A 2-year-old infant is diagnosed with meningitis. A lumbar puncture reveals numerous neutrophils and gram-positive cocci in pairs that appear encapsulated. She is admitted to the hospital and started on intravenous (IV) b-lactams. Which of the following targets would most likely play a role in the development of resistance to this antibiotic in the most likely etiologic agent of this child's meningitis?

Trans peptidases, or penicillin-binding proteins (PBPs) (c), are inactivated when bound to penicillin. Altered PBPs no longer bind the b-lactam antibiotic. The acquisition of a new PBP or modification of the existing one is the mechanism by which S. pneumoniae, the most likely etiologic of this child's meningitis, become resistant to b-lactams. Altered PBPs are also seen in N. gonorrhoeae, S. aureus, and other bacteria. Bactoprenol (a) is not known to be involved in antibiotic resistance. Fluoroquinolones target the DNA gyrase (b), while rifamycins target the bacterial RNA polymerase (e). Bacteria do not utilize reverse transcriptase (d).