New spectrum of fungal infections in patients with cancer

Clinical significance of non-Candida fungal blood isolation in patients undergoing high-risk allogeneic hematopoietic stem cell transplantation (1993-2001)

BACKGROUND

The clinical relevance of mold isolated from blood cultures, even in severely immunosuppressed allogeneic hematopoietic stem cell transplantation (HSCT) recipients, remains uncertain. The authors hypothesized that isolation of non-Candida fungi from blood cultures in patients undergoing high-risk HSCT would have clinical significance.

METHODS

The authors reviewed the records of 73 allogeneic HSCT recipients between January 1, 1993 and January 1, 2001 in whom fungal species were isolated from blood cultures.

RESULTS

Fifty-two episodes of non-Candida fungemia occurred in 48 patients (66%) after a median of 10 days (range, 2-341) after transplantation. All 48 patients had indwelling intravascular catheters, and 23 patients (48%) had profound neutropenia. Thirty-five of 48 patients had received partially matched, related donor stem cell grafts (19 patients had 3-antigen-mismatched grafts); 35 patients had undergone T-cell depleted transplantation and 9 patients were receiving treatment for acute graft-versus-host disease. In 5 of 48 patients (10%), death was attributed to fungemia that occurred 8-11 days after the initial fungal blood culture was obtained; all 5 patients were age > 30 years. No deaths occurred in the younger age group (n = 22 patients; P = 0.05). In the 24 patients who did not receive systemic antifungal therapy, 4 deaths (17%) were attributed to infections with Penicillium (n = 2 patients), Epicoccum (n = 1 patient), or Penicillium plus Cladosporium species (n = 1 patient). Of the 24 patients who received amphotericin B, only 1 patient (4%) died as a result of a probable hematogenous Aspergillus species infection; this difference in outcome, however, was not significant (P = 0.2).

CONCLUSIONS

Most of the non-Candida fungal blood culture isolates in recipients of high-risk, mismatched donor transplantation were clinically nonsignificant. However, because these low-virulence saprophytes occasionally may cause life-threatening disease, a reevaluation of the existing diagnostic paradigm is needed so that clinically significant fungemia may be differentiated from pseudofungemia.

Genotyping of clinical Rhodotorula mucilaginosa isolates by pulsed field gel electrophoresis

Identification and typing of fungal isolates is a prerequisite for control and prevention of nosocomial infections. As the discriminatory power of phenotypic methods is not sufficient for epidemiological purposes, genotyping methods such as DNA fingerprinting, random amplification of polymorphic DNA (RAPD) analysis, or pulsed field gel electrophoresis (PFGE) are preferred. To our knowledge, this study is the first application of PFGE for typing Rhodotorula mucilaginosa strains. The PFGE patterns of six clinical isolates produced two different karyotypes, which were confirmed by RAPD analysis. Five strains isolated from bloodstream infections from three different institutions showed the same karyotype and RAPD patterns, while the urological specimen differed slightly.

[Guidelines for the treatment of invasive fungal infection. Invasive fungal infection by Candida spp. Invasive Fungal Infection Study Group (MICOMED) and Infection in Transplantation Study Group (GESITRA) of the Spanish Society for Infectious Diseases and Clinical Microbiology (SEIMC)]

These guidelines resume different issues related to the clinical management of invasive candidosis in the immunossuppressed patients. They are based on the recommendations of the different Drug's Agencies.

Fatal pulmonary scedosporiosis. Letal verlaufende pulmonale Scedosporiose

We report on a case of scedosporiosis in a 72-year-old German woman. Her disease started with a purulent ulceration of unknown course at her left foot. Soon after onset of oral antibacterial therapy she needed in-hospital treatment because of an acute pneumonia. The infection progressed despite the application of different antibiotics. Microscopic examination of tracheal fluid revealed fungal hyphae and therefore treatment with itraconazole was initiated. However, the patient developed renal failure, required mechanical ventilation and finally died in treatment-resistant septic shock. Post-mortem Scedosporium apiospermum was cultured from lung tissue taken during autopsy. This is the fourth case of human infection caused by Scedosporium species diagnosed in our laboratory during the last 4 years.

Immunopathogenesis of pulmonary granulomas in the guinea pig after infection with Mycobacterium tuberculosis

Pulmonary tuberculosis in guinea pigs is similar to the disease in humans and is accordingly widely used as a model to test tuberculosis vaccines. The primary site of expression of acquired immunity and the hallmark of tuberculosis is the granuloma. Granuloma morphology is well described, but there is limited information regarding T-cell subset influx. We monitored the course of pulmonary tuberculosis in guinea pigs and observed four distinct immunohistopathological stages. In all stages there were similar numbers and arrangement of CD4 and CD8 T cells. There were only small numbers of apoptotic lymphocytes, scattered around and within the necrotic core, and acid-fast bacilli were visible both within macrophages and free within airway debris. A key finding of the study was the observation that the development of the necrotic core was an early event and almost certainly preceded the emergence of the acquired immune response. This in turn suggests that innate mechanisms are the basis of the early lesions and that subsequent acquired responses are unable to moderate them. This hypothesis differs from the current dogma that excessive activity of T cells mediates delayed-type hypersensitivity and that cellular cytolysis is the root cause of the necrosis.

Emerging and less common fungal pathogens

Less common and emerging fungal pathogens are often resistant to conventional antifungal therapy and may cause severe morbidity and mortality in immunocompromised hosts. Some Scedosporium species may be completely resistant to antifungal therapy. Hyaline septated filamentous fungi, such as Fusarium species, Acremonium species, Paecilomyces species, and Trichoderma species, are increasingly reported as causing invasive mycoses refractory to amphotericin B therapy. Dematiaceous septated filamentous fungi, such as Bipolaris species may cause pneumonia, sinusitis, and CNS infections that are unresponsive to current medical interventions. Trichosporon spp are resistant to the fungicidal effects of amphotericin B. An increasing number of different members of the class Zygomycetes are reported as causing lethal infections, despite aggressive medical and surgical interventions. Infections due to these and other less common and emergent fungal pathogens will likely continue to develop in the settings of selective anti-fungal pressure, permissive environmental conditions, and an expanding population of immunocompromised hosts.

