Rhinocladiella mackenziei as an emerging cause of cerebral phaeohyphomycosis in Pakistan: a case series

Fungal thalamic abscess caused by Rhinocladiella mackenziei in an immunocompetent patient

Cerebral phaeohyphomycosis (CP) stands as an exceedingly uncommon yet severe type of fungal infection affecting the central nervous system, attributable to dematiaceous fungi. Despite the patient's immune status, CP is associated with grave prognosis. In the present study, authors describe the first case of left thalamic fungal abscess due to Rhinocladiella mackenziei in an immunocompetent 39-year-old male patient in Jaipur, Rajasthan. Early diagnosis by direct microscopy of aspirated pus and extensive management with surgical excision and prolonged antifungal coverage showed favourable outcome. The present case is one of the few cases documented globally who has survived.

Post covid cerebral phaeohyphomycosis by Rhinocladiella mackenziei: An unusual association

Cerebral phaeohyphomycosis (CP) is a rare but a highly morbid fungal infection of the central nervous system caused by the fungi belonging to the order Chaetothyriales, which includes Cladophialophora bantiana, Exophiala dermatitidis, Rhinocladiella mackenziei (RM) etc. This disease is associated with poor clinical outcomes, with reported mortality of over 80%. We present the case of a 65-year gentleman who developed CP secondary to RM infection following COVID-19 and the associated challenges in his medical and surgical management.

First case of Rhinocladiella mackenziei brain abscess in Turkey: Case report and review of the literature

Rhinocladiella mackenziei is a highly neurotropic fungus, mainly reported from the Middle East. However, in recent years, there have been some cases from outside this region. We described an additional fatal case of R. mackenziei cerebral infection for the first time from Turkey and made a literature review of all previously reported cases. During 34 years (1988-2022), there have been 42 R. mackenziei brain abscess cases. Most patients have been reported from Saudi Arabia (n = 14, 33.3%). It is noteworthy that 40.5% of patients, including our case, were immunocompetent at initial diagnosis and mostly presented with a single lesion (n = 10, 23.8%). The most frequent comorbidities were solid organ transplant (n = 9, 21.4%), diabetes mellitus (n = 6, 14.3%), malignancy (n = 6, 14.3%) and prior surgery (n = 3, 7.1%). The most commonly used initial antifungal regimen were amphotericin B together with itraconazole (n = 9, 21.4%), combinations of lipid preparations of amphotericin B, voriconazole and/or posaconazole (n = 9, 21.4%) and amphotericin B alone (n = 8, 19%). Although both surgical procedures and antifungal medication in the majority of patients were performed, mortality rates remained high (90.4%). The area at risk of R. mackenziei cerebral abscess cases extends to other countries. Clinicians should be aware of this emerging disease and take a detailed travel history in patients with atypical and undocumented brain abscesses. Our case confirms the hypothesis that this fungus might spread more widely than previously predicted regions.

Rhinocladiella mackenziei cerebral phaeohyphomycosis with a definitive outcome

A right-handed man in his early 60s with hypertension controlled by a single prescription medication presented with left-sided heaviness and intermittent right occipital headache. Initial diagnostic workup was unremarkable. CT revealed an enhancing lesion located in the right parietal lobe, with mild mass effect on the right occipital horn, indicative of a brain abscess. The patient was initially treated with a course of empirical antibiotics, including ceftriaxone, vancomycin, metronidazole and dexamethasone. The neurosurgery team aspirated the abscess the following day and extracted yellow pus that was sampled for bacterial and fungal cultures. These cultures returned positive for Rhinocladiella mackenziei, prompting a discontinuation of the empirical antibiotics and initiation of intravenous liposomal amphotericin B for 4 weeks. Intravenous posaconazole was added to the patient's existing therapy regimen, which was substituted with oral isavuconazole on discharge. The patient continues to take isavuconazole, and follow-up imaging has demonstrated regression of the abscess.

