DOI Y, KUROKAWA H, SHIBATA N, SHIBAYAMA K, ARAKAWA Y; Interscience Conference on Antimicrobial Agents and Chemotherapy (41st : 2001 : Chicago, Ill.).
Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2001 Dec 16-19; 41: abstract no. C1-153.
National Institute of Infectious Diseases, Tokyo, Japan
BACKGROUND: We characterized CMY-9, a novel AmpC-type beta-lactamase from a clinical isolate of Escherichia coli at the 101st ASM General Meeting. These constitutively expressed cephalosporinases are reported with increasing frequency, now constituting an extended family of clinically important enzymes. The genetic organization of the genes encoding these enzymes, however, has not been elucidated to date. METHODS: The transferable plasmid of E. coli strain HKY-M68, from which blaCMY-9 was originally reported, was digested with various enzymes (BamHI, EcoRI or XhoI) and ligated into plasmid pBCSK(+), transforming E. coli XL1-Blue. Clones with resistance to either ampicillin or kanamycin were selected. As a result, plasmids with three overlapping inserts were obtained, forming an approximately 8 kb region including blaCMY-9. The entire region was then sequenced. RESULTS: The genetic environment comprised a class 1 integron, with blaCMY-9 downstream of the 3-conserved segment (3-CS). The integron contained the integrase gene int, fused aacA1/orfG, qacEdelta1, and sul1 gene cassettes, followed by orf341 and blaCMY-9. This structure was similar to that reported for pSAL-1, a plasmid encoding an inducible AmpC-type beta-lactamase gene blaDHA-1, by Verdet et al. (Antimicrob. Agents Chemother. 44: 222-225.), but no duplication of 3-CS was found, leaving blaCMY-9 adjacent to but outside the integron. CONCLUSION: blaCMY-9 was shown to be part of a genetic environment comprising an In6/7-like integron. This is the first example of a constitutively expressed AmpC-type cephalosporinase gene associated with an integron.
Publication Types:
Keywords:
- AmpC beta-lactamases
- Bacterial Proteins
- Base Sequence
- Cephalosporinase
- Escherichia coli
- Escherichia coli Infections
- Integrases
- Integrons
- Plasmids
- beta-Lactamases
- genetics
Other ID:
UI: 102270373
From Meeting Abstracts