A 23-year-old man comes to the emergency department with fever, severe headache, and vomiting. He has not felt well for the past 2 weeks due to fatigue, intermittent low-grade fevers, and headaches. The patient is HIV positive and spent several months in prison 3 years ago. Temperature is 38.6 C (101.5 F). Neck stiffness is present on physical examination. A CT scan reveals no intracranial lesions. Cerebrospinal fluid analysis is notable for the following: Cerebrospinal fluid cultures grow Mycobacterium tuberculosis with significantly decreased activity of intracellular catalase peroxidase. The isolates would most likely exhibit resistance to which of the following agents?

Question

A 23-year-old man comes to the emergency department with fever, severe headache, and vomiting.  He has not felt well for the past 2 weeks due to fatigue, intermittent low-grade fevers, and headaches.  The patient is HIV positive and spent several months in prison 3 years ago.  Temperature is 38.6 C (101.5 F).  Neck stiffness is present on physical examination.  A CT scan reveals no intracranial lesions.  Cerebrospinal fluid analysis is notable for the following:  Cerebrospinal fluid cultures grow Mycobacterium tuberculosis with significantly decreased activity of intracellular catalase peroxidase.  The isolates would most likely exhibit resistance to which of the following agents?

Quizplus · Accepted Answer

Eductional Objective: Mycobacterial resistance to isoniazid (INH) can be accomplished through non-expression of the catalase-peroxidase enzyme or through genetic modification of the INH binding site on the mycolic acid synthesis enzyme.

A 23-Year-Old Man Comes to the Emergency Department with Fever