Letter: Pneumococcus with increased resistance to penicillin.
D000368:Aged; D002170:Canada; D006801:Humans; D008297:Male; D010403:Penicillin Resistance; D010406:Penicillins / Q000494:pharmacology*; D013183:Sputum / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification
D010406:Penicillins