Molecular epidemiology of clinical filamentous fungi in Qatar beyond Aspergillus and Fusarium with notes on the rare species

Due to an increasing number of patients at risk (i.e., those with a highly compromised immune system and/or receiving aggressive chemotherapy treatment), invasive fungal infections (IFI) are increasingly being reported and associated with high mortality rates. Aspergillus spp., particularly A. fumigatus, is the major cause of IFI caused by filamentous fungi around the world followed by Fusarium spp., however, other fungi are emerging as human pathogens. The aim of this study was to explore the epidemiology and prevalence of the non-Aspergillus and non-Fusarium filamentous fungi in human clinical samples over an 11-year period in Qatar using molecular techniques. We recovered 53 filamentous fungal isolates from patients with various clinical conditions. Most patients were males (75.5%), 9.4% were immunocompromised, 20.7% had IFI, and 11.3% died within 30 days of diagnosis. The fungal isolates were recovered from a variety of clinical samples, including the nasal cavity, wounds, respiratory samples, body fluids, eye, ear, tissue, abscess, and blood specimens. Among the fungi isolated, 49% were dematiaceous fungi, followed by Mucorales (30%), with the latter group Mucorales being the major cause of IFI (5/11, 45.5%). The current study highlights the epidemiology and spectrum of filamentous fungal genera, other than Aspergillus and Fusarium, recovered from human clinical samples in Qatar, excluding superficial infections, which can aid in the surveillance of uncommon and emerging mycoses.

Cerebral phaeohyphomycosis in liver transplant recipient: A case report

Cerebral phaeohyphomycosis is a fungal brain infection with a high fatality rate. It is caused by dematiaceous fungi and is increasingly recognized as a cause of serious illness in both immunocompetent and immunocompromised patients. We report cerebral phaeohyphomycosis in a liver transplant recipient. He was treated with multiple surgeries and antifungals and made a complete recovery. This report highlights that early and aggressive surgical intervention and extended antifungal coverage can have a positive outcome even in immunocompromised patients. The fungal infection in immunocompromised patients should be considered and treated aggressively.

Intracranial fungal Cladophialophora bantiana infection in a nonimmunocompromised patient: A case report and review of the literature

Background:

Cladophialophora bantiana is a dematiaceous fungus that rarely infects the central nervous system (CNS). It is associated with a mortality rate of over 70% despite treatment.

Case Description:

An 81-year-old female with a remote history of renal cell carcinoma presented with progressive headache and an expressive aphasia for 3 days. Computed tomography imaging revealed a left frontotemporal mass with surrounding vasogenic edema. A left frontotemporal craniotomy was performed and cultures revealed C. bantiana. The initial management with IV voriconazole was unsuccessful and the patient had a recurrence of the cranial infection and developed pulmonary abscesses. Following the addition of oral flucytosine, the patient showed a significant improvement with a complete radiographic resolution of both the cranial and pulmonary lesions.

Conclusion:

C. bantiana involving the CNS is a rare and often fatal disease. Surgical management along with standard antifungal treatment may not provide definitive therapy. The addition of flucytosine to IV voriconazole resulted in a positive outcome for this patient who is alive, living independently 1 year from the original diagnosis. In this rare fungal infection, standard antifungal treatment may not provide adequate coverage and the utilization of additional therapy may be required.

Novel cases of cutaneous phaeohyphomycosis by Alternaria alstromeriae, Epicoccum tritici and Phialemonium obovatum from North India

BACKGROUND

A growing number of non-dermatophytic moulds and yeasts with the ability to act as human pathogens are reported every year. Dematiaceous fungi cause phaeohyphomycosis which encompasses a broad spectrum of diseases ranging from superficial (cutaneous and subcutaneous) to disseminated infections. Such fungal infections are responsible for causing significant morbidity and mortality, frequently in immunocompromised patients and rarely in immunocompetent patients.

OBJECTIVES

To investigate the prevalence of cutaneous mycosis in Jammu district (India) and to isolate and identify the recovered causal agents from the affected skin of the patients.

METHODS

For direct microscopy, 10% KOH was used. Skin samples were collected carefully from the affected areas of suspected patients, followed by the isolation and identification of the causal agents by cultural examination, morphological examination and ITS sequencing.

RESULTS

Herein, we report and describe three new cases of cutaneous phaeohyphomycosis from District Jammu of Union Territory Jammu and Kashmir, India. The age of the patients under study ranged from 17 to 42 years and the duration of infection from 1 to 2 years. The etiological agents that were recovered from the patients under study were Alternaria alstromeriae, Epicoccum tritici and Phialemonium obovatum. These dematiaceous fungal species were isolated from the skin specimen of immunocompetent hosts.

CONCLUSION

Among the three isolated etiological agents, two (Alternaria alstromeriae, Epicoccum tritici) represent new global records and one (Phialemonium obovatum) new record to India as causal agents of cutaneous phaeohyphomycosis. Careful microscopic and mycological examination form the basis of correct diagnosis of such fungal infections in the absence of simple and reliable laboratory tests (serologic or antigen tests).

