A hospital's antimicrobial stewardship committee is reviewing mechanisms of antibiotic resistance among distinct bacterial isolates. Match each clinical isolate and its characteristic resistance profile with the primary molecular mechanism responsible for its resistance.
- Streptococcus pneumoniae with high-level resistance to ceftriaxoneAcquisition of mosaic genes leading to altered penicillin-binding proteins (PBPs)
- Pseudomonas aeruginosa with isolated resistance to imipenemDecreased outer membrane permeability due to mutational loss of specific porins (e.g., OprD)
- Klebsiella pneumoniae resistant to all beta-lactams including carbapenems via a plasmidHydrolytic inactivation of the antimicrobial agent by a serine beta-lactamase
- Mycoplasma pneumoniae intrinsically resistant to penicillins and cephalosporinsComplete intrinsic absence of a peptidoglycan cell wall target
Cevap
Streptococcus pneumoniae pairs with altered PBPs; Pseudomonas aeruginosa pairs with loss of porins; Klebsiella pneumoniae pairs with hydrolytic inactivation by a beta-lactamase; Mycoplasma pneumoniae pairs with absence of a cell wall target.
Each bacterial isolate utilizes a distinct, well-characterized mechanism to evade antimicrobial action. S. pneumoniae alters its target site (PBPs). P. aeruginosa restricts drug entry by losing the OprD porin. K. pneumoniae enzymatically destroys the drug via a carbapenemase. M. pneumoniae intrinsically lacks the structural target (cell wall) entirely.
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Anahtar Kavram
Molecular mechanisms of antimicrobial resistance in clinically significant bacteria