Mycology and Parasitology

1

INI CET 2021 May

Question

Which is a dematiaceous fungus?

OPTION 2

֍ A group of filamentous fungi with dark-pigmented hyphae, which can cause severe infections.
֍ Cladophialophora bantiana is a well-known agent of cerebral infection in normal hosts.
֍ Cladophialophora bantiana has a remarkable neurotropism.
֍ This fungus can be isolated from detritus.
֍ In many cases immunocompetent hosts are infected; often multiple abscesses are present, suggesting a hematogenous seeding of the brain.
֍ The lesion is usually located in the frontoparietal lobes and is either well demarcated or poorly circumscribed, the latter having a worse outcome.
֍ The course of disease is generally slow, allowing confirmed diagnosis by aspiration or surgical resection.
֍ Cladophialophora bantiana is known to cause a cerebral phaeohyphomycosis affecting the central nervous system in humans.
֍ It is hypothesized that predilection of this species for the central nervous system is due to the presence of melanin, which may be able to cross the blood-brain barrier.
֍ Clinical symptoms of infection are varied and can include headache, seizure, arm pain, and ataxia.
֍ The mortality rate is about 70%, with better outcomes observed in patients who underwent complete excision of the abscess.
֍ Since infection is very rare, there is no standard therapy for treatment of C. bantiana phaeohyphomycosis, however combination of amphotericin B, flucytosine, and itraconazole has been associated with improved outcomes.
֍ Cases of infection are most commonly found in subtropical regions with high average humidity although cases have also been identified in the US, Canada and the UK Cases from regions with hot, arid climate are rare.
֍ It has also been suggested to occupations with high exposure to dust and dirt such as farming and gardening are associated with higher risk of infection.
⸙ Key Concept:     
֍ Cladophialophora bantiana is a highly neurotropic dematiaceous fungus and a rare cause of cerebral abscesses.
֍  Such infections carry a high mortality of up to 70% and neurosurgical radical resection associated with powerful antifungal treatment is the most successful therapeutic strategy reported to date.