Chromosomal beta-lactamase genes of Klebsiella oxytoca are divided into two main groups, blaOXY-1 and blaOXY-2.
The chromosomally encoded beta-lactamase gene (blaOXY-2) of the wild-type Klebsiella oxytoca SL911 was cloned and sequenced. Its nucleotide sequence similarity with the previously sequenced K. oxytoca beta-lactamase gene (blaOXY-1) (Y. Arakawa, M. Ohta, N. Kido, M. Mori, H. Ito, T. Komatsu, Y. Fujii, and N. Kato, Antimicrob. Agents Chemother. 33:63-70, 1989) is 87.3%, and its amino acid similarity is 89.7%. This group of K. oxytoca beta-lactamases is related to chromosomal beta-lactamases of Citrobacter diversus, Proteus vulgaris, and Yersinia enterocolitica and to the plasmid-mediated extended-spectrum beta-lactamases MEN-1 and Toho-1. By colony hybridization with 86 strains susceptible and resistant to aztreonam, isolated in six countries, K. oxytoca beta-lactamase genes hybridized with either a specific blaOXY-1 DNA probe (668 bp) or a blaOXY-2 DNA probe (723 bp). Thus, beta-lactamase genes could be divided into two groups: blaOXY-1 (47% of the strains) and blaOXY-2 (53% of the strains). A study of isoelectric points confirmed the great variability reported in the literature. However, the two beta-lactamase groups were each represented by four different pIs: for OXY-2, 5.2, 5.7, 6.4, and 6.8, with the 5.2 form representing 59% of all OXY-2 enzymes, and for OXY-1, 7.1, 7.5, 8.2, and 8.8, with the 7.5 form representing 88% of all OXY-1 enzymes.
Fournier
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B
Laboratoire de Microbiologie, Université Paris VII, France.
Roy
P H
PH
Lagrange
P H
PH
Philippon
A
A
D000595:Amino Acid Sequence; D001483:Base Sequence; D002876:Chromosomes, Bacterial / Q000235:genetics*; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D006088:Gram-Negative Aerobic Bacteria / Q000235:genetics; D007709:Klebsiella / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid; D018440:beta-Lactam Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics*
D011994:Recombinant Proteins; D001618:beta-Lactamases