Clinical utility of bronchoalveolar lavage in pediatric cancer patients

BACKGROUND

Pulmonary disease in the pediatric cancer patient continues to pose a difficult clinical dilemma. Bronchoalveolar lavage (BAL) is commonly utilized for the diagnosis of pulmonary complications in the immunocompromised child.

PROCEDURE

We retrospectively reviewed 53 BAL procedures performed in pediatric cancer patients with pulmonary disease between 1988 and 1998 to determine the diagnostic and clinical utility of BAL. Patients who had undergone prior myeloablative therapy were excluded from analysis.

RESULTS

The majority of patients (83%) had an underlying diagnosis of acute leukemia or lymphoma. BAL yielded a specific diagnosis in 16 patients (30%), including 15 infections and 1 malignant infiltration. Medical management was altered in an additional 14 patients (26%) as a consequence of a negative BAL result. Severe but transient complications associated with the BAL procedure occurred in four patients (8%). Minor complications following the BAL occurred in 21 patients (40%) and included transiently increased oxygen requirement and anesthesia-related gastrointestinal complaints. The mortality from lung disease in this patient population was 7.5%.

CONCLUSIONS

Both positive and negative BAL results contribute to the management of pediatric cancer patients with pulmonary disease. The low incidence of significant complications associated with BAL and the high mortality rate in this patient population support the choice of BAL as an initial diagnostic test in pediatric cancer patients with pulmonary disease.

Identification of the first isolates of Trichosporon asahii var asahii from disseminated trichosporonosis in China

Infection with Trichosporon asahii is a major cause of deep-seated and disseminated trichosporonosis, which is associated with a high mortality rate. Disseminated trichosporonosis in individuals with no underlying disease has not been reported. In this study, we report the identification of the first isolate of Trichosporon asahii var. asahii in China. Two isolates were obtained from the liver and skin of a patient with disseminated trichosporonosis who displayed no evidence of underlying disease. The morphologic and physiologic characteristics of the two isolates differed slightly from those of usual strains of T. asahii var. asahii, including the type strain CBS 2479. Ubiquinone-9 was identified as the major ubiquinone in both isolates. Sequence analysis of the LSUrDNA D1/D2, ITS, and IGS1 regions from the two isolates showed them to be T. asahii var. asahii, and random amplified polymorphic DNA analysis strongly suggested that they were the same strain.

Endogenous endophthalmitis following disseminated fungemia due to Fusarium solani in a patient with acute myeloid leukemia

We report the case of a young man with a resistant acute myeloid leukemia (AML) who developed a disseminated fungemia due to Fusarium solani involving the skin and lungs, during the neutropenic phase following a chemotherapy course. Despite continuous therapy with liposomal amphotericin B, he developed a bilateral endophthalmitis that rapidly evolved to complete blindness. The patient underwent two procedures of vitrectomy, with detection of F. solani in the vitreous fluid, and continued antifungal therapy, without any recovery of visual acuity. When he eventually died due to recurrence of leukemia and hemorrhagic shock, autopsy revealed a diffuse fusarial involvement of the central nervous system.

Safety, tolerance, and pharmacokinetics of high-dose liposomal amphotericin B (AmBisome) in patients infected with Aspergillus species and other filamentous fungi: maximum tolerated dose study

We conducted a phase I-II study of the safety, tolerance, and plasma pharmacokinetics of liposomal amphotericin B (L-AMB; AmBisome) in order to determine its maximally tolerated dosage (MTD) in patients with infections due to Aspergillus spp. and other filamentous fungi. Dosage cohorts consisted of 7.5, 10.0, 12.5, and 15.0 mg/kg of body weight/day; a total of 44 patients were enrolled, of which 21 had a proven or probable infection (13 aspergillosis, 5 zygomycosis, 3 fusariosis). The MTD of L-AMB was at least 15 mg/kg/day. Infusion-related reactions of fever occurred in 8 (19%) and chills and/or rigors occurred in 5 (12%) of 43 patients. Three patients developed a syndrome of substernal chest tightness, dyspnea, and flank pain, which was relieved by diphenhydramine. Serum creatinine increased two times above baseline in 32% of the patients, but this was not dose related. Hepatotoxicity developed in one patient. Steady-state plasma pharmacokinetics were achieved by day 7. The maximum concentration of drug in plasma (C(max)) of L-AMB in the dosage cohorts of 7.5, 10.0, 12.5, and 15.0 mg/kg/day changed to 76, 120, 116, and 105 microg/ml, respectively, and the mean area under the concentration-time curve at 24 h (AUC(24)) changed to 692, 1,062, 860, and 554 microg x h/ml, respectively, while mean CL changed to 23, 18, 16, and 25 ml/h/kg, respectively. These data indicate that L-AMB follows dose-related changes in disposition processing (e.g., clearance) at dosages of >or=7.5 mg/kg/day. Because several extremely ill patients had early death, success was determined for both the modified intent-to-treat and evaluable (7 days of therapy) populations. Response rates (defined as complete response and partial response) were similar for proven and probable infections. Response and stabilization, respectively, were achieved in 36 and 16% of the patients in the modified intent-to-treat population (n = 43) and in 52 and 13% of the patients in the 7-day evaluable population (n = 31). These findings indicate that L-AMB at dosages as high as 15 mg/kg/day follows nonlinear saturation-like kinetics, is well tolerated, and can provide effective therapy for aspergillosis and other filamentous fungal infections.

