A 60-year-old hospitalized woman is evaluated for high temperature. Four days ago, she was admitted to the hospital for sepsis, for which she has received broad-spectrum empiric intravenous antibiotic therapy. Her temperature is 38.9 C (102 F), blood pressure is 110/80 mm Hg, pulse is 98/min, and respirations are 18/min. Cardiac examination reveals a new diastolic murmur. Multiple blood cultures drawn at different times grow Enterococcus. Echocardiogram reveals mitral valve vegetation suggestive of endocarditis. An intravenous antibiotic is added to the patient's treatment regimen for synergy. Several days later, she develops tinnitus and hearing loss attributed to this antibiotic. The additional antibiotic most directly affects which of the following processes?

Question

A 60-year-old hospitalized woman is evaluated for high temperature.  Four days ago, she was admitted to the hospital for sepsis, for which she has received broad-spectrum empiric intravenous antibiotic therapy.  Her temperature is 38.9 C (102 F), blood pressure is 110/80 mm Hg, pulse is 98/min, and respirations are 18/min.  Cardiac examination reveals a new diastolic murmur.  Multiple blood cultures drawn at different times grow Enterococcus.  Echocardiogram reveals mitral valve vegetation suggestive of endocarditis.  An intravenous antibiotic is added to the patient's treatment regimen for synergy.  Several days later, she develops tinnitus and hearing loss attributed to this antibiotic.  The additional antibiotic most directly affects which of the following processes?

Quizplus · Accepted Answer

Eductional Objective: This patient with enterococcal endocarditis likely received an aminoglycoside (AG) such as gentamicin, a ribosome-targeting antibiotic. AGs are associated with ototoxicity (hearing loss, tinnitus) and nephrotoxicity.
Aminoglycosides inhibit genetic code reading and protein synthesis by binding to the prokaryotic 30S ribosomal subunit.

A 60-Year-Old Hospitalized Woman Is Evaluated for High Temperature