Necrotizing cerebritis in an allogeneic bone marrow transplant recipient due to Cladophialophora bantiana

[Fungal infection by Cladophialophora bantiana and development of cerebral phaeohyphomycosis. A systematic review of 58 case reports]

INTRODUCTION

INTRODUCTION

Cladophialophora bantiana is a filamentous fungus, known as a dematiaceous fungus because of the presence of melanin. This fungus is of clinical importance because it is neurotropic and causes cerebral phaeohyphomycosis.

MATERIAL AND METHODS

The available scientific information on the development of cerebral phaeohyphomycosis caused by Cladophialophora bantiana was analysed by selecting articles from the PubMed, Scopus and Google Scholar databases that describe case reports of fungal infection by C. bantiana in adults, taking into account the analysis of the patients' symptomatology, clinical history and neuroanatomical damage, in addition to considering the mortality of the condition.

RESULTS

India and United States were the countries with most case reports, with 32 and 11 cases respectively. Moreover, in terms of neuroanatomical lesions, the majority of patients suffered mixed lesions (29%) and frontal lobe lesions (22%). In accordance with the patients' condition, the pathology has a mortality rate of 62%.

CONCLUSIONS

It is concluded that cerebral phaeohyphomycosis has a high mortality rate, there is no standardised treatment and, in most cases, the fungal infection of the brain is mixed and affects several different parts of it. Furthermore, if not diagnosed and treated in time, it can lead to the patients' death.

Cladophialophora bantiana orbital cellulitis after penetrating injury

A 75-year-old immunocompetent male presented with a right orbital cellulitis after a foreign body penetrating injury. He was taken for orbitotomy with foreign body removal and started on broad-spectrum antibiotics. Intra-operative cultures were positive for Cladophialophora bantiana, a mold known for causing brain abscesses with no prior reports of orbital invasion in the literature. Following culture results, the patient was managed with voriconazole and required multiple orbitotomies and washouts for infection control.

CNS Infections Caused by Brown-Black Fungi

Central nervous system (CNS) infections caused by brown-black or dematiaceous fungi are distinctly rare and represent a small proportion of infections termed phaeohyphomycoses. However, these are becoming more commonly reported. Though many fungi have been implicated in disease, most cases are caused by only a few species, Cladophialophora bantiana being the most common. Most of the fungi described are molds, and often cause infection in immunocompetent individuals, in contrast to infection with other more common molds such as Aspergillus, which is usually seen in highly immunocompromised patients. Diagnosis is challenging, as there are no specific tests for this group of fungi. In addition, these infections are often refractory to standard drug therapies, requiring an aggressive combined surgical and medical approach to improve outcomes, yet mortality remains high. There are no standardized treatments due to a lack of randomized clinical trials, though guidelines have been published based on available data and expert opinion.

An updated comprehensive systematic review of Cladophialophora bantiana and analysis of epidemiology, clinical characteristics, and outcome of cerebral cases

Cladophialophora bantiana is a phaeoid fungus that only rarely has been isolated from sources other than the human brain. It has a particular tropism for the central nervous system (CNS). We have integrated and updated large-scale data related to several aspects of C. Bantiana and reviewed all the available reports on its cerebral infections, focusing on their geographical distribution, infection routes, immune status of infected individuals, type and location of infections, clinical manifestations and treatment and outcome, briefly looking over the spectrum of other disease entities associated with C. bantiana, that is, extra-cerebral and animal infections and on the environmental sources of this fungus. Among the agents of phaeohyphomycosis, a term used to describe an infection caused by a dark pigmented fungus, C. bantiana has some significant specific features. A total of 120 case reports were identified with a significantly higher percentage of healthy subjects than immune-debilitated patients (58.3% vs. 41.7%). Infections due to C. bantiana occur worldwide. The main clinical manifestations are brain abscess (97.5%), coinfection of brain tissue and meninges (14.2%) and meningitis alone (2.5%). Among immunocompetent patients, cerebral infection occurred in the absence of pulmonary lesions. The mortality rate is 65.0% regardless of the patient's immune status. The therapeutic options used include surgery or antifungals alone, and the combination of both, in most cases the fatal outcome being rapid after admission. Since the fungus is a true pathogen, laboratory workers should be made aware that BioSafety Level-3 precautions might be necessary.

