A novel class C beta-lactamase (FOX-2) in Escherichia coli conferring resistance to cephamycins.
An Escherichia coli strain resistant to a broad spectrum of beta-lactams, including cephamycins, was isolated from a patient suffering from urinary tract infection. A resistance plasmid (pMVP-7) was transferred from the clinical isolate to an Escherichia coli recipient. Both strains produce a cefoxitin-hydrolyzing beta-lactamase focusing at pI 6.7. The phenotype was similar to that of a Klebsiella pneumoniae strain producing cephamycinase FOX-1, so primers were selected from the FOX-1 sequence to amplify the bla gene of the transconjugant. The PCR product obtained was sequenced. The percentage of identity of the deduced amino acid sequence with sequences of other AmpC-type beta-lactamases was 96.9% with FOX-1, 74.9% with CMY-1, and 67.7% with MOX-1. This new plasmid-mediated enzyme is most closely related to FOX-1 (11 amino acid exchanges). We therefore propose the designation FOX-2.
Bauernfeind
A
A
Max von Pettenkofer-Institut, Munich, Federal Republic of Germany. Adolf.Bauernfeind@mvp-bak.med.uni-muenchen.de
Wagner
S
S
Jungwirth
R
R
Schneider
I
I
Meyer
D
D
D000328:Adult; D000595:Amino Acid Sequence; D001483:Base Sequence; D002440:Cefoxitin / Q000378:metabolism; D002513:Cephamycins / Q000378:metabolism / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology*; D029968:Escherichia coli Proteins; D006801:Humans; D006868:Hydrolysis; D007526:Isoelectric Point; D008297:Male; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010957:Plasmids; D016133:Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000737:chemistry* / Q000235:genetics
D002513:Cephamycins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D002440:Cefoxitin; C108589:beta-lactamase FOX-2, E coli; D001618:beta-Lactamases