating between patient isolates, which showed much strain diversity. Further surveillance of A. terreus may better define epidemiology and determine whether this organism is becoming more frequent in relation to other Aspergillus species.

Invasive pulmonary aspergillosis soon after therapy with infliximab, a tumor necrosis factor-alpha-neutralizing antibody: a possible healthcare-associated case?

BACKGROUND

Infliximab is a chimeric monoclonal antibody against tumor necrosis factor (TNF)-alpha, used for the treatment of Crohn's disease and rheumatoid arthritis. Recently, an increased risk of infection due to Mycobacterium tuberculosis and rare cases of invasive fungal disease have been reported following infliximab therapy.

CASE REPORT

A 73-year-old woman with chronic rheumatoid arthritis who had been treated with methotrexate, leflunomide, and prednisone was given the first of three doses of infliximab in June 2001. In July 2001, she presented with cough, and in August, she had a right upper lobe infiltrate that was treated with levofloxacin without improvement. In October, the patient had right upper and middle lobe infiltrates on a chest X-ray and computed tomography scan. At bronchoscopy, an endobronchial mass was biopsied, which demonstrated Aspergills fumigatus. Our patient had frequently accompanied her daughter on visits to another medical center following a stem cell transplant, where her daughter was instructed to wear a mask during all visits because of extensive building construction. We postulate that our patient may have acquired pulmonary aspergillosis during this period. Literature reviews on granulomatous diseases following infliximab therapy and hospital-acquired aspergillosis are presented.

CONCLUSION

The temporal relationship between the administration of infliximab and A. fumigatus infection in this patient suggests a causal relationship and possible healthcare-associated acquisition. These data underscore the importance of both patient and family education on prevention strategies when potent immune-modulating medications such as infliximab have been prescribed.

Acute myelogenous leukemia complicated by acute necrotizing ulcerative gingivitis due to Aspergillus terreus

Infections caused by Aspergillus terreus are rare but have been associated with a poor outcome in immunocompromised patients due to frequent resistance to conventional antifungal therapy. This report describes a case of a woman who developed acute necrotizing ulcerative gingivitis (ANUG) due to A. terreus during induction chemotherapy for acute myelogenous leukemia. She initially failed to respond to treatment with amphotericin B but the infection resolved following the introduction of oral itraconazole. Opportunistic infections caused by A. terreus are an emerging problem and can be associated with a high mortality rate. Early microbiological diagnosis is critical since resistance to amphotericin B is likely and itraconazole appears to be an effective treatment for this infection.

Studies of in vitro activities of voriconazole and itraconazole against Aspergillus hyphae using viability staining

The minimal fungicidal concentrations (MFCs) of voriconazole and itraconazole for five clinical isolates each of Aspergillus terreus, Aspergillus fumigatus, Aspergillus flavus, and Aspergillus niger were determined by a broth macrodilution method. Conidial suspensions as inocula were compared to hyphae as inocula since the invasive form of aspergillosis is manifested by the appearance of hyphal structures. In addition, cell viability staining with the dye FUN-1 was performed to assess time-dependent damage of hyphae exposed to various concentrations of the antifungal agents. With conidial inocula the MFC ranges of voriconazole were 0.5 to 4 microg/ml and those of itraconazole were 0.25 to 2 microg/ml, whereas the MFCs (2 to >16 microg/ml) with hyphal inocula were substantially higher (P < 0.01) for both itraconazole and voriconazole. Only minor differences between the tested antifungals were observed since 16 of 20 and 17 of 20 of the isolates of Aspergillus spp. tested appeared to be killed by voriconazole and itraconazole, respectively. The results of FUN-1 viability staining correlated closely to colony counts, but various time- and dose-dependent levels of viability of hyphae were also observed. In conclusion, our study demonstrates the importance of the type of inoculum used to test antifungals and the applicability of FUN-1 staining as a rapid and sensitive method for assaying the viability of hyphae.