Cladophialophora Bantiana : A Rare Intracerebral Fungal Abscess-Case Series and Review of Literature

Background  Intracerebral Cladophialophora bantiana may carry up to a 70% mortality rate despite advances in surgical resection capabilities and the use of both systemic and intrathecal antifungal treatments.

Objectives  The authors examined a retrospective case series of two patients with intracerebral infection from the rare, neurotropic fungus Cladophialophora bantiana and conducted a literature review to evaluate optimal therapies.

Patients/Methods  At our institution, the patients' cases presented with raised intracranial features of headache, visual field cut, and/or memory loss, with a correspondingly wide variety of radiological differential diagnoses. It was the microbiological, histopathological, and genomic identification of C. bantiana that ensured targeted, individualized patient therapies.

Results and Conclusions  Successful treatment depends on obtaining a complete surgical resection, an accurate microbiological diagnoses for mold identification, and an effective long-term, personalized antifungal treatment. Close radiographic surveillance is necessary to ensure complete eradication of pheoid fungi.

A case of central nervous system infection due to Cladophialophora bantiana

BACKGROUND

Cladophialophora bantiana is a melanised mold with a pronounced tropism for the central nervous system, almost exclusively causing human brain abscesses.

CASE REPORT

We describe a case of cerebral infection by this fungus in an otherwise healthy 28-year-old coal-miner. Environmental occurrence, route of entry, and incubation period of this fungus are unknown, but our case is informative in that the first symptoms occurred about eight weeks after known traumatic inoculation. Lesions were compatible with tuberculous granulomas, and the patient initially received antitubercular treatment. Melanised fungal cells were seen in a brain biopsy and abscess materials. Therapy was switched from empirical antitubercular treatment to amphotericin B (0.5mg/kg/d), but was changed to voriconazole 200mg/d, i.v. on the basis of antifungal susceptibility test results. The patient responded clinically, and gradually improved. The isolate was identified by sequencing of the Internal Transcribed Spacer domain of rDNA.

CONCLUSIONS

Given the non-specific clinical manifestations of C. bantiana cerebral abscesses, clinicians and laboratory workers should suspect infections caused by C. bantiana, particularly in immunocompromised patients with a trauma history.

Epidemiology, Clinical Manifestations, and Therapy of Infections Caused by Dematiaceous Fungi

The dematiaceous (brown-pigmented) fungi are a large and heterogenous group of moulds that cause a wide range of diseases including phaeohyphomycosis, chromoblastomycosis, and eumycotic mycetoma. Among the more important human pathogens are Alternaria species, Bipolaris species, Cladophialophora bantiana, Curvularia species, Exophiala species, Fonsecaea pedrosoi, Madurella species, Phialophora species, Scedosporium prolificans, Scytalidium dimidiatum, and Wangiella dermatitidis. These organisms are widespread in the environment, being found in soil, wood, and decomposing plant debris. Cutaneous, subcutaneous, and corneal infections with dematiaceous fungi occur worldwide, but are more common in tropical and subtropical climates. Infection results from traumatic implantation. Most cases occur in immunocompetent individuals. Dematiaceous moulds are also important causes of invasive sinusitis and allergic fungal sinusitis. Infection is thought to follow inhalation. Although cerebral infection is the commonest form of systemic phaeohyphomycosis, other localized deep forms of the disease, such as arthritis, and endocarditis, have been reported. Disseminated infection is uncommon, but its incidence is increasing, particularly among immunocompromised individuals. Scedosporium prolificans is the most frequent cause. A number of dematiaceous fungi are neurotropic, including Cladophialophora bantiana, Ramichloridium mackenziei, and Wangiella dermatitidis. Although cases have occurred in immunocompromised persons, cerebral phaeohyphomycosis is most common in immunocompetent individuals with no obvious risk factors. Most forms of disease caused by dematiaceous fungi require both surgical and medical treatment. Itraconazole is currently the most effective antifungal agent for chromoblastomycosis and subcutaneous phaeohyphomycosis, while ketoconazole remains useful for mycetoma. Extensive surgical debridement combined with amphotericin B treatment is recommended for chronic invasive sinusitis. Long-term treatment with itraconazole has led to improvement or remission in some patients that had failed to respond to amphotericin B. Allergic fungal sinusitis requires surgical removal of impacted mucin combined with postoperative oral corticosteroids. Antifungal treatment is not usually of benefit, but post-operative itraconazole may reduce the need for reoperation. The clinical outcome of cerebral and other deep-seated forms of phaeohyphomycosis is dismal, with long-term survival being reported only when complete surgical resection of discrete lesions is possible. The development of new antifungal agents and combination treatment may help to improve the management of these infections.

Melanized fungi in human disease

Melanized or dematiaceous fungi are associated with a wide variety of infectious syndromes, including chromoblastomycosis, mycetoma, and phaeohyphomycosis. [corrected]. Many are soil organisms and are generally distributed worldwide, though certain species appear to have restricted geographic ranges. Though they are uncommon causes of disease, melanized fungi have been increasingly recognized as important pathogens, with most reports occurring in the past 20 years. The spectrum of diseases with which they are associated has also broadened and includes allergic disease, superficial and deep local infections, pneumonia, brain abscess, and disseminated infection. For some infections in immunocompetent individuals, such as allergic fungal sinusitis and brain abscess, they are among the most common etiologic fungi. Melanin is a likely virulence factor for these fungi. Diagnosis relies on careful microscopic and pathological examination, as well as clinical assessment of the patient, as these fungi are often considered contaminants. Therapy varies depending upon the clinical syndrome. Local infection may be cured with excision alone, while systemic disease is often refractory to therapy. Triazoles such as voriconazole, posaconazole, and itraconazole have the most consistent in vitro activity. Further studies are needed to better understand the pathogenesis and optimal treatment of these uncommon infections.

Use of amplified fragment length polymorphism to identify 42 Cladophialophora strains related to cerebral phaeohyphomycosis with in vitro antifungal susceptibility

The amplified fragment length polymorphism technique has been applied to identify neurotropic chaetothyrialean black yeasts and relatives from clinical sources. Cladophialophora bantiana, C. emmonsii, C. arxii, C. devriesii, and C. modesta, previously identified on the basis of sequencing and phenotypic and physiological criteria, were confirmed by cluster analysis, demonstrating the clear separation of C. bantiana as a rather homogeneous group from the other species. C. bantiana is a neurotropic fungus causing cerebral abscesses with a mortality of up to 70%. Successful therapy consists of neurosurgical intervention and optimal antifungal therapy. Since the latter is not clearly defined in a large series, we tested the in vitro activities of eight antifungal drugs against clinical isolates of C. bantiana (n = 37), C. modesta (n = 2), C. arxii (n = 1), C. emmonsii (n = 1), and C. devriesii (n = 1), all of which had caused invasive infections. The resulting MIC(90)s for all neurotropic C. bantiana strains were as follows, in increasing order: posaconazole, 0.125 microg/ml; itraconazole, 0.125 microg/ml; isavuconazole, 0.5 microg/ml; amphotericin B, 1 microg/ml; voriconazole, 2 microg/ml; anidulafungin, 2 microg/ml; caspofungin, 4 microg/ml; and fluconazole, 64 microg/ml. On the basis of these in vitro results and the findings of previous clinical and animal studies, posaconazole seems to be a good alternative to the standard treatment, amphotericin B, for C. bantiana cerebral infections. The new agent isavuconazole, which is also available as an intravenous preparation, has adequate activity against C. bantiana.

Cerebral phaeohyphomycosis--a cure at what lengths?

Cerebral phaeohyphomycosis is a fungal infection of the brain typically caused by Cladophialophora bantiana, Exophiala dermatitidis, and Rhinocladiella mackenziei, all of which belong to the order Chaetothyriales. The disease results in black, necrotic brain tissue, black pus, and black cerebrospinal fluid. Pathogens usually reach the brain through the bloodstream or lymphatic fluid and occasionally through direct spreading or accidental inoculation. Patients can present with hemiparesis, tonic spasm, headache, fever, sensory variation, cerebral irritation, and even psychotic behavioural changes. Radiological images are characterised by ring-enhanced signs and hyperdense and hypodense lesions. Pathological features frequently include black-to-brown necrotic tissue or dark-coloured pus, granulomatous inflammation, giant cell vasculitis, and pigmented fungal elements, which are easily seen on a direct potassium hydroxide smear, a rapid method for diagnosis. Black fungi can be cultured from a biopsy specimen. Combined antifungal chemotherapy, surgical debridement, and careful immunological interventions are strongly recommended to eradicate these intractable infections.

Non-Aspergillus Fungal Pneumonia in Transplant Recipients

Although species of Aspergillus and Candida account for most deeply invasive and life-threatening fungal infections, the past decades have seen a rise in the immunocompromised population. With this increase, additional fungi have emerged as important agents of morbidity and mortality. These opportunistic fungi are characterized by their ubiquitous presence in the environment, their ability to cause disease in immunosuppressed patients, and their diminished susceptibility to the currently available antifungal agents. Pneumonia, one aspect of a myriad of clinical manifestations caused by these fungal pathogens, is discussed in this article.

Primary Central Nervous System Phaeohyphomycosis: A Review of 101 Cases

Phaeohyphomycosis refers to infections caused by darkly pigmented fungi. These fungi rarely cause life-threatening disease. We reviewed 101 cases of culture-proven primary central nervous system phaeohyphomycosis reported in the English-language literature from 1966 to 2002. The most frequently isolated species was Cladophialophora bantiana. The next most frequent isolate was Ramichloridium mackenziei, seen exclusively in patients from the Middle East. More than one-half of the cases occurred in patients with no known underlying immunodeficiency. Mortality rates were high regardless of immune status. Therapy is not standardized, although the combination of amphotericin B, flucytosine, and itraconazole may improve survival rates. Newer azoles, such as voriconazole, also have a broad spectrum of activity against these fungi, although clinical experience is limited. Complete excision of brain lesions may provide better results than simple aspiration. An aggressive medical and surgical approach is warranted in treating these infections to optimize outcomes.

Disseminated Cladophialophora bantiana infection in a heart transplant recipient

Cerebral phaeohyphomycosis caused by Cladophialophora bantiana, a dematiaceous fungus, is a rare disease. The majority of cases have been reported among immunocompetent patients; only 4 cases have been published that describe transplantation patients. The overall prognosis is poor. Surgical therapy in combination with chemotherapy with itraconazole is recommended. We report the case of a heart transplant recipient with cutaneous, cerebral, and lung manifestation of Cladophialophora bantiana who died despite surgical and systemic, high-dosage itraconazole treatment.

Uncommon opportunistic fungi: new nosocomial threats

During the past two decades opportunistic fungal infections have emerged as important causes of morbidity and mortality in patients with severe underlying illnesses and compromised host defenses. While Aspergillus and Candida spp. collectively account for the majority of these infections, recent epidemiological trends indicate a shift towards infections by Aspergillus spp., nonalbicans Candida spp., as well as previously uncommon opportunistic fungi. Apart from an expanding number of different Zygomycetes, previously uncommon hyaline filamentous fungi (such as Fusarium species, Acremonium species, Paecilomyces species, Pseudallescheria boydii, and Scedosporium prolificans), dematiaceous filamentous fungi (such as Bipolaris species, Cladophialophora bantiana, Dactylaria gallopava, Exophiala species, and Alternaria species) and yeast-like pathogens (such as Trichosporon species, Blastoschizomyces capitatus, Malassezia species, Rhodotorula rubra and others) are increasingly encountered as causing life threatening invasive infections that are often refractory to conventional therapies. On the basis of past and current trends, the spectrum of fungal pathogens will continue to evolve in the settings of an expanding population of immunocompromised hosts, selective antifungal pressures, and shifting conditions in hospitals and the environment. An expanded and refined drug arsenal, further elucidation of pathogenesis and resistance mechanisms, establishment of in vitro/in vivo correlations, incorporation of pharmacodynamics, combination- and immunotherapies offer hope for substantial progress in prevention and treatment.

Emerging fungal pathogens: evolving challenges to immunocompromised patients for the twenty-first century

Opportunistic fungi have emerged during the past decade as important causes of morbidity and mortality in immunocompromised patients. Candida species constitute the third to fourth most common causes of nosocomial blood stream infections, and Aspergillus species have emerged as the most common infectious cause of pneumonic mortality in bone marrow/stem cell transplant recipients. Among HIV-infected patients, meningoencephalitis due to Cryptococcus neoformans ranks among the most common AIDS-defining infections. Hyaline septated filamentous fungi, such as Fusarium species, Acremonium species, Paecilomyces species, and Trichoderma species, are increasingly reported as causing invasive mycoses refractory to conventional therapy. Dematiaceous septated filamentous fungi, such as Pseudallescheria boydii, Bipolaris species, and Cladophialophora bantiana cause pneumonia, sinusitis, and CNS infection unresponsive to current therapy. An increasing number of different members of the class of Zygomycetes are reported as causing lethal infections, despite aggressive medical and surgical interventions. Yet the treatment for zygomycosis has not changed in approximately 40 years. The prevalence of the endemic mycoses, such as those due to Penicillium marneffei, Coccidioides immitis, and Histoplasma capsulatum, has been reported to expand rapidly in response to environmental exposures and increased numbers of vulnerable hosts in endemic regions of the world. Dermatophytoses are occurring with increasing prevalence and morbidity in elderly and immunocompromised patients. As we enter the next millennium, we may anticipate that emergent fungal infections will continue to develop in the settings of permissive environmental conditions, selective antifungal pressure, and an expanding population of immunocompromised hosts.

Developments in fungal taxonomy

Fungal infections, especially those caused by opportunistic species, have become substantially more common in recent decades. Numerous species cause human infections, and several new human pathogens are discovered yearly. This situation has created an increasing interest in fungal taxonomy and has led to the development of new methods and approaches to fungal biosystematics which have promoted important practical advances in identification procedures. However, the significance of some data provided by the new approaches is still unclear, and results drawn from such studies may even increase nomenclatural confusion. Analyses of rRNA and rDNA sequences constitute an important complement of the morphological criteria needed to allow clinical fungi to be more easily identified and placed on a single phylogenetic tree. Most of the pathogenic fungi so far described belong to the kingdom Fungi; two belong to the kingdom Chromista. Within the Fungi, they are distributed in three phyla and in 15 orders (Pneumocystidales, Saccharomycetales, Dothideales, Sordariales, Onygenales, Eurotiales, Hypocreales, Ophiostomatales, Microascales, Tremellales, Poriales, Stereales, Agaricales, Schizophyllales, and Ustilaginales).

Cerebral fungal infections in the immunocompromised host: a literature review and a new pathogen--Chaetomium atrobrunneum: case report

OBJECTIVE AND IMPORTANCE

A case of a cerebral abscess, occurring in a patient who had undergone bone marrow transplant, caused by a new pathogen, Chaetomium atrobrunneum, and a review of the literature are presented. Although Aspergillus species are by far the most common fungi found in cerebral abscesses in immunocompromised patients, an increasing number of fungi commonly found in nature but not usually associated with infections in humans have been isolated from cerebral abscesses in these patients.

CLINICAL PRESENTATION

A 31-year-old male patient, who had undergone a recent bone marrow transplantation for multiple myeloma, presented 3 months after transplantation with right-sided hemiplegia caused by a left parietal hemorrhagic lesion.

INTERVENTION

A biopsy guided by computed tomography showed that the abscess contained the fungus C. atrobrunneum. The final identification of the organism was based on cultures, scanning electron microscopic studies, and consultation with the Fungus Testing Laboratory at the University of Texas Health Science Center, San Antonio, TX. The patient was treated with several antifungal medications but developed uncontrolled cerebral edema, which led to further neurological deterioration and eventual death.

CONCLUSION

Cerebral abscesses in the immunocompromised patient may no longer be assumed to be caused solely by Aspergillus species. The literature reveals several rare cases of uncommon fungi found in these abscesses. Only four cases of cerebral infections caused by the genus Chaetomium have been reported. The case presented represents the first time a patient who had undergone a bone marrow transplant with a cerebral abscess was found to be caused by the pathogen C. atrobrunneum.