Morocco as a possible source for acquisition of Rhinocladiella mackenziei

Rhinocladiella mackenziei cerebral phaeohyphomycosis is a rare severe disease that has been typically described in the Middle East. Here, we report 2 cases of R. mackenziei cerebral phaeohyphomycosis in patients from Morocco, diagnosed and treated in France, and raise a concern about the ever-going extension of the area at risk for this devastating invasive fungal infection.

Disseminated Rhinocladiella mackenziei infection in a kidney transplant recipient: A case report and literature review

Rhinocladiella mackenziei is a rare fungal pathogen which belongs to a large group of pigmented fungi causing phaeohyphomycosis. R. mackenziei primarily infects the brain and leads to high fatality rates among both immunocompetent and immunocompromised individuals. Among solid organ transplant recipients, the infection may disseminate to extra-neuronal sites, necessitating comprehensive radiologic imaging. Here we describe a new case of R. mackenziei infection in a renal transplant patient involving the brain and renal allograft. She received liposomal amphotericin B and voriconazole but no surgical intervention. Ultimately, the patient died after two months of hospital stay. A review of all reported cases of transplant patients infected with R. mackenziei is also presented.

Cerebral phaeohyphomycosis due to Rhinocladiella mackenziei in an immunocompetent patient: A case report and review of literature

Background and Purpose

Rhinocladiella mackenziei is a neurotropic fungus, which can cause devastating intracerebral infections with up to 100% fatality rate. It is difficult to isolate this fungus in laboratory as it grows slowly and requires diagnostic skills.

Case report

A 42-year-old Pakistani man presented with headache, facial numbness, progressive upper limb weakness, and dysarthria. Magnetic resonance imaging of the brain showed a space-occupying lesion in the basal ganglia region. The patient underwent supratentorial craniotomy for biopsy and excision. Histopathology of the specimen revealed granulomatous inflammation with abscess formation. Periodic acid- Schiff special stains highlighted the presence of numerous septate fungal hyphae. The results revealed the growth of dematiaceous fungi, which were morphologically classified as R. mackenziei. The patient is currently stable and is being on amphotericin and posaconazole, along with neurorehabilitation therapy.

Conclusion

Rhinocladiella mackenziei brain abscess is a devastating infection with significant mortality. This condition should be suspected in patients with brain abscess from high endemic areas.

The Lichens' Microbiota, Still a Mystery?

Lichens represent self-supporting symbioses, which occur in a wide range of terrestrial habitats and which contribute significantly to mineral cycling and energy flow at a global scale. Lichens usually grow much slower than higher plants. Nevertheless, lichens can contribute substantially to biomass production. This review focuses on the lichen symbiosis in general and especially on the model species Lobaria pulmonaria L. Hoffm., which is a large foliose lichen that occurs worldwide on tree trunks in undisturbed forests with long ecological continuity. In comparison to many other lichens, L. pulmonaria is less tolerant to desiccation and highly sensitive to air pollution. The name-giving mycobiont (belonging to the Ascomycota), provides a protective layer covering a layer of the green-algal photobiont (Dictyochloropsis reticulata) and interspersed cyanobacterial cell clusters (Nostoc spec.). Recently performed metaproteome analyses confirm the partition of functions in lichen partnerships. The ample functional diversity of the mycobiont contrasts the predominant function of the photobiont in production (and secretion) of energy-rich carbohydrates, and the cyanobiont's contribution by nitrogen fixation. In addition, high throughput and state-of-the-art metagenomics and community fingerprinting, metatranscriptomics, and MS-based metaproteomics identify the bacterial community present on L. pulmonaria as a surprisingly abundant and structurally integrated element of the lichen symbiosis. Comparative metaproteome analyses of lichens from different sampling sites suggest the presence of a relatively stable core microbiome and a sampling site-specific portion of the microbiome. Moreover, these studies indicate how the microbiota may contribute to the symbiotic system, to improve its health, growth and fitness.

Fine needle aspiration of nodular cystic swelling showing a rare melanized fungus Medicopsis romeroi: A case report

A young woman on long term corticosteroid therapy presented with a discrete hyperpigmented nodular cystic swelling on her upper thigh to the buttock region. There was history of discharging sinuses however at presentation the lesion was painless nondischarging. The lesion was subjected to fine-needle aspiration. The cytological smears on routine and special stains showed branching, septate fungal hyphae present extracellularly and intracellularly. The background showed dense mixed inflammation and granulomatous inflammation. The aspirated material was further subjected to culture. A nonsporulating melanized fungus was obtained and a culture isolate was sent for molecular characterization. Medicopsis romeroi, a rare melanized fungus belonging to the order Pleosporales was isolated on Internal transcribed spacer sequencing.