Case report. Disseminated infection of Blastoschizomyces capitatus in a patient with acute myelocytic leukaemia

Blastoschizomyces capitatus infection in a 48-year-old man with acute myelocytic leukaemia is reported. A multiorgan involvement and fulminant course of the fungal infection resulted in the patient's death despite fluconazole prophylaxis, therapy with amphotericin B and administration of granulocyte colony-stimulating factor. Predisposing factors to the infection, clinical relevance of surveillance strains and in vitro antifungal susceptibility testing are discussed.

FR131535, a novel water-soluble echinocandin-like lipopeptide: synthesis and biological properties

The synthesis and biological properties of a novel water-soluble echinocandin-like lipopeptide, FR131535, are described. This compound displayed potent in vitro and in vivo antifungal activities. The hemolytic activity of FR901379 was reduced by replacing the acyl side chain. This compound showed good water-solubility, comparable to the natural product FR901379.

Acrophialophora fusispora brain abscess in a child with acute lymphoblastic leukemia: review of cases and taxonomy

A 12-year-old girl with acute lymphoblastic leukemia was referred to King Faisal Specialist Hospital and Research Center. The diagnosis without central nervous system (CNS) involvement was confirmed on admission, and chemotherapy was initiated according to the Children Cancer Group (CCG) 1882 protocol for high-risk-group leukemia. During neutropenia amphotericin B (AMB) (1 mg/kg of body weight/day) was initiated for presumed fungal infection when a computed tomography (CT) scan of the chest revealed multiple nodular densities. After 3 weeks of AMB therapy, a follow-up chest CT revealed progression of the pulmonary nodules. The patient subsequently suffered a seizure, and a CT scan of the brain was consistent with infarction or hemorrhage. Because of progression of pulmonary lesions while receiving AMB, antifungal therapy was changed to liposomal AMB (LAMB) (6 mg/kg/day). Despite 26 days of LAMB, the patient continued to have intermittent fever, and CT and magnetic resonance imaging of the brain demonstrated findings consistent with a brain abscess. Aspiration of brain abscess was performed and the Gomori methenamine silver stain was positive for hyphal elements. Culture of this material grew Acrophialophora fusispora. Lung biopsy showed necrotizing fungal pneumonia with negative culture. The dosage of LAMB was increased, and itraconazole (ITRA) was added; subsequently LAMB was discontinued and therapy was continued with ITRA alone. The patient demonstrated clinical and radiological improvement. In vitro, the isolate was susceptible to low concentrations of AMB and ITRA. A. fusispora is a thermotolerant, fast-growing fungus with neurotropic potential. We report the first case of human infection involving the CNS. Acrophialophora resembles Paecilomyces but differs in having colonies that become dark and in the development of phialides along the sides or at the tips of echinulate brown conidiophores. Conidia are borne in long chains and are smooth or ornamented with fine-to-coarse echinulations, sometimes in spiral bands. The taxonomy of the genus Acrophialophora is reviewed, and Acrophialophora nainiana and Acrophialophora levis are considered as synonyms of A. fusispora.

Cluster of pulmonary infections caused by Cunninghamella bertholletiae in immunocompromised patients

Cunninghamella bertholletiae is a rare cause of pulmonary mucormycosis. We describe a cluster of invasive pulmonary infections caused by C. bertholletiae in 4 immunocompromised patients that occurred during a 2-year period at 1 center. Three of the patients were receiving antifungal prophylaxis with itraconazole. Presenting symptoms were fever unresponsive to antibacterial chemotherapy, hemoptysis, and infiltrates on chest radiograms. Three patients were treated with liposomal amphotericin B. Only 1 patient survived.

The epidemiology of fusariosis in patients with haematological diseases. Gimema Infection Programme

Fusariosis has been considered an emerging infection in patients with haematological malignancies. In a multicentre retrospective study on filamentous fungi infections in patients with haematological diseases over a period of 10 years in Italy, fusariosis was documented in six patients from two of the 14 centres with a 0.06% incidence in acute leukaemia. A literature search yielded 177 cases of Fusarium infections in haematological diseases and acute leukaemia accounted for 71% of the underlying conditions. An increase from 0.5 to 3.8 cases per year was observed at the M.D. Anderson Cancer Center of Houston in the periods 1975-85 and 1986-95 respectively. Conversely, only 5.1 and 6.3 cases per year have been reported in the periods 1981-90 and 1991-96, respectively, from the other centres in the world. Half of the cases have been observed in the USA. In Europe, most of the cases have been observed in France and Italy. Invasive fusariosis is a rare complication in haematological diseases, as its overall frequency does not seem to be significantly increased within the last 20 years. However, its epidemiological distribution is not homogeneous and the possibility of local clusters of infections by this deadly pathogen should be carefully considered.

Scopulariopsis brevicaulis: a keratinophilic or a keratinolytic fungus?

The morphologic expression of human hair and nail invasion in vitro by Scopulariopsis brevicaulis isolates was studied by light microscopy on whole material and on semi-thin sections, and also by scanning and transmission electron microscopy. Only three isolates of the nine that were examined were keratinolytic, capable of both attacking keratinic substrates and demolishing their keratin. The process showed all the characteristic of enzymatic digestion and was in agreement with the biochemical and morphogenetic scheme proposed for other keratinolytic fungi during their invasion of human hair in vitro. All the active isolates were capable of developing structures related to surface erosion and radial penetration contemporaneously. However the extent and rate of keratinolysis were rather low when compared with the efficiency of other keratinolytic fungi. This finding suggests that S. brevicaulis is of secondary importance in the mineralization of keratinic substrates in natural environments. From the medical standpoint the mere demonstration of keratinolytic activity means that it may be regarded as a real cause of primary infection.

