Question 1

Question

A 68-year-old man with a prosthetic mitral valve develops fever and malaise 6 months after valve replacement. Blood cultures grow coagulase-negative Staphylococcus epidermidis resistant to methicillin. Echocardiography shows vegetations on the prosthetic valve. Despite 4 weeks of appropriate antibiotic therapy with vancomycin, he continues to have positive blood cultures. What mechanism best explains the persistence of infection in this patient?

Accepted Answer

Bacteria embedded in biofilm matrix with reduced metabolic activity

Answer

Intracellular bacterial survival in cardiac myocytes

Answer

Inadequate penetration of vancomycin into cardiac tissue

Answer

Presence of L-form bacterial variants lacking cell walls

Answer

Development of vancomycin resistance due to vanA gene acquisition

Biofilms — MCQs

Biofilms — MCQs

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