Answer:
Pseudomonas aeruginosa
Explanation:
The important points that have been mentioned in the question are -
All these facts indicate that the etiologic agent is most likely Pseudomonas aeruginosa.
It is a rod-shaped gram positive bacteria and an infectious agent.
It is found in soil and water.
In skin it mainly infects the hair follicles due to which redness in the skin is seen.
It can also infect the external ear canal in which swelling, ear pain and itching inside the ear like symptoms are found.