Penicillin-resistaant pneumococci.
D006801:Humans; D009154:Mutation; D010403:Penicillin Resistance; D010406:Penicillins / Q000008:administration & dosage / Q000494:pharmacology; D011008:Pneumococcal Infections / Q000188:drug therapy; D013296:Streptococcus pneumoniae / Q000187:drug effects*
D010406:Penicillins