title: Plasmid-determined beta-lactamase indistinguishable from the chromosomal beta-lactamase of Escherichia coli.
abstract: A plasmid, derived from a naturally occurring strain of Proteus mirabilis, conferred resistance to cephalosporins, apparently mediated by a beta-lactamase indistinguishable from that determined by the chromosomal gene of Escherichia coli K-12. There was evidence for a recombination event between the wild-type plasmid and a defective F factor (Fsp) in the Escherichia coli K-12 culture in which it was stored.
mesh_terms: D002511:Cephalosporins / Q000494:pharmacology; D002512:Cephalothin / Q000494:pharmacology; D002876:Chromosomes, Bacterial; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000032:analysis; D004926:Escherichia coli / Q000032:analysis / Q000187:drug effects / Q000201:enzymology*; D005111:Extrachromosomal Inheritance; D005144:F Factor; D007525:Isoelectric Focusing; D008970:Molecular Weight; D010403:Penicillin Resistance; D010405:Penicillinase / Q000378:metabolism; D010406:Penicillins / Q000494:pharmacology; D010957:Plasmids; D011513:Proteus mirabilis / Q000187:drug effects
chemical_list: D002511:Cephalosporins; D004269:DNA, Bacterial; D010406:Penicillins; D010405:Penicillinase; D002512:Cephalothin