<prompt> The molecular basis of penicillin resistance in S.Pneumoniae is:Alteration of penicillin-binding proteinAlteration in cell membranesAlteration in the cell wallNone of the above  <response>: The molecular basis of penicillin resistance in S. pneumoniae is the alteration of penicillin-binding protein PBP genes which result in lower affinity for penicillins. Penicillin G is the drug of choice for disease caused by susceptible organisms, including community-acquired pneumonia. Ref: Harisson, Edition - 18, Page 1156 