a 45-year old lawyer presents to you office complaining of sporadic cough, fatigue, and low-grade fever for the past seven days. ten days prior, he attended a convention in chicago where the air conditionaer was set at 68 f. physical examination is unremarkable. sputum is sent for culture and sensitivity. the organism grows on a buffered charcoal/yeast extract requireing iron and cysteine. what is the most likely organism? what is the drug of choice?