Robert, A 50-year-old HIV-positive Male, Presents To His Primary Care

Robert, a 50-year-old HIV-positive male, presents to his primary care physician with a 3-month history of fevers, night sweats, productive cough, and an 11-kilogram weight loss. He is not an injection drug user or homosexual, but admits to numerous heterosexual encounters. The patient was released from jail 3 years ago, has a past history of numerous stab wounds, and is a confirmed alcoholic. Acid-fast stains of his sputum are positive, and the bacteria were isolated from the right middle lobe of his lung.
What organism is Robert infected with?

What risk factors does Robert have for infection with this organism?

What treatment should be given?

What information is irrelevant to his disease?