Final answer:
The tests for hydrogen sulfide production, motility, and indole production are positive for Pseudomonas aeruginosa (PV), which is known for its motility and the production of distinctive pigments, such as pyocyanin. In contrast, Staphylococcus aureus (SA) is known for fermenting mannitol on mannitol salt agar but not for the other characteristics mentioned.
Step-by-step explanation:
The bacterium that is positive for hydrogen sulfide production, motility, and indole production tests is Pseudomonas aeruginosa (PV). When subjected to these tests, Pseudomonas aeruginosa demonstrates motility by swimming through the semi-solid agar, making the medium appear cloudy. It also produces a blue-green pigment called pyocyanin, which can be observed when the bacteria grow on certain types of media. Although not detailed specifically in this set of notes, typically, Pseudomonas aeruginosa can produce hydrogen sulfide, which would turn the media black. It can also break down tryptophan to produce indole, which, when detected with a reactive chemical, turns deep pink. However, Staphylococcus aureus (SA) is known to grow on mannitol salt agar and ferment mannitol, which is showcased by the change to yellow of the medium due to acid production. So, the bacterium that matches the description of hydrogen sulfide production, motility, and indole production tests is Pseudomonas aeruginosa, not Staphylococcus aureus.