Diffusion-weighted magnetic resonance imaging may be useful in differentiating fungal abscess from malignant intracranial lesion: Case report

Background

Diffusion-weighted magnetic resonance has a well-defined role in differentiating between important intracranial lesions. Sometimes, the surgeon is faced with a dilemma of how to diagnose an infectious versus malignant lesion.

Case Description

A 28-year-old male presented to the neurosurgery clinic with complaints of headache and left-sided weakness for 2 weeks. Neurological examination was intact. Magnetic resonance imaging (MRI) scan showed a large infiltrating heterogeneous mass involving the right parietal lobe. On further reviewing, there was homogenous diffusion restriction in the center of lesion. In addition, its aggressive behavior confirmed it to be a fungal abscess.

Conclusions

Correctly identifying an infectious versus tumor etiology is important. Research has been carried out to employ diffusion-weighted imaging (DWI) in differentiating the variable radiological findings. The role of DWI in diagnosing bacterial abscess is more commonly seen in comparison to fungal abscess. DWI has a high diagnostic potential, but more works need to be done.

Neuroinfections caused by fungi

BACKGROUND

Fungal infections of the central nervous system (FIs-CNS) have become significantly more common over the past 2 decades. Invasion of the CNS largely depends on the immune status of the host and the virulence of the fungal strain. Infections with fungi cause a significant morbidity in immunocompromised hosts, and the involvement of the CNS may lead to fatal consequences.

METHODS

One hundred and thirty-five articles on fungal neuroinfection in PubMed, Google Scholar, and Cochrane databases were selected for review using the following search words: "fungi and CNS mycoses", CNS fungal infections", "fungal brain infections", " fungal cerebritis", fungal meningitis", "diagnostics of fungal infections", and "treatment of CNS fungal infections". All were published in English with the majority in the period 2000-2018. This review focuses on the current knowledge of the epidemiology, clinical presentations, diagnosis, and treatment of selected FIs-CNS.

RESULTS

The FIs-CNS can have various clinical presentations, mainly meningitis, encephalitis, hydrocephalus, cerebral abscesses, and stroke syndromes. The etiologic factors of neuroinfections are yeasts (Cryptococcus neoformans, Candida spp., Trichosporon spp.), moniliaceous moulds (Aspergillus spp., Fusarium spp.), Mucoromycetes (Mucor spp., Rhizopus spp.), dimorphic fungi (Blastomyces dermatitidis, Coccidioides spp., Histoplasma capsulatum), and dematiaceous fungi (Cladophialophora bantiana, Exophiala dermatitidis). Their common route of transmission is inhalation or inoculation from trauma or surgery, with subsequent hematogenous or contiguous spread. As the manifestations of FIs-CNS are often non-specific, their diagnosis is very difficult. A fast identification of the etiological factor of neuroinfection and the application of appropriate therapy are crucial in preventing an often fatal outcome. The choice of effective drug depends on its extent of CNS penetration and spectrum of activity. Pharmaceutical formulations of amphotericin B (AmB) (among others, deoxycholate-AmBd and liposomal L-AmB) have relatively limited distribution in the cerebrospinal fluid (CSF); however, their detectable therapeutic concentrations in the CNS makes them recommended drugs for the treatment of cryptococcal meningoencephalitis (AmBd with flucytosine) and CNS candidiasis (L-AmB) and mucormycosis (L-AmB). Voriconazole, a moderately lipophilic molecule with good CNS penetration, is recommended in the first-line therapy of CNS aspergillosis. Other triazoles, such as posaconazole and itraconazole, with negligible concentrations in the CSF are not considered effective drugs for therapy of CNS fungal neuroinfections. In contrast, clinical data have shown that a novel triazole, isavuconazole, achieved considerable efficacy for the treatment of some fungal neuroinfections. Echinocandins with relatively low or undetectable concentrations in the CSF do not play meaningful role in the treatment of FIs-CNS.

CONCLUSION

Although the number of fungal species causing CNS mycosis is increasing, only some possess well-defined treatment standards (e.g., cryptococcal meningitis and CNS aspergillosis). The early diagnosis of fungal infection, accompanied by identification of the etiological factor, is needed to allow the selection of effective therapy in patients with FIs-CNS and limit their high mortality.