Zygomycetes in human disease

The Zygomycetes represent relatively uncommon isolates in the clinical laboratory, reflecting either environmental contaminants or, less commonly, a clinical disease called zygomycosis. There are two orders of Zygomycetes containing organisms that cause human disease, the Mucorales and the Entomophthorales. The majority of human illness is caused by the Mucorales. While disease is most commonly linked to Rhizopus spp., other organisms are also associated with human infection, including Mucor, Rhizomucor, Absidia, Apophysomyces, Saksenaea, Cunninghamella, Cokeromyces, and Syncephalastrum spp. Although Mortierella spp. do cause disease in animals, there is no longer sufficient evidence to suggest that they are true human pathogens. The spores from these molds are transmitted by inhalation, via a variety of percutaneous routes, or by ingestion of spores. Human zygomycosis caused by the Mucorales generally occurs in immunocompromised hosts as opportunistic infections. Host risk factors include diabetes mellitus, neutropenia, sustained immunosuppressive therapy, chronic prednisone use, iron chelation therapy, broad-spectrum antibiotic use, severe malnutrition, and primary breakdown in the integrity of the cutaneous barrier such as trauma, surgical wounds, needle sticks, or burns. Zygomycosis occurs only rarely in immunocompetent hosts. The disease manifestations reflect the mode of transmission, with rhinocerebral and pulmonary diseases being the most common manifestations. Cutaneous, gastrointestinal, and allergic diseases are also seen. The Mucorales are associated with angioinvasive disease, often leading to thrombosis, infarction of involved tissues, and tissue destruction mediated by a number of fungal proteases, lipases, and mycotoxins. If the diagnosis is not made early, dissemination often occurs. Therapy, if it is to be effective, must be started early and requires combinations of antifungal drugs, surgical intervention, and reversal of the underlying risk factors. The Entomophthorales are closely related to the Mucorales on the basis of sexual growth by production of zygospores and by the production of coenocytic hyphae. Despite these similarities, the Entomophthorales and Mucorales have dramatically different gross morphologies, asexual reproductive characteristics, and disease manifestations. In comparison to the floccose aerial mycelium of the Mucorales, the Entomophthorales produce a compact, glabrous mycelium. The asexually produced spores of the Entomophthorales may be passively released or actively expelled into the environment. Human disease with these organisms occurs predominantly in tropical regions, with transmission occurring by implantation of spores via minor trauma such as insect bites or by inhalation of spores into the sinuses. Conidiobolus typically infects mucocutaneous sites to produce sinusitis disease, while Basidiobolus infections occur as subcutaneous mycosis of the trunk and extremities. The Entomophthorales are true pathogens, infecting primarily immunocompetent hosts. They generally do not invade blood vessels and rarely disseminate. Occasional cases of disseminated and angioinvasive disease have recently been described, primarily in immunocompromised patients, suggesting a possible emerging role for this organism as an opportunist.

Zygomycetes in human disease

The Zygomycetes represent relatively uncommon isolates in the clinical laboratory, reflecting either environmental contaminants or, less commonly, a clinical disease called zygomycosis. There are two orders of Zygomycetes containing organisms that cause human disease, the Mucorales and the Entomophthorales. The majority of human illness is caused by the Mucorales. While disease is most commonly linked to Rhizopus spp., other organisms are also associated with human infection, including Mucor, Rhizomucor, Absidia, Apophysomyces, Saksenaea, Cunninghamella, Cokeromyces, and Syncephalastrum spp. Although Mortierella spp. do cause disease in animals, there is no longer sufficient evidence to suggest that they are true human pathogens. The spores from these molds are transmitted by inhalation, via a variety of percutaneous routes, or by ingestion of spores. Human zygomycosis caused by the Mucorales generally occurs in immunocompromised hosts as opportunistic infections. Host risk factors include diabetes mellitus, neutropenia, sustained immunosuppressive therapy, chronic prednisone use, iron chelation therapy, broad-spectrum antibiotic use, severe malnutrition, and primary breakdown in the integrity of the cutaneous barrier such as trauma, surgical wounds, needle sticks, or burns. Zygomycosis occurs only rarely in immunocompetent hosts. The disease manifestations reflect the mode of transmission, with rhinocerebral and pulmonary diseases being the most common manifestations. Cutaneous, gastrointestinal, and allergic diseases are also seen. The Mucorales are associated with angioinvasive disease, often leading to thrombosis, infarction of involved tissues, and tissue destruction mediated by a number of fungal proteases, lipases, and mycotoxins. If the diagnosis is not made early, dissemination often occurs. Therapy, if it is to be effective, must be started early and requires combinations of antifungal drugs, surgical intervention, and reversal of the underlying risk factors. The Entomophthorales are closely related to the Mucorales on the basis of sexual growth by production of zygospores and by the production of coenocytic hyphae. Despite these similarities, the Entomophthorales and Mucorales have dramatically different gross morphologies, asexual reproductive characteristics, and disease manifestations. In comparison to the floccose aerial mycelium of the Mucorales, the Entomophthorales produce a compact, glabrous mycelium. The asexually produced spores of the Entomophthorales may be passively released or actively expelled into the environment. Human disease with these organisms occurs predominantly in tropical regions, with transmission occurring by implantation of spores via minor trauma such as insect bites or by inhalation of spores into the sinuses. Conidiobolus typically infects mucocutaneous sites to produce sinusitis disease, while Basidiobolus infections occur as subcutaneous mycosis of the trunk and extremities. The Entomophthorales are true pathogens, infecting primarily immunocompetent hosts. They generally do not invade blood vessels and rarely disseminate. Occasional cases of disseminated and angioinvasive disease have recently been described, primarily in immunocompromised patients, suggesting a possible emerging role for this organism as an opportunist.

