Molecular characterization of FOX-4, a new AmpC-type plasmid-mediated beta-lactamase from an Escherichia coli strain isolated in Spain.
A clinical strain of Escherichia coli (Ec GCE) displayed resistance to cefoxitin, cefotetan, cefotaxime, and ceftazidime. Susceptibility was not restored by the addition of clavulanic acid. Two beta-lactamases with apparent pIs of 5.4 and 6.4 were identified; the beta-lactamase with a pI of 6.4 was transferred by conjugation and associated with a 40-kb plasmid. Analysis of the nucleotide sequence showed a new ampC beta-lactamase gene that is closely related to those encoding the FOX-3, FOX-2, and FOX-1 beta-lactamases but whose product has four novel amino acid mutations, at positions 11 (M-->T), 43 (A-->E), 233 (V-->A), and 280 (Y-->H). This first cephamycinase from Spain was named FOX-4.
Bou
G
G
Servicio de Microbiología, Hospital Ramón y Cajal, Madrid, Spain.
Oliver
A
A
Ojeda
M
M
Monzón
C
C
Martínez-Beltrán
J
J
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins; D006801:Humans; D006868:Hydrolysis; D007525:Isoelectric Focusing; D007700:Kinetics; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013030:Spain; D001618:beta-Lactamases / Q000737:chemistry / Q000187:drug effects / Q000235:genetics*; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D047090:beta-Lactams; C413413:fox-4 protein, E coli; C048795:AmpC beta-lactamases; D001618:beta-Lactamases