The bacterial species staphylococus aureus is found on the skin and in the nasal passages of about 20% of the human population. in healthy individuals, s. aureus is benign (does not cause harm) in these locations. however, if it is introduced into the bloodstream through, for example, a wound, it can make a person gravely ill. thus, the ecological relationship of s. aureus with a human:

Thus, the ecological relationship of S. aureus with a human can be mutualistic or antagonistic.

Explanation:

A mutualistic relationship can be described as a relationship in which two organisms of different species live together and benefit each other in some ways.

In biology, an antagonistic relationship can be described as the one in which two organisms of different species react where one organism benefits from the relationship wheres the other one gets harmed. As the introduction of S.aures will harm the humans but benefit the bacteria, hence it will be antagonistic in such a condition.