Efficacy of FK463, a new lipopeptide antifungal agent, in mouse models of disseminated candidiasis and aspergillosis

The efficacy of intravenous injection of FK463, a novel water-soluble lipopeptide, was evaluated in mouse models of disseminated candidiasis and aspergillosis and was compared with those of fluconazole (FLCZ) and amphotericin B (AMPH-B). In the candidiasis model, FK463 significantly prolonged the survival of intravenously infected mice at doses of 0.125 mg/kg of body weight or higher. In disseminated candidiasis caused by Candida species, including FLCZ-resistant Candida albicans, FK463 exhibited an efficacy 1.4 to 18 times inferior to that of AMPH-B, with 50% effective doses (ED(50)s) ranging from 0.21 to 1.00 mg/kg and 0.06 to 0.26 mg/kg, respectively, and was much more active than FLCZ. The protective effect of FK463 was not obviously influenced by the fungal inoculum size, the starting time of the treatment, or the immunosuppressed status of the host. The reduction in efficacy was less than that observed with FLCZ or AMPH-B. The efficacy of FK463 was also evaluated in the disseminated candidiasis target organ assay and was compared with those of FLCZ and AMPH-B. Efficacies were evaluated on the basis of a comparison between the mean log(10) CFU in kidneys in the groups treated with antifungal agents and that in control group. A single dose of FK463 at 0.5 mg/kg or higher significantly reduced the viable counts in kidneys compared with the numbers of yeast cells before treatment, and its efficacy was comparable to that of AMPH-B, while FLCZ at 4 mg/kg showed only a suppressive effect on the growth of C. albicans in the kidneys. In the disseminated aspergillosis model, FK463 given at doses of 0.5 mg/kg or higher significantly prolonged the survival of mice infected intravenously with Aspergillus fumigatus conidia. The efficacy of FK463 was about 2 times inferior to that of AMPH-B, with ED(50)s ranging from 0.25 to 0.50 mg/kg and 0.11 to 0.29 mg/kg, respectively. These results indicate that FK463 may be a potent parenterally administered therapeutic agent for disseminated candidiasis and aspergillosis.

Fungal infections of the central nervous system

This review discusses a practical approach to the patient with possible fungal infection of the central nervous system (CNS). Difficulties in establishing the diagnosis come from the nonspecific clinical syndromes (subacute meningitis, meningoencephalitis, and brain abscess) and the low isolation rate of fungi from cerebrospinal fluid (CSF). Helpful diagnostic clues often come from knowledge of the patient's geographic travels, risk factors, evidence of systemic organ infection, and fungal serologic tests. Standard and new antifungal agents are evaluated and the initial and suppressive drug management of the common fungal infections is presented.

Fungal infections of the genitourinary system: manifestations, diagnosis, and treatment

There is an increasing pool of immunocompromised patients who are at an increased risk to fungi infections, which now cause 8% of nosocomial infections. Premature infants and elderly, transplant, and HIV patients are prime candidates for invasive fungal infections. The genitourinary system can be a source or target of disseminated fungal infection. Although candidal species are the most frequent pathogen, other species such as aspergila, cryptoccoccus have become major pathogens. "Environmental fungi," which include blastomyces, coccidioides and histoplasma, have become more aggressive in the vulnerable patient.

Lipid-based amphotericin B formulations: from animals to man

Amphotericin B has been the mainstay of systemic antifungal therapy for over 30 years, despite its serious side-effects, and, although numerous alternative antifungal agents have been developed, none to date has matched the efficacy of amphotericin B. However, modern drug delivery technology has improved the safety of amphotericin B by incorporating it into lipid-based delivery systems, including liposomes. Three such formulations, based on the natural affinity of amphotericin B for lipids, are currently marketed. All increase the therapeutic index of amphotericin B, thereby allowing more aggressive treatment than is possible with the conventional product. However, they differ in structure, side-effect profiles and evidence of proven efficacy as discussed in this review.

Invasive yeast infections other than Candida spp. in acute leukaemia

During the last two decades, the treatment of leukaemia has changed significantly; increasing intensity of chemotherapy and bone marrow transplantation have lead to profound immunosuppression, prolonged stays in hospital, vascular catheterization, administration of broad spectrum antimicrobial agents and extensive use of prophylactic antifungal drugs. All but the last of these risk factors have increased the incidence of fungal infections in leukaemic patients and have significantly changed the spectrum of pathogens in favour of non-Candida species. In major haematological centres in Europe and the US, the proportion of non-Candida yeast isolated from patients increased from 1 to 5% in 1980 to 10 to 25% after 1990. However, there are not enough data to assess whether mortality due to these species is higher than that due to Candida spp. (30-40%) or filamentous fungi (50-70%). In this article, specific risk factors and therapeutic outcome of yeast infections other than Candida spp. in leukaemia such as Malassezia furfur, Trichosporon spp., Blastoschizomyces capitatus, Rhodotorula rubra, Saccharomyces cerevisiae, Clavispora lusitaniae, Cryptococcus laurentii and Hansenula anomala are reviewed. An analysis of risk factors from the National Cancer Institute, Bratislava has shown that non-Candida yeast infections (N = 15) in cancer patients are associated with leukaemia and neutropenia (P = < 0.002, 0.005), more often fatal than those caused by C. albicans (N = 51) (P < 0.006) but not non-albicans Candida (N = 34) and are associated with quinolone (P < 0.0001) and itraconazole prophylaxis (P < or = 0.05, 0.015) compared to both C. albicans or non-albicans Candida respectively.

In vitro activity of five antifungal agents against clinical isolates of Saccharomyces cerevisiae

We evaluated the in vitro activity of fluconazole, itraconazole, ketoconazole, 5-fluorocytosine and amphotericin B against 30 clinical isolates of Saccharomyces cerevisiae by a broth microdilution method, following the NCCLS recommendation. Testing was performed either in RPMI-1640 or yeast nitrogen base (YNB). YNB supported the growth of all isolates tested, while results in RPMI-1640 were not obtained for six isolates (20%). The MIC of all three azoles in YNB were one or two dilutions higher than those obtained in RPMI-1640 (P=0.0001 for fluconazole and itraconazole, P=0.03 for ketoconazole). Elevated MICs were observed for all three azoles, while all the isolates were susceptible to 5-fluorocytosine and amphotericin B. All MIC values were confirmed by spectrophotometric reading. Six strains of S. cerevisiae isolated from the faeces and consecutive blood cultures from an AIDS patient over a 7-month period were typed by electrophoretic karyotyping (EK). EK showed the maintenance of the same karyotype over time suggesting that the faecal isolate changed from a colonizing to infection-causing strain. The relative resistance of S. cerevisiae to azole drugs as well as its ability to cause widespread infections may promote the emergence of this species as a pathogen in immunosuppressed patients.

