Systemic Phaeohyphomycosis Caused by Cladosporium Cladosporioides: In Vitro Sensitivity and its Serological Diagnosis

Abstract

Phaeohyphomycosis is a clinical entity caused by dematiaceous fungi. Cladosporium cladosporioides is a phaeoid fungi commonly found in man’s environment and has been reported to cause infection in man.  We report a cause of pheohyphomycosis in a 60 year old male suffering from tuberculosis and gangrene. C. Cladoporioides was isolated from peripheral blood of the patient.  The direct microscopic examination of the blood sample revealed the presence of dark color dematiaceous septate & branched mycelium.                 In-vitro antifungal sensitivity of C. cladosporioides against Ketoconazole, Fluconazole, Itaconazole and Clotrimazole performed by Polak’s 1:3 dilution method.  Ketoconazole was the most effective drug against the isolated strain with MIC 10 ?g ml^–1 after 96 hrs. of incubation. The exoantigen of C. cladosporioides was prepared and subjected to SDS PAGE (Polyacrylamide gel electrophoresis) analysis which revealed two bands of 15 and 67 K Dalton.  Antisera was raised against the antigen and subjected to ODD (Ouchterlony’s double diffusion) test which showed highly specific band of identity.  No cross reactivity was observed against the exoantigen of  C. cladosporioides with antisera of 2 strains of Curvularia verruculosa and one strain of Alternaria alternata. In this study it is concluded that cases of phaeohyphomycoses caused by C. cladosporioides can be rapidly diagnosed using exoantigenic method.

Keywords; opportunistic, phaeohypomycosis, Cladosporium cladosporioides , minimal inhibitory concentration (MIC)