Ecthyma gangrenosum in a neutropenic patient is caused by which of the following organism?

Ecthyma gangrenosum is a localized cellulitis with necrotizing and ulcerative evolution occurring in immunocompromised or neutropenic patients, mainly caused by Pseudomonas aeruginosa. Two pathogenic mechanisms are recognized; one occurring as the result of the presence of P. aeruginosa during bacteriemia, and the second as a primary lesion. Treatment is systemic antibiotics.