Cerebral phaeohyphomycosis due to Cladophialophora bantiana: case report and systematic review of cases

PURPOSE

Cladophialophora bantiana is a wonted melanized fungus causing brain abscess. In past many cases were reported from Asia, particularly from India. Of late, there is a rise in cases in places besides Asia and hence a review of the cases is warranted.

METHODS

We present a case of fatal cerebral phaeohyphomycosis caused by C. bantiana and conduct a systematic review of culture confirmed brain abscess due to C. bantiana reported between 2015 and 2022.

RESULTS

Of the 39 cases found, majority (68%) were immunocompromised. The various clinical presentations were headache (53%), hemiparesis (34%), visual disturbance (25%), altered sensorium (18%), aphasia/dysarthria (12%) and seizures (9%). Isolated lesion was observed in 18 (60%) patients. In the sequence of occurrence, the lesions were in frontal (30%), temporal (27%) and parietal (20%) region. There were five cases with coinfections such as concurrent detection of Nocardia pneumonia in two cases, toxoplasma DNA in brain abscess, coexisting pulmonary Cryptococcus neoformans infection and coexisting Candida in a case of brain abscess in one case each. Surgical intervention was performed in 84% cases. Antifungal therapy included voriconazole (80%), liposomal amphotericin B (76%), 5-fluorocytosine (30%), posaconazole (10%), and amphotericin B deoxycholate (6%). The overall mortality was 50% with lower mortality (42%) in regions outside Asia compared to Asia (63.6%) though not statistically significant.

CONCLUSIONS

C. bantiana brain abscess is an emerging infection worldwide. Next generation sequencing is an upcoming promising diagnostic test. Early complete excision of the lesion with effective antifungals may improve the outcome.

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.

Genomic Analyses of Cladophialophora bantiana, a Major Cause of Cerebral Phaeohyphomycosis Provides Insight into Its Lifestyle, Virulence and Adaption in Host

Cladophialophora bantiana is a dematiaceous fungus with a predilection for causing central nervous system (CNS) infection manifesting as brain abscess in both immunocompetent and immunocompromised patients. In this paper, we report comprehensive genomic analyses of C. bantiana isolated from the brain abscess of an immunocompetent man, the first reported case in Malaysia and Southeast Asia. The identity of the fungus was determined using combined morphological analysis and multilocus phylogeny. The draft genome sequence of a neurotrophic fungus, C. bantiana UM 956 was generated using Illumina sequencing technology to dissect its genetic fundamental and basic biology. The assembled 37.1 Mb genome encodes 12,155 putative coding genes, of which, 1.01% are predicted transposable elements. Its genomic features support its saprophytic lifestyle, renowned for its versatility in decomposing hemicellulose and pectin components. The C. bantiana UM 956 was also found to carry some important putative genes that engaged in pathogenicity, iron uptake and homeostasis as well as adaptation to various stresses to enable the organism to survive in hostile microenvironment. This wealth of resource will further catalyse more downstream functional studies to provide better understanding on how this fungus can be a successful and persistent pathogen in human.

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.