Epidemiology of infectious complications in cancer patients

Patients with underlying malignancies are at risk for a wide array of infectious diseases that cause significant morbidity and mortality. To develop a clear etiologic understanding of the infectious agents involved first requires a knowledge of the factors that predispose to infection. Neutropenia is clearly the single most important risk factor for infection in the cancer patient. However, a variety of both host and treatment-associated factors act together to predispose these patients to opportunistic infections. Approaching the individual malignancies with a knowledge of the underlying risk factors helps logically guide diagnosis and therapy. The astute clinician must also be aware of new and emerging infections in this patient population. As new pathogens are discovered and established pathogens become increasingly drug resistant, they will continue to present challenges for physicians caring for these patients in the years ahead.

Successful polymerase chain reaction-based diagnosis of fungal meningitis in a patient with chronic granulomatous disease

Meningitis is not a common complication of chronic granulomatous disease (CGD). Here, we present details of a 3-year-old boy with X-linked CGD, who suffered from fungal meningitis. While 19 samplings using conventional cerebrospinal fluid (CSF) cultures failed to detect any organisms, fungal DNA was identified in the CSF by a new polymerase chain reaction (PCR)-based method. The patient recovered without any sequelae after treatment with a combination of antifungal agents, interferon-gamma and granulocyte infusions. This case report demonstrates that fungal meningitis must be included in the differential diagnosis of infections in CGD patients and that the PCR-based detection of fungal DNA is a powerful tool for diagnosis.

[Geotrichum capitatum infection in a neutropenic patient. Apropos of a case and review of the literature]

INTRODUCTION

Geotrichum capitatum sepsis are rare, occurring exclusively in immunocompromised patients.

EXEGESIS

We report the case of a patient with acute leukemia, presenting with chemotherapy-induced neutropenia and hospitalized in an intensive care unit for a severe sepsis. In spite of an antibiotic and antifungal treatment, the patient died of cardiorespiratory failure. Later on, blood cultures proved to be positive for Geotrichum capitatum.

CONCLUSION

If fungal infections are common in neutropenic patients, Geotrichum capitatum sepsis remain exceptional. The portal of entry is digestive or respiratory, and the invasion is favored by immunodepression and suppression of the normal microbial flora. Induced lesions can be multiorganic. The treatment is not well established, and the association of either amphotericine B and 5-fluorocytosine or amphotericine B and itraconazole would lead to better results. Nevertheless, the prognosis is still unfavorable, with a mortality rate of approximately 75%.

Invasive infection with Fusarium chlamydosporum in a patient with aplastic anemia

We report the first case of invasive disease caused by Fusarium chlamydosporum. The patient had aplastic anemia with prolonged neutropenia and was treated with immunosuppressive therapy. While she was receiving empirical amphotericin B, a dark crusted lesion developed on her nasal turbinate. Histologic analysis revealed invasive hyaline hyphae and some darkly pigmented structures that resembled conidia of dematiaceous molds. Only after the mold was grown in culture were characteristic colonial morphology, phialides, conidia, and chlamydospores evident, thus permitting the identification of F. chlamydosporum. This case illustrates the ever-increasing spectrum of pathogenic Fusarium spp. in immunocompromised patients and emphasizes the potential pitfalls in histologic diagnosis, which may have important treatment implications.

Systemic Fusarium oxysporum infection in an immunocompetent patient with an adult respiratory distress syndrome (ARDS) and extracorporal membrane oxygenation (ECMO)

We report a case of disseminated fusariosis in a 42-year-old patient with adult respiratory distress syndrome (ARDS) and extracorporal membrane oxygenation (ECMO), but without definite immunosuppression. Fusarium oxysporum was isolated from a bronchial lavage taken 6 days ante mortem. Despite antifungal treatment with amphotericin B and flucytosine the patient died in septic multiorgan failure. A post-mortem examination was performed. The patient's liver was found to contain fungus cells and F. oxysporum could be cultured from ascites.

Aspergillus flavus endocarditis in a child with neuroblastoma

We report a case of Aspergillus flavus endocarditis in a 6-year-old boy with stage IV neuroblastoma with no pre-existing cardiac disease. The infection was successfully treated with high-dose liposomal amphotericin (AmBisome) once daily. Recurrence was prevented with itraconazole oral solution once daily as maintenance therapy. Adjunctive surgery was not required. The patient's cardiac function was uncompromised, but subsequent death from progressive neuroblastoma prevented long-term follow-up.

In vitro preclinical evaluation studies with the echinocandin antifungal MK-0991 (L-743,872)

