Abstract
Nocardiosis is a rare but well-established opportunistic infection. We are presenting two cases of Nocardiosis diagnosed in the microbiology laboratory, one in an immuno-competent elderly patient and the other in a immunocompromised patient with AIDS. The first case was of pulmonary Nocardiosis which was caused by the Nocardia asteroides complex and concomitant infections with Staphylococcus aureus and Blastoschizomyces capitatus. In the second case, Nocardia brasiliensis was isolated from the pus which was extracted from an HIV positive patient, with lymphoadenopathy in the neck, at the upper right clavicular region. Interestingly, in both the cases, the primary identification Was done using 20% H2SO4 as decolourizer for ZN staining method.