Mycotic aneurysm of the thoracic aorta due to Aspergillus terreus: case report and review

Mycotic aneurysms of the aorta caused by fungi are uncommon. We describe an unusual case of aortic aneurysm infection caused by Aspergillus terreus, which most likely spread from an adjacent pulmonary focus. Successful treatment included partial pneumonectomy, resection of the aneurysm with graft repair, and prolonged sequential administration of amphotericin B and itraconazole. A review of the published experience with aortic aneurysms caused by Aspergillus species is also presented. When invasive aspergillosis is suspected in proximity to areas with major vascular structures in immunocompromised patients, further investigation to rule out vascular invasion may be warranted. If the diagnosis is confirmed, aggressive and prompt treatment with antifungal agents combined with surgical debridement is essential to improve outcome.

Aspergillus terreus infections in haematological malignancies: molecular epidemiology suggests association with in-hospital plants

During a three-year period nine patients with haematological diseases after myeloablative chemotherapy died from invasive fungal infections caused by Aspergillus terreus. The hospital inanimate environment was monitored and A. terreus was cultured from potted plants in the vicinity of the patients. The patients (N = 14) and the environmental isolates (N = 2) were fingerprinted by RAPD-PCR with four different primers. Based on RAPD patterns the patients' isolates were differentiated into five different types; the environmental isolates represented two types. The isolates of four patients were identical to those found in the environment. Five additional patients were infected by RAPD types not found in the environment. One patient was infected with two different types. The data indicate a hospital-acquired infection in many of the patients and underline the need for careful environmental monitoring of units in which high-risk patients are housed.

Bilateral pulmonary aspergilloma caused by an atypical isolate of Aspergillus terreus

A case of bilateral pulmonary aspergilloma caused by an atypical isolate of Aspergillus terreus is described. The diagnosis was established by the presence of septate, dichotomously branched fungal elements in freshly collected bronchoalveolar lavage and sputum specimens and by repeated isolation of the fungus in culture. Specific precipitating antibodies against the A. terreus isolate were demonstrated in the patient's serum. The isolate was atypical as it failed to produce fruiting structures on routine mycological media, but it did so on extended incubation on potato flake agar and produced globose, relatively heavy-walled, hyaline accessory conidia (formerly termed aleurioconidia) on both vegetative and aerial mycelia. Also, it produced an intense yellow diffusing pigment in the medium. The report underscores the increasing importance of A. terreus in the etiology of pulmonary aspergillosis. It is suggested that A. terreus antigen be included in the battery of serodiagnostic reagents to facilitate the early diagnosis of infections caused by this species.

Molecular typing of Aspergillus terreus isolates by random amplification of polymorphic DNA

Forty three isolates of Aspergillus terreus of environmental or clinical origin were typed by random amplification of polymorphic DNA (RAPD) with two different primers NS3 and NS7 from the fungal ribosomal 18S subunit gene. For the 31 epidemiologically unrelated isolates tested, the primers NS3 and NS7 gave rise to 23 and 24 different genotypes, respectively, and combining the results obtained with the two primers allowed the differentiation of all these isolates. No clustering was found in relation to pathogenicity, clinical signs, or geographic origin of the isolates. Five groups of related isolates of A. terreus were also typed. Analysis of sequential isolates from patients with cystic fibrosis or with invasive aspergillosis showed the clonality of the colonization or infection by A. terreus. Likewise, this straightforward typing method demonstrated the clonal origin of a massive contamination of the environment in a haematology unit. Therefore this RAPD typing method may constitute a valuable tool for the epidemiological follow-up of airway colonization in patients with cystic fibrosis or investigations of links between nosocomial outbreaks of invasive aspergillosis and environmental contamination.

In vitro amphotericin B resistance in clinical isolates of Aspergillus terreus, with a head-to-head comparison to voriconazole

Amphotericin B therapy continues to be the "gold standard" in the treatment of invasive aspergillosis in the immunocompromised host. Although Aspergillus fumigatus and Aspergillus flavus constitute the major species, several reports have described invasive pulmonary or disseminated disease due to the less common Aspergillus terreus and dismal clinical outcomes with high-dose amphotericin B. We therefore evaluated 101 clinical isolates of A. terreus for their susceptibility to amphotericin B and the investigational triazole voriconazole by using the National Committee for Clinical Laboratory Standards M27-A method modified for mould testing. Forty-eight-hour MICs indicated 98 and 0% resistance to amphotericin B and voriconazole, respectively. We conclude that A. terreus should be added to the list of etiologic agents refractory to conventional amphotericin B therapy and suggest the potential clinical utility of voriconazole in aspergillosis due to this species.

