A 30-year-old man comes to the physician because of a 4-month history of increasing shortness of breath on exertion, dry cough, and fatigue. His wife was diagnosed with an active tuberculosis and started on a 4-drug combination therapy and she has an episode of red staining of her contact lenses and red urine. Pulmonary examination shows diffuse crackles bilaterally. An x-ray of the chest shows well-defined calcification of the rims of hilar lymph nodes and scattered nodules in both upper lung fields. Mycobacterium tuberculosis is isloated from his sputum and shows resistance to several antimycobacterial agents. Which of the following best explains the bacterial resistance to the drug responsible for this patient's wife red staining presentation?

Question

A 30-year-old man comes to the physician because of a 4-month history of increasing shortness of breath on exertion, dry cough, and fatigue. His wife was diagnosed with an active tuberculosis and started on a 4-drug combination therapy and she has an episode of red staining of her contact lenses and red urine. Pulmonary examination shows diffuse crackles bilaterally. An x-ray of the chest shows well-defined calcification of the rims of hilar lymph nodes and scattered nodules in both upper lung fields. Mycobacterium tuberculosis is isloated from his sputum and shows resistance to several antimycobacterial agents.  Which of the following best explains the bacterial resistance to the drug responsible for this patient's wife red staining presentation?

Quizplus · Accepted Answer

Eductional Objective: The rifamycins block the action of the bacterial DNA-dependent RNA polymerase, thereby inhibiting transcription. Resistance is acquired by modification of the rifampin binding site on the bacterial DNA-dependent RNA polymerase. Common side effects include hepatotoxicity, blood dyscrasias, and harmless red-orange discoloration of body fluids.

A 30-Year-Old Man Comes to the Physician Because of a 4-Month