Pathogenicity of Alternaria chlamydospora Mouchacca for albino rats: Studyof a clinical isolate from human skin lesion

Objectives. Pathogenic effect of a clinical isolate of Alternaria chlamydos pora was studied in albino rats using the parameters of survival/mortality, clinical symptoms, histopathology and organ culture. Materials and methods. The animals when infected intravenously with 5 x 10( 2), 12 x 10(3) colony forming units (CFU), 40-50 % of the cortisone treated (CT) animals survived with some developing neurodeficiency. Results. There was no survival when CT animals were infected with 15 x 10(6 ) CFU. No mortality was seen in without cortisone treated (WCT) rats. When infected intradermally (TD) and by scarification (S), the skin of WCT and C T rats developed subcutaneous lesions. Histopathology revealed mixed inflam matory reaction. Vessels of the skin were seen invaded by the pathogen. Amo ng visceral organs, pathological symptoms were seen on liver, brain, kidney s, lungs and stomach of CT rats, The rate of brain infection in CT animals as determined quantitatively by organ culture was high as compared to WCT a nimals (P < 0.05). infected skin and visceral organs of CT and WCT experime ntal rats were culture positive for A. chlamydospora upto 30 days post-infe ction. Conclusion. The present study confirmed the pathogenicity of A. chlamydospo ra for skin and visceral organs of the rats. It further highlights the sign ificance of this opportunistic pathogen for immunosuppressed patients.