Pseudomonas maltophilia exoenzyme activity as correlate in pathogenesis of ecthyma gangrenosum

Ecthyma gangrenosum has not been described during the course of blood stream invasion with Pseudomonas maltophilia, although it occurs with a 30% frequency in Pseudomonas aeruginosa septicemia. We isolated P. maltophilia from the blood and an ecthyma lesion in a leukemic patient. The organism was an avid protease and elastase producer and hence mimicked the exoenzyme profile of invasive P. aeruginosa. The patient responded to moxalactam to which the isolate was susceptible in vitro. On the basis of this report, P. maltophilia may be included among an emerging number of gram-negative bacillary species capable of producing severe cutaneous manifestations of bacteremia.