Cerebral phaeohyphomycosis due to Rhinocladiella mackenziei in Persian Gulf region: A case and review

Cerebral phaeohyphomycosis is frequently a fatal disease caused by truly neurotropic dematiaceous fungi. Although rare, this infection occurs especially among immunocompetent patients, and the clinical symptoms are often misdiagnosed as a cerebral tumour or bacterial brain abscess. The appropriate diagnosis and therapy of cerebral infections by melanized fungi are very challenging if they are caused by mysterious fungi with unknown ecological niche. We reported the second case of cerebral phaeohyphomycosis due to Rhinocladiella mackenziei in Iran and the first culture-confirmed case. In this report, the differential diagnosis and histopathological findings are discussed and a review of the literature is provided.

Multiple brain abscesses caused by Rhinocladiella mackenziei in an immunocompetent patient: a case report and literature review

Primary cerebral phaeohyphomycosis due to Rhinocladiella mackenziei is an extremely rare infection carrying more than 80% mortality, with most cases reported from the Middle East region. This darkly pigmented black yeast is highly neurotropic, aggressive and refractory to most antifungal agents. Here we present an immunocompetent elderly male, presenting with multiple brain abscesses, with R. mackenziei confirmed by nuclear ribosomal repeat region sequencing, who was successfully treated by surgical debridement and intravenous voriconazole. To our knowledge this is the first case reported from the United Kingdom. We also present a review of all such cases so far reported in the English literature world-wide, which we believe is a step further to understanding the pathogenesis and establishing effective treatment of this rare, yet often fatal disease.

Subcutaneous Phaeohyphomycosis Cyst Associated with Medicopsis romeroi in an Immunocompromised Host

An 88-year-old man, receiving prednisolone for sarcoidosis, presented with a discrete keratotic lesion on the dorsum of his right hand following the placement of an intravenous cannula a month prior to its appearance. Medicopsis romeroi was isolated from the tissue and identified by sequencing the internal transcribed spacer region ITS-1 and the D1-2 fragment of the 28S rDNA gene. Histopathological examination showed fungal hyphae in the internal inflammatory cells layer and within the histocyte-macrophage layer, highly suggestive of deep mycosis. The patient was successfully treated with surgical excision of the cyst. M. romeroi exhibited high MIC values for echinocandin drugs in vitro, but appeared susceptible to newer triazole agents, amphotericin B and terbinafine. This is the first report of a subcutaneous phaeohyphomycotic cyst occurring following the placement of an intravenous cannula. This report highlights the potential role of M. romeroi as an emerging cause of deep, non-mycetomatous infection in immunocompromised patients.

First fatal cerebral phaeohyphomycosis due to Rhinocladiella mackenziei in Iran, based on ITS rDNA

Black yeast-like fungi and relatives as agents of cerebral phaeohyphomycosis are often encountered in human fatal brain abscesses and lead to almost 100% mortality despite the application of antifungal and surgical therapy. We report to our knowledge the first case of brain infection due to Rhinocladiella mackenziei in a 54-year-old immunocompetent male in Iran where R. mackenziei has not been reported previously. The initial diagnosis was brain fungal infection because of pigmented, irregular, branched, septated hyphae based on histopathological staining. The patient was treated with intravenous amphotericin B deoxycholate (0.5mg/kg/day) combined with oral itraconazole (200mg twice daily), nevertheless, his neurological function deteriorated rapidly and ultimately the patient died due to respiratory failure later two weeks. R. mackenziei was identified based on the sequencing of internal transcribed spacer (ITS rDNA region) (KJ140287). Therefore, considerable attention for this life-threatening infection is highly recommended.

Cerebral phaeohyphomycosis: a rare cause of brain abscess

Cerebral phaeohyphomycosis (CP) is a very rare but serious form of central nervous system fungal infection that is caused by dematiaceous fungi. It is commonly associated with poor prognosis irrespective of the immune status of the patient. In this study, the authors describe the first case of CP in Korea that occurred in a 75-year-old man without immunodeficiency and showed favorable outcome after surgical excision and antifungal therapy. In addition, the authors herein review the literature regarding characteristics of this rare clinical entity with previously reported cases.

Black Molds and Melanized Yeasts Pathogenic to Humans

A review is given of melanized fungi involved in human infection, including species forming budding cells and strictly filamentous representatives. Classically, they are known as "phaeoid" or "dematiaceous" fungi, and, today, agents are recognized to belong to seven orders of fungi, of which the Chaetothyriales and Pleosporales are the most important. Infections range from cutaneous or pulmonary colonization to systemic or disseminated invasion. Subcutaneous involvement, either primary or after dissemination, may lead to host tissue proliferation of dermis or epidermis. Particularly in the Chaetothyriales, subcutaneous and systemic infections may occur in otherwise apparently healthy individuals. Infections are mostly chronic and require extended antifungal therapy and/or surgery.