This was interesting to know about copper:
"Copper has long been known for its antimicrobial properties, which have been linked to the production of toxic hydroxyl radicals and the inhibition of Fe–S-dependent enzymes. However, the fungal pathogen Cryptococcus neoformans is resistant to copper toxicity, and copper has been implicated in C. neoformans virulence.." http://www.nature.com/nrmicro/journal/v11/n5/full/nrmicro3013.html