NASA got a bad day some weeks ago.

A microbiologist discovered that Acetinobacter can eat the desinfectant
that NASA sprays in their clean rooms...

A soil bacteria.

Now, NASA is selecting the hardest microbes to send to space... All
other normal microbes are dead, and Actetinobacter has no competition.

Arrived to destination (say Mars) Acetinobacter could be devasting for a
local biota. Since it is extremely resistant, it could spread unchecked.

Is it a good idea to desinfect spaceships?

Or it would be better to have as much as possible of weak, normal
bacteria that are surely dead if confronted to space?

Or coat the spaceships with very fragile bacteria that would prevent
Acetinobacter to thrive and would be immediately dead in space?

What is important is that in space no earth bacteria survive unchecked.