Which of the following changes in a bacterial cell might reduce the effectiveness of beta-lactam antibiotics?

• A. Production of beta-lactamase enzymes
• B. Decreased expression of ribosomal proteins
• C. Enhanced uptake of antibiotics through porins
• D. Increased synthesis of peptidoglycan

Answer: (A)

Verified step by step guidance

1. Understand the mechanism of action of beta-lactam antibiotics: they target bacterial cell wall synthesis by inhibiting enzymes called penicillin-binding proteins (PBPs) involved in peptidoglycan cross-linking.
2. Recognize that beta-lactamase enzymes are bacterial enzymes that hydrolyze the beta-lactam ring of these antibiotics, rendering them ineffective.
3. Analyze how decreased expression of ribosomal proteins would affect the cell: since beta-lactams target cell wall synthesis, changes in ribosomal proteins (which affect protein synthesis) are unlikely to reduce beta-lactam effectiveness.
4. Consider the effect of enhanced uptake of antibiotics through porins: increased uptake would generally increase antibiotic effectiveness, not reduce it.
5. Evaluate increased synthesis of peptidoglycan: while it might alter cell wall structure, it does not directly neutralize the antibiotic like beta-lactamase enzymes do, so it is less likely to reduce antibiotic effectiveness.