Here is a photo of something I never thought I'd see, let alone have it happen in my own bathroom!
This is the handle of a Braun Oral-B electric toothbrush that I bought some time in the past year.
It developed spreading dark areas which resisted removal.
Though the brush was never left in water, and was kept dry, the areas grew and amalgamated.
Being an environmental mycologist, I eventually made a tape-lift, and was rather surprised to see
that the dark areas were colonies of a sporulating mould - probably a species of Phoma.
When I phoned Braun, they suggested I send it to their depot somewhere in Vancouver,
which would get it back to me in 3 weeks.
You'd think they could do better than that.   I don't want it back!
It doesn't look as if there's any mould-retardant in the plastic.
But perhaps more importantly, I may have inadvertently discovered a mould that can eat plastic...