title: Comparison of penicillinases produced by R factors isolated from ampicillin-resistant gram-negative bacteria.
mesh_terms: D000667:Ampicillin / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects / Q000201:enzymology*; D002509:Cephaloridine / Q000494:pharmacology; D003470:Culture Media; D004926:Escherichia coli / Q000201:enzymology; D007564:Japan; D007709:Klebsiella / Q000201:enzymology; D008826:Microbial Sensitivity Tests; D010403:Penicillin Resistance; D010405:Penicillinase / Q000096:biosynthesis*; D010406:Penicillins / Q000494:pharmacology; D012760:Shigella / Q000201:enzymology*
chemical_list: D003470:Culture Media; D010406:Penicillins; D000667:Ampicillin; D010405:Penicillinase; D002509:Cephaloridine