Molecular characterization of the gene encoding a new AmpC beta-lactamase in a clinical strain of acinetobacter genomic species 3

Abstract

A presumptive chromosomal cephalosporinase (pI, 9.0) from a clinical strain of Acinetobacter genomic species 3 (AG3) is reported. The nucleotide sequence of this beta-lactamase shows for the first time the gene encoding an AmpC enzyme in AG3. In addition, the biochemical properties of the novel AG3 AmpC beta-lactamase are reported

FIG. 1.

Nucleotide sequence of the 1.3-kb fragment. The amino acid sequence deduced for AmpC G3 β-lactamase is shown on the linebelow the nucleotide triplets. The ATG and TAA shown in boldface type represent the initiation and termination codons, respectively. A putative Shine-Dalgarno (S.D.) ribosomal recognition site is indicated. The positions of the primers used to sequence the gene and to detect the ampC gene in several AG3 strains are indicated by arrows. The positions of the primers used for amplification and further cloning of the gene are indicated by discontinuous arrows. The putative sequence of the signal peptide is indicated by boldface type and lowercase letters. The β-lactamase active site SVSK, the conserved triad KTG, and the typical class C motif YXN are shown in boldface type (12).