The echinocandin MK-0991, formerly L-743,872, is a water-soluble lipopeptide that has been demonstrated in preclinical studies to have potent activity against Candida spp., Aspergillus fumigatus, and Pneumocystis carinii. An extensive in vitro biological evaluation of MK-0991 was performed to better define the potential activities of this novel compound. Susceptibility testing with MK-0991 against approximately 200 clinical isolates of Candida, Cryptococcus neoformans, and Aspergillus isolates was conducted to determine MICs and minimum fungicidal concentrations MF(s). The MFC at which 90% of isolates are inhibited for 40 C. albicans clinical isolates was 0.5 microg/ml. Susceptibility testing with panels of antifungal agent-resistant species of Candida and C. neoformans isolates indicated that the MK-0991 MFCs for these isolates are comparable to those obtained for susceptible isolates. Growth kinetic studies of MK-0991 against Candida albicans and Candida tropicalis isolates showed that the compound exhibited fungicidal activity (i.e., a 99% reduction in viability) within 3 to 7 h at concentrations ranging from 0.06 to 1 microg/ml (0.25 to 4 times the MIC). Drug combination studies with MK-0991 plus amphotericin B found that this combination was not antagonistic against C. albicans, C. neoformans, or A. fumigatus in vitro. Studies with 0 to 50% pooled human or mouse serum established that fungal susceptibility to MK-0991 was not significantly influenced by the presence of human or mouse serum. Results from resistance induction studies suggested that the susceptibility of C. albicans was not altered by repeated exposure (40 passages) to MK-0991. Erythrocyte hemolysis studies with MK-0991 with washed and unwashed human or mouse erythrocytes indicated minimal hemolytic potential with this compound. These favorable results of preclinical studies support further studies with MK-0991 with humans.

Experimental disseminated trichosporonosis in mice: tissue distribution and therapy with antifungal agents

Mice treated with cyclophosphamide were infected intravenously with titrated doses of Trichosporon asahii TIMM3140 or TIMM3144. Mortality and survival time correlated with inoculum size and fungal growth was found in the lung, heart, liver, spleen, kidney and brain. Fluconazole and amphotericin B prolonged survival time and reduced the CFU in the kidney, with fluconazole being superior to amphotericin B. The serum level of (1-->3)-beta-D-glucan was reduced by antifungal therapy and correlated well with the CFU/organ in kidney, but not CFU/ml in blood.

Genetic diversity among clinical and environmental isolates of Aspergillus fumigatus

To determine if cases of invasive aspergillosis (IA) were caused by strains of Aspergillus fumigatus with unique characteristics, strains from immunosuppressed patients with IA were compared to strains obtained from sputa of patients with cystic fibrosis and to strains from the environment. An extremely high genomic diversity was observed among the 879 strains typed by Southern blotting with a retrotransposon-like element from A. fumigatus (C. Neuvéglise, J. Sarfati, J. P. Latgé, and S. Paris, Nucleic Acids Res. 24:1428-1434, 1996). Analysis of Southern blot hybridization patterns showed the absence of clustering between environmental isolates and clinical isolates from patients with IA or cystic fibrosis. In addition, strains could not be clustered depending on their geographical location. This study implies that practically any strain of A. fumigatus is potentially pathogenic and can provoke a case of IA when it encounters a favorable environment in an immunosuppressed host.

Antifungal prophylaxis during neutropenia and immunodeficiency

Fungal infections represent a major source of morbidity and mortality in patients with almost all types of immunodeficiencies. These infections may be nosocomial (aspergillosis) or community acquired (cryptococcosis), or both (candidiasis). Endemic mycoses such as histoplasmosis, coccidioidomycosis, and penicilliosis may infect many immunocompromised hosts in some geographic areas and thereby create major public health problems. With the wide availability of oral azoles, antifungal prophylactic strategies have been extensively developed. However, only a few well-designed studies involving strict criteria have been performed, mostly in patients with hematological malignancies or AIDS. In these situations, the best dose and duration of administration of the antifungal drug often remain to be determined. In high-risk neutropenic or bone marrow transplant patients, fluconazole is effective for the prevention of superficial and/or systemic candidal infections but is not always able to prolong overall survival and potentially selects less susceptible or resistant Candida spp. Primary prophylaxis against aspergillosis remains investigative. At present, no standard general recommendation for primary antifungal prophylaxis can be proposed for AIDS patients or transplant recipients. However, for persistently immunocompromised patients who previously experienced a noncandidal systemic fungal infection, prolonged suppressive antifungal therapy is often indicated to prevent a relapse. Better strategies for controlling immune deficiencies should also help to avoid some potentially life-threatening deep mycoses. When prescribing antifungal prophylaxis, physicians should be aware of the potential emergence of resistant strains, drug-drug interactions, and the cost. Well-designed, randomized, multicenter clinical trials in high-risk immunocompromised hosts are urgently needed to better define how to prevent severe invasive mycoses.

Increasing fungal isolation from clinical specimens: experience in a university hospital over a decade

The local patterns of fungal isolates were studied by a retrospective analysis of fungal species isolated from clinical specimens in a university hospital in Jerusalem. Between 1984 and 1993, 5630 fungi [4071 patient unique isolates (PUI)] were isolated and identified. During the study decade, the annual incidence of all isolates increased 2.7-fold, and PUI increased 1.6-fold. Candida albicans accounted for 61% of PUI; urine was the source of 53%. The intensive care units (ICUs) and the Bone Marrow Transplantation (BMT) Department had the highest incidence of fungal isolation. The following trends were observed: (1) a decrease in the relative frequency of C. albicans and increase in Candida tropicalis; (2) increased number of isolates from urine, surgical wounds and intra-abdominal sites; (3) increased number of isolates from ICUs and BMT. Fungi are emerging as important hospital-acquired pathogens in tertiary care and teaching hospitals, and are associated with high rates of morbidity and mortality. It is important to be familiar with the local patterns of fungal isolation in order to improve treatment.

Trichoderma longibrachiatum infection in a pediatric patient with aplastic anemia

Trichoderma longibrachiatum infection of the skin in an 11-year-old child with severe aplastic anemia and prolonged neutropenia is reported. The patient received systemic antifungal therapy and underwent bone marrow transplantation. To our knowledge, this is the first description of T. longibrachiatum infection in a pediatric patient. It also is the first case successfully treated with medical therapy. A review of the literature suggests that Trichoderma spp. are recognized as human pathogens with increasing frequency, particularly for immunocompromised patients, and should be considered in the differential diagnosis of fungal infections in the pediatric population.

