Why is M. luteus common among laboratory contaminants?

Answer 1

M. luteus is considered to be part of the normal flora of human skin. So pretty much anything a laboratory worker touches (or anywhere his skin might flake off and go... which is pretty much everywhere) might potentially become infected by this bacterium. To make matters worse, M. luteus has been demonstrated to survive for very long periods in environments with little to nothing that would normally sustain life. So once it has moved in it cannot be expected to just die off on its own!