title: The increasing frequency of beta-lactamase-producing Haemophilus influenzae B.
mesh_terms: D006193:Haemophilus influenzae / Q000201:enzymology / Q000302:isolation & purification*; D006801:Humans; D014481:United States; D001618:beta-Lactamases / Q000096:biosynthesis
chemical_list: D001618:beta-Lactamases