title: R-factor mediated beta-lactamase production by Haemophilus influenzae.
abstract: Production of beta-lactamase by 15 strains of Haemophilus influenzae has been investigated. All the strains produce a constitutive beta-lactamase, which readily hydrolyses penicillin G, ampicillin, and cephaloridine. The beta-lactamase produced by these strains is indistinguishable from the type-IIIa enzyme commonly found in strains of Escherichia coli. The beta-lactamase gene has been transferred from the enzyme-producing strains of Haemophilus to strains of H. parainfluenzae and a strain of E. coli.
mesh_terms: D000581:Amidohydrolases / Q000096:biosynthesis*; D000667:Ampicillin / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002509:Cephaloridine / Q000378:metabolism; D002510:Cephalosporinase / Q000096:biosynthesis*; D003227:Conjugation, Genetic; D006193:Haemophilus influenzae / Q000187:drug effects / Q000201:enzymology*; D006868:Hydrolysis; D010400:Penicillin G / Q000378:metabolism; D010403:Penicillin Resistance; D010405:Penicillinase / Q000096:biosynthesis*; D011815:R Factors; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D000667:Ampicillin; D000581:Amidohydrolases; D002510:Cephalosporinase; D010405:Penicillinase; D002509:Cephaloridine; D010400:Penicillin G