Isolation of a Nodulisporium species from a case of cerebral phaeohyphomycosis

Nodulisporium Fungal Brain Abscess In Early Post-Renal Transplant: A Rare, Unexpected, Mysterious Pathogen

BACKGROUND Central nervous system fungal infections are rarely encountered in current medicine, with fungal abscesses even less commonly seen. Clinical entities and their development largely depend on the interplay between the host's immune system and fungal virulence factors. Due to the large size of fungal organisms, they are prevented from entering the meningeal circulation. Hence, they cause focal diseases like cerebritis, abscesses, vasculitis of larger vessels, vascular occlusion, cerebral infarcts, and aneurysms. CASE REPORT A 34-year-old male patient of Indian descent diagnosed with stage 5 chronic kidney disease, bilaterally small kidneys, and hypertension underwent cadaveric renal transplantation and subsequent immunosuppression. Three months later, he returned with complaints of high-grade fever with chills and rigor, along with massive headaches. Plain brain computed tomography showed an intra-axial heterogeneously hypodense area with a hyperdense rim in the right temporal lobe. MRI revealed a well-defined enhancing lesion with irregular crenated margins and satellite lesions. Abscess wall biopsy showed fragments of hyaline septate filamentous fungal hyphae. Craniotomy with excision and drainage of the abscess was done and sent for histopathological examination along with culture. The results showed the growth of Nodulisporium fungus. The patient was then managed on amphotericin B and voriconazole for completion of treatment. CONCLUSIONS This is the first case reported of a Nodulisporium species fungal abscess developing in the brain after cadaveric kidney transplantation. Urgent evaluation via imaging and biopsy is crucial in determining the exact causal organism of brain abscesses, which can lead to better patient outcomes.

Mycosis of the Plantar Surface of Foot Owing to Nondermatophyte Mold Nodulisporium griseobrunneum Mimicking a Tinea Pedis

Nondermatophyte molds (NDM) and dematiaceous molds are less frequently implicated as the etiological agents of tinea-like infections of the foot. Among the etiological agents, Hendersonula toruloidea (now, Nattrassia mangiferae), Scytalidium hyalinum, Alternaria species (spp.), and Fusarium spp. are infrequently associated with foot mycoses. Nodulisporium (N.) spp. is a mitosporic NDM, which has been implicated in human infections like cerebral phaeohyphomycosis and allergic fungal sinusitis. Here, we report N. griseobrunneum in a 9-year-old female with mycosis of the plantar surface of foot mimicking a tinea pedis. Potassium hydroxide mount of skin specimen demonstrated dichotomous branching septate hyphae. Fungal culture and molecular sequencing established N. griseobrunneum as the etiological agent. Antifungal susceptibility testing revealed lower MICs to all seven drugs tested including itraconazole (ITR). The patient was treated with ITR and topical terbinafine. To the best of our knowledge, this is the first communication depicting molecular confirmation of the etiologic agent and antifungal susceptibility data of the mycosis of the plantar surface of foot owing to N. griseobrunneum from India.

Cerebral phaeohyphomycosis: case report

Cerebral phaeohyphomycosis is a rare and frequently fatal disease. This disease is often caused by hematogenous spread of pathogens that are inoculated in the skin of the extremities after slight or minor trauma, and its mortality rate is rather high despite aggressive treatment. Our patient presented with headache and pyrexia. She was diagnosed with fungal meningitis and treated by systemic administration of voriconazole (VRCZ). However, after initial improvement, meningitis recurred. MRI of the brain showed multiple small masses in the cerebral hemisphere and she was thus referred to our Department of Neurosurgery. On admission, an examination showed that the masses were deeply located in the brain and were too small to be excised; therefore, treatment with systemic VRCZ and intrathecal amphotericin B was initially selected. However, the intracerebral masses continued to grow; therefore, they were surgically excised. Histological examination of the surgical specimens at that time identified the masses as granuloma caused by infection with Aspergillus niger. After the surgery, her general condition improved; therefore treatment with systemic and intrathecal antifungal agents were continued. However, the intracerebral masses recurred, and despite further aggressive surgical treatment and systemic and intrathecal antifungal administration, she died 43 months after the initial diagnosis. Autopsy examination showed that the cerebral lesions were phaeohyphomycotic granulomas. This paper describes the clinical presentation, histopathological results and treatment for this rare disease.

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.

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.