In vitro susceptibility testing and DNA typing of Saccharomyces cerevisiae clinical isolates

Saccharomyces spp. are widely distributed in nature and may colonize the normal human gastrointestinal tract. Although Saccharomyces cerevisiae isolates have been previously considered nonpathogenic, they appear to be increasingly associated with infections in immunocompromised or otherwise debilitated patients. The antifungal susceptibility and epidemiology of S. cerevisiae are poorly defined at present. A series of 76 isolates (mostly stool surveillance and throat swab isolates) from 70 bone marrow transplant patients hospitalized at two different medical centers were characterized by antifungal susceptibility testing and restriction endonuclease analysis of chromosomal DNA. For DNA typing, digestion with NotI followed by pulsed-field gel electrophoresis was applied. Typing results revealed 62 distinct DNA types among the 76 clinical isolates. Despite this genomic diversity, clusters of identical isolates were identified among different patients hospitalized concurrently in the same unit, indicating possible nosocomial transmission. The MICs of amphotericin B, 5-fluorocytosine, fluconazole, and itraconazole were determined by a broth microdilution method, as recommended by the National Committee for Clinical Laboratory Standards. The MICs at which 90% of the strains were inhibited were as follows: amphotericin B, 1.0 micrograms/ml; 5-fluorocytosine, 0.25 micrograms/ml; fluconazole, 8.0 micrograms/ml; and itraconazole, 1.0 micrograms/ml. The relative resistance of S. cerevisiae to fluconazole and itraconazole may promote the emergence of this species as a pathogen among immunosuppressed patients.

Pulmonary infiltrates in the cancer patient. New approaches to an old problem

A variety of etiologies may produce pulmonary infiltrates in a patient with cancer. Infectious etiologies, of an ever-increasing number, are always of paramount concern due to their high mortality in this patient population. Patients may be rendered immunosuppressed for prolonged periods of time and therefore are highly susceptible to infection. We present an overview of the many causes of pulmonary infiltrates in the cancer patient and an approach to diagnosis and treatment.

Recent progress and current problems in treatment of invasive fungal infections in neutropenic patients

Invasive fungal infections, including disseminated candidiasis and invasive pulmonary aspergillosis, are important causes of morbidity and mortality in neutropenic patients. The recent development of fluconazole, itraconazole, lipid formulations of amphotericin B, and recombinant cytokines have expanded our therapeutic armamentarium. Clinical trials have elucidated new strategies for utilizing these compounds in the prevention and treatment of opportunistic mycoses. The population of more severely immunocompromised patients, however, continues to expand and the spectrum of drug-resistant fungi, including but not limited to Candida spp, Fusarium spp, Zygomycetes, and dematiaceous moulds, continues to evolve, thus presenting new challenges to recent therapeutic advances. Development of new antifungal chemotherapeutic agents and novel approaches for augmentation of host response will be required to meet these new mycologic challenges.

Routine use of CHROMagar Candida medium for presumptive identification of Candida yeast species and detection of mixed fungal populations

OBJECTIVE: To assess the value of the new differential culture medium CHROMagar Candida for routine investigation of clinical specimens. METHODS: During a whole year, 6150 clinical samples were plated on CHROMagar Candida medium. After incubation, the green colonies were considered to be Candida albicans. The colonies of other colors were identified using Bichrolatex-krusei, or by their assimilation pattern on ID 32C test strips and their morphology on rice cream-agar-Tween. RESULTS: Among the 6150 clinical samples, 1643 were positive for fungi. Aspergillus fumigatus and Geotrichum sp. were the predominant filamentous fungi isolated. Candida albicans was the most common species isolated (1274 of the positive samples; 77.5%), and Candida glabrata was the second most common yeast isolated (174 positive samples; 10.6%). Other yeast species were detected at lower frequencies, mainly Candida tropicalis (3.8%), Candida krusei (2.7%), Saccharomyces cerevisiae (2.7%) and Candida kefyr (2.3%), and 16 samples revealed a lipophilic species, Malassezia furfur. Mixed fungal populations accounted for 14.7% of the positive samples. Two or more yeast species were detected in 206 of the 242 specimens containing mixed fungal populations, and five yeast species were detected in one sample. Additionally, we did not observe significant differences in the isolation of yeasts or filamentous fungi from the 366 samples simultaneously plated on CHROMagar Candida and Sabouraud dextrose agar. Close agreement between the two culture media was observed for 89.9% of these samples. CONCLUSIONS: CHROMagar Candida medium was shown to be extremely helpful in a routine clinical mycology service, facilitating the detection of mixed cultures of yeasts and allowing direct identification of C. albicans, as well as rapid presumptive identification of the other yeasts: C. glabrata, C. tropicalis, C. krusei and S. cerevisiae. This chromogenic medium thus appears to be suitable as a primary culture medium, particularly for the mycologic surveillance of immunocompromised patients.

Invasive mold infections in cancer patients: 5 years' experience with Aspergillus, Mucor, Fusarium and Acremonium infections

Twenty systemic mold infections due to hyphic fungi (molds) arising within the last 5 years in a 60-bed cancer department are analyzed. The most frequent risk factors were plants in ward (75%), prior therapy with broad spectrum antibiotics (70%), catheter insertion (70%), acute leukemia (65%) and neutropenia (60%). Before death, a definitive diagnosis was made in 40%, and a presumptive diagnosis in 60% of patients: post mortem the presumptive antemortem diagnosis was confirmed in all cases (100% of patients). Aspergillosis was the most common invasive fungal disease (55%), followed by mucormycosis (15%), fusariosis (15%), and acremoniosis (10%). Of 20 patients, 8 (40%) were cured or improved after antifungal therapy with amphotericin B, ambisome and/or itraconazole; 8/20 (40%) died of fungal infection and 4/20 (20%) of underlying disease with fungal infection. Even though the diagnosis was made and antifungal therapy started before death in 15/ 20 (75%), invasive mold infection had a 60% overall mortality in patients with malignant disease.