title: Letter: Penicillinase production by Haemophilus influenzae.
mesh_terms: D000667:Ampicillin / Q000494:pharmacology*; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000378:metabolism; D010403:Penicillin Resistance; D010405:Penicillinase / Q000096:biosynthesis*
chemical_list: D000667:Ampicillin; D010405:Penicillinase