Fungal endocarditis in bone marrow transplantation: case report and review of literature

We report a case of fungal endocarditis due to Aspergillus terreus in a leukaemia patient who received a bone marrow allograft from a matched unrelated donor. He presented with persistent fever. microangiopathic haemolytic anaemia but there was no cardiac signs and symptoms. He died despite intravenous amphotericin B. Review of the English literature showed five other patients with fungal endocarditis in the setting of bone marrow transplantation and revealed the same features of difficult diagnosis and poor outcome.

Endocarditis and aortal embolization caused by Aspergillus terreus in a patient with acute lymphoblastic leukemia in remission: diagnosis by peripheral-blood culture

Disseminated infection with Aspergillus terreus is a rare disease that affects only the immunocompromised host. We report a case of systemic infection with A. terreus resulting in endocarditis, aortic embolization, and splenic infarction in a patient with acute lymphoblastic leukemia. Diagnosis through peripheral blood culture, lack of pulmonary involvement, and onset of disease during complete remission from leukemia constitute uncommon features of this case.

A fatal infection with Alternaria alternata and Aspergillus terreus in a child with agranulocytosis of unknown origin

Alternaria alternata and Aspergillus terreus were isolated from cutaneous nodules in a 5-year-old girl with agranulocytosis of unknown origin. Histopathological examination supported the diagnosis of an infection with two opportunistic moulds. Aspergillus terreus was also isolated from the secretions of the maxillary sinuses of the patient. In spite of antimycotic therapy, the child eventually died from respiratory failure.

Nosocomial invasive aspergillosis in lymphoma patients treated with bone marrow or peripheral stem cell transplants

OBJECTIVES

To determine the prevalence of aspergillosis in lymphoma patients housed in a protective environment while undergoing a bone marrow transplant or peripheral stem cell transplant and its relation to lymphoma type, type of transplant, period of neutropenia, method of diagnosis, species of Aspergillus, and the use of empiric amphotericin B.

DESIGN

Clinical, autopsy, and microbiology records were reviewed retrospectively to determine the presence or absence of invasive aspergillosis. All positive specimens underwent further review to determine parameters outlined above.

SETTING

The review took place at the University of Nebraska Medical Center with lymphoma patients housed in the oncology/hematology special care unit, which consists of 30 single-patient rooms under positive pressure with high-efficiency particulate air filtration.

PATIENTS

417 lymphoma patients admitted to the oncology/hematology special care unit who underwent 427 courses of high-dose chemotherapy with or without total body irradiation followed by a stem cell rescue.

RESULTS

Twenty-two cases (5.2%) of nosocomial invasive aspergillosis (14 caused by Aspergillus flavus, 2 by Aspergillus terreus, 2 by Aspergillus fumigatus, and 4 by characteristic histology) were diagnosed. The prevalence of disease according to transplant was 8.7% for allogeneic bone marrow transplant (2/23 treatments), 5.6% for autologous peripheral stem cell transplant (9/161), and 4.5% for autologous bone marrow transplant (11/243). Fifteen patients were presumptively diagnosed prior to death (68.2%) most commonly by histologic examination of skin biopsies. All 22 patients received amphotericin B therapy, 17 prior to aspergillosis diagnosis, and 7 (31.8%) survived. No patient with disseminated disease survived.

CONCLUSIONS

Even when housing lymphoma patients undergoing myeloablative therapy in a protective environment containing high-efficiency particulate air filtration, there was a risk of developing aspergillosis. These data also showed that antemortem diagnosis with aggressive amphotericin B therapy was most effective in the management of infected lymphoma patients when engraftment occurred and the disease did not become disseminated.

Aspergillus endocarditis and myocarditis in a patient with the acquired immunodeficiency syndrome (AIDS). A review of the literature

We report the post-mortem findings of the case of a 31-year-old male who, through sexual contacts with a female drug addict, was found to be HIV-positive and developed the acquired immunodeficiency syndrome (AIDS) 2 years later. He was treated for various opportunistic infections over the next 7 years when he presented with cardiac abnormalities and multiple cerebral lesions which were responsible for his death. The results revealed Aspergillus fumigatus endocarditis and myocarditis with mycotic thromboembolic extension to the brain, spleen, kidney and pancreas. We review the literature of Aspergillus infection in patients with AIDS and more specifically cardiac involvement with this pathogen.