How does Penicillium escape the effect of the penicillin it secretes? ?

The cell walls of bacteria contain a substance called peptidoglycan. Penicillin blocks one of the steps in the production of peptidoglycan. Penicillium mold is a fungus, a eukaryote, and it does not produce or require peptidoglycan. In this way penicillin selectively attacks bacteria.