Pathology of fungal infections of the central nervous system: 17 years' experience from Southern India

AIMS

To describe the pathology of central nervous system (CNS) fungal infections with particular reference to India.

METHODS AND RESULTS

This was a retrospective study from 1988 to 2004 constituting 130 cases. The diagnosis was based on morphology of biopsy/autopsy material. These included aspergillosis (n=73), zygomycosis (n=40), cryptococcosis (n=2), rhodotorulosis (n=1), candidiasis (n=5), maduramycosis (n=1), pheohyphomycosis (n=3) and mixed infections (n=5). Predisposing risk factors were present in 49 (38%) patients only. The majority of the patients were immunocompetent. The commonest risk factor was diabetes mellitus, the commonest route of infection was from a contiguous site and the commonest pathology was granuloma. Culture positivity was seen in only 31%.

CONCLUSION

Environmental factors in tropical countries such as India play a significant role in the pathogenesis of CNS fungal infections.

Sinusitis caused by the fungus Xylaria enteroleuca in a lung transplant recipient

We report the 1st case of sinusitis and human infection by Xylaria enteroleuca (anamorph Nodulisporium sp.), a rare fungal endophyte of rain forest trees. The patient was a Brazilian woman who had her lung transplanted. Diagnosis was established by direct microscopic examination, computed tomographic scan, cultures, and sequencing of a ribosomal RNA gene. The in vitro antifungal susceptibility of the isolate is provided.

Fungi growing on aromatic hydrocarbons: biotechnology's unexpected encounter with biohazard?

The biodegradation of aromatic hydrocarbons by fungi has traditionally been considered to be of a cometabolic nature. Recently, however, an increasing number of fungi isolated from air biofilters exposed to hydrocarbon-polluted gas streams have been shown to assimilate volatile aromatic hydrocarbons as the sole source of carbon and energy. The biosystematics, ecology, and metabolism of such fungi are reviewed here, based in part on re-evaluation of a collection of published hydrocarbon-degrading isolates obtained from authors around the world. Incorrect or outdated identifications in original publications are corrected by ribosomal DNA sequence analysis. The data show that many volatile-hydrocarbon-degrading strains are closely related to, or in some cases clearly conspecific with, the very restricted number of human-pathogenic fungal species causing severe mycoses, especially neurological infections, in immunocompetent individuals. Neurochemistry features a distinctive array of phenolic and aliphatic compounds that are related to molecules involved in the metabolism of aromatic hydrocarbons. Hence, there may be physiological connections between hydrocarbon assimilation and certain patterns of mammalian infection.

Infections of the central nervous system by melanized fungi: a review of cases presented between 1999 and 2004

Several types of infections of the central nervous system by melanized fungi can be distinguished: (a) single-organ infection of the cerebrum, (b) extension into the cerebrum from adjacent cavities, (c) fungal presence in the cerebrospinal fluid, or (d) meningitis. The fungal order Chaetothyriales (containing Exophiala-like black yeasts and relatives) is particularly rich in fungi causing cerebral infections. Cases by the main agents, Cladophialophora bantiana, Exophiala dermatitidis, and Ramichloridium mackenziei, published during the last 5 years are reviewed. Most of these infections prove to be fatal. Resection of the lesions in combination with antimycotic therapy may reduce mortality.

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.

Brain abscess caused by Cladophialophora (Xylohypha) bantiana in a renal transplant patient

Infectious disease is the most significant cause of morbidity and mortality in allotransplantation because of heavy immunosuppression. Brain abscesses caused by melanized fungi have been found occasionally and are an example of this complication. In this paper, we describe a case in a 61-year-old black man, who received a cadaveric kidney transplantation in December 1993, followed by triple therapy with cyclosporine, azathioprine, and prednisone. The patient developed right hemiparesis at the beginning of April 1998. A computed tomography scan showed a mass in the left parieto-temporal region of the brain. The patient underwent surgery and a brown-colored encapsulated brain abscess was resected. Histology of the tissue revealed a large number of pigmented fungal hyphae. Culture in a Sabouraud dextrose medium with cyclohexamide and chloramphenicol at 25 degrees C resulted in the growth of dark-green colonies. The fungus identified was Cladophialophora bantiana, based on characteristic microscopic features and on growth at 40 degrees C. The abscess recurred in spite of treatment with fluconazole. The patient was submitted to a second brain surgical procedure and was treated with amphotericin B in addition to fluconazole. Ten days later the patient's blood cultures became positive for Escherichia coli. After 3 days